\input texinfo @c -*-texinfo-*-
-@c Copyright 1988 1989 1990 1991 1992 1993 1994 1995
+@c Copyright 1988-1999
@c Free Software Foundation, Inc.
@c
@c %**start of header
@c
@include gdb-cfg.texi
@c
-@ifset GENERIC
@settitle Debugging with @value{GDBN}
-@end ifset
-@ifclear GENERIC
-@settitle Debugging with @value{GDBN} (@value{TARGET})
-@end ifclear
-@clear RENAMED
@setchapternewpage odd
@c %**end of header
@syncodeindex vr cp
@c !!set GDB manual's edition---not the same as GDB version!
-@set EDITION 4.12
+@set EDITION Seventh
@c !!set GDB manual's revision date
-@set DATE January 1994
-
-@c GDB CHANGELOG CONSULTED BETWEEN:
-@c Fri Oct 11 23:27:06 1991 John Gilmore (gnu at cygnus.com)
-@c Sat Dec 22 02:51:40 1990 John Gilmore (gnu at cygint)
+@set DATE February 1999
@c THIS MANUAL REQUIRES TEXINFO-2 macros and info-makers to format properly.
This file documents the @sc{gnu} debugger @value{GDBN}.
-This is Edition @value{EDITION}, @value{DATE},
+This is the @value{EDITION} Edition, @value{DATE},
of @cite{Debugging with @value{GDBN}: the @sc{gnu} Source-Level Debugger}
for @value{GDBN} Version @value{GDBVN}.
-Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995
-Free Software Foundation, Inc.
+Copyright (C) 1988-1999 Free Software Foundation, Inc.
Permission is granted to make and distribute verbatim copies of
this manual provided the copyright notice and this permission notice
@titlepage
@title Debugging with @value{GDBN}
@subtitle The @sc{gnu} Source-Level Debugger
-@ifclear GENERIC
-@subtitle (@value{TARGET})
-@end ifclear
@sp 1
-@subtitle Edition @value{EDITION}, for @value{GDBN} version @value{GDBVN}
+@subtitle @value{EDITION} Edition, for @value{GDBN} version @value{GDBVN}
@subtitle @value{DATE}
@author Richard M. Stallman and Roland H. Pesch
@page
@tex
{\parskip=0pt
-\hfill (Send bugs and comments on @value{GDBN} to bug-gdb\@prep.ai.mit.edu.)\par
+\hfill (Send bugs and comments on @value{GDBN} to bug-gdb\@gnu.org.)\par
\hfill {\it Debugging with @value{GDBN}}\par
\hfill \TeX{}info \texinfoversion\par
-\hfill doc\@cygnus.com\par
}
@end tex
+@c ISBN seems to be wrong...
+
@vskip 0pt plus 1filll
-Copyright @copyright{} 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995
-Free Software Foundation, Inc.
+Copyright @copyright{} 1988-1999 Free Software Foundation, Inc.
@sp 2
Published by the Free Software Foundation @*
-675 Massachusetts Avenue, @*
-Cambridge, MA 02139 USA @*
+59 Temple Place - Suite 330, @*
+Boston, MA 02111-1307 USA @*
Printed copies are available for $20 each. @*
ISBN 1-882114-11-6 @*
This file describes @value{GDBN}, the @sc{gnu} symbolic debugger.
-This is Edition @value{EDITION}, @value{DATE}, for @value{GDBN} Version
+This is the @value{EDITION} Edition, @value{DATE}, for @value{GDBN} Version
@value{GDBVN}.
+Copyright (C) 1988-1999 Free Software Foundation, Inc.
@menu
* Summary:: Summary of @value{GDBN}
-@ifclear BARETARGET
* Sample Session:: A sample @value{GDBN} session
-@end ifclear
* Invocation:: Getting in and out of @value{GDBN}
* Commands:: @value{GDBN} commands
* Stack:: Examining the stack
* Source:: Examining source files
* Data:: Examining data
-@ifclear CONLY
+
* Languages:: Using @value{GDBN} with different languages
-@end ifclear
-@ifset CONLY
-* C:: C language support
-@end ifset
-@c remnant makeinfo bug, blank line needed after two end-ifs?
* Symbols:: Examining the symbol table
* Altering:: Altering execution
* GDB Files:: @value{GDBN} files
* Targets:: Specifying a debugging target
+* Configurations:: Configuration-specific information
* Controlling GDB:: Controlling @value{GDBN}
* Sequences:: Canned sequences of commands
-@ifclear DOSHOST
* Emacs:: Using @value{GDBN} under @sc{gnu} Emacs
-@end ifclear
* GDB Bugs:: Reporting bugs in @value{GDBN}
-* Command Line Editing:: Facilities of the readline library
-* Using History Interactively::
-@c @ifset NOVEL
-@c * Renamed Commands::
-@c @end ifset
-@ifclear PRECONFIGURED
* Formatting Documentation:: How to format and print @value{GDBN} documentation
-* Installing GDB:: Installing GDB
-@end ifclear
+* Command Line Editing:: Command Line Editing
+* Using History Interactively:: Using History Interactively
+* Installing GDB:: Installing GDB
* Index:: Index
@end menu
+
@end ifinfo
@node Summary
effects of one bug and go on to learn about another.
@end itemize
-@ifclear CONLY
-You can use @value{GDBN} to debug programs written in C or C++.
-@c "MOD2" used as a "miscellaneous languages" flag here.
-@c This is acceptable while there is no real doc for Chill and Pascal.
-@ifclear MOD2
+You can use @value{GDBN} to debug programs written in C and C++.
For more information, see @ref{Support,,Supported languages}.
-@end ifclear
-@ifset MOD2
For more information, see @ref{C,,C and C++}.
+@cindex Chill
+@cindex Modula-2
Support for Modula-2 and Chill is partial. For information on Modula-2,
-see @ref{Modula-2,,Modula-2}. There is no further documentation on Chill yet.
+see @ref{Modula-2,,Modula-2}. For information on Chill, see @ref{Chill}.
-Debugging Pascal programs which use sets, subranges, file variables, or nested
-functions does not currently work. @value{GDBN} does not support
-entering expressions, printing values, or similar features using Pascal syntax.
+@cindex Pascal
+Debugging Pascal programs which use sets, subranges, file variables, or
+nested functions does not currently work. @value{GDBN} does not support
+entering expressions, printing values, or similar features using Pascal
+syntax.
-@end ifset
-@ifset FORTRAN
@cindex Fortran
@value{GDBN} can be used to debug programs written in Fortran, although
-it does not yet support entering expressions, printing values, or
-similar features using Fortran syntax. It may be necessary to refer to
-some variables with a trailing underscore.
-@end ifset
-@end ifclear
+it may be necessary to refer to some variables with a trailing
+underscore.
@menu
* Free Software:: Freely redistributable software
@node Contributors
@unnumberedsec Contributors to GDB
-Richard Stallman was the original author of GDB, and of many other @sc{gnu}
-programs. Many others have contributed to its development. This
-section attempts to credit major contributors. One of the virtues of
-free software is that everyone is free to contribute to it; with
+Richard Stallman was the original author of GDB, and of many other
+@sc{gnu} programs. Many others have contributed to its development.
+This section attempts to credit major contributors. One of the virtues
+of free software is that everyone is free to contribute to it; with
regret, we cannot actually acknowledge everyone here. The file
-@file{ChangeLog} in the @value{GDBN} distribution approximates a blow-by-blow
-account.
+@file{ChangeLog} in the @value{GDBN} distribution approximates a
+blow-by-blow account.
Changes much prior to version 2.0 are lost in the mists of time.
omitted from this list, we would like to add your names!
@end quotation
-So that they may not regard their long labor as thankless, we
-particularly thank those who shepherded GDB through major releases:
-Stan Shebs (release 4.14),
-Fred Fish (releases 4.13, 4.12, 4.11, 4.10, and 4.9),
-Stu Grossman and John Gilmore (releases 4.8, 4.7, 4.6, 4.5, and 4.4),
+So that they may not regard their many labors as thankless, we
+particularly thank those who shepherded @value{GDBN} through major
+releases:
+Jim Blandy (release 4.18);
+Jason Molenda (release 4.17);
+Stan Shebs (release 4.14);
+Fred Fish (releases 4.16, 4.15, 4.13, 4.12, 4.11, 4.10, and 4.9);
+Stu Grossman and John Gilmore (releases 4.8, 4.7, 4.6, 4.5, and 4.4);
John Gilmore (releases 4.3, 4.2, 4.1, 4.0, and 3.9);
Jim Kingdon (releases 3.5, 3.4, and 3.3);
and Randy Smith (releases 3.2, 3.1, and 3.0).
-As major maintainer of @value{GDBN} for some period, each
-contributed significantly to the structure, stability, and capabilities
-of the entire debugger.
Richard Stallman, assisted at various times by Peter TerMaat, Chris
Hanson, and Richard Mlynarik, handled releases through 2.8.
-@ifclear CONLY
Michael Tiemann is the author of most of the @sc{gnu} C++ support in GDB,
with significant additional contributions from Per Bothner. James
Clark wrote the @sc{gnu} C++ demangler. Early work on C++ was by Peter
TerMaat (who also did much general update work leading to release 3.0).
-@end ifclear
@value{GDBN} 4 uses the BFD subroutine library to examine multiple
object-file formats; BFD was a joint project of David V.
David Johnson wrote the original COFF support; Pace Willison did
the original support for encapsulated COFF.
+Brent Benson of Harris Computer Systems contributed DWARF 2 support.
+
Adam de Boor and Bradley Davis contributed the ISI Optimum V support.
Per Bothner, Noboyuki Hikichi, and Alessandro Forin contributed MIPS
support.
Pace Willison contributed Intel 386 support.
Jay Vosburgh contributed Symmetry support.
+Andreas Schwab contributed M68K Linux support.
+
Rich Schaefer and Peter Schauer helped with support of SunOS shared
libraries.
-Jay Fenlason and Roland McGrath ensured that @value{GDBN} and GAS agree about
-several machine instruction sets.
+Jay Fenlason and Roland McGrath ensured that @value{GDBN} and GAS agree
+about several machine instruction sets.
-Patrick Duval, Ted Goldstein, Vikram Koka and Glenn Engel helped
-develop remote debugging. Intel Corporation and Wind River Systems
-contributed remote debugging modules for their products.
+Patrick Duval, Ted Goldstein, Vikram Koka and Glenn Engel helped develop
+remote debugging. Intel Corporation, Wind River Systems, AMD, and ARM
+contributed remote debugging modules for the i960, VxWorks, A29K UDI,
+and RDI targets, respectively.
Brian Fox is the author of the readline libraries providing
command-line editing and command history.
-Andrew Beers of SUNY Buffalo wrote the language-switching code,
-@ifset MOD2
-the Modula-2 support,
-@end ifset
-and contributed the Languages chapter of this manual.
+Andrew Beers of SUNY Buffalo wrote the language-switching code, the
+Modula-2 support, and contributed the Languages chapter of this manual.
Fred Fish wrote most of the support for Unix System Vr4.
-@ifclear CONLY
He also enhanced the command-completion support to cover C++ overloaded
symbols.
-@end ifclear
-Hitachi America, Ltd. sponsored the support for Hitachi microprocessors.
+Hitachi America, Ltd. sponsored the support for H8/300, H8/500, and
+Super-H processors.
+
+NEC sponsored the support for the v850, Vr4xxx, and Vr5xxx processors.
+
+Mitsubishi sponsored the support for D10V, D30V, and M32R/D processors.
+
+Toshiba sponsored the support for the TX39 Mips processor.
+
+Matsushita sponsored the support for the MN10200 and MN10300 processors.
+
+Fujitsu sponsored the support for SPARClite and FR30 processors
Kung Hsu, Jeff Law, and Rick Sladkey added support for hardware
watchpoints.
+Michael Snyder added support for tracepoints.
+
Stu Grossman wrote gdbserver.
Jim Kingdon, Peter Schauer, Ian Taylor, and Stu Grossman made
nearly innumerable bug fixes and cleanups throughout GDB.
-@ifclear BARETARGET
+The following people at the Hewlett-Packard Company contributed
+support for the PA-RISC 2.0 architecture, HP-UX 10.20, 10.30, and 11.0
+(narrow mode), HP's implementation of kernel threads, HP's aC++
+compiler, and the terminal user interface: Ben Krepp, Richard Title,
+John Bishop, Susan Macchia, Kathy Mann, Satish Pai, India Paul, Steve
+Rehrauer, and Elena Zannoni. Kim Haase provided HP-specific
+information in this manual.
+
+Cygnus Solutions has sponsored GDB maintenance and much of its
+development since 1991. Cygnus engineers who have worked on GDB
+fulltime include Mark Alexander, Jim Blandy, Per Bothner, Kevin
+Buettner, Edith Epstein, Chris Faylor, Fred Fish, Martin Hunt, Jim
+Ingham, John Gilmore, Stu Grossman, Kung Hsu, Jim Kingdon, John Metzler,
+Fernando Nasser, Geoffrey Noer, Dawn Perchik, Rich Pixley, Zdenek
+Radouch, Keith Seitz, Stan Shebs, David Taylor, and Elena Zannoni. In
+addition, Dave Brolley, Ian Carmichael, Steve Chamberlain, Nick Clifton,
+JT Conklin, Stan Cox, DJ Delorie, Ulrich Drepper, Frank Eigler, Doug
+Evans, Sean Fagan, David Henkel-Wallace, Richard Henderson, Jeff
+Holcomb, Jeff Law, Jim Lemke, Tom Lord, Bob Manson, Michael Meissner,
+Jason Merrill, Catherine Moore, Drew Moseley, Ken Raeburn, Gavin
+Romig-Koch, Rob Savoye, Jamie Smith, Mike Stump, Ian Taylor, Angela
+Thomas, Michael Tiemann, Tom Tromey, Ron Unrau, Jim Wilson, and David
+Zuhn have made contributions both large and small.
+
+
@node Sample Session
@chapter A Sample @value{GDBN} Session
There is absolutely no warranty for @value{GDBN}; type "show warranty"
for details.
-@value{GDBN} @value{GDBVN}, Copyright 1995 Free Software Foundation, Inc...
+@value{GDBN} @value{GDBVN}, Copyright 1999 Free Software Foundation, Inc...
(@value{GDBP})
@end smallexample
@smallexample
(@value{GDBP}) @b{quit}
@end smallexample
-@end ifclear
@node Invocation
@chapter Getting In and Out of @value{GDBN}
The essentials are:
@itemize @bullet
@item
-type @samp{@value{GDBP}} to start GDB.
+type @samp{@value{GDBP}} to start @value{GDBN}.
@item
type @kbd{quit} or @kbd{C-d} to exit.
@end itemize
@menu
* Invoking GDB:: How to start @value{GDBN}
-* Quitting GDB:: How to quit @value{GDBN}
+* Quitting GDB:: How to quit @value{GDBN}
* Shell Commands:: How to use shell commands inside @value{GDBN}
@end menu
@node Invoking GDB
@section Invoking @value{GDBN}
-@ifset H8EXCLUSIVE
-For details on starting up @value{GDBP} as a
-remote debugger attached to a Hitachi microprocessor, see @ref{Hitachi
-Remote,,@value{GDBN} and Hitachi Microprocessors}.
-@end ifset
-
Invoke @value{GDBN} by running the program @code{@value{GDBP}}. Once started,
@value{GDBN} reads commands from the terminal until you tell it to exit.
You can also run @code{@value{GDBP}} with a variety of arguments and options,
to specify more of your debugging environment at the outset.
-@ifset GENERIC
The command-line options described here are designed
to cover a variety of situations; in some environments, some of these
options may effectively be unavailable.
-@end ifset
The most usual way to start @value{GDBN} is with one argument,
specifying an executable program:
@value{GDBP} @var{program}
@end example
-@ifclear BARETARGET
@noindent
You can also start with both an executable program and a core file
specified:
named @file{1234}; @value{GDBN} does check for a core file first).
Taking advantage of the second command-line argument requires a fairly
-complete operating system; when you use @value{GDBN} as a remote debugger
-attached to a bare board, there may not be any notion of ``process'',
-and there is often no way to get a core dump.
-@end ifclear
+complete operating system; when you use @value{GDBN} as a remote
+debugger attached to a bare board, there may not be any notion of
+``process'', and there is often no way to get a core dump. @value{GDBN}
+will warn you if it is unable to attach or to read core dumps.
You can run @code{gdb} without printing the front material, which describes
@value{GDBN}'s non-warranty, by specifying @code{-silent}:
@smallexample
-@value{GDBP} @var{-silent}
+@value{GDBP} -silent
@end smallexample
@noindent
@menu
-@ifclear GENERIC
-@ifset REMOTESTUB
-* Remote Serial:: @value{GDBN} remote serial protocol
-@end ifset
-@ifset I960
-* i960-Nindy Remote:: @value{GDBN} with a remote i960 (Nindy)
-@end ifset
-@ifset AMD29K
-* UDI29K Remote:: The UDI protocol for AMD29K
-* EB29K Remote:: The EBMON protocol for AMD29K
-@end ifset
-@ifset VXWORKS
-* VxWorks Remote:: @value{GDBN} and VxWorks
-@end ifset
-@ifset ST2000
-* ST2000 Remote:: @value{GDBN} with a Tandem ST2000
-@end ifset
-@ifset H8
-* Hitachi Remote:: @value{GDBN} and Hitachi Microprocessors
-@end ifset
-@ifset MIPS
-* MIPS Remote:: @value{GDBN} and MIPS boards
-@end ifset
-@ifset SIMS
-* Simulator:: Simulated CPU target
-@end ifset
-@end ifclear
-@c remnant makeinfo bug requires this blank line after *two* end-ifblahs:
-
* File Options:: Choosing files
* Mode Options:: Choosing modes
@end menu
-@ifclear GENERIC
-@include remote.texi
-@end ifclear
-
@node File Options
@subsection Choosing files
-@ifclear BARETARGET
When @value{GDBN} starts, it reads any arguments other than options as
specifying an executable file and core file (or process ID). This is
the same as if the arguments were specified by the @samp{-se} and
@samp{-se} option followed by that argument; and the second argument
that does not have an associated option flag, if any, as equivalent to
the @samp{-c} option followed by that argument.)
-@end ifclear
-@ifset BARETARGET
-When @value{GDBN} starts, it reads any argument other than options as
-specifying an executable file. This is the same as if the argument was
-specified by the @samp{-se} option.
-@end ifset
+
+If @value{GDBN} has not been configured to included core file support,
+such as for most embedded targets, then it will complain about a second
+argument and ignore it.
Many options have both long and short forms; both are shown in the
following list. @value{GDBN} also recognizes the long forms if you truncate
@item -exec @var{file}
@itemx -e @var{file}
-Use file @var{file} as the executable file to execute when
-@ifset BARETARGET
-appropriate.
-@end ifset
-@ifclear BARETARGET
-appropriate, and for examining pure data in conjunction with a core
-dump.
-@end ifclear
+Use file @var{file} as the executable file to execute when appropriate,
+and for examining pure data in conjunction with a core dump.
@item -se @var{file}
Read symbol table from file @var{file} and use it as the executable
file.
-@ifclear BARETARGET
@item -core @var{file}
@itemx -c @var{file}
Use file @var{file} as a core dump to examine.
Connect to process ID @var{number}, as with the @code{attach} command
(unless there is a file in core-dump format named @var{number}, in which
case @samp{-c} specifies that file as a core dump to read).
-@end ifclear
@item -command @var{file}
@itemx -x @var{file}
@itemx -d @var{directory}
Add @var{directory} to the path to search for source files.
-@ifclear BARETARGET
@item -m
@itemx -mapped
@emph{Warning: this option depends on operating system facilities that are not
The @file{.syms} file is specific to the host machine where @value{GDBN}
is run. It holds an exact image of the internal @value{GDBN} symbol
table. It cannot be shared across multiple host platforms.
-@end ifclear
@item -r
@itemx -readnow
Read each symbol file's entire symbol table immediately, rather than
the default, which is to read it incrementally as it is needed.
This makes startup slower, but makes future operations faster.
+
@end table
-@ifclear BARETARGET
-The @code{-mapped} and @code{-readnow} options are typically combined in
+You typically combine the @code{-mapped} and @code{-readnow} options in
order to build a @file{.syms} file that contains complete symbol
information. (@xref{Files,,Commands to specify files}, for information
-
-a @file{.syms} file for future use is:
+on @file{.syms} files.) A simple @value{GDBN} invocation to do nothing
+but build a @file{.syms} file for future use is:
@example
- gdb -batch -nx -mapped -readnow programname
+gdb -batch -nx -mapped -readnow programname
@end example
-@end ifclear
@node Mode Options
@subsection Choosing modes
@table @code
@item -nx
@itemx -n
-Do not execute commands from any initialization files (normally called
-@file{@value{GDBINIT}}). Normally, the commands in these files are
-executed after all the command options and arguments have been
-processed. @xref{Command Files,,Command files}.
+Do not execute commands found in any initialization files (normally
+called @file{.gdbinit}, or @file{gdb.ini} on PCs). Normally,
+@value{GDBN} executes the commands in these files after all the command
+options and arguments have been processed. @xref{Command Files,,Command
+files}.
@item -quiet
@itemx -q
nonzero status if an error occurs in executing the @value{GDBN} commands
in the command files.
-Batch mode may be useful for running @value{GDBN} as a filter, for example to
-download and run a program on another computer; in order to make this
-more useful, the message
+Batch mode may be useful for running @value{GDBN} as a filter, for
+example to download and run a program on another computer; in order to
+make this more useful, the message
@example
Program exited normally.
@end example
@noindent
-(which is ordinarily issued whenever a program running under @value{GDBN} control
-terminates) is not issued when running in batch mode.
+(which is ordinarily issued whenever a program running under
+@value{GDBN} control terminates) is not issued when running in batch
+mode.
+
+@item -nowindows
+@itemx -nw
+``No windows''. If @value{GDBN} comes with a graphical user interface
+(GUI) built in, then this option tells GDB to only use the command-line
+interface. If no GUI is available, this option has no effect.
+
+@item -windows
+@itemx -w
+If @value{GDBN} includes a GUI, then this option requires it to be
+used if possible.
@item -cd @var{directory}
Run @value{GDBN} using @var{directory} as its working directory,
instead of the current directory.
-@ifset LUCID
-@item -context @var{authentication}
-When the Energize programming system starts up @value{GDBN}, it uses this
-option to trigger an alternate mode of interaction.
-@var{authentication} is a pair of numeric codes that identify @value{GDBN}
-as a client in the Energize environment. Avoid this option when you run
-@value{GDBN} directly from the command line. See @ref{Energize,,Using
-@value{GDBN} with Energize} for more discussion of using @value{GDBN} with Energize.
-@end ifset
-
-@ifclear DOSHOST
@item -fullname
@itemx -f
-@sc{gnu} Emacs sets this option when it runs @value{GDBN} as a subprocess. It tells @value{GDBN}
-to output the full file name and line number in a standard,
-recognizable fashion each time a stack frame is displayed (which
-includes each time your program stops). This recognizable format looks
-like two @samp{\032} characters, followed by the file name, line number
-and character position separated by colons, and a newline. The
-Emacs-to-@value{GDBN} interface program uses the two @samp{\032} characters as
-a signal to display the source code for the frame.
-@end ifclear
-
-@ifset SERIAL
-@item -b @var{bps}
+@sc{gnu} Emacs sets this option when it runs @value{GDBN} as a
+subprocess. It tells @value{GDBN} to output the full file name and line
+number in a standard, recognizable fashion each time a stack frame is
+displayed (which includes each time your program stops). This
+recognizable format looks like two @samp{\032} characters, followed by
+the file name, line number and character position separated by colons,
+and a newline. The Emacs-to-@value{GDBN} interface program uses the two
+@samp{\032} characters as a signal to display the source code for the
+frame.
+
+@item -baud @var{bps}
+@itemx -b @var{bps}
Set the line speed (baud rate or bits per second) of any serial
interface used by @value{GDBN} for remote debugging.
@item -tty @var{device}
Run using @var{device} for your program's standard input and output.
@c FIXME: kingdon thinks there is more to -tty. Investigate.
-@end ifset
+
+@c resolve the situation of these eventually
+@c @item -tui
+@c Use a Terminal User Interface. For information, use your Web browser to
+@c read the file @file{TUI.html}, which is usually installed in the
+@c directory @code{/opt/langtools/wdb/doc} on HP-UX systems. Do not use
+@c this option if you run @value{GDBN} from Emacs (see @pxref{Emacs, ,Using
+@c @value{GDBN} under @sc{gnu} Emacs}).
+
+@c @item -xdb
+@c Run in XDB compatibility mode, allowing the use of certain XDB commands.
+@c For information, see the file @file{xdb_trans.html}, which is usually
+@c installed in the directory @code{/opt/langtools/wdb/doc} on HP-UX
+@c systems.
+
@end table
@node Quitting GDB
@cindex leaving @value{GDBN}
@table @code
-@kindex quit
+@kindex quit @r{[}@var{expression}@r{]}
@kindex q
@item quit
To exit @value{GDBN}, use the @code{quit} command (abbreviated @code{q}), or
-type an end-of-file character (usually @kbd{C-d}).
+type an end-of-file character (usually @kbd{C-d}). If you do not supply
+@var{expression}, @value{GDBN} will terminate normally; otherwise it will
+terminate using the result of @var{expression} as the error code.
@end table
@cindex interrupt
character at any time because @value{GDBN} does not allow it to take effect
until a time when it is safe.
-@ifclear BARETARGET
If you have been using @value{GDBN} to control an attached process or
device, you can release it with the @code{detach} command
(@pxref{Attach, ,Debugging an already-running process}).
-@end ifclear
@node Shell Commands
@section Shell commands
@kindex shell
@cindex shell escape
@item shell @var{command string}
-Invoke a the standard shell to execute @var{command string}.
-@ifclear DOSHOST
+Invoke a standard shell to execute @var{command string}.
If it exists, the environment variable @code{SHELL} determines which
-shell to run. Otherwise @value{GDBN} uses @code{/bin/sh}.
-@end ifclear
+shell to run. Otherwise @value{GDBN} uses the default shell
+(@file{/bin/sh} on Unix systems, @file{COMMAND.COM} on MS-DOS, etc.).
@end table
The utility @code{make} is often needed in development environments.
If you just want to see the list of alternatives in the first place, you
can press @kbd{M-?} rather than pressing @key{TAB} twice. @kbd{M-?}
-means @kbd{@key{META} ?}. You can type this
-@ifclear DOSHOST
-either by holding down a
+means @kbd{@key{META} ?}. You can type this either by holding down a
key designated as the @key{META} shift on your keyboard (if there is
-one) while typing @kbd{?}, or
-@end ifclear
-as @key{ESC} followed by @kbd{?}.
+one) while typing @kbd{?}, or as @key{ESC} followed by @kbd{?}.
@cindex quotes in commands
@cindex completion of quoted strings
Sometimes the string you need, while logically a ``word'', may contain
-parentheses or other characters that @value{GDBN} normally excludes from its
-notion of a word. To permit word completion to work in this situation,
-you may enclose words in @code{'} (single quote marks) in @value{GDBN} commands.
+parentheses or other characters that @value{GDBN} normally excludes from
+its notion of a word. To permit word completion to work in this
+situation, you may enclose words in @code{'} (single quote marks) in
+@value{GDBN} commands.
-@ifclear CONLY
The most likely situation where you might need this is in typing the
name of a C++ function. This is because C++ allows function overloading
(multiple definitions of the same function, distinguished by argument
In general, @value{GDBN} can tell that a quote is needed (and inserts it) if
you have not yet started typing the argument list when you ask for
completion on an overloaded symbol.
-@end ifclear
+
+For more information about overloaded functions, see @ref{C plus plus
+expressions, ,C++ expressions}. You can use the command @code{set
+overload-resolution off} to disable overload resolution;
+see @ref{Debugging C plus plus, ,@value{GDBN} features for C++}.
@node Help
(@value{GDBP}) help
List of classes of commands:
-running -- Running the program
-stack -- Examining the stack
-data -- Examining data
+aliases -- Aliases of other commands
breakpoints -- Making program stop at certain points
+data -- Examining data
files -- Specifying and examining files
+internals -- Maintenance commands
+obscure -- Obscure features
+running -- Running the program
+stack -- Examining the stack
status -- Status inquiries
support -- Support facilities
+tracepoints -- Tracing of program execution without stopping the program
user-defined -- User-defined commands
-aliases -- Aliases of other commands
-obscure -- Obscure features
Type "help" followed by a class name for a list of
commands in that class.
@c Line break in "show" line falsifies real output, but needed
@c to fit in smallbook page size.
-show -- Generic command for showing things set
- with "set"
-info -- Generic command for printing status
+info -- Generic command for showing things
+ about the program being debugged
+show -- Generic command for showing things
+ about the debugger
Type "help" followed by command name for full
documentation.
@noindent results in:
@smallexample
+@group
+if
+ignore
info
inspect
-ignore
+@end group
@end smallexample
@noindent This is intended for use by @sc{gnu} Emacs.
@kindex set
@item set
-You can assign the result of an expresson to an environment variable with
+You can assign the result of an expression to an environment variable with
@code{set}. For example, you can set the @value{GDBN} prompt to a $-sign with
@code{set prompt $}.
@cindex version number
@item show version
Show what version of @value{GDBN} is running. You should include this
-information in @value{GDBN} bug-reports. If multiple versions of @value{GDBN} are in
-use at your site, you may occasionally want to determine which version
-of @value{GDBN} you are running; as @value{GDBN} evolves, new commands are introduced,
-and old ones may wither away. The version number is also announced
-when you start @value{GDBN}.
+information in @value{GDBN} bug-reports. If multiple versions of
+@value{GDBN} are in use at your site, you may need to determine which
+version of @value{GDBN} you are running; as @value{GDBN} evolves, new
+commands are introduced, and old ones may wither away. Also, many
+system vendors ship variant versions of @value{GDBN}, and there are
+variant versions of @value{GDBN} in GNU/Linux distributions as well.
+The version number is the same as the one announced when you start
+@value{GDBN}.
@kindex show copying
@item show copying
@kindex show warranty
@item show warranty
-Display the @sc{gnu} ``NO WARRANTY'' statement.
+Display the @sc{gnu} ``NO WARRANTY'' statement, or a warranty,
+if your version of @value{GDB} comes with one.
+
@end table
@node Running
When you run a program under @value{GDBN}, you must first generate
debugging information when you compile it.
-@ifclear BARETARGET
-You may start @value{GDBN} with its arguments, if any, in an environment
-of your choice. You may redirect your program's input and output, debug an
-already running process, or kill a child process.
-@end ifclear
+
+You may start @value{GDBN} with its arguments, if any, in an environment
+of your choice. If you are doing native debugging, you may redirect
+your program's input and output, debug an already running process, or
+kill a child process.
@menu
* Compilation:: Compiling for debugging
* Starting:: Starting your program
-@ifclear BARETARGET
* Arguments:: Your program's arguments
* Environment:: Your program's environment
+
* Working Directory:: Your program's working directory
* Input/Output:: Your program's input and output
* Attach:: Debugging an already-running process
* Kill Process:: Killing the child process
-* Process Information:: Additional process information
-* Threads:: Debugging programs with multiple threads
+
+* Threads:: Debugging programs with multiple threads
* Processes:: Debugging programs with multiple processes
-@end ifclear
@end menu
@node Compilation
options together. Using those compilers, you cannot generate optimized
executables containing debugging information.
-@value{NGCC}, the @sc{gnu} C compiler, supports @samp{-g} with or without
-@samp{-O}, making it possible to debug optimized code. We recommend
-that you @emph{always} use @samp{-g} whenever you compile a program.
-You may think your program is correct, but there is no sense in pushing
-your luck.
+@value{NGCC}, the @sc{gnu} C compiler, supports @samp{-g} with or
+without @samp{-O}, making it possible to debug optimized code. We
+recommend that you @emph{always} use @samp{-g} whenever you compile a
+program. You may think your program is correct, but there is no sense
+in pushing your luck.
@cindex optimized code, debugging
@cindex debugging optimized code
@kindex run
@item run
@itemx r
-Use the @code{run} command to start your program under @value{GDBN}. You must
-first specify the program name
-@ifset VXWORKS
-(except on VxWorks)
-@end ifset
-with an argument to @value{GDBN} (@pxref{Invocation, ,Getting In and
-Out of @value{GDBN}}), or by using the @code{file} or @code{exec-file}
-command (@pxref{Files, ,Commands to specify files}).
+Use the @code{run} command to start your program under @value{GDBN}.
+You must first specify the program name (except on VxWorks) with an
+argument to @value{GDBN} (@pxref{Invocation, ,Getting In and Out of
+@value{GDBN}}), or by using the @code{file} or @code{exec-file} command
+(@pxref{Files, ,Commands to specify files}).
@end table
-@ifclear BARETARGET
If you are running your program in an execution environment that
supports processes, @code{run} creates an inferior process and makes
that process run your program. (In environments without processes,
@code{run} command. If a shell is available on your target, the shell
is used to pass the arguments, so that you may use normal conventions
(such as wildcard expansion or variable substitution) in describing
-the arguments. In Unix systems, you can control which shell is used
-with the @code{SHELL} environment variable. @xref{Arguments, ,Your
-program's arguments}.
+the arguments.
+In Unix systems, you can control which shell is used with the
+@code{SHELL} environment variable.
+@xref{Arguments, ,Your program's arguments}.
@item The @emph{environment.}
Your program normally inherits its environment from @value{GDBN}, but you can
program; if you attempt this, @value{GDBN} is likely to wind up debugging the
wrong program.
@end table
-@end ifclear
When you issue the @code{run} command, your program begins to execute
immediately. @xref{Stopping, ,Stopping and continuing}, for discussion
table, and reads it again. When it does this, @value{GDBN} tries to retain
your current breakpoints.
-@ifclear BARETARGET
@node Arguments
@section Your program's arguments
@cindex arguments (to your program)
The arguments to your program can be specified by the arguments of the
-@code{run} command. They are passed to a shell, which expands wildcard
-characters and performs redirection of I/O, and thence to your program.
-Your @code{SHELL} environment variable (if it exists) specifies what
-shell @value{GDBN} uses. If you do not define @code{SHELL},
-@value{GDBN} uses @code{/bin/sh}.
+@code{run} command.
+They are passed to a shell, which expands wildcard characters and
+performs redirection of I/O, and thence to your program. Your
+@code{SHELL} environment variable (if it exists) specifies what shell
+@value{GDBN} uses. If you do not define @code{SHELL}, @value{GDBN} uses
+the default shell (@file{/bin/sh} on Unix).
+
+On non-Unix systems, the program is usually invoked directly by
+@value{GDBN}, which emulates I/O redirection via the appropriate system
+calls, and the wildcard characters are expanded by the startup code of
+the program, not by the shell.
@code{run} with no arguments uses the same arguments used by the previous
@code{run}, or those set by the @code{set args} command.
@item path @var{directory}
Add @var{directory} to the front of the @code{PATH} environment variable
(the search path for executables), for both @value{GDBN} and your program.
-You may specify several directory names, separated by @samp{:} or
-whitespace. If @var{directory} is already in the path, it is moved to
-the front, so it is searched sooner.
+You may specify several directory names, separated by whitespace or by a
+system-dependent separator character (@samp{:} on Unix, @samp{;} on
+MS-DOS and MS-Windows). If @var{directory} is already in the path, it
+is moved to the front, so it is searched sooner.
You can use the string @samp{$cwd} to refer to whatever is the current
working directory at the time @value{GDBN} searches the path. If you
your program. You can abbreviate @code{environment} as @code{env}.
@kindex set environment
-@item set environment @var{varname} @r{[}=@r{]} @var{value}
+@item set environment @var{varname} @r{[}=@var{value}@r{]}
Set environment variable @var{varname} to @var{value}. The value
changes for your program only, not for @value{GDBN} itself. @var{value} may
be any string; the values of environment variables are just strings, and
@end example
@noindent
-tells a Unix program, when subsequently run, that its user is named
+tells the debugged program, when subsequently run, that its user is named
@samp{foo}. (The spaces around @samp{=} are used for clarity here; they
are not actually required.)
rather than assigning it an empty value.
@end table
-@emph{Warning:} @value{GDBN} runs your program using the shell indicated
+@emph{Warning:} On Unix systems, @value{GDBN} runs your program using
+the shell indicated
by your @code{SHELL} environment variable if it exists (or
@code{/bin/sh} if not). If your @code{SHELL} variable names a shell
that runs an initialization file---such as @file{.cshrc} for C-shell, or
programs on bare-board targets that lack an operating system. You must
also have permission to send the process a signal.
-When using @code{attach}, you should first use the @code{file} command
-to specify the program running in the process and load its symbol table.
-@xref{Files, ,Commands to Specify Files}.
+When you use @code{attach}, the debugger finds the program running in
+the process first by looking in the current working directory, then (if
+the program is not found) by using the source file search path
+(@pxref{Source Path, ,Specifying source directories}). You can also use
+the @code{file} command to load the program. @xref{Files, ,Commands to
+Specify Files}.
The first thing @value{GDBN} does after arranging to debug the specified
process is to stop it. You can examine and modify an attached process
-with all the @value{GDBN} commands that are ordinarily available when you start
-processes with @code{run}. You can insert breakpoints; you can step and
-continue; you can modify storage. If you would rather the process
-continue running, you may use the @code{continue} command after
+with all the @value{GDBN} commands that are ordinarily available when
+you start processes with @code{run}. You can insert breakpoints; you
+can step and continue; you can modify storage. If you would rather the
+process continue running, you may use the @code{continue} command after
attaching @value{GDBN} to the process.
@table @code
messages}).
@node Kill Process
-@c @group
@section Killing the child process
@table @code
This command is useful if you wish to debug a core dump instead of a
running process. @value{GDBN} ignores any core dump file while your program
is running.
-@c @end group
On some operating systems, a program cannot be executed outside @value{GDBN}
while you have breakpoints set on it inside @value{GDBN}. You can use the
reads the symbol table again (while trying to preserve your current
breakpoint settings).
-@node Process Information
-@section Additional process information
-
-@kindex /proc
-@cindex process image
-Some operating systems provide a facility called @samp{/proc} that can
-be used to examine the image of a running process using file-system
-subroutines. If @value{GDBN} is configured for an operating system with this
-facility, the command @code{info proc} is available to report on several
-kinds of information about the process running your program.
-@code{info proc} works only on SVR4 systems that support @code{procfs}.
-
-@table @code
-@kindex info proc
-@item info proc
-Summarize available information about the process.
-
-@kindex info proc mappings
-@item info proc mappings
-Report on the address ranges accessible in the program, with information
-on whether your program may read, write, or execute each range.
-
-@kindex info proc times
-@item info proc times
-Starting time, user CPU time, and system CPU time for your program and
-its children.
-
-@kindex info proc id
-@item info proc id
-Report on the process IDs related to your program: its own process ID,
-the ID of its parent, the process group ID, and the session ID.
-
-@kindex info proc status
-@item info proc status
-General information on the state of the process. If the process is
-stopped, this report includes the reason for stopping, and any signal
-received.
-
-@item info proc all
-Show all the above information about the process.
-@end table
-
@node Threads
@section Debugging programs with multiple threads
@cindex threads of execution
@cindex multiple threads
@cindex switching threads
-In some operating systems, a single program may have more than one
-@dfn{thread} of execution. The precise semantics of threads differ from
-one operating system to another, but in general the threads of a single
-program are akin to multiple processes---except that they share one
-address space (that is, they can all examine and modify the same
-variables). On the other hand, each thread has its own registers and
-execution stack, and perhaps private memory.
+In some operating systems, such as HP-UX and Solaris, a single program
+may have more than one @dfn{thread} of execution. The precise semantics
+of threads differ from one operating system to another, but in general
+the threads of a single program are akin to multiple processes---except
+that they share one address space (that is, they can all examine and
+modify the same variables). On the other hand, each thread has its own
+registers and execution stack, and perhaps private memory.
@value{GDBN} provides these facilities for debugging multi-thread
programs:
at threadtest.c:68
@end smallexample
+On HP-UX systems:
+
+@cindex thread number
+@cindex thread identifier (GDB)
+For debugging purposes, @value{GDBN} associates its own thread
+number---a small integer assigned in thread-creation order---with each
+thread in your program.
+
+@kindex New @var{systag}
+@cindex thread identifier (system)
+@c FIXME-implementors!! It would be more helpful if the [New...] message
+@c included GDB's numeric thread handle, so you could just go to that
+@c thread without first checking `info threads'.
+Whenever @value{GDBN} detects a new thread in your program, it displays
+both @value{GDBN}'s thread number and the target system's identification for the thread with a message in the
+form @samp{[New @var{systag}]}. @var{systag} is a thread identifier
+whose form varies depending on the particular system. For example, on
+HP-UX, you see
+
+@example
+[New thread 2 (system thread 26594)]
+@end example
+
+@noindent
+when @value{GDBN} notices a new thread.
+
+@table @code
+@kindex info threads
+@item info threads
+Display a summary of all threads currently in your
+program. @value{GDBN} displays for each thread (in this order):
+
+@enumerate
+@item the thread number assigned by @value{GDBN}
+
+@item the target system's thread identifier (@var{systag})
+
+@item the current stack frame summary for that thread
+@end enumerate
+
+@noindent
+An asterisk @samp{*} to the left of the @value{GDBN} thread number
+indicates the current thread.
+
+For example,
+@end table
+@c end table here to get a little more width for example
+
+@example
+(@value{GDBP}) info threads
+ * 3 system thread 26607 worker (wptr=0x7b09c318 "@@") at quicksort.c:137
+ 2 system thread 26606 0x7b0030d8 in __ksleep () from /usr/lib/libc.2
+ 1 system thread 27905 0x7b003498 in _brk () from /usr/lib/libc.2
+@end example
+
@table @code
@kindex thread @var{threadno}
@item thread @var{threadno}
@xref{Set Watchpoints,,Setting watchpoints}, for information about
watchpoints in programs with multiple threads.
-@end ifclear
@node Processes
@section Debugging programs with multiple processes
@cindex fork, debugging programs which call
@cindex multiple processes
@cindex processes, multiple
-@value{GDBN} has no special support for debugging programs which create
-additional processes using the @code{fork} function. When a program
-forks, @value{GDBN} will continue to debug the parent process and the
-child process will run unimpeded. If you have set a breakpoint in any
-code which the child then executes, the child will get a @code{SIGTRAP}
-signal which (unless it catches the signal) will cause it to terminate.
+On most systems, @value{GDBN} has no special support for debugging
+programs which create additional processes using the @code{fork}
+function. When a program forks, @value{GDBN} will continue to debug the
+parent process and the child process will run unimpeded. If you have
+set a breakpoint in any code which the child then executes, the child
+will get a @code{SIGTRAP} signal which (unless it catches the signal)
+will cause it to terminate.
However, if you want to debug the child process there is a workaround
which isn't too painful. Put a call to @code{sleep} in the code which
on the child. While the child is sleeping, use the @code{ps} program to
get its process ID. Then tell @value{GDBN} (a new invocation of
@value{GDBN} if you are also debugging the parent process) to attach to
-the child process (see @ref{Attach}). From that point on you can debug
+the child process (@pxref{Attach}). From that point on you can debug
the child process just like any other process which you attached to.
+On HP-UX (11.x and later only?), @value{GDBN} provides support for
+debugging programs that create additional processes using the
+@code{fork} or @code{vfork} function.
+
+By default, when a program forks, @value{GDBN} will continue to debug
+the parent process and the child process will run unimpeded.
+
+If you want to follow the child process instead of the parent process,
+use the command @w{@code{set follow-fork-mode}}.
+
+@table @code
+@kindex set follow-fork-mode
+@item set follow-fork-mode @var{mode}
+Set the debugger response to a program call of @code{fork} or
+@code{vfork}. A call to @code{fork} or @code{vfork} creates a new
+process. The @var{mode} can be:
+
+@table @code
+@item parent
+The original process is debugged after a fork. The child process runs
+unimpeded. This is the default.
+
+@item child
+The new process is debugged after a fork. The parent process runs
+unimpeded.
+
+@item ask
+The debugger will ask for one of the above choices.
+@end table
+
+@item show follow-fork-mode
+Display the current debugger response to a @code{fork} or @code{vfork} call.
+@end table
+
+If you ask to debug a child process and a @code{vfork} is followed by an
+@code{exec}, @value{GDBN} executes the new target up to the first
+breakpoint in the new target. If you have a breakpoint set on
+@code{main} in your original program, the breakpoint will also be set on
+the child process's @code{main}.
+
+When a child process is spawned by @code{vfork}, you cannot debug the
+child or parent until an @code{exec} call completes.
+
+If you issue a @code{run} command to @value{GDBN} after an @code{exec}
+call executes, the new target restarts. To restart the parent process,
+use the @code{file} command with the parent executable name as its
+argument.
+
+You can use the @code{catch} command to make @value{GDBN} stop whenever
+a @code{fork}, @code{vfork}, or @code{exec} call is made. @xref{Set
+Catchpoints, ,Setting catchpoints}.
+
@node Stopping
@chapter Stopping and Continuing
program before it terminates; or so that, if your program runs into
trouble, you can investigate and find out why.
-Inside @value{GDBN}, your program may stop for any of several reasons, such
-as
-@ifclear BARETARGET
-a signal,
-@end ifclear
-a breakpoint, or reaching a new line after a @value{GDBN}
-command such as @code{step}. You may then examine and change
-variables, set new breakpoints or remove old ones, and then continue
-execution. Usually, the messages shown by @value{GDBN} provide ample
-explanation of the status of your program---but you can also explicitly
-request this information at any time.
+Inside @value{GDBN}, your program may stop for any of several reasons,
+such as a signal, a breakpoint, or reaching a new line after a
+@value{GDBN} command such as @code{step}. You may then examine and
+change variables, set new breakpoints or remove old ones, and then
+continue execution. Usually, the messages shown by @value{GDBN} provide
+ample explanation of the status of your program---but you can also
+explicitly request this information at any time.
@table @code
@kindex info program
@item info program
Display information about the status of your program: whether it is
-running or not,
-@ifclear BARETARGET
-what process it is,
-@end ifclear
-and why it stopped.
+running or not, what process it is, and why it stopped.
@end table
@menu
-@ifclear CONLY
-* Breakpoints:: Breakpoints, watchpoints, and exceptions
-@end ifclear
-@ifset CONLY
-* Breakpoints:: Breakpoints and watchpoints
-@end ifset
-@c Remnant makeinfo bug requires blank line after *successful* end-if in menu:
-
+* Breakpoints:: Breakpoints, watchpoints, and catchpoints
* Continuing and Stepping:: Resuming execution
-@ifset POSIX
* Signals:: Signals
-@end ifset
-@ifclear BARETARGET
-* Thread Stops:: Stopping and starting multi-thread programs
-@end ifclear
+* Thread Stops:: Stopping and starting multi-thread programs
@end menu
-@c makeinfo node-defaulting requires adjacency of @node and sectioning cmds
-@c ...hence distribute @node Breakpoints over two possible @if expansions.
-@c
-@ifclear CONLY
-@node Breakpoints
-@section Breakpoints, watchpoints, and exceptions
-@end ifclear
-@ifset CONLY
@node Breakpoints
-@section Breakpoints and watchpoints
-@end ifset
+@section Breakpoints, watchpoints, and catchpoints
@cindex breakpoints
A @dfn{breakpoint} makes your program stop whenever a certain point in
-the program is reached. For each breakpoint, you can add
-conditions to control in finer detail whether your program stops.
-You can set breakpoints with the @code{break} command and its variants
-(@pxref{Set Breaks, ,Setting breakpoints}), to specify the place where
-your program should stop by line number, function name or exact address
-in the program.
-@ifclear CONLY
-In languages with exception handling (such as @sc{gnu} C++), you can also set
-breakpoints where an exception is raised (@pxref{Exception Handling,,
-Breakpoints and exceptions}).
-@end ifclear
-
-In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
-breakpoints in shared libraries before the executable is run.
+the program is reached. For each breakpoint, you can add conditions to
+control in finer detail whether your program stops. You can set
+breakpoints with the @code{break} command and its variants (@pxref{Set
+Breaks, ,Setting breakpoints}), to specify the place where your program
+should stop by line number, function name or exact address in the
+program.
+
+In HP-UX, SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can set
+breakpoints in shared libraries before the executable is run. There is
+a minor limitation on HP-UX systems: you must wait until the executable
+is run in order to set breakpoints in shared library routines that are
+not called directly by the program (for example, routines that are
+arguments in a @code{pthread_create} call).
@cindex watchpoints
@cindex memory tracing
whenever @value{GDBN} stops at a breakpoint. @xref{Auto Display,,
Automatic display}.
+@cindex catchpoints
+@cindex breakpoint on events
+A @dfn{catchpoint} is another special breakpoint that stops your program
+when a certain kind of event occurs, such as the throwing of a C++
+exception or the loading of a library. As with watchpoints, you use a
+different command to set a catchpoint (@pxref{Set Catchpoints, ,Setting
+catchpoints}), but aside from that, you can manage a catchpoint like any
+other breakpoint. (To stop when your program receives a signal, use the
+@code{handle} command; see @ref{Signals, ,Signals}.)
+
@cindex breakpoint numbers
@cindex numbers for breakpoints
-@value{GDBN} assigns a number to each breakpoint or watchpoint when you
-create it; these numbers are successive integers starting with one. In
-many of the commands for controlling various features of breakpoints you
-use the breakpoint number to say which breakpoint you want to change.
-Each breakpoint may be @dfn{enabled} or @dfn{disabled}; if disabled, it has
-no effect on your program until you enable it again.
+@value{GDBN} assigns a number to each breakpoint, watchpoint, or
+catchpoint when you create it; these numbers are successive integers
+starting with one. In many of the commands for controlling various
+features of breakpoints you use the breakpoint number to say which
+breakpoint you want to change. Each breakpoint may be @dfn{enabled} or
+@dfn{disabled}; if disabled, it has no effect on your program until you
+enable it again.
@menu
* Set Breaks:: Setting breakpoints
* Set Watchpoints:: Setting watchpoints
-@ifclear CONLY
-* Exception Handling:: Breakpoints and exceptions
-@end ifclear
-
+* Set Catchpoints:: Setting catchpoints
* Delete Breaks:: Deleting breakpoints
* Disabling:: Disabling breakpoints
* Conditions:: Break conditions
* Break Commands:: Breakpoint command lists
-@ifclear CONLY
* Breakpoint Menus:: Breakpoint menus
-@end ifclear
-@c @ifclear BARETARGET
-@c * Error in Breakpoints:: ``Cannot insert breakpoints''
-@c @end ifclear
+* Error in Breakpoints:: ``Cannot insert breakpoints''
@end menu
@node Set Breaks
@table @code
@item break @var{function}
Set a breakpoint at entry to function @var{function}.
-@ifclear CONLY
When using source languages that permit overloading of symbols, such as
C++, @var{function} may refer to more than one possible place to break.
@xref{Breakpoint Menus,,Breakpoint menus}, for a discussion of that situation.
-@end ifclear
@item break +@var{offset}
@itemx break -@var{offset}
Set a breakpoint some number of lines forward or back from the position
-at which execution stopped in the currently selected frame.
+at which execution stopped in the currently selected @dfn{stack frame}.
+(@xref{Frames, ,Frames}, for a description of stack frames.)
@item break @var{linenum}
Set a breakpoint at line @var{linenum} in the current source file.
-That file is the last file whose source text was printed. This
-breakpoint stops your program just before it executes any of the
+The current source file is the last file whose source text was printed.
+The breakpoint will stop your program just before it executes any of the
code on that line.
@item break @var{filename}:@var{linenum}
@kindex hbreak
@item hbreak @var{args}
-Set a hardware-assisted breakpoint. @var{args} are the same as for the
-@code{break} command and the breakpoint is set in the same way, but the
+Set a hardware-assisted breakpoint. @var{args} are the same as for the
+@code{break} command and the breakpoint is set in the same way, but the
breakpoint requires hardware support and some target hardware may not
have this support. The main purpose of this is EPROM/ROM code
-debugging, so you can set a breakpoint at an instruction without
-changing the instruction. This can be used with the new trap-generation
-provided by SPARClite DSU. DSU will generate traps when a program accesses
-some date or instruction address that is assigned to the debug registers.
-However the hardware breakpoint registers can only take two data breakpoints,
-and @value{GDBN} will reject this command if more than two are used.
-Delete or disable usused hardware breakpoints before setting
-new ones. @xref{Conditions, ,Break conditions}.
+debugging, so you can set a breakpoint at an instruction without
+changing the instruction. This can be used with the new trap-generation
+provided by SPARClite DSU and some x86-based targets. These targets
+will generate traps when a program accesses some data or instruction
+address that is assigned to the debug registers. However the hardware
+breakpoint registers can take a limited number of breakpoints. For
+example, on the DSU, only two data breakpoints can be set at a time, and
+@value{GDBN} will reject this command if more than two are used. Delete
+or disable unused hardware breakpoints before setting new ones
+(@pxref{Disabling, ,Disabling}). @xref{Conditions, ,Break conditions}.
@kindex thbreak
@item thbreak @var{args}
first time your program stops there. Also, like the @code{hbreak}
command, the breakpoint requires hardware support and some target hardware
may not have this support. @xref{Disabling, ,Disabling breakpoints}.
-Also @xref{Conditions, ,Break conditions}.
+See also @ref{Conditions, ,Break conditions}.
@kindex rbreak
@cindex regular expression
@item rbreak @var{regex}
-@c FIXME what kind of regexp?
Set breakpoints on all functions matching the regular expression
-@var{regex}. This command
-sets an unconditional breakpoint on all matches, printing a list of all
-breakpoints it set. Once these breakpoints are set, they are treated
-just like the breakpoints set with the @code{break} command. You can
-delete them, disable them, or make them conditional the same way as any
-other breakpoint.
-
-@ifclear CONLY
+@var{regex}. This command sets an unconditional breakpoint on all
+matches, printing a list of all breakpoints it set. Once these
+breakpoints are set, they are treated just like the breakpoints set with
+the @code{break} command. You can delete them, disable them, or make
+them conditional the same way as any other breakpoint.
+
+The syntax of the regular expression is the standard one used with tools
+like @file{grep}. Note that this is different from the syntax used by
+shells, so for instance @code{foo*} matches all functions that include
+an @code{fo} followed by zero or more @code{o}s. There is an implicit
+@code{.*} leading and trailing the regular expression you supply, so to
+match only functions that begin with @code{foo}, use @code{^foo}.
+
When debugging C++ programs, @code{rbreak} is useful for setting
breakpoints on overloaded functions that are not members of any special
classes.
-@end ifclear
@kindex info breakpoints
@cindex @code{$_} and @code{info breakpoints}
@item info breakpoints @r{[}@var{n}@r{]}
@itemx info break @r{[}@var{n}@r{]}
@itemx info watchpoints @r{[}@var{n}@r{]}
-Print a table of all breakpoints and watchpoints set and not
-deleted, with the following columns for each breakpoint:
+Print a table of all breakpoints, watchpoints, and catchpoints set and
+not deleted, with the following columns for each breakpoint:
@table @emph
@item Breakpoint Numbers
@item Type
-Breakpoint or watchpoint.
+Breakpoint, watchpoint, or catchpoint.
@item Disposition
Whether the breakpoint is marked to be disabled or deleted when hit.
@item Enabled or Disabled
Enabled breakpoints are marked with @samp{y}. @samp{n} marks breakpoints
that are not enabled.
@item Address
-Where the breakpoint is in your program, as a memory address
+Where the breakpoint is in your program, as a memory address.
@item What
Where the breakpoint is in the source for your program, as a file and
line number.
listed (@pxref{Memory, ,Examining memory}).
@noindent
-@code{info break} now displays a count of the number of times the
-breakpoint has been hit. This is especially useful in conjunction with
-the @code{ignore} command. You can ignore a large number of breakpoint
-hits, look at the breakpoint info to see how many times the
-breakpoint was hit, and then run again, ignoring one less than that
-number. This will get you quickly to the last hit of that breakpoint.
+@code{info break} displays a count of the number of times the breakpoint
+has been hit. This is especially useful in conjunction with the
+@code{ignore} command. You can ignore a large number of breakpoint
+hits, look at the breakpoint info to see how many times the breakpoint
+was hit, and then run again, ignoring one less than that number. This
+will get you quickly to the last hit of that breakpoint.
@end table
@value{GDBN} allows you to set any number of breakpoints at the same place in
@item finish
Temporary internal breakpoint used by the @value{GDBN} @code{finish} command.
+
+@item shlib events
+Shared library events.
+
@end table
@end table
@node Set Watchpoints
@subsection Setting watchpoints
-@cindex setting watchpoints
+@cindex setting watchpoints
+@cindex software watchpoints
+@cindex hardware watchpoints
You can use a watchpoint to stop execution whenever the value of an
-expression changes, without having to predict a particular place
-where this may happen.
-
-Watchpoints currently execute two orders of magnitude more slowly than
-other breakpoints, but this can be well worth it to catch errors where
-you have no clue what part of your program is the culprit.
-
-@c FIXME - did Stan mean to @ignore this out?
-@ignore
-Some processors provide special hardware to support watchpoint
-evaluation; @value{GDBN} will use such hardware if it is available,
-and if the support code has been added for that configuration.
-@end ignore
+expression changes, without having to predict a particular place where
+this may happen.
+
+Depending on your system, watchpoints may be implemented in software or
+hardware. @value{GDBN} does software watchpointing by single-stepping your
+program and testing the variable's value each time, which is hundreds of
+times slower than normal execution. (But this may still be worth it, to
+catch errors where you have no clue what part of your program is the
+culprit.)
+
+On some systems, such as HP-UX, Linux and some other x86-based targets,
+@value{GDBN} includes support for
+hardware watchpoints, which do not slow down the running of your
+program.
@table @code
@kindex watch
@item watch @var{expr}
Set a watchpoint for an expression. @value{GDBN} will break when @var{expr}
is written into by the program and its value changes.
-This can be used with the new trap-generation provided by
-SPARClite DSU. DSU will generate traps when a program accesses
-some date or instruction address that is assigned to the debug registers.
-For the data addresses, DSU facilitates the @code{watch} command.
-However the hardware breakpoint registers can only take two data watchpoints,
-and both watchpoints must be the same kind. For example, you can set two
-watchpoints with @code{watch} commands, two with @code{rwatch}
-commands, @strong{or} two with @code{awatch} commands, but you cannot set one
-watchpoint with one command and the other with a different command.
-@value{GBDN} will reject the command if you try to mix watchpoints.
-Delete or disable unused watchpoint commands before setting new ones.
@kindex rwatch
@item rwatch @var{expr}
-Set a watchpoint that will break when watch @var{args} is read by the program.
-If you use both watchpoints, both must be set with the @code{rwatch}
-command.
+Set a watchpoint that will break when watch @var{expr} is read by the program.
@kindex awatch
@item awatch @var{expr}
-Set a watchpoint that will break when @var{args} is read and written into
-by the program. If you use both watchpoints, both must be set with the
-@code{awatch} command.
+Set a watchpoint that will break when @var{expr} is either read or written into
+by the program.
@kindex info watchpoints
@item info watchpoints
-This command prints a list of watchpoints and breakpoints; it is the
-same as @code{info break}.
+This command prints a list of watchpoints, breakpoints, and catchpoints;
+it is the same as @code{info break}.
@end table
-@ifclear BARETARGET
+@value{GDBN} sets a @dfn{hardware watchpoint} if possible. Hardware
+watchpoints execute very quickly, and the debugger reports a change in
+value at the exact instruction where the change occurs. If @value{GDBN}
+cannot set a hardware watchpoint, it sets a software watchpoint, which
+executes more slowly and reports the change in value at the next
+statement, not the instruction, after the change occurs.
+
+When you issue the @code{watch} command, @value{GDBN} reports
+
+@example
+Hardware watchpoint @var{num}: @var{expr}
+@end example
+
+@noindent
+if it was able to set a hardware watchpoint.
+
+Currently, the @code{awatch} and @code{rwatch} commands can only set
+hardware watchpoints, because accesses to data that don't change the
+value of the watched expression cannot be detected without examining
+every instruction as it is being executed, and @value{GDBN} does not do
+that currently. If @value{GDBN} finds that it is unable to set a
+hardware breakpoint with the @code{awatch} or @code{rwatch} command, it
+will print a message like this:
+
+@smallexample
+Expression cannot be implemented with read/access watchpoint.
+@end smallexample
+
+Sometimes, @value{GDBN} cannot set a hardware watchpoint because the
+data type of the watched expression is wider than what a hardware
+watchpoint on the target machine can handle. For example, some systems
+can only watch regions that are up to 4 bytes wide; on such systems you
+cannot set hardware watchpoints for an expression that yields a
+double-precision floating-point number (which is typically 8 bytes
+wide). As a work-around, it might be possible to break the large region
+into a series of smaller ones and watch them with separate watchpoints.
+
+If you set too many hardware watchpoints, @value{GDBN} might be unable
+to insert all of them when you resume the execution of your program.
+Since the precise number of active watchpoints is unknown until such
+time as the program is about to be resumed, @value{GDBN} might not be
+able to warn you about this when you set the watchpoints, and the
+warning will be printed only when the program is resumed:
+
+@smallexample
+Hardware watchpoint @var{num}: Could not insert watchpoint
+@end smallexample
+
+@noindent
+If this happens, delete or disable some of the watchpoints.
+
+The SPARClite DSU will generate traps when a program accesses some data
+or instruction address that is assigned to the debug registers. For the
+data addresses, DSU facilitates the @code{watch} command. However the
+hardware breakpoint registers can only take two data watchpoints, and
+both watchpoints must be the same kind. For example, you can set two
+watchpoints with @code{watch} commands, two with @code{rwatch} commands,
+@strong{or} two with @code{awatch} commands, but you cannot set one
+watchpoint with one command and the other with a different command.
+@value{GDBN} will reject the command if you try to mix watchpoints.
+Delete or disable unused watchpoint commands before setting new ones.
+
+If you call a function interactively using @code{print} or @code{call},
+any watchpoints you have set will be inactive until @value{GDBN} reaches another
+kind of breakpoint or the call completes.
+
+@value{GDBN} automatically deletes watchpoints that watch local
+(automatic) variables, or expressions that involve such variables, when
+they go out of scope, that is, when the execution leaves the block in
+which these variables were defined. In particular, when the program
+being debugged terminates, @emph{all} local variables go out of scope,
+and so only watchpoints that watch global variables remain set. If you
+rerun the program, you will need to set all such watchpoints again. One
+way of doing that would be to set a code breakpoint at the entry to the
+@code{main} function and when it breaks, set all the watchpoints.
+
@quotation
@cindex watchpoints and threads
@cindex threads and watchpoints
-@emph{Warning:} in multi-thread programs, watchpoints have only limited
+@emph{Warning:} In multi-thread programs, watchpoints have only limited
usefulness. With the current watchpoint implementation, @value{GDBN}
can only watch the value of an expression @emph{in a single thread}. If
you are confident that the expression can only change due to the current
can become current), then you can use watchpoints as usual. However,
@value{GDBN} may not notice when a non-current thread's activity changes
the expression.
+
+@c FIXME: this is almost identical to the previous paragraph.
+@emph{HP-UX Warning:} In multi-thread programs, software watchpoints
+have only limited usefulness. If @value{GDBN} creates a software
+watchpoint, it can only watch the value of an expression @emph{in a
+single thread}. If you are confident that the expression can only
+change due to the current thread's activity (and if you are also
+confident that no other thread can become current), then you can use
+software watchpoints as usual. However, @value{GDBN} may not notice
+when a non-current thread's activity changes the expression. (Hardware
+watchpoints, in contrast, watch an expression in all threads.)
@end quotation
-@end ifclear
-@ifclear CONLY
-@node Exception Handling
-@subsection Breakpoints and exceptions
+@node Set Catchpoints
+@subsection Setting catchpoints
+@cindex catchpoints, setting
@cindex exception handlers
+@cindex event handling
-Some languages, such as @sc{gnu} C++, implement exception handling. You can
-use @value{GDBN} to examine what caused your program to raise an exception,
-and to list the exceptions your program is prepared to handle at a
-given point in time.
+You can use @dfn{catchpoints} to cause the debugger to stop for certain
+kinds of program events, such as C++ exceptions or the loading of a
+shared library. Use the @code{catch} command to set a catchpoint.
@table @code
@kindex catch
-@item catch @var{exceptions}
-You can set breakpoints at active exception handlers by using the
-@code{catch} command. @var{exceptions} is a list of names of exceptions
-to catch.
+@item catch @var{event}
+Stop when @var{event} occurs. @var{event} can be any of the following:
+@table @code
+@item throw
+@kindex catch throw
+The throwing of a C++ exception.
+
+@item catch
+@kindex catch catch
+The catching of a C++ exception.
+
+@item exec
+@kindex catch exec
+A call to @code{exec}. This is currently only available for HP-UX.
+
+@item fork
+@kindex catch fork
+A call to @code{fork}. This is currently only available for HP-UX.
+
+@item vfork
+@kindex catch vfork
+A call to @code{vfork}. This is currently only available for HP-UX.
+
+@item load
+@itemx load @var{libname}
+@kindex catch load
+The dynamic loading of any shared library, or the loading of the library
+@var{libname}. This is currently only available for HP-UX.
+
+@item unload
+@itemx unload @var{libname}
+@kindex catch unload
+The unloading of any dynamically loaded shared library, or the unloading
+of the library @var{libname}. This is currently only available for HP-UX.
+@end table
+
+@item tcatch @var{event}
+Set a catchpoint that is enabled only for one stop. The catchpoint is
+automatically deleted after the first time the event is caught.
+
@end table
-You can use @code{info catch} to list active exception handlers.
-@xref{Frame Info, ,Information about a frame}.
+Use the @code{info break} command to list the current catchpoints.
-There are currently some limitations to exception handling in @value{GDBN}:
+There are currently some limitations to C++ exception handling
+(@code{catch throw} and @code{catch catch}) in @value{GDBN}:
@itemize @bullet
@item
If you call a function interactively, @value{GDBN} normally returns
control to you when the function has finished executing. If the call
raises an exception, however, the call may bypass the mechanism that
-returns control to you and cause your program to simply continue
-running until it hits a breakpoint, catches a signal that @value{GDBN} is
-listening for, or exits.
+returns control to you and cause your program either to abort or to
+simply continue running until it hits a breakpoint, catches a signal
+that @value{GDBN} is listening for, or exits. This is the case even if
+you set a catchpoint for the exception; catchpoints on exceptions are
+disabled within interactive calls.
@item
You cannot raise an exception interactively.
@example
/* @var{addr} is where the exception identifier is stored.
- ID is the exception identifier. */
- void __raise_exception (void **@var{addr}, void *@var{id});
+ @var{id} is the exception identifier. */
+ void __raise_exception (void **addr, void *id);
@end example
@noindent
a specific exception is raised. You can use multiple conditional
breakpoints to stop your program when any of a number of exceptions are
raised.
-@end ifclear
+
@node Delete Breaks
@subsection Deleting breakpoints
-@cindex clearing breakpoints, watchpoints
-@cindex deleting breakpoints, watchpoints
-It is often necessary to eliminate a breakpoint or watchpoint once it
-has done its job and you no longer want your program to stop there. This
-is called @dfn{deleting} the breakpoint. A breakpoint that has been
-deleted no longer exists; it is forgotten.
+@cindex clearing breakpoints, watchpoints, catchpoints
+@cindex deleting breakpoints, watchpoints, catchpoints
+It is often necessary to eliminate a breakpoint, watchpoint, or
+catchpoint once it has done its job and you no longer want your program
+to stop there. This is called @dfn{deleting} the breakpoint. A
+breakpoint that has been deleted no longer exists; it is forgotten.
With the @code{clear} command you can delete breakpoints according to
where they are in your program. With the @code{delete} command you can
-delete individual breakpoints or watchpoints by specifying their
-breakpoint numbers.
+delete individual breakpoints, watchpoints, or catchpoints by specifying
+their breakpoint numbers.
It is not necessary to delete a breakpoint to proceed past it. @value{GDBN}
automatically ignores breakpoints on the first instruction to be executed
when you continue execution without changing the execution address.
@table @code
-@item clear
@kindex clear
+@item clear
Delete any breakpoints at the next instruction to be executed in the
selected stack frame (@pxref{Selection, ,Selecting a frame}). When
the innermost frame is selected, this is a good way to delete a
@kindex delete
@kindex d
@item delete @r{[}breakpoints@r{]} @r{[}@var{bnums}@dots{}@r{]}
-Delete the breakpoints or watchpoints of the numbers specified as
-arguments. If no argument is specified, delete all breakpoints (@value{GDBN}
-asks confirmation, unless you have @code{set confirm off}). You
-can abbreviate this command as @code{d}.
+Delete the breakpoints, watchpoints, or catchpoints of the numbers
+specified as arguments. If no argument is specified, delete all
+breakpoints (@value{GDBN} asks confirmation, unless you have @code{set
+confirm off}). You can abbreviate this command as @code{d}.
@end table
@node Disabling
@kindex disable breakpoints
@kindex enable breakpoints
-Rather than deleting a breakpoint or watchpoint, you might prefer to
-@dfn{disable} it. This makes the breakpoint inoperative as if it had
-been deleted, but remembers the information on the breakpoint so that
-you can @dfn{enable} it again later.
+Rather than deleting a breakpoint, watchpoint, or catchpoint, you might
+prefer to @dfn{disable} it. This makes the breakpoint inoperative as if
+it had been deleted, but remembers the information on the breakpoint so
+that you can @dfn{enable} it again later.
-You disable and enable breakpoints and watchpoints with the
-@code{enable} and @code{disable} commands, optionally specifying one or
-more breakpoint numbers as arguments. Use @code{info break} or
-@code{info watch} to print a list of breakpoints or watchpoints if you
-do not know which numbers to use.
+You disable and enable breakpoints, watchpoints, and catchpoints with
+the @code{enable} and @code{disable} commands, optionally specifying one
+or more breakpoint numbers as arguments. Use @code{info break} or
+@code{info watch} to print a list of breakpoints, watchpoints, and
+catchpoints if you do not know which numbers to use.
-A breakpoint or watchpoint can have any of four different states of
-enablement:
+A breakpoint, watchpoint, or catchpoint can have any of four different
+states of enablement:
@itemize @bullet
@item
Disabled. The breakpoint has no effect on your program.
@item
Enabled once. The breakpoint stops your program, but then becomes
-disabled. A breakpoint set with the @code{tbreak} command starts out in
-this state.
+disabled.
@item
Enabled for deletion. The breakpoint stops your program, but
-immediately after it does so it is deleted permanently.
+immediately after it does so it is deleted permanently. A breakpoint
+set with the @code{tbreak} command starts out in this state.
@end itemize
-You can use the following commands to enable or disable breakpoints and
-watchpoints:
+You can use the following commands to enable or disable breakpoints,
+watchpoints, and catchpoints:
@table @code
@kindex disable breakpoints
deletes any of these breakpoints as soon as your program stops there.
@end table
+@c FIXME: I think the following ``Except for [...] @code{tbreak}'' is
+@c confusing: tbreak is also initially enabled.
Except for a breakpoint set with @code{tbreak} (@pxref{Set Breaks,
,Setting breakpoints}), breakpoints that you set are initially enabled;
subsequently, they become disabled or enabled only when you use one of
unless there is another enabled breakpoint at the same address. (In
that case, @value{GDBN} might see the other breakpoint first and stop your
program without checking the condition of this one.) Note that
-breakpoint commands are usually more convenient and flexible for the
+breakpoint commands are usually more convenient and flexible than break
+conditions for the
purpose of performing side effects when a breakpoint is reached
(@pxref{Break Commands, ,Breakpoint command lists}).
Break conditions can be specified when a breakpoint is set, by using
@samp{if} in the arguments to the @code{break} command. @xref{Set
Breaks, ,Setting breakpoints}. They can also be changed at any time
-with the @code{condition} command. The @code{watch} command does not
-recognize the @code{if} keyword; @code{condition} is the only way to
-impose a further condition on a watchpoint.
+with the @code{condition} command.
+
+You can also use the @code{if} keyword with the @code{watch} command.
+The @code{catch} command does not recognize the @code{if} keyword;
+@code{condition} is the only way to impose a further condition on a
+catchpoint.
@table @code
@kindex condition
@item condition @var{bnum} @var{expression}
-Specify @var{expression} as the break condition for breakpoint or
-watchpoint number @var{bnum}. After you set a condition, breakpoint
-@var{bnum} stops your program only if the value of @var{expression} is
-true (nonzero, in C). When you use @code{condition}, @value{GDBN}
-checks @var{expression} immediately for syntactic correctness, and to
-determine whether symbols in it have referents in the context of your
-breakpoint.
-@c FIXME so what does GDB do if there is no referent? Moreover, what
-@c about watchpoints?
+Specify @var{expression} as the break condition for breakpoint,
+watchpoint, or catchpoint number @var{bnum}. After you set a condition,
+breakpoint @var{bnum} stops your program only if the value of
+@var{expression} is true (nonzero, in C). When you use
+@code{condition}, @value{GDBN} checks @var{expression} immediately for
+syntactic correctness, and to determine whether symbols in it have
+referents in the context of your breakpoint. If @var{expression} uses
+symbols not referenced in the context of the breakpoint, @value{GDBN}
+prints an error message:
+
+@example
+No symbol "foo" in current context.
+@end example
+
+@noindent
@value{GDBN} does
not actually evaluate @var{expression} at the time the @code{condition}
-command is given, however. @xref{Expressions, ,Expressions}.
+command (or a command that sets a breakpoint with a condition, like
+@code{break if @dots{}}) is given, however. @xref{Expressions, ,Expressions}.
@item condition @var{bnum}
Remove the condition from breakpoint number @var{bnum}. It becomes
variables}.
@end table
+Ignore counts apply to breakpoints, watchpoints, and catchpoints.
+
+
@node Break Commands
@subsection Breakpoint command lists
@cindex breakpoint commands
-You can give any breakpoint (or watchpoint) a series of commands to
-execute when your program stops due to that breakpoint. For example, you
-might want to print the values of certain expressions, or enable other
-breakpoints.
+You can give any breakpoint (or watchpoint or catchpoint) a series of
+commands to execute when your program stops due to that breakpoint. For
+example, you might want to print the values of certain expressions, or
+enable other breakpoints.
@table @code
@kindex commands
follow it immediately with @code{end}; that is, give no commands.
With no @var{bnum} argument, @code{commands} refers to the last
-breakpoint or watchpoint set (not to the breakpoint most recently
-encountered).
+breakpoint, watchpoint, or catchpoint set (not to the breakpoint most
+recently encountered).
@end table
Pressing @key{RET} as a means of repeating the last @value{GDBN} command is
end
@end example
-@ifclear CONLY
@node Breakpoint Menus
@subsection Breakpoint menus
@cindex overloading
@c FIXME! This is likely to change to show arg type lists, at least
@smallexample
+@group
(@value{GDBP}) b String::after
[0] cancel
[1] all
Use the "delete" command to delete unwanted
breakpoints.
(@value{GDBP})
+@end group
@end smallexample
-@end ifclear
@c @ifclear BARETARGET
-@c @node Error in Breakpoints
-@c @subsection ``Cannot insert breakpoints''
+@node Error in Breakpoints
+@subsection ``Cannot insert breakpoints''
@c
@c FIXME!! 14/6/95 Is there a real example of this? Let's use it.
@c
-@c Under some operating systems, breakpoints cannot be used in a program if
-@c any other process is running that program. In this situation,
-@c attempting to run or continue a program with a breakpoint causes
-@c @value{GDBN} to stop the other process.
-@c
-@c When this happens, you have three ways to proceed:
-@c
-@c @enumerate
-@c @item
-@c Remove or disable the breakpoints, then continue.
-@c
-@c @item
-@c Suspend @value{GDBN}, and copy the file containing your program to a new
-@c name. Resume @value{GDBN} and use the @code{exec-file} command to specify
-@c that @value{GDBN} should run your program under that name.
-@c Then start your program again.
-@c
-@c @item
-@c Relink your program so that the text segment is nonsharable, using the
-@c linker option @samp{-N}. The operating system limitation may not apply
-@c to nonsharable executables.
-@c @end enumerate
-@c @end ifclear
+Under some operating systems, breakpoints cannot be used in a program if
+any other process is running that program. In this situation,
+attempting to run or continue a program with a breakpoint causes
+@value{GDBN} to print an error message:
-@node Continuing and Stepping
-@section Continuing and stepping
+@example
+Cannot insert breakpoints.
+The same program may be running in another process.
+@end example
-@cindex stepping
-@cindex continuing
-@cindex resuming execution
-@dfn{Continuing} means resuming program execution until your program
-completes normally. In contrast, @dfn{stepping} means executing just
-one more ``step'' of your program, where ``step'' may mean either one
-line of source code, or one machine instruction (depending on what
-particular command you use). Either when continuing
-or when stepping, your program may stop even sooner, due to
-@ifset BARETARGET
-a breakpoint.
-@end ifset
-@ifclear BARETARGET
-a breakpoint or a signal. (If due to a signal, you may want to use
-@code{handle}, or use @samp{signal 0} to resume execution.
-@xref{Signals, ,Signals}.)
-@end ifclear
+When this happens, you have three ways to proceed:
-@table @code
-@kindex continue
-@kindex c
-@kindex fg
-@item continue @r{[}@var{ignore-count}@r{]}
+@enumerate
+@item
+Remove or disable the breakpoints, then continue.
+
+@item
+Suspend @value{GDBN}, and copy the file containing your program to a new
+name. Resume @value{GDBN} and use the @code{exec-file} command to specify
+that @value{GDBN} should run your program under that name.
+Then start your program again.
+
+@item
+Relink your program so that the text segment is nonsharable, using the
+linker option @samp{-N}. The operating system limitation may not apply
+to nonsharable executables.
+@end enumerate
+@c @end ifclear
+
+A similar message can be printed if you request too many active
+hardware-assisted breakpoints and watchpoints:
+
+@c FIXME: the precise wording of this message may change; the relevant
+@c source change is not committed yet (Sep 3, 1999).
+@smallexample
+Stopped; cannot insert breakpoints.
+You may have requested too many hardware breakpoints and watchpoints.
+@end smallexample
+
+@noindent
+This message is printed when you attempt to resume the program, since
+only then @value{GDBN} knows exactly how many hardware breakpoints and
+watchpoints it needs to insert.
+
+When this message is printed, you need to disable or remove some of the
+hardware-assisted breakpoints and watchpoints, and then continue.
+
+
+@node Continuing and Stepping
+@section Continuing and stepping
+
+@cindex stepping
+@cindex continuing
+@cindex resuming execution
+@dfn{Continuing} means resuming program execution until your program
+completes normally. In contrast, @dfn{stepping} means executing just
+one more ``step'' of your program, where ``step'' may mean either one
+line of source code, or one machine instruction (depending on what
+particular command you use). Either when continuing or when stepping,
+your program may stop even sooner, due to a breakpoint or a signal. (If
+it stops due to a signal, you may want to use @code{handle}, or use
+@samp{signal 0} to resume execution. @xref{Signals, ,Signals}.)
+
+@table @code
+@kindex continue
+@kindex c
+@kindex fg
+@item continue @r{[}@var{ignore-count}@r{]}
@itemx c @r{[}@var{ignore-count}@r{]}
@itemx fg @r{[}@var{ignore-count}@r{]}
Resume program execution, at the address where your program last stopped;
stopped due to a breakpoint. At other times, the argument to
@code{continue} is ignored.
-The synonyms @code{c} and @code{fg} are provided purely for convenience,
-and have exactly the same behavior as @code{continue}.
+The synonyms @code{c} and @code{fg} (for @dfn{foreground}, as the
+debugged program is deemed to be the foreground program) are provided
+purely for convenience, and have exactly the same behavior as
+@code{continue}.
@end table
To resume execution at a different place, you can use @code{return}
different address}) to go to an arbitrary location in your program.
A typical technique for using stepping is to set a breakpoint
-@ifclear CONLY
-(@pxref{Breakpoints, ,Breakpoints; watchpoints; and exceptions})
-@end ifclear
-@ifset CONLY
-(@pxref{Breakpoints, ,Breakpoints and watchpoints})
-@end ifset
-at the
-beginning of the function or the section of your program where a
-problem is believed to lie, run your program until it stops at that
-breakpoint, and then step through the suspect area, examining the
-variables that are interesting, until you see the problem happen.
+(@pxref{Breakpoints, ,Breakpoints; watchpoints; and catchpoints}) at the
+beginning of the function or the section of your program where a problem
+is believed to lie, run your program until it stops at that breakpoint,
+and then step through the suspect area, examining the variables that are
+interesting, until you see the problem happen.
@table @code
@kindex step
below.
@end quotation
-The @code{step} command now only stops at the first instruction of a
-source line. This prevents the multiple stops that used to occur in
+The @code{step} command only stops at the first instruction of a
+source line. This prevents the multiple stops that could otherwise occur in
switch statements, for loops, etc. @code{step} continues to stop if a
function that has debugging information is called within the line.
+In other words, @code{step} @emph{steps inside} any functions called
+within the line.
-Also, the @code{step} command now only enters a subroutine if there is line
-number information for the subroutine. Otherwise it acts like the
+Also, the @code{step} command only enters a function if there is line
+number information for the function. Otherwise it acts like the
@code{next} command. This avoids problems when using @code{cc -gl}
on MIPS machines. Previously, @code{step} entered subroutines if there
was any debugging information about the routine.
@item step @var{count}
Continue running as in @code{step}, but do so @var{count} times. If a
-breakpoint is reached,
-@ifclear BARETARGET
-or a signal not related to stepping occurs before @var{count} steps,
-@end ifclear
-stepping stops right away.
+breakpoint is reached, or a signal not related to stepping occurs before
+@var{count} steps, stepping stops right away.
@kindex next
@kindex n
@item next @r{[}@var{count}@r{]}
Continue to the next source line in the current (innermost) stack frame.
-This is similar to @code{step}, but function calls that appear within the line
-of code are executed without stopping. Execution stops when control
-reaches a different line of code at the original stack level that was
-executing when you gave the @code{next} command. This command is abbreviated
-@code{n}.
+This is similar to @code{step}, but function calls that appear within
+the line of code are executed without stopping. Execution stops when
+control reaches a different line of code at the original stack level
+that was executing when you gave the @code{next} command. This command
+is abbreviated @code{n}.
An argument @var{count} is a repeat count, as for @code{step}.
@c @code{step}, but any function calls appearing within the code of the
@c function are executed without stopping.
-The @code{next} command now only stops at the first instruction of a
-source line. This prevents the multiple stops that used to occur in
-swtch statements, for loops, etc.
+The @code{next} command only stops at the first instruction of a
+source line. This prevents multiple stops that could otherwise occur in
+switch statements, for loops, etc.
@kindex finish
@item finish
,Returning from a function}).
@kindex until
-@itemx u
@kindex u
@item until
+@itemx u
Continue running until a source line past the current line, in the
current stack frame, is reached. This command is used to avoid single
stepping through a loop more than once. It is like the @code{next}
An argument is a repeat count, as in @code{next}.
@end table
-@ifset POSIX
@node Signals
@section Signals
@cindex signals
A signal is an asynchronous event that can happen in a program. The
operating system defines the possible kinds of signals, and gives each
kind a name and a number. For example, in Unix @code{SIGINT} is the
-signal a program gets when you type an interrupt (often @kbd{C-c});
+signal a program gets when you type an interrupt character (often @kbd{C-c});
@code{SIGSEGV} is the signal a program gets from referencing a place in
memory far away from all the areas in use; @code{SIGALRM} occurs when
the alarm clock timer goes off (which happens only if your program has
@cindex fatal signals
Some signals, including @code{SIGALRM}, are a normal part of the
functioning of your program. Others, such as @code{SIGSEGV}, indicate
-errors; these signals are @dfn{fatal} (kill your program immediately) if the
+errors; these signals are @dfn{fatal} (they kill your program immediately) if the
program has not specified in advance some other way to handle the signal.
@code{SIGINT} does not indicate an error in your program, but it is normally
fatal so it can carry out the purpose of the interrupt: to kill the program.
handle each one. You can use this to see the signal numbers of all
the defined types of signals.
-@code{info handle} is the new alias for @code{info signals}.
+@code{info handle} is an alias for @code{info signals}.
@kindex handle
@item handle @var{signal} @var{keywords}@dots{}
@end table
@c @end group
-When a signal stops your program, the signal is not visible until you
+When a signal stops your program, the signal is not visible to the
+program until you
continue. Your program sees the signal then, if @code{pass} is in
effect for the signal in question @emph{at that time}. In other words,
after @value{GDBN} reports a signal, you can use the @code{handle}
a result of the fatal signal once it saw the signal. To prevent this,
you can continue with @samp{signal 0}. @xref{Signaling, ,Giving your
program a signal}.
-@end ifset
-@ifclear BARETARGET
@node Thread Stops
@section Stopping and starting multi-thread programs
breakpoint condition, like this:
@smallexample
-(gdb) break frik.c:13 thread 28 if bartab > lim
+(@value{GDBP}) break frik.c:13 thread 28 if bartab > lim
@end smallexample
@end table
continuing or even single-stepping. This happens whenever some other
thread runs into a breakpoint, a signal, or an exception before the
first thread completes whatever you requested.
-@end ifclear
+
+On some OSes, you can lock the OS scheduler and thus allow only a single
+thread to run.
+
+@table @code
+@item set scheduler-locking @var{mode}
+Set the scheduler locking mode. If it is @code{off}, then there is no
+locking and any thread may run at any time. If @code{on}, then only the
+current thread may run when the inferior is resumed. The @code{step}
+mode optimizes for single-stepping. It stops other threads from
+``seizing the prompt'' by preempting the current thread while you are
+stepping. Other threads will only rarely (or never) get a chance to run
+when you step. They are more likely to run when you @samp{next} over a
+function call, and they are completely free to run when you use commands
+like @samp{continue}, @samp{until}, or @samp{finish}. However, unless another
+thread hits a breakpoint during its timeslice, they will never steal the
+@value{GDBN} prompt away from the thread that you are debugging.
+
+@item show scheduler-locking
+Display the current scheduler locking mode.
+@end table
+
@node Stack
@chapter Examining the Stack
* Backtrace:: Backtraces
* Selection:: Selecting a frame
* Frame Info:: Information on a frame
-@ifset MIPS
-* MIPS Stack:: MIPS machines and the function stack
-@end ifset
+
@end menu
@node Frames
@section Stack frames
-@cindex frame
+@cindex frame, definition
@cindex stack frame
The call stack is divided up into contiguous pieces called @dfn{stack
frames}, or @dfn{frames} for short; each frame is the data associated
no provision for frameless functions elsewhere in the stack.
@table @code
-@kindex frame
+@kindex frame@r{, command}
@item frame @var{args}
The @code{frame} command allows you to move from one stack frame to another,
and to print the stack frame you select. @var{args} may be either the
-address of the frame of the stack frame number. Without an argument,
+address of the frame or the stack frame number. Without an argument,
@code{frame} prints the current stack frame.
@kindex select-frame
@node Backtrace
@section Backtraces
+@cindex backtraces
+@cindex tracebacks
+@cindex stack traces
A backtrace is a summary of how your program got where it is. It shows one
line per frame, for many frames, starting with the currently executing
frame (frame zero), followed by its caller (frame one), and on up the
of the stack frame just selected.
@table @code
-@kindex frame
+@kindex frame@r{, selecting}
@kindex f
@item frame @var{n}
@itemx f @var{n}
addition, this can be useful when your program has multiple stacks and
switches between them.
-@ifclear H8EXCLUSIVE
On the SPARC architecture, @code{frame} needs two addresses to
select an arbitrary frame: a frame pointer and a stack pointer.
@c note to future updaters: this is conditioned on a flag
@c SETUP_ARBITRARY_FRAME in the tm-*.h files. The above is up to date
@c as of 27 Jan 1994.
-@end ifclear
@kindex up
@item up @var{n}
This command prints a verbose description of the selected stack frame,
including:
-@itemize
+@itemize @bullet
@item
the address of the frame
@item
@item
the address of the frame's arguments
@item
+the address of the frame's local variables
+@item
the program counter saved in it (the address of execution in the caller frame)
@item
which registers were saved in the frame
line. These are all variables (declared either static or automatic)
accessible at the point of execution of the selected frame.
-@ifclear CONLY
@kindex info catch
-@cindex catch exceptions
-@cindex exception handlers
+@cindex catch exceptions, list active handlers
+@cindex exception handlers, how to list
@item info catch
Print a list of all the exception handlers that are active in the
current stack frame at the current point of execution. To see other
exception handlers, visit the associated frame (using the @code{up},
@code{down}, or @code{frame} commands); then type @code{info catch}.
-@xref{Exception Handling, ,Breakpoints and exceptions}.
-@end ifclear
-@end table
+@xref{Set Catchpoints, , Setting catchpoints}.
-@ifset MIPS
-@node MIPS Stack
-@section MIPS machines and the function stack
-
-@cindex stack on MIPS
-@cindex MIPS stack
-MIPS based computers use an unusual stack frame, which sometimes
-requires @value{GDBN} to search backward in the object code to find the
-beginning of a function.
-
-@cindex response time, MIPS debugging
-To improve response time (especially for embedded applications, where
-@value{GDBN} may be restricted to a slow serial line for this search)
-you may want to limit the size of this search, using one of these
-commands:
-
-@table @code
-@cindex @code{heuristic-fence-post} (MIPS)
-@item set heuristic-fence-post @var{limit}
-Restrict @value{GDBN} to examining at most @var{limit} bytes in its search
-for the beginning of a function. A value of @var{0} (the default)
-means there is no limit. However, except for @var{0}, the larger the
-limit the more bytes @code{heuristic-fence-post} must search and
-therefore the longer it takes to run.
-
-@item show heuristic-fence-post
-Display the current limit.
@end table
-@noindent
-These commands are available @emph{only} when @value{GDBN} is configured
-for debugging programs on MIPS processors.
-@end ifset
@node Source
@chapter Examining Source Files
execution in that frame has stopped. You can print other portions of
source files by explicit command.
-@ifclear DOSHOST
-If you use @value{GDBN} through its @sc{gnu} Emacs interface, you may prefer
-to use
-Emacs facilities to view source; @pxref{Emacs, ,Using @value{GDBN} under @sc{gnu} Emacs}.
-@end ifclear
+If you use @value{GDBN} through its @sc{gnu} Emacs interface, you may
+prefer to use Emacs facilities to view source; see @ref{Emacs, ,Using
+@value{GDBN} under @sc{gnu} Emacs}.
@menu
* List:: Printing source lines
-@ifclear DOSHOST
* Search:: Searching source files
-@end ifclear
-
* Source Path:: Specifying source directories
* Machine Code:: Source and machine code
@end menu
@cindex linespec
In general, the @code{list} command expects you to supply zero, one or two
@dfn{linespecs}. Linespecs specify source lines; there are several ways
-of writing them but the effect is always to specify some source line.
+of writing them, but the effect is always to specify some source line.
Here is a complete description of the possible arguments for @code{list}:
@table @code
@var{address} may be any expression.
@end table
-@ifclear DOSHOST
@node Search
@section Searching source files
@cindex searching
for @var{regexp}. It lists the line that is found. You can abbreviate
this command as @code{rev}.
@end table
-@end ifclear
@node Source Path
@section Specifying source directories
@kindex directory
@kindex dir
-When you start @value{GDBN}, its source path is empty.
+When you start @value{GDBN}, its source path includes only @samp{cdir}
+and @samp{cwd}, in that order.
To add other directories, use the @code{directory} command.
@table @code
@item directory @var{dirname} @dots{}
@item dir @var{dirname} @dots{}
Add directory @var{dirname} to the front of the source path. Several
-directory names may be given to this command, separated by @samp{:} or
+directory names may be given to this command, separated by @samp{:}
+(@samp{;} on MS-DOS and MS-Windows, where @samp{:} usually appears as
+part of absolute file names) or
whitespace. You may specify a directory that is already in the source
path; this moves it forward, so @value{GDBN} searches it sooner.
You can use the command @code{info line} to map source lines to program
addresses (and vice versa), and the command @code{disassemble} to display
a range of addresses as machine instructions. When run under @sc{gnu} Emacs
-mode, the @code{info line} command now causes the arrow to point to the
+mode, the @code{info line} command causes the arrow to point to the
line specified. Also, @code{info line} prints addresses in symbolic form as
well as hex.
the object code for the first line of function
@code{m4_changequote}:
+@c FIXME: I think this example should also show the addresses in
+@c symbolic form, as they usually would be displayed.
@smallexample
(@value{GDBP}) info line m4_changecom
Line 895 of "builtin.c" starts at pc 0x634c and ends at 0x6350.
@end smallexample
@cindex @code{$_} and @code{info line}
+@kindex x@r{, and }@code{info line}
After @code{info line}, the default address for the @code{x} command
is changed to the starting address of the line, so that @samp{x/i} is
sufficient to begin examining the machine code (@pxref{Memory,
(first inclusive, second exclusive) to dump.
@end table
-@ifclear H8EXCLUSIVE
-We can use @code{disassemble} to inspect the object code
-range shown in the last @code{info line} example (the example
-shows SPARC machine instructions):
-
+The following example shows the disassembly of a range of addresses of
+HP PA-RISC 2.0 code:
@smallexample
-(@value{GDBP}) disas 0x63e4 0x6404
-Dump of assembler code from 0x63e4 to 0x6404:
-0x63e4 <builtin_init+5340>: ble 0x63f8 <builtin_init+5360>
-0x63e8 <builtin_init+5344>: sethi %hi(0x4c00), %o0
-0x63ec <builtin_init+5348>: ld [%i1+4], %o0
-0x63f0 <builtin_init+5352>: b 0x63fc <builtin_init+5364>
-0x63f4 <builtin_init+5356>: ld [%o0+4], %o0
-0x63f8 <builtin_init+5360>: or %o0, 0x1a4, %o0
-0x63fc <builtin_init+5364>: call 0x9288 <path_search>
-0x6400 <builtin_init+5368>: nop
+(@value{GDBP}) disas 0x32c4 0x32e4
+Dump of assembler code from 0x32c4 to 0x32e4:
+0x32c4 <main+204>: addil 0,dp
+0x32c8 <main+208>: ldw 0x22c(sr0,r1),r26
+0x32cc <main+212>: ldil 0x3000,r31
+0x32d0 <main+216>: ble 0x3f8(sr4,r31)
+0x32d4 <main+220>: ldo 0(r31),rp
+0x32d8 <main+224>: addil -0x800,dp
+0x32dc <main+228>: ldo 0x588(r1),r26
+0x32e0 <main+232>: ldil 0x3000,r31
End of assembler dump.
@end smallexample
-@end ifclear
-@ifset H8EXCLUSIVE
-For example, here is the beginning of the output for the
-disassembly of a function @code{fact}:
+Some architectures have more than one commonly-used set of instruction
+mnemonics or other syntax.
+@table @code
+@kindex set disassembly-flavor
+@cindex assembly instructions
+@cindex instructions, assembly
+@cindex machine instructions
+@cindex listing machine instructions
+@cindex Intel disassembly flavor
+@cindex AT&T disassembly flavor
+@item set disassembly-flavor @var{instruction-set}
+Select the instruction set to use when disassembling the
+program via the @code{disassemble} or @code{x/i} commands.
+
+Currently this command is only defined for the Intel x86 family. You
+can set @var{instruction-set} to either @code{intel} or @code{att}.
+The default is @code{att}, the AT&T flavor used by default by Unix
+assemblers for x86-based targets.
+@end table
-@smallexample
-(@value{GDBP}) disas fact
-Dump of assembler code for function fact:
-to 0x808c:
-0x802c <fact>: 6d f2 mov.w r2,@@-r7
-0x802e <fact+2>: 6d f3 mov.w r3,@@-r7
-0x8030 <fact+4>: 6d f6 mov.w r6,@@-r7
-0x8032 <fact+6>: 0d 76 mov.w r7,r6
-0x8034 <fact+8>: 6f 70 00 08 mov.w @@(0x8,r7),r0
-0x8038 <fact+12> 19 11 sub.w r1,r1
- .
- .
- .
-@end smallexample
-@end ifset
@node Data
@chapter Examining Data
@c document because it is nonstandard... Under Epoch it displays in a
@c different window or something like that.
The usual way to examine data in your program is with the @code{print}
-command (abbreviated @code{p}), or its synonym @code{inspect}.
-@ifclear CONLY
-It evaluates and prints the value of an expression of the language your
-program is written in (@pxref{Languages, ,Using @value{GDBN} with Different
-Languages}).
-@end ifclear
-
-@table @code
-@item print @var{exp}
-@itemx print /@var{f} @var{exp}
-@var{exp} is an expression (in the source language). By default the
-value of @var{exp} is printed in a format appropriate to its data type;
+command (abbreviated @code{p}), or its synonym @code{inspect}. It
+evaluates and prints the value of an expression of the language your
+program is written in (@pxref{Languages, ,Using @value{GDBN} with
+Different Languages}).
+
+@table @code
+@item print @var{expr}
+@itemx print /@var{f} @var{expr}
+@var{expr} is an expression (in the source language). By default the
+value of @var{expr} is printed in a format appropriate to its data type;
you can choose a different format by specifying @samp{/@var{f}}, where
-@var{f} is a letter specifying the format; @pxref{Output Formats,,Output
+@var{f} is a letter specifying the format; see @ref{Output Formats,,Output
formats}.
@item print
@itemx print /@var{f}
-If you omit @var{exp}, @value{GDBN} displays the last value again (from the
+If you omit @var{expr}, @value{GDBN} displays the last value again (from the
@dfn{value history}; @pxref{Value History, ,Value history}). This allows you to
conveniently inspect the same value in an alternative format.
@end table
It examines data in memory at a specified address and prints it in a
specified format. @xref{Memory, ,Examining memory}.
-If you are interested in information about types, or about how the fields
-of a struct
-@ifclear CONLY
-or class
-@end ifclear
-are declared, use the @code{ptype @var{exp}}
-command rather than @code{print}. @xref{Symbols, ,Examining the Symbol Table}.
+If you are interested in information about types, or about how the
+fields of a struct or a class are declared, use the @code{ptype @var{exp}}
+command rather than @code{print}. @xref{Symbols, ,Examining the Symbol
+Table}.
@menu
* Expressions:: Expressions
* Value History:: Value history
* Convenience Vars:: Convenience variables
* Registers:: Registers
-@ifclear HAVE-FLOAT
* Floating Point Hardware:: Floating point hardware
-@end ifclear
@end menu
@node Expressions
and string constants. It unfortunately does not include symbols defined
by preprocessor @code{#define} commands.
-@value{GDBN} now supports array constants in expressions input by
-the user. The syntax is @var{element, element@dots{}}. For example,
-you can now use the command @code{print @{1 2 3@}} to build up an array in
-memory that is malloc'd in the target program.
+@value{GDBN} supports array constants in expressions input by
+the user. The syntax is @{@var{element}, @var{element}@dots{}@}. For example,
+you can use the command @code{print @{1, 2, 3@}} to build up an array in
+memory that is @code{malloc}ed in the target program.
-@ifclear CONLY
Because C is so widespread, most of the expressions shown in examples in
this manual are in C. @xref{Languages, , Using @value{GDBN} with Different
Languages}, for information on how to use expressions in other
useful to cast a number into a pointer in order to examine a structure
at that address in memory.
@c FIXME: casts supported---Mod2 true?
-@end ifclear
@value{GDBN} supports these operators, in addition to those common
to programming languages:
Variables in expressions are understood in the selected stack frame
(@pxref{Selection, ,Selecting a frame}); they must be either:
-@itemize
+@itemize @bullet
@item
-global (or static)
+global (or file-static)
@end itemize
@noindent or
-@itemize
+@itemize @bullet
@item
visible according to the scope rules of the
programming language from the point of execution in that frame
you can specify a static variable in a particular function or file,
using the colon-colon notation:
-@cindex colon-colon
+@cindex colon-colon, context for variables/functions
@iftex
@c info cannot cope with a :: index entry, but why deprive hard copy readers?
@kindex ::
(@value{GDBP}) p 'f2.c'::x
@end example
-@ifclear CONLY
@cindex C++ scope resolution
This use of @samp{::} is very rarely in conflict with the very similar
use of the same notation in C++. @value{GDBN} also supports use of the C++
scope resolution operator in @value{GDBN} expressions.
@c FIXME: Um, so what happens in one of those rare cases where it's in
@c conflict?? --mew
-@end ifclear
@cindex wrong values
@cindex variable values, wrong
after you begin stepping through that group of instructions, local
variable definitions may be gone.
+This may also happen when the compiler does significant optimizations.
+To be sure of always seeing accurate values, turn off all optimization
+when compiling.
+
+@cindex ``No symbol "foo" in current context''
+Another possible effect of compiler optimizations is to optimize
+unused variables out of existence, or assign variables to registers (as
+opposed to memory addresses). Depending on the support for such cases
+offered by the debug info format used by the compiler, @value{GDBN}
+might not be able to display values for such local variables. If that
+happens, @value{GDBN} will print a message like this:
+
+@example
+No symbol "foo" in current context.
+@end example
+
+To solve such problems, either recompile without optimizations, or use a
+different debug info format, if the compiler supports several such
+formats. For example, @value{NGCC}, the @sc{gnu} C/C++ compiler usually
+supports the @samp{-gstabs} option. @samp{-gstabs} produces debug info
+in a format that is superior to formats such as COFF. You may be able
+to use DWARF-2 (@samp{-gdwarf-2}), which is also an effective form for
+debug info. See @ref{Debugging Options,,Options for Debugging Your
+Program or @sc{gnu} CC, gcc.info, Using @sc{gnu} CC}, for more
+information.
+
+
@node Arrays
@section Artificial arrays
@end example
As a convenience, if you leave the array length out (as in
-@samp{(@var{type})[])@var{value}}) gdb calculates the size to fill
+@samp{(@var{type}[])@var{value}}) @value{GDBN} calculates the size to fill
the value (as @samp{sizeof(@var{value})/sizeof(@var{type})}:
@example
(@value{GDBP}) p/x (short[])0x12345678
Print as integer in binary. The letter @samp{t} stands for ``two''.
@footnote{@samp{b} cannot be used because these format letters are also
used with the @code{x} command, where @samp{b} stands for ``byte'';
-@pxref{Memory,,Examining memory}.}
+see @ref{Memory,,Examining memory}.}
@item a
@cindex unknown address, locating
(@code{h}) of memory, formatted as unsigned decimal integers (@samp{u}),
starting at address @code{0x54320}. @samp{x/4xw $sp} prints the four
words (@samp{w}) of memory above the stack pointer (here, @samp{$sp};
-@pxref{Registers}) in hexadecimal (@samp{x}).
+@pxref{Registers, ,Registers}) in hexadecimal (@samp{x}).
Since the letters indicating unit sizes are all distinct from the
letters specifying output formats, you do not have to remember whether
and @samp{i}, you might still want to use a count @var{n}; for example,
@samp{3i} specifies that you want to see three machine instructions,
including any operands. The command @code{disassemble} gives an
-alternative way of inspecting machine instructions; @pxref{Machine
+alternative way of inspecting machine instructions; see @ref{Machine
Code,,Source and machine code}.
All the defaults for the arguments to @code{x} are designed to make it
@table @code
@kindex display
-@item display @var{exp}
-Add the expression @var{exp} to the list of expressions to display
+@item display @var{expr}
+Add the expression @var{expr} to the list of expressions to display
each time your program stops. @xref{Expressions, ,Expressions}.
@code{display} does not repeat if you press @key{RET} again after using it.
-@item display/@var{fmt} @var{exp}
+@item display/@var{fmt} @var{expr}
For @var{fmt} specifying only a display format and not a size or
-count, add the expression @var{exp} to the auto-display list but
+count, add the expression @var{expr} to the auto-display list but
arrange to display it each time in the specified format @var{fmt}.
@xref{Output Formats,,Output formats}.
For example, @samp{display/i $pc} can be helpful, to see the machine
instruction about to be executed each time execution stops (@samp{$pc}
-is a common name for the program counter; @pxref{Registers}).
+is a common name for the program counter; @pxref{Registers, ,Registers}).
@table @code
@kindex delete display
If @value{GDBN} is printing a large array, it stops printing after it has
printed the number of elements set by the @code{set print elements} command.
This limit also applies to the display of strings.
+When @value{GDBN} starts, this limit is set to 200.
Setting @var{number-of-elements} to zero means that the printing is unlimited.
@kindex show print elements
@kindex set print null-stop
@item set print null-stop
Cause @value{GDBN} to stop printing the characters of an array when the first
-@sc{NULL} is encountered. This is useful when large arrays actually
+@sc{null} is encountered. This is useful when large arrays actually
contain only short strings.
+The default is off.
@kindex set print pretty
@item set print pretty on
@end smallexample
@end table
-@ifclear CONLY
@need 1000
@noindent
These settings are of interest when debugging C++ programs:
@itemx set print demangle on
Print C++ names in their source form rather than in the encoded
(``mangled'') form passed to the assembler and linker for type-safe
-linkage. The default is @samp{on}.
+linkage. The default is on.
@kindex show print demangle
@item show print demangle
Decode based on the @sc{gnu} C++ compiler (@code{g++}) encoding algorithm.
This is the default.
+@item hp
+Decode based on the HP ANSI C++ (@code{aCC}) encoding algorithm.
+
@item lucid
Decode based on the Lucid C++ compiler (@code{lcc}) encoding algorithm.
debugging @code{cfront}-generated executables. @value{GDBN} would
require further enhancement to permit that.
-@item foo
-Show the list of formats.
@end table
+If you omit @var{style}, you will see a list of possible formats.
@kindex show demangle-style
@item show demangle-style
@item show print object
Show whether actual, or declared, object types are displayed.
+@kindex set print static-members
+@item set print static-members
+@itemx set print static-members on
+Print static members when displaying a C++ object. The default is on.
+
+@item set print static-members off
+Do not print static members when displaying a C++ object.
+
+@kindex show print static-members
+@item show print static-members
+Show whether C++ static members are printed, or not.
+
+@c These don't work with HP ANSI C++ yet.
@kindex set print vtbl
@item set print vtbl
@itemx set print vtbl on
Pretty print C++ virtual function tables. The default is off.
+(The @code{vtbl} commands do not work on programs compiled with the HP
+ANSI C++ compiler (@code{aCC}).)
@item set print vtbl off
Do not pretty print C++ virtual function tables.
@item show print vtbl
Show whether C++ virtual function tables are pretty printed, or not.
@end table
-@end ifclear
@node Value History
@section Value history
Convenience variables are prefixed with @samp{$}. Any name preceded by
@samp{$} can be used for a convenience variable, unless it is one of
-the predefined machine-specific register names (@pxref{Registers}).
+the predefined machine-specific register names (@pxref{Registers, ,Registers}).
(Value history references, in contrast, are @emph{numbers} preceded
by @samp{$}. @xref{Value History, ,Value history}.)
@kindex show convenience
@item show convenience
Print a list of convenience variables used so far, and their values.
-Abbreviated @code{show con}.
+Abbreviated @code{show conv}.
@end table
One of the ways to use a convenience variable is as a counter to be
print bar[$i++]->contents
@end example
-@noindent Repeat that command by typing @key{RET}.
+@noindent
+Repeat that command by typing @key{RET}.
Some convenience variables are created automatically by @value{GDBN} and given
values likely to be useful.
The variable @code{$__} is automatically set by the @code{x} command
to the value found in the last address examined. Its type is chosen
to match the format in which the data was printed.
+
+@item $_exitcode
+@kindex $_exitcode
+The variable @code{$_exitcode} is automatically set to the exit code when
+the program being debugged terminates.
@end table
+On HP-UX systems, if you refer to a function or variable name that
+begins with a dollar sign, @value{GDBN} searches for a user or system
+name first, before it searches for a convenience variable.
+
@node Registers
@section Registers
stack frame is selected; setting @code{$sp} is not allowed when other
stack frames are selected. To pop entire frames off the stack,
regardless of machine architecture, use @code{return};
-@pxref{Returning, ,Returning from a function}.} with
+see @ref{Returning, ,Returning from a function}.} with
@example
set $sp += 4
so long as there is no conflict. The @code{info registers} command
shows the canonical names. For example, on the SPARC, @code{info
registers} displays the processor status register as @code{$psr} but you
-can also refer to it as @code{$ps}.
+can also refer to it as @code{$ps}; and on x86-based machines @code{$ps}
+is an alias for the @sc{eflags} register.
@value{GDBN} always considers the contents of an ordinary register as an
integer when the register is examined in this way. Some machines have
@value{GDBN} is unable to locate the saved registers, the selected stack
frame makes no difference.
-@ifset AMD29K
-@table @code
-@kindex set rstack_high_address
-@cindex AMD 29K register stack
-@cindex register stack, AMD29K
-@item set rstack_high_address @var{address}
-On AMD 29000 family processors, registers are saved in a separate
-``register stack''. There is no way for @value{GDBN} to determine the extent
-of this stack. Normally, @value{GDBN} just assumes that the stack is ``large
-enough''. This may result in @value{GDBN} referencing memory locations that
-do not exist. If necessary, you can get around this problem by
-specifying the ending address of the register stack with the @code{set
-rstack_high_address} command. The argument should be an address, which
-you probably want to precede with @samp{0x} to specify in
-hexadecimal.
-
-@kindex show rstack_high_address
-@item show rstack_high_address
-Display the current limit of the register stack, on AMD 29000 family
-processors.
-@end table
-@end ifset
-
-@ifclear HAVE-FLOAT
@node Floating Point Hardware
@section Floating point hardware
@cindex floating point
floating point chip. Currently, @samp{info float} is supported on
the ARM and x86 machines.
@end table
-@end ifclear
-@ifclear CONLY
@node Languages
@chapter Using @value{GDBN} with Different Languages
@cindex languages
-@ifset MOD2
Although programming languages generally have common aspects, they are
rarely expressed in the same manner. For instance, in ANSI C,
dereferencing a pointer @code{p} is accomplished by @code{*p}, but in
Modula-2, it is accomplished by @code{p^}. Values can also be
represented (and displayed) differently. Hex numbers in C appear as
@samp{0x1ae}, while in Modula-2 they appear as @samp{1AEH}.
-@end ifset
@cindex working language
Language-specific information is built into @value{GDBN} for some languages,
@menu
* Setting:: Switching between source languages
* Show:: Displaying the language
-@ifset MOD2
* Checks:: Type and range checks
-@end ifset
-
* Support:: Supported languages
@end menu
language from the name of the file. The language of a source file
controls whether C++ names are demangled---this way @code{backtrace} can
show each frame appropriately for its own language. There is no way to
-set the language of a source file from within @value{GDBN}.
+set the language of a source file from within @value{GDBN}, but you can
+set the language associated with a filename extension. @xref{Show, ,
+Displaying the language}.
This is most commonly a problem when you use a program, such
as @code{cfront} or @code{f2c}, that generates C but is written in
@value{GDBN} infers that its language is the one indicated.
@table @file
-@ifset MOD2
-@item .mod
-Modula-2 source file
-@end ifset
@item .c
C source file
@item .C
@itemx .cc
-@itemx .cxx
-@itemx .cpp
@itemx .cp
+@itemx .cpp
+@itemx .cxx
@itemx .c++
C++ source file
+@item .f
+@itemx .F
+Fortran source file
+
@item .ch
@itemx .c186
@itemx .c286
CHILL source file.
+@item .mod
+Modula-2 source file
+
@item .s
@itemx .S
Assembler source file. This actually behaves almost like C, but
@value{GDBN} does not skip over function prologues when stepping.
@end table
+In addition, you may set the language associated with a filename
+extension. @xref{Show, , Displaying the language}.
+
@node Manually
@subsection Setting the working language
If you wish, you may set the language manually. To do this, issue the
command @samp{set language @var{lang}}, where @var{lang} is the name of
a language, such as
-@ifclear MOD2
-@code{c}.
-@end ifclear
-@ifset MOD2
@code{c} or @code{modula-2}.
-@end ifset
For a list of the supported languages, type @samp{set language}.
-@ifset MOD2
Setting the language manually prevents @value{GDBN} from updating the working
language automatically. This can lead to confusion if you try
to debug a program when the working language is not the same as the
@code{b} and @code{c} and place the result in @code{a}. The result
printed would be the value of @code{a}. In Modula-2, this means to compare
@code{a} to the result of @code{b+c}, yielding a @code{BOOLEAN} value.
-@end ifset
@node Automatically
@subsection Having @value{GDBN} infer the source language
working language, and also what language source files were written in.
@kindex show language
-@kindex info frame
-@kindex info source
+@kindex info frame@r{, show the source language}
+@kindex info source@r{, show the source language}
@table @code
@item show language
Display the current working language. This is the
information listed here.
@end table
-@ifset MOD2
+In unusual circumstances, you may have source files with extensions
+not in the standard list. You can then set the extension associated
+with a language explicitly:
+
+@kindex set extension-language
+@kindex info extensions
+@table @code
+@item set extension-language @var{.ext} @var{language}
+Set source files with extension @var{.ext} to be assumed to be in
+the source language @var{language}.
+
+@item info extensions
+List all the filename extensions and the associated languages.
+@end table
+
@node Checks
@section Type and range checking
@value{GDBN} provides some additional commands for controlling the type checker:
-@kindex set check
+@kindex set check@r{, type}
@kindex set check type
@kindex show check type
@table @code
Set type checking on or off, overriding the default setting for the
current working language. Issue a warning if the setting does not
match the language default. If any type mismatches occur in
-evaluating an expression while typechecking is on, @value{GDBN} prints a
+evaluating an expression while type checking is on, @value{GDBN} prints a
message and aborts evaluation of the expression.
@item set check type warn
@value{GDBN} provides some additional commands for controlling the range checker:
-@kindex set check
+@kindex set check@r{, range}
@kindex set check range
@kindex show check range
@table @code
@itemx set check range off
Set range checking on or off, overriding the default setting for the
current working language. A warning is issued if the setting does not
-match the language default. If a range error occurs, then a message
-is printed and evaluation of the expression is aborted.
+match the language default. If a range error occurs and range checking is on,
+then a message is printed and evaluation of the expression is aborted.
@item set check range warn
Output messages when the @value{GDBN} range checker detects a range error,
Show the current setting of the range checker, and whether or not it is
being set automatically by @value{GDBN}.
@end table
-@end ifset
@node Support
@section Supported languages
-@ifset MOD2
-@value{GDBN} 4 supports C, C++, and Modula-2.
-@end ifset
-@ifclear MOD2
-@value{GDBN} 4 supports C, and C++.
-@end ifclear
+@value{GDBN} supports C, C++, Fortran, Java, Chill, assembly, and Modula-2.
+@c This is false ...
Some @value{GDBN} features may be used in expressions regardless of the
language you use: the @value{GDBN} @code{@@} and @code{::} operators,
and the @samp{@{type@}addr} construct (@pxref{Expressions,
books written on each of these languages; please look to these for a
language reference or tutorial.
-@ifset MOD2
@menu
-* C:: C and C++
-* Modula-2:: Modula-2
+* C:: C and C++
+* Modula-2:: Modula-2
+* Chill:: Chill
@end menu
@node C
@subsection C and C++
+
@cindex C and C++
@cindex expressions in C or C++
Since C and C++ are so closely related, many features of @value{GDBN} apply
to both languages. Whenever this is the case, we discuss those languages
together.
-@end ifset
-@ifclear MOD2
-@c Cancel this below, under same condition, at end of this chapter!
-@raisesections
-@end ifclear
@cindex C++
@kindex g++
@cindex @sc{gnu} C++
-The C++ debugging facilities are jointly implemented by the @sc{gnu} C++
+The C++ debugging facilities are jointly implemented by the C++
compiler and @value{GDBN}. Therefore, to debug your C++ code
-effectively, you must compile your C++ programs with the @sc{gnu} C++
-compiler, @code{g++}.
+effectively, you must compile your C++ programs with a supported
+C++ compiler, such as @sc{gnu} @code{g++}, or the HP ANSI C++
+compiler (@code{aCC}).
-For best results when debugging C++ programs, use the stabs debugging
+For best results when using @sc{gnu} C++, use the stabs debugging
format. You can select that format explicitly with the @code{g++}
command-line options @samp{-gstabs} or @samp{-gstabs+}. See
-@ref{Debugging Options,,Options for Debugging Your Program or @sc{gnu} CC,
-gcc.info, Using @sc{gnu} CC}, for more information.
-@end ifclear
-@ifset CONLY
-@node C
-@chapter C Language Support
-@cindex C language
-@cindex expressions in C
+@ref{Debugging Options,,Options for Debugging Your Program or @sc{gnu}
+CC, gcc.info, Using @sc{gnu} CC}, for more information.
-Information specific to the C language is built into @value{GDBN} so that you
-can use C expressions while degugging. This also permits @value{GDBN} to
-output values in a manner consistent with C conventions.
-
-@menu
-* C Operators:: C operators
-* C Constants:: C constants
-* Debugging C:: @value{GDBN} and C
-@end menu
-@end ifset
-@ifclear CONLY
@menu
* C Operators:: C and C++ operators
* C Constants:: C and C++ constants
-* Cplus expressions:: C++ expressions
+* C plus plus expressions:: C++ expressions
* C Defaults:: Default settings for C and C++
-@ifset MOD2
* C Checks:: C and C++ type and range checks
-@end ifset
-
* Debugging C:: @value{GDBN} and C
-* Debugging C plus plus:: Special features for C++
+* Debugging C plus plus:: @value{GDBN} features for C++
@end menu
-@end ifclear
-@ifclear CONLY
-@cindex C and C++ operators
@node C Operators
@subsubsection C and C++ operators
-@end ifclear
-@ifset CONLY
-@cindex C operators
-@node C Operators
-@section C operators
-@end ifset
+
+@cindex C and C++ operators
Operators must be defined on values of specific types. For instance,
@code{+} is defined on numbers, but not on structures. Operators are
often defined on groups of types.
-@ifclear CONLY
For the purposes of C and C++, the following definitions hold:
-@end ifclear
@itemize @bullet
+
@item
@emph{Integral types} include @code{int} with any of its storage-class
-specifiers; @code{char}; and @code{enum}.
+specifiers; @code{char}; @code{enum}; and, for C++, @code{bool}.
@item
-@emph{Floating-point types} include @code{float} and @code{double}.
+@emph{Floating-point types} include @code{float}, @code{double}, and
+@code{long double} (if supported by the target platform).
@item
-@emph{Pointer types} include all types defined as @code{(@var{type}
-*)}.
+@emph{Pointer types} include all types defined as @code{(@var{type} *)}.
@item
@emph{Scalar types} include all of the above.
+
@end itemize
@noindent
@item @var{op}=
Used in an expression of the form @w{@code{@var{a} @var{op}= @var{b}}},
and translated to @w{@code{@var{a} = @var{a op b}}}.
-@w{@code{@var{op}=}} and @code{=} have the same precendence.
+@w{@code{@var{op}=}} and @code{=} have the same precedence.
@var{op} is any one of the operators @code{|}, @code{^}, @code{&},
@code{<<}, @code{>>}, @code{+}, @code{-}, @code{*}, @code{/}, @code{%}.
@item &
Address operator. Defined on variables. Same precedence as @code{++}.
-@ifclear CONLY
For debugging C++, @value{GDBN} implements a use of @samp{&} beyond what is
allowed in the C++ language itself: you can use @samp{&(&@var{ref})}
(or, if you prefer, simply @samp{&&@var{ref}}) to examine the address
where a C++ reference variable (declared with @samp{&@var{ref}}) is
stored.
-@end ifclear
@item -
Negative. Defined on integral and floating-point types. Same
pointer based on the stored type information.
Defined on @code{struct} and @code{union} data.
+@item .*@r{, }->*
+Dereferences of pointers to members.
+
@item []
Array indexing. @code{@var{a}[@var{i}]} is defined as
@code{*(@var{a}+@var{i})}. Same precedence as @code{->}.
@item ()
Function parameter list. Same precedence as @code{->}.
-@ifclear CONLY
@item ::
-C++ scope resolution operator. Defined on
-@code{struct}, @code{union}, and @code{class} types.
-@end ifclear
+C++ scope resolution operator. Defined on @code{struct}, @code{union},
+and @code{class} types.
@item ::
-Doubled colons
-@ifclear CONLY
-also
-@end ifclear
-represent the @value{GDBN} scope operator (@pxref{Expressions,
-,Expressions}).
-@ifclear CONLY
-Same precedence as @code{::}, above.
-@end ifclear
-@end table
-
-@ifclear CONLY
-@cindex C and C++ constants
+Doubled colons also represent the @value{GDBN} scope operator
+(@pxref{Expressions, ,Expressions}). Same precedence as @code{::},
+above.
+@end table
+
+If an operator is redefined in the user code, @value{GDBN} usually
+attempts to invoke the redefined version instead of using the operator's
+predefined meaning.
+
+@menu
+* C Constants::
+@end menu
+
@node C Constants
@subsubsection C and C++ constants
-@value{GDBN} allows you to express the constants of C and C++ in the
-following ways:
-@end ifclear
-@ifset CONLY
-@cindex C constants
-@node C Constants
-@section C constants
+@cindex C and C++ constants
-@value{GDBN} allows you to express the constants of C in the
+@value{GDBN} allows you to express the constants of C and C++ in the
following ways:
-@end ifset
@itemize @bullet
@item
exponent. An exponent is of the form:
@samp{@w{e@r{[[}+@r{]|}-@r{]}@var{nnn}}}, where @var{nnn} is another
sequence of digits. The @samp{+} is optional for positive exponents.
+A floating-point constant may also end with a letter @samp{f} or
+@samp{F}, specifying that the constant should be treated as being of
+the @code{float} (as opposed to the default @code{double}) type; or with
+a letter @samp{l} or @samp{L}, which specifies a @code{long double}
+constant.
@item
Enumerated constants consist of enumerated identifiers, or their
@item
Character constants are a single character surrounded by single quotes
(@code{'}), or a number---the ordinal value of the corresponding character
-(usually its @sc{ASCII} value). Within quotes, the single character may
+(usually its @sc{ascii} value). Within quotes, the single character may
be represented by a letter or by @dfn{escape sequences}, which are of
the form @samp{\@var{nnn}}, where @var{nnn} is the octal representation
of the character's ordinal value; or of the form @samp{\@var{x}}, where
and @samp{@{&"hi", &"there", &"fred"@}} is a three-element array of pointers.
@end itemize
-@ifclear CONLY
-@node Cplus expressions
+@menu
+* C plus plus expressions::
+* C Defaults::
+* C Checks::
+
+* Debugging C::
+@end menu
+
+@node C plus plus expressions
@subsubsection C++ expressions
@cindex expressions in C++
-@value{GDBN} expression handling has a number of extensions to
-interpret a significant subset of C++ expressions.
+@value{GDBN} expression handling can interpret most C++ expressions.
@cindex C++ support, not in @sc{coff}
@cindex @sc{coff} versus C++
@c FIXME!! GDB may eventually be able to debug C++ using DWARF; check
@c periodically whether this has happened...
@quotation
-@emph{Warning:} @value{GDBN} can only debug C++ code if you compile with
-the @sc{gnu} C++ compiler. Moreover, C++ debugging depends on the use of
+@emph{Warning:} @value{GDBN} can only debug C++ code if you use the
+proper compiler. Typically, C++ debugging depends on the use of
additional debugging information in the symbol table, and thus requires
-special support. @value{GDBN} has this support @emph{only} with the
-stabs debug format. In particular, if your compiler generates a.out,
-MIPS @sc{ecoff}, RS/6000 @sc{xcoff}, or @sc{elf} with stabs extensions
-to the symbol table, these facilities are all available. (With @sc{gnu} CC,
+special support. In particular, if your compiler generates a.out, MIPS
+@sc{ecoff}, RS/6000 @sc{xcoff}, or @sc{elf} with stabs extensions to the
+symbol table, these facilities are all available. (With @sc{gnu} CC,
you can use the @samp{-gstabs} option to request stabs debugging
extensions explicitly.) Where the object code format is standard
@sc{coff} or @sc{dwarf} in @sc{elf}, on the other hand, most of the C++
pointer @code{this} following the same rules as C++.
@cindex call overloaded functions
+@cindex overloaded functions, calling
@cindex type conversions in C++
@item
You can call overloaded functions; @value{GDBN} resolves the function
-call to the right definition, with one restriction---you must use
-arguments of the type required by the function that you want to call.
-@value{GDBN} does not perform conversions requiring constructors or
-user-defined type operators.
+call to the right definition, with some restrictions. @value{GDBN} does not
+perform overload resolution involving user-defined type conversions,
+calls to constructors, or instantiations of templates that do not exist
+in the program. It also cannot handle ellipsis argument lists or
+default arguments.
+
+It does perform integral conversions and promotions, floating-point
+promotions, arithmetic conversions, pointer conversions, conversions of
+class objects to base classes, and standard conversions such as those of
+functions or arrays to pointers; it requires an exact match on the
+number of function arguments.
+
+Overload resolution is always performed, unless you have specified
+@code{set overload-resolution off}. @xref{Debugging C plus plus,
+,@value{GDBN} features for C++}.
+
+You must specify @code{set overload-resolution off} in order to use an
+explicit function signature to call an overloaded function, as in
+@smallexample
+p 'foo(char,int)'('x', 13)
+@end smallexample
+
+The @value{GDBN} command-completion facility can simplify this;
+see @ref{Completion, ,Command completion}.
@cindex reference declarations
@item
debugging (@pxref{Variables, ,Program variables}).
@end enumerate
+In addition, when used with HP's C++ compiler, @value{GDBN} supports
+calling virtual functions correctly, printing out virtual bases of
+objects, calling functions in a base subobject, casting objects, and
+invoking user-defined operators.
+
@node C Defaults
@subsubsection C and C++ defaults
+
@cindex C and C++ defaults
If you allow @value{GDBN} to set type and range checking automatically, they
C or C++. This happens regardless of whether you or @value{GDBN}
selects the working language.
-If you allow @value{GDBN} to set the language automatically, it recognizes
-source files whose names end with @file{.c}, @file{.C}, or @file{.cc}, and
-when @value{GDBN} enters code compiled from one of these files,
-it sets the working language to C or C++.
-@xref{Automatically, ,Having @value{GDBN} infer the source language}, for
-further details.
+If you allow @value{GDBN} to set the language automatically, it
+recognizes source files whose names end with @file{.c}, @file{.C}, or
+@file{.cc}, etc, and when @value{GDBN} enters code compiled from one of
+these files, it sets the working language to C or C++.
+@xref{Automatically, ,Having @value{GDBN} infer the source language},
+for further details.
-@ifset MOD2
@c Type checking is (a) primarily motivated by Modula-2, and (b)
@c unimplemented. If (b) changes, it might make sense to let this node
-@c appear even if Mod-2 does not, but meanwhile ignore it. pesch 16jul93.
+@c appear even if Mod-2 does not, but meanwhile ignore it. roland 16jul93.
+
@node C Checks
@subsubsection C and C++ type and range checks
+
@cindex C and C++ checks
By default, when @value{GDBN} parses C or C++ expressions, type checking
Range checking, if turned on, is done on mathematical operations. Array
indices are not checked, since they are often used to index a pointer
that is not itself an array.
-@end ifset
-@end ifclear
-@ifclear CONLY
@node Debugging C
@subsubsection @value{GDBN} and C
-@end ifclear
-@ifset CONLY
-@node Debugging C
-@section @value{GDBN} and C
-@end ifset
The @code{set print union} and @code{show print union} commands apply to
the @code{union} type. When set to @samp{on}, any @code{union} that is
-inside a @code{struct}
-@ifclear CONLY
-or @code{class}
-@end ifclear
-is also printed.
-Otherwise, it appears as @samp{@{...@}}.
+inside a @code{struct} or @code{class} is also printed. Otherwise, it
+appears as @samp{@{...@}}.
The @code{@@} operator aids in the debugging of dynamic arrays, formed
with pointers and a memory allocation function. @xref{Expressions,
,Expressions}.
-@ifclear CONLY
+@menu
+* Debugging C plus plus::
+@end menu
+
@node Debugging C plus plus
@subsubsection @value{GDBN} features for C++
@cindex commands for C++
+
Some @value{GDBN} commands are particularly useful with C++, and some are
designed specifically for use with C++. Here is a summary:
@xref{Set Breaks, ,Setting breakpoints}.
@cindex C++ exception handling
-@item catch @var{exceptions}
-@itemx info catch
-Debug C++ exception handling using these commands. @xref{Exception
-Handling, ,Breakpoints and exceptions}.
+@item catch throw
+@itemx catch catch
+Debug C++ exception handling using these commands. @xref{Set
+Catchpoints, , Setting catchpoints}.
@cindex inheritance
@item ptype @var{typename}
@itemx show print vtbl
Control the format for printing virtual function tables.
@xref{Print Settings, ,Print settings}.
+(The @code{vtbl} commands do not work on programs compiled with the HP
+ANSI C++ compiler (@code{aCC}).)
+
+@kindex set overload-resolution
+@cindex overloaded functions, overload resolution
+@item set overload-resolution on
+Enable overload resolution for C++ expression evaluation. The default
+is on. For overloaded functions, @value{GDBN} evaluates the arguments
+and searches for a function whose signature matches the argument types,
+using the standard C++ conversion rules (see @ref{C plus plus expressions, ,C++
+expressions}, for details). If it cannot find a match, it emits a
+message.
+
+@item set overload-resolution off
+Disable overload resolution for C++ expression evaluation. For
+overloaded functions that are not class member functions, @value{GDBN}
+chooses the first function of the specified name that it finds in the
+symbol table, whether or not its arguments are of the correct type. For
+overloaded functions that are class member functions, @value{GDBN}
+searches for a function whose signature @emph{exactly} matches the
+argument types.
@item @r{Overloaded symbol names}
You can specify a particular definition of an overloaded symbol, using
available choices, or to finish the type list for you.
@xref{Completion,, Command completion}, for details on how to do this.
@end table
-@ifclear MOD2
-@c cancels "raisesections" under same conditions near bgn of chapter
-@lowersections
-@end ifclear
-@ifset MOD2
@node Modula-2
@subsection Modula-2
-@cindex Modula-2
+
+@cindex Modula-2, @value{GDBN} support
The extensions made to @value{GDBN} to support Modula-2 only support
output from the @sc{gnu} Modula-2 compiler (which is currently being
@cindex expressions in Modula-2
@menu
* M2 Operators:: Built-in operators
-* Built-In Func/Proc:: Built-in functions and procedures
+* Built-In Func/Proc:: Built-in functions and procedures
* M2 Constants:: Modula-2 constants
* M2 Defaults:: Default settings for Modula-2
* Deviations:: Deviations from standard Modula-2
Boolean disjunction. Defined on boolean types.
@item AND@r{, }&
-Boolean conjuction. Defined on boolean types.
+Boolean conjunction. Defined on boolean types.
@item @@
The @value{GDBN} ``artificial array'' operator (@pxref{Expressions, ,Expressions}).
@item CAP(@var{c})
If @var{c} is a lower case letter, it returns its upper case
-equivalent, otherwise it returns its argument
+equivalent, otherwise it returns its argument.
@item CHR(@var{i})
Returns the character whose ordinal value is @var{i}.
@item DEC(@var{v})
-Decrements the value in the variable @var{v}. Returns the new value.
+Decrements the value in the variable @var{v} by one. Returns the new value.
@item DEC(@var{v},@var{i})
Decrements the value in the variable @var{v} by @var{i}. Returns the
Returns the index of the last member of @var{a}.
@item INC(@var{v})
-Increments the value in the variable @var{v}. Returns the new value.
+Increments the value in the variable @var{v} by one. Returns the new value.
@item INC(@var{v},@var{i})
Increments the value in the variable @var{v} by @var{i}. Returns the
@item ORD(@var{x})
Returns the ordinal value of its argument. For example, the ordinal
-value of a character is its ASCII value (on machines supporting the
-ASCII character set). @var{x} must be of an ordered type, which include
+value of a character is its @sc{ascii} value (on machines supporting the
+@sc{ascii} character set). @var{x} must be of an ordered type, which include
integral, character and enumerated types.
@item SIZE(@var{x})
@item
Character constants consist of a single character enclosed by a pair of
like quotes, either single (@code{'}) or double (@code{"}). They may
-also be expressed by their ordinal value (their ASCII value, usually)
+also be expressed by their ordinal value (their @sc{ascii} value, usually)
followed by a @samp{C}.
@item
If type and range checking are set automatically by @value{GDBN}, they
both default to @code{on} whenever the working language changes to
-Modula-2. This happens regardless of whether you, or @value{GDBN},
+Modula-2. This happens regardless of whether you or @value{GDBN}
selected the working language.
If you allow @value{GDBN} to set the language automatically, then entering
code compiled from a file whose name ends with @file{.mod} sets the
-working language to Modula-2. @xref{Automatically, ,Having @value{GDBN} set
+working language to Modula-2. @xref{Automatically, ,Having @value{GDBN} set
the language automatically}, for further details.
@node Deviations
@kindex .
@cindex colon, doubled as scope operator
@ifinfo
-@kindex colon-colon
+@kindex colon-colon@r{, in Modula-2}
@c Info cannot handle :: but TeX can.
@end ifinfo
@iftex
analogue in Modula-2.
The @code{@@} operator (@pxref{Expressions, ,Expressions}), while available
-while using any language, is not useful with Modula-2. Its
+with any language, is not useful with Modula-2. Its
intent is to aid the debugging of @dfn{dynamic arrays}, which cannot be
created in Modula-2 as they can in C or C++. However, because an
address can be specified by an integral constant, the construct
-@samp{@{@var{type}@}@var{adrexp}} is still useful. (@pxref{Expressions, ,Expressions})
+@samp{@{@var{type}@}@var{adrexp}} is still useful.
@cindex @code{#} in Modula-2
In @value{GDBN} scripts, the Modula-2 inequality operator @code{#} is
interpreted as the beginning of a comment. Use @code{<>} instead.
-@end ifset
-@end ifclear
-@node Symbols
-@chapter Examining the Symbol Table
+@node Chill
+@subsection Chill
-The commands described in this section allow you to inquire about the
-symbols (names of variables, functions and types) defined in your
-program. This information is inherent in the text of your program and
-does not change as your program executes. @value{GDBN} finds it in your
-program's symbol table, in the file indicated when you started @value{GDBN}
-(@pxref{File Options, ,Choosing files}), or by one of the
-file-management commands (@pxref{Files, ,Commands to specify files}).
+The extensions made to @value{GDBN} to support Chill only support output
+from the @sc{gnu} Chill compiler. Other Chill compilers are not currently
+supported, and attempting to debug executables produced by them is most
+likely to give an error as @value{GDBN} reads in the executable's symbol
+table.
-@cindex symbol names
-@cindex names of symbols
-@cindex quoting names
-Occasionally, you may need to refer to symbols that contain unusual
-characters, which @value{GDBN} ordinarily treats as word delimiters. The
-most frequent case is in referring to static variables in other
-source files (@pxref{Variables,,Program variables}). File names
-are recorded in object files as debugging symbols, but @value{GDBN} would
-ordinarily parse a typical file name, like @file{foo.c}, as the three words
-@samp{foo} @samp{.} @samp{c}. To allow @value{GDBN} to recognize
-@samp{foo.c} as a single symbol, enclose it in single quotes; for example,
+@c This used to say "... following Chill related topics ...", but since
+@c menus are not shown in the printed manual, it would look awkward.
+This section covers the Chill related topics and the features
+of @value{GDBN} which support these topics.
-@example
-p 'foo.c'::x
-@end example
+@menu
+* How modes are displayed:: How modes are displayed
+* Locations:: Locations and their accesses
+* Values and their Operations:: Values and their Operations
+* Chill type and range checks::
+* Chill defaults::
+@end menu
-@noindent
-looks up the value of @code{x} in the scope of the file @file{foo.c}.
+@node How modes are displayed
+@subsubsection How modes are displayed
+The Chill Datatype- (Mode) support of @value{GDBN} is directly related
+with the functionality of the @sc{gnu} Chill compiler, and therefore deviates
+slightly from the standard specification of the Chill language. The
+provided modes are:
+
+@c FIXME: this @table's contents effectively disable @code by using @r
+@c on every @item. So why does it need @code?
@table @code
-@kindex info address
-@item info address @var{symbol}
-Describe where the data for @var{symbol} is stored. For a register
-variable, this says which register it is kept in. For a non-register
-local variable, this prints the stack-frame offset at which the variable
-is always stored.
+@item @r{@emph{Discrete modes:}}
+@itemize @bullet
+@item
+@emph{Integer Modes} which are predefined by @code{BYTE, UBYTE, INT,
+UINT, LONG, ULONG},
+@item
+@emph{Boolean Mode} which is predefined by @code{BOOL},
+@item
+@emph{Character Mode} which is predefined by @code{CHAR},
+@item
+@emph{Set Mode} which is displayed by the keyword @code{SET}.
+@smallexample
+(@value{GDBP}) ptype x
+type = SET (karli = 10, susi = 20, fritzi = 100)
+@end smallexample
+If the type is an unnumbered set the set element values are omitted.
+@item
+@emph{Range Mode} which is displayed by @code{type = <basemode>
+(<lower bound> : <upper bound>)}, where @code{<lower bound>, <upper
+bound>} can be of any discrete literal expression (e.g. set element
+names).
+@end itemize
-Note the contrast with @samp{print &@var{symbol}}, which does not work
-at all for a register variable, and for a stack local variable prints
-the exact address of the current instantiation of the variable.
+@item @r{@emph{Powerset Mode:}}
+A Powerset Mode is displayed by the keyword @code{POWERSET} followed by
+the member mode of the powerset. The member mode can be any discrete mode.
+@smallexample
+(@value{GDBP}) ptype x
+type = POWERSET SET (egon, hugo, otto)
+@end smallexample
-@kindex whatis
-@item whatis @var{exp}
-Print the data type of expression @var{exp}. @var{exp} is not
-actually evaluated, and any side-effecting operations (such as
-assignments or function calls) inside it do not take place.
-@xref{Expressions, ,Expressions}.
+@item @r{@emph{Reference Modes:}}
+@itemize @bullet
+@item
+@emph{Bound Reference Mode} which is displayed by the keyword @code{REF}
+followed by the mode name to which the reference is bound.
+@item
+@emph{Free Reference Mode} which is displayed by the keyword @code{PTR}.
+@end itemize
-@item whatis
-Print the data type of @code{$}, the last value in the value history.
+@item @r{@emph{Procedure mode}}
+The procedure mode is displayed by @code{type = PROC(<parameter list>)
+<return mode> EXCEPTIONS (<exception list>)}. The @code{<parameter
+list>} is a list of the parameter modes. @code{<return mode>} indicates
+the mode of the result of the procedure if any. The exceptionlist lists
+all possible exceptions which can be raised by the procedure.
-@kindex ptype
-@item ptype @var{typename}
-Print a description of data type @var{typename}. @var{typename} may be
-the name of a type, or for C code it may have the form
-@ifclear CONLY
-@samp{class @var{class-name}},
-@end ifclear
-@samp{struct @var{struct-tag}}, @samp{union @var{union-tag}} or
-@samp{enum @var{enum-tag}}.
-
-@item ptype @var{exp}
-@itemx ptype
-Print a description of the type of expression @var{exp}. @code{ptype}
-differs from @code{whatis} by printing a detailed description, instead
-of just the name of the type.
+@ignore
+@item @r{@emph{Instance mode}}
+The instance mode is represented by a structure, which has a static
+type, and is therefore not really of interest.
+@end ignore
-For example, for this variable declaration:
+@item @r{@emph{Synchronization Modes:}}
+@itemize @bullet
+@item
+@emph{Event Mode} which is displayed by @code{EVENT (<event length>)},
+where @code{(<event length>)} is optional.
+@item
+@emph{Buffer Mode} which is displayed by @code{BUFFER (<buffer length>)
+<buffer element mode>}, where @code{(<buffer length>)} is optional.
+@end itemize
+
+@item @r{@emph{Timing Modes:}}
+@itemize @bullet
+@item
+@emph{Duration Mode} which is predefined by @code{DURATION}
+@item
+@emph{Absolute Time Mode} which is predefined by @code{TIME}
+@end itemize
+
+@item @r{@emph{Real Modes:}}
+Real Modes are predefined with @code{REAL} and @code{LONG_REAL}.
+
+@item @r{@emph{String Modes:}}
+@itemize @bullet
+@item
+@emph{Character String Mode} which is displayed by @code{CHARS(<string
+length>)}, followed by the keyword @code{VARYING} if the String Mode is
+a varying mode
+@item
+@emph{Bit String Mode} which is displayed by @code{BOOLS(<string
+length>)}.
+@end itemize
+
+@item @r{@emph{Array Mode:}}
+The Array Mode is displayed by the keyword @code{ARRAY(<range>)}
+followed by the element mode (which may in turn be an array mode).
+@smallexample
+(@value{GDBP}) ptype x
+type = ARRAY (1:42)
+ ARRAY (1:20)
+ SET (karli = 10, susi = 20, fritzi = 100)
+@end smallexample
+
+@item @r{@emph{Structure Mode}}
+The Structure mode is displayed by the keyword @code{STRUCT(<field
+list>)}. The @code{<field list>} consists of names and modes of fields
+of the structure. Variant structures have the keyword @code{CASE <field>
+OF <variant fields> ESAC} in their field list. Since the current version
+of the GNU Chill compiler doesn't implement tag processing (no runtime
+checks of variant fields, and therefore no debugging info), the output
+always displays all variant fields.
+@smallexample
+(@value{GDBP}) ptype str
+type = STRUCT (
+ as x,
+ bs x,
+ CASE bs OF
+ (karli):
+ cs a
+ (ott):
+ ds x
+ ESAC
+)
+@end smallexample
+@end table
+
+@node Locations
+@subsubsection Locations and their accesses
+
+A location in Chill is an object which can contain values.
+
+A value of a location is generally accessed by the (declared) name of
+the location. The output conforms to the specification of values in
+Chill programs. How values are specified
+is the topic of the next section, @ref{Values and their Operations}.
+
+The pseudo-location @code{RESULT} (or @code{result}) can be used to
+display or change the result of a currently-active procedure:
+
+@smallexample
+set result := EXPR
+@end smallexample
+
+@noindent
+This does the same as the Chill action @code{RESULT EXPR} (which
+is not available in @value{GDBN}).
+
+Values of reference mode locations are printed by @code{PTR(<hex
+value>)} in case of a free reference mode, and by @code{(REF <reference
+mode>) (<hex-value>)} in case of a bound reference. @code{<hex value>}
+represents the address where the reference points to. To access the
+value of the location referenced by the pointer, use the dereference
+operator @samp{->}.
+
+Values of procedure mode locations are displayed by @code{@{ PROC
+(<argument modes> ) <return mode> @} <address> <name of procedure
+location>}. @code{<argument modes>} is a list of modes according to the
+parameter specification of the procedure and @code{<address>} shows the
+address of the entry point.
+
+@ignore
+Locations of instance modes are displayed just like a structure with two
+fields specifying the @emph{process type} and the @emph{copy number} of
+the investigated instance location@footnote{This comes from the current
+implementation of instances. They are implemented as a structure (no
+na). The output should be something like @code{[<name of the process>;
+<instance number>]}.}. The field names are @code{__proc_type} and
+@code{__proc_copy}.
+
+Locations of synchronization modes are displayed like a structure with
+the field name @code{__event_data} in case of a event mode location, and
+like a structure with the field @code{__buffer_data} in case of a buffer
+mode location (refer to previous paragraph).
+
+Structure Mode locations are printed by @code{[.<field name>: <value>,
+...]}. The @code{<field name>} corresponds to the structure mode
+definition and the layout of @code{<value>} varies depending of the mode
+of the field. If the investigated structure mode location is of variant
+structure mode, the variant parts of the structure are enclosed in curled
+braces (@samp{@{@}}). Fields enclosed by @samp{@{,@}} are residing
+on the same memory location and represent the current values of the
+memory location in their specific modes. Since no tag processing is done
+all variants are displayed. A variant field is printed by
+@code{(<variant name>) = .<field name>: <value>}. (who implements the
+stuff ???)
+@smallexample
+(@value{GDBP}) print str1 $4 = [.as: 0, .bs: karli, .<TAG>: { (karli) =
+[.cs: []], (susi) = [.ds: susi]}]
+@end smallexample
+@end ignore
+
+Substructures of string mode-, array mode- or structure mode-values
+(e.g. array slices, fields of structure locations) are accessed using
+certain operations which are described in the next section, @ref{Values
+and their Operations}.
+
+A location value may be interpreted as having a different mode using the
+location conversion. This mode conversion is written as @code{<mode
+name>(<location>)}. The user has to consider that the sizes of the modes
+have to be equal otherwise an error occurs. Furthermore, no range
+checking of the location against the destination mode is performed, and
+therefore the result can be quite confusing.
+
+@smallexample
+(@value{GDBP}) print int (s(3 up 4)) XXX TO be filled in !! XXX
+@end smallexample
+
+@node Values and their Operations
+@subsubsection Values and their Operations
+
+Values are used to alter locations, to investigate complex structures in
+more detail or to filter relevant information out of a large amount of
+data. There are several (mode dependent) operations defined which enable
+such investigations. These operations are not only applicable to
+constant values but also to locations, which can become quite useful
+when debugging complex structures. During parsing the command line
+(e.g. evaluating an expression) @value{GDBN} treats location names as
+the values behind these locations.
+
+This section describes how values have to be specified and which
+operations are legal to be used with such values.
+
+@table @code
+@item Literal Values
+Literal values are specified in the same manner as in @sc{gnu} Chill programs.
+For detailed specification refer to the @sc{gnu} Chill implementation Manual
+chapter 1.5.
+@c FIXME: if the Chill Manual is a Texinfo documents, the above should
+@c be converted to a @ref.
+
+@ignore
+@itemize @bullet
+@item
+@emph{Integer Literals} are specified in the same manner as in Chill
+programs (refer to the Chill Standard z200/88 chpt 5.2.4.2)
+@item
+@emph{Boolean Literals} are defined by @code{TRUE} and @code{FALSE}.
+@item
+@emph{Character Literals} are defined by @code{'<character>'}. (e.g.
+@code{'M'})
+@item
+@emph{Set Literals} are defined by a name which was specified in a set
+mode. The value delivered by a Set Literal is the set value. This is
+comparable to an enumeration in C/C++ language.
+@item
+@emph{Emptiness Literal} is predefined by @code{NULL}. The value of the
+emptiness literal delivers either the empty reference value, the empty
+procedure value or the empty instance value.
+
+@item
+@emph{Character String Literals} are defined by a sequence of characters
+enclosed in single- or double quotes. If a single- or double quote has
+to be part of the string literal it has to be stuffed (specified twice).
+@item
+@emph{Bitstring Literals} are specified in the same manner as in Chill
+programs (refer z200/88 chpt 5.2.4.8).
+@item
+@emph{Floating point literals} are specified in the same manner as in
+(gnu-)Chill programs (refer @sc{gnu} Chill implementation Manual chapter 1.5).
+@end itemize
+@end ignore
+
+@item Tuple Values
+A tuple is specified by @code{<mode name>[<tuple>]}, where @code{<mode
+name>} can be omitted if the mode of the tuple is unambiguous. This
+unambiguity is derived from the context of a evaluated expression.
+@code{<tuple>} can be one of the following:
+
+@itemize @bullet
+@item @emph{Powerset Tuple}
+@item @emph{Array Tuple}
+@item @emph{Structure Tuple}
+Powerset tuples, array tuples and structure tuples are specified in the
+same manner as in Chill programs refer to z200/88 chpt 5.2.5.
+@end itemize
+
+@item String Element Value
+A string element value is specified by @code{<string value>(<index>)},
+where @code{<index>} is a integer expression. It delivers a character
+value which is equivalent to the character indexed by @code{<index>} in
+the string.
+
+@item String Slice Value
+A string slice value is specified by @code{<string value>(<slice
+spec>)}, where @code{<slice spec>} can be either a range of integer
+expressions or specified by @code{<start expr> up <size>}.
+@code{<size>} denotes the number of elements which the slice contains.
+The delivered value is a string value, which is part of the specified
+string.
+
+@item Array Element Values
+An array element value is specified by @code{<array value>(<expr>)} and
+delivers a array element value of the mode of the specified array.
+
+@item Array Slice Values
+An array slice is specified by @code{<array value>(<slice spec>)}, where
+@code{<slice spec>} can be either a range specified by expressions or by
+@code{<start expr> up <size>}. @code{<size>} denotes the number of
+arrayelements the slice contains. The delivered value is an array value
+which is part of the specified array.
+
+@item Structure Field Values
+A structure field value is derived by @code{<structure value>.<field
+name>}, where @code{<field name>} indicates the name of a field specified
+in the mode definition of the structure. The mode of the delivered value
+corresponds to this mode definition in the structure definition.
+
+@item Procedure Call Value
+The procedure call value is derived from the return value of the
+procedure@footnote{If a procedure call is used for instance in an
+expression, then this procedure is called with all its side
+effects. This can lead to confusing results if used carelessly.}.
+
+Values of duration mode locations are represented by @code{ULONG} literals.
+
+Values of time mode locations are represented by @code{TIME(<secs>:<nsecs>)}.
+
+@ignore
+This is not implemented yet:
+@item Built-in Value
+@noindent
+The following built in functions are provided:
+
+@table @code
+@item @code{ADDR()}
+@item @code{NUM()}
+@item @code{PRED()}
+@item @code{SUCC()}
+@item @code{ABS()}
+@item @code{CARD()}
+@item @code{MAX()}
+@item @code{MIN()}
+@item @code{SIZE()}
+@item @code{UPPER()}
+@item @code{LOWER()}
+@item @code{LENGTH()}
+@item @code{SIN()}
+@item @code{COS()}
+@item @code{TAN()}
+@item @code{ARCSIN()}
+@item @code{ARCCOS()}
+@item @code{ARCTAN()}
+@item @code{EXP()}
+@item @code{LN()}
+@item @code{LOG()}
+@item @code{SQRT()}
+@end table
+
+For a detailed description refer to the GNU Chill implementation manual
+chapter 1.6.
+@end ignore
+
+@item Zero-adic Operator Value
+The zero-adic operator value is derived from the instance value for the
+current active process.
+
+@item Expression Values
+The value delivered by an expression is the result of the evaluation of
+the specified expression. If there are error conditions (mode
+incompatibility, etc.) the evaluation of expressions is aborted with a
+corresponding error message. Expressions may be parenthesised which
+causes the evaluation of this expression before any other expression
+which uses the result of the parenthesised expression. The following
+operators are supported by @value{GDBN}:
+
+@table @code
+@item @code{OR, ORIF, XOR}
+@itemx @code{AND, ANDIF}
+@itemx @code{NOT}
+Logical operators defined over operands of boolean mode.
+
+@item @code{=, /=}
+Equality and inequality operators defined over all modes.
+
+@item @code{>, >=}
+@itemx @code{<, <=}
+Relational operators defined over predefined modes.
+
+@item @code{+, -}
+@itemx @code{*, /, MOD, REM}
+Arithmetic operators defined over predefined modes.
+
+@item @code{-}
+Change sign operator.
+
+@item @code{//}
+String concatenation operator.
+
+@item @code{()}
+String repetition operator.
+
+@item @code{->}
+Referenced location operator which can be used either to take the
+address of a location (@code{->loc}), or to dereference a reference
+location (@code{loc->}).
+
+@item @code{OR, XOR}
+@itemx @code{AND}
+@itemx @code{NOT}
+Powerset and bitstring operators.
+
+@item @code{>, >=}
+@itemx @code{<, <=}
+Powerset inclusion operators.
+
+@item @code{IN}
+Membership operator.
+@end table
+@end table
+
+@node Chill type and range checks
+@subsubsection Chill type and range checks
+
+@value{GDBN} considers two Chill variables mode equivalent if the sizes
+of the two modes are equal. This rule applies recursively to more
+complex datatypes which means that complex modes are treated
+equivalent if all element modes (which also can be complex modes like
+structures, arrays, etc.) have the same size.
+
+Range checking is done on all mathematical operations, assignment, array
+index bounds and all built in procedures.
+
+Strong type checks are forced using the @value{GDBN} command @code{set
+check strong}. This enforces strong type and range checks on all
+operations where Chill constructs are used (expressions, built in
+functions, etc.) in respect to the semantics as defined in the z.200
+language specification.
+
+All checks can be disabled by the @value{GDBN} command @code{set check
+off}.
+
+@ignore
+@c Deviations from the Chill Standard Z200/88
+see last paragraph ?
+@end ignore
+
+@node Chill defaults
+@subsubsection Chill defaults
+
+If type and range checking are set automatically by @value{GDBN}, they
+both default to @code{on} whenever the working language changes to
+Chill. This happens regardless of whether you or @value{GDBN}
+selected the working language.
+
+If you allow @value{GDBN} to set the language automatically, then entering
+code compiled from a file whose name ends with @file{.ch} sets the
+working language to Chill. @xref{Automatically, ,Having @value{GDBN} set
+the language automatically}, for further details.
+
+@node Symbols
+@chapter Examining the Symbol Table
+
+The commands described in this chapter allow you to inquire about the
+symbols (names of variables, functions and types) defined in your
+program. This information is inherent in the text of your program and
+does not change as your program executes. @value{GDBN} finds it in your
+program's symbol table, in the file indicated when you started @value{GDBN}
+(@pxref{File Options, ,Choosing files}), or by one of the
+file-management commands (@pxref{Files, ,Commands to specify files}).
+
+@cindex symbol names
+@cindex names of symbols
+@cindex quoting names
+Occasionally, you may need to refer to symbols that contain unusual
+characters, which @value{GDBN} ordinarily treats as word delimiters. The
+most frequent case is in referring to static variables in other
+source files (@pxref{Variables,,Program variables}). File names
+are recorded in object files as debugging symbols, but @value{GDBN} would
+ordinarily parse a typical file name, like @file{foo.c}, as the three words
+@samp{foo} @samp{.} @samp{c}. To allow @value{GDBN} to recognize
+@samp{foo.c} as a single symbol, enclose it in single quotes; for example,
+
+@example
+p 'foo.c'::x
+@end example
+
+@noindent
+looks up the value of @code{x} in the scope of the file @file{foo.c}.
+
+@table @code
+@kindex info address
+@item info address @var{symbol}
+Describe where the data for @var{symbol} is stored. For a register
+variable, this says which register it is kept in. For a non-register
+local variable, this prints the stack-frame offset at which the variable
+is always stored.
+
+Note the contrast with @samp{print &@var{symbol}}, which does not work
+at all for a register variable, and for a stack local variable prints
+the exact address of the current instantiation of the variable.
+
+@kindex whatis
+@item whatis @var{expr}
+Print the data type of expression @var{expr}. @var{expr} is not
+actually evaluated, and any side-effecting operations (such as
+assignments or function calls) inside it do not take place.
+@xref{Expressions, ,Expressions}.
+
+@item whatis
+Print the data type of @code{$}, the last value in the value history.
+
+@kindex ptype
+@item ptype @var{typename}
+Print a description of data type @var{typename}. @var{typename} may be
+the name of a type, or for C code it may have the form @samp{class
+@var{class-name}}, @samp{struct @var{struct-tag}}, @samp{union
+@var{union-tag}} or @samp{enum @var{enum-tag}}.
+
+@item ptype @var{expr}
+@itemx ptype
+Print a description of the type of expression @var{expr}. @code{ptype}
+differs from @code{whatis} by printing a detailed description, instead
+of just the name of the type.
+
+For example, for this variable declaration:
@example
struct complex @{double real; double imag;@} v;
@kindex info types
@item info types @var{regexp}
@itemx info types
-Print a brief description of all types whose name matches @var{regexp}
+Print a brief description of all types whose names match @var{regexp}
(or all types in your program, if you supply no argument). Each
complete typename is matched as though it were a complete line; thus,
@samp{i type value} gives information on all types in your program whose
-name includes the string @code{value}, but @samp{i type ^value$} gives
+names include the string @code{value}, but @samp{i type ^value$} gives
information only on types whose complete name is @code{value}.
This command differs from @code{ptype} in two ways: first, like
@cindex reloading symbols
Some systems allow individual object files that make up your program to
-be replaced without stopping and restarting your program.
-@ifset VXWORKS
-For example, in VxWorks you can simply recompile a defective object file
-and keep on running.
-@end ifset
-If you are running on one of these systems, you can allow @value{GDBN} to
-reload the symbols for automatically relinked modules:
+be replaced without stopping and restarting your program. For example,
+in VxWorks you can simply recompile a defective object file and keep on
+running. If you are running on one of these systems, you can allow
+@value{GDBN} to reload the symbols for automatically relinked modules:
@table @code
@kindex set symbol-reloading
Show the current @code{on} or @code{off} setting.
@end table
+@kindex set opaque-type-resolution
+@item set opaque-type-resolution on
+Tell @value{GDBN} to resolve opaque types. An opaque type is a type
+declared as a pointer to a @code{struct}, @code{class}, or
+@code{union}---for example, @code{struct MyType *}---that is used in one
+source file although the full declaration of @code{struct MyType} is in
+another source file. The default is on.
+
+A change in the setting of this subcommand will not take effect until
+the next time symbols for a file are loaded.
+
+@item set opaque-type-resolution off
+Tell @value{GDBN} not to resolve opaque types. In this case, the type
+is printed as follows:
+@smallexample
+@{<no data fields>@}
+@end smallexample
+
+@kindex show opaque-type-resolution
+@item show opaque-type-resolution
+Show whether opaque types are resolved or not.
+
@kindex maint print symbols
@cindex symbol dump
@kindex maint print psymbols
program.
For example, you can store new values into variables or memory
-locations,
-@ifclear BARETARGET
-give your program a signal, restart it
-@end ifclear
-@ifset BARETARGET
-restart your program
-@end ifset
-at a different address, or even return prematurely from a function.
+locations, give your program a signal, restart it at a different
+address, or even return prematurely from a function.
@menu
* Assignment:: Assignment to variables
* Jumping:: Continuing at a different address
-@ifclear BARETARGET
* Signaling:: Giving your program a signal
-@end ifclear
-
* Returning:: Returning from a function
* Calling:: Calling your program's functions
* Patching:: Patching your program
@noindent
stores the value 4 into the variable @code{x}, and then prints the
value of the assignment expression (which is 4).
-@ifclear CONLY
@xref{Languages, ,Using @value{GDBN} with Different Languages}, for more
information on operators in supported languages.
-@end ifclear
@kindex set variable
@cindex variables, setting
If the beginning of the argument string of the @code{set} command
appears identical to a @code{set} subcommand, use the @code{set
variable} command instead of just @code{set}. This command is identical
-to @code{set} except for its lack of subcommands. For example, if
-your program has a variable @code{width}, you get
-an error if you try to set a new value with just @samp{set width=13},
-because @value{GDBN} has the command @code{set width}:
+to @code{set} except for its lack of subcommands. For example, if your
+program has a variable @code{width}, you get an error if you try to set
+a new value with just @samp{set width=13}, because @value{GDBN} has the
+command @code{set width}:
@example
(@value{GDBP}) whatis width
(@value{GDBP}) set var width=47
@end example
+Because the @code{set} command has many subcommands that can conflict
+with the names of program variables, it is a good idea to use the
+@code{set variable} command instead of just @code{set}. For example, if
+your program has a variable @code{g}, you run into problems if you try
+to set a new value with just @samp{set g=4}, because @value{GDBN} has
+the command @code{set gnutarget}, abbreviated @code{set g}:
+
+@example
+@group
+(@value{GDBP}) whatis g
+type = double
+(@value{GDBP}) p g
+$1 = 1
+(@value{GDBP}) set g=4
+(@value{GDBP}) p g
+$2 = 1
+(@value{GDBP}) r
+The program being debugged has been started already.
+Start it from the beginning? (y or n) y
+Starting program: /home/smith/cc_progs/a.out
+"/home/smith/cc_progs/a.out": can't open to read symbols: Invalid bfd target.
+(@value{GDBP}) show g
+The current BFD target is "=4".
+@end group
+@end example
+
+@noindent
+The program variable @code{g} did not change, and you silently set the
+@code{gnutarget} to an invalid value. In order to set the variable
+@code{g}, use
+
+@example
+(@value{GDBP}) set var g=4
+@end example
+
@value{GDBN} allows more implicit conversions in assignments than C; you can
freely store an integer value into a pointer variable or vice versa,
and you can convert any structure to any other structure that is the
same length or shorter.
@comment FIXME: how do structs align/pad in these conversions?
-@comment /pesch@cygnus.com 18dec1990
+@comment /doc@cygnus.com 18dec1990
To store values into arbitrary places in memory, use the @samp{@{@dots{}@}}
construct to generate a value of specified type at a specified address
Resume execution at line @var{linespec}. Execution stops again
immediately if there is a breakpoint there. @xref{List, ,Printing
source lines}, for a description of the different forms of
-@var{linespec}.
+@var{linespec}. It is common practice to use the @code{tbreak} command
+in conjunction with @code{jump}. @xref{Set Breaks, ,Setting
+breakpoints}.
The @code{jump} command does not change the current stack frame, or
the stack pointer, or the contents of any memory location or any
Resume execution at the instruction at address @var{address}.
@end table
-You can get much the same effect as the @code{jump} command by storing a
-new value into the register @code{$pc}. The difference is that this
-does not start your program running; it only changes the address of where it
-@emph{will} run when you continue. For example,
+@c Doesn't work on HP-UX; have to set $pcoqh and $pcoqt.
+On many systems, you can get much the same effect as the @code{jump}
+command by storing a new value into the register @code{$pc}. The
+difference is that this does not start your program running; it only
+changes the address of where it @emph{will} run when you continue. For
+example,
@example
set $pc = 0x485
address @code{0x485}, rather than at the address where your program stopped.
@xref{Continuing and Stepping, ,Continuing and stepping}.
-The most common occasion to use the @code{jump} command is to back up--
-perhaps with more breakpoints set--over a portion of a program that has
-already executed, in order to examine its execution in more detail.
+The most common occasion to use the @code{jump} command is to back
+up---perhaps with more breakpoints set---over a portion of a program
+that has already executed, in order to examine its execution in more
+detail.
-@ifclear BARETARGET
@c @group
@node Signaling
@section Giving your program a signal
the signal handling tables (@pxref{Signals}). The @code{signal} command
passes the signal directly to your program.
-@end ifclear
@node Returning
@section Returning from a function
with @code{void} returned values. If the result is not void, it
is printed and saved in the value history.
-A new user-controlled variable, @var{call_scratch_address}, specifies
-the location of a scratch area to be used when @value{GDBN} calls a
-function in the target. This is necessary because the usual method
-of putting the scratch area on the stack does not work in systems that
-have separate instruction and data spaces.
+For the A29K, a user-controlled variable @code{call_scratch_address},
+specifies the location of a scratch area to be used when @value{GDBN}
+calls a function in the target. This is necessary because the usual
+method of putting the scratch area on the stack does not work in systems
+that have separate instruction and data spaces.
@node Patching
@section Patching programs
+
@cindex patching binaries
@cindex writing into executables
-@ifclear BARETARGET
@cindex writing into corefiles
-@end ifclear
-By default, @value{GDBN} opens the file containing your program's executable
-code
-@ifclear BARETARGET
-(or the corefile)
-@end ifclear
-read-only. This prevents accidental alterations
-to machine code; but it also prevents you from intentionally patching
-your program's binary.
+By default, @value{GDBN} opens the file containing your program's
+executable code (or the corefile) read-only. This prevents accidental
+alterations to machine code; but it also prevents you from intentionally
+patching your program's binary.
If you'd like to be able to patch the binary, you can specify that
explicitly with the @code{set write} command. For example, you might
@kindex set write
@item set write on
@itemx set write off
-If you specify @samp{set write on}, @value{GDBN} opens executable
-@ifclear BARETARGET
-and core
-@end ifclear
-files for both reading and writing; if you specify @samp{set write
+If you specify @samp{set write on}, @value{GDBN} opens executable and
+core files for both reading and writing; if you specify @samp{set write
off} (the default), @value{GDBN} opens them read-only.
If you have already loaded a file, you must load it again (using the
-@code{exec-file}
-@ifclear BARETARGET
-or @code{core-file}
-@end ifclear
-command) after changing @code{set write}, for your new setting to take
-effect.
+@code{exec-file} or @code{core-file} command) after changing @code{set
+write}, for your new setting to take effect.
@item show write
@kindex show write
-Display whether executable files
-@ifclear BARETARGET
-and core files
-@end ifclear
-are opened for writing as well as reading.
+Display whether executable files and core files are opened for writing
+as well as reading.
@end table
@node GDB Files
@chapter @value{GDBN} Files
-@value{GDBN} needs to know the file name of the program to be debugged, both in
-order to read its symbol table and in order to start your program.
-@ifclear BARETARGET
-To debug a core dump of a previous run, you must also tell @value{GDBN}
-the name of the core dump file.
-@end ifclear
+@value{GDBN} needs to know the file name of the program to be debugged,
+both in order to read its symbol table and in order to start your
+program. To debug a core dump of a previous run, you must also tell
+@value{GDBN} the name of the core dump file.
@menu
* Files:: Commands to specify files
@node Files
@section Commands to specify files
-@cindex symbol table
-@ifclear BARETARGET
+@cindex symbol table
@cindex core dump file
-You may want to specify executable and core dump file names.
-The usual way to do this is at start-up time, using the arguments to
-@value{GDBN}'s start-up commands (@pxref{Invocation, ,
-Getting In and Out of @value{GDBN}}).
-@end ifclear
-@ifset BARETARGET
-The usual way to specify an executable file name is with
-the command argument given when you start @value{GDBN}, (@pxref{Invocation,
-,Getting In and Out of @value{GDBN}}.
-@end ifset
+
+You may want to specify executable and core dump file names. The usual
+way to do this is at start-up time, using the arguments to
+@value{GDBN}'s start-up commands (@pxref{Invocation, , Getting In and
+Out of @value{GDBN}}).
Occasionally it is necessary to change to a different file during a
@value{GDBN} session. Or you may run @value{GDBN} and forget to specify
When @value{GDBN} is configured for a particular environment, it
understands debugging information in whatever format is the standard
generated for that environment; you may use either a @sc{gnu} compiler, or
-other compilers that adhere to the local conventions. Best results are
-usually obtained from @sc{gnu} compilers; for example, using @code{@value{GCC}}
-you can generate debugging information for optimized code.
-
-On some kinds of object files, the @code{symbol-file} command does not
-normally read the symbol table in full right away. Instead, it scans
-the symbol table quickly to find which source files and which symbols
-are present. The details are read later, one source file at a time,
-as they are needed.
-
-The purpose of this two-stage reading strategy is to make @value{GDBN} start up
-faster. For the most part, it is invisible except for occasional
-pauses while the symbol table details for a particular source file are
-being read. (The @code{set verbose} command can turn these pauses
-into messages if desired. @xref{Messages/Warnings, ,Optional warnings
-and messages}.)
+other compilers that adhere to the local conventions.
+Best results are usually obtained from @sc{gnu} compilers; for example,
+using @code{@value{GCC}} you can generate debugging information for
+optimized code.
+
+For most kinds of object files, with the exception of old SVR3 systems
+using COFF, the @code{symbol-file} command does not normally read the
+symbol table in full right away. Instead, it scans the symbol table
+quickly to find which source files and which symbols are present. The
+details are read later, one source file at a time, as they are needed.
+
+The purpose of this two-stage reading strategy is to make @value{GDBN}
+start up faster. For the most part, it is invisible except for
+occasional pauses while the symbol table details for a particular source
+file are being read. (The @code{set verbose} command can turn these
+pauses into messages if desired. @xref{Messages/Warnings, ,Optional
+warnings and messages}.)
We have not implemented the two-stage strategy for COFF yet. When the
symbol table is stored in COFF format, @code{symbol-file} reads the
-symbol table data in full right away.
+symbol table data in full right away. Note that ``stabs-in-COFF''
+still does the two-stage strategy, since the debug info is actually
+in stabs format.
@kindex readnow
@cindex reading symbols immediately
load symbol table information, if you want to be sure @value{GDBN} has the
entire symbol table available.
-@ifclear BARETARGET
If memory-mapped files are available on your system through the
@code{mmap} system call, you can use another option, @samp{-mapped}, to
cause @value{GDBN} to write the symbols for your program into a reusable
to be used.
Note that the core file is ignored when your program is actually running
-under @value{GDBN}. So, if you have been running your program and you wish to
-debug a core file instead, you must kill the subprocess in which the
-program is running. To do this, use the @code{kill} command
+under @value{GDBN}. So, if you have been running your program and you
+wish to debug a core file instead, you must kill the subprocess in which
+the program is running. To do this, use the @code{kill} command
(@pxref{Kill Process, ,Killing the child process}).
-@end ifclear
-
-@kindex load @var{filename}
-@item load @var{filename}
-@ifset GENERIC
-Depending on what remote debugging facilities are configured into
-@value{GDBN}, the @code{load} command may be available. Where it exists, it
-is meant to make @var{filename} (an executable) available for debugging
-on the remote system---by downloading, or dynamic linking, for example.
-@code{load} also records the @var{filename} symbol table in @value{GDBN}, like
-the @code{add-symbol-file} command.
-
-If your @value{GDBN} does not have a @code{load} command, attempting to
-execute it gets the error message ``@code{You can't do that when your
-target is @dots{}}''
-@end ifset
-
-The file is loaded at whatever address is specified in the executable.
-For some object file formats, you can specify the load address when you
-link the program; for other formats, like a.out, the object file format
-specifies a fixed address.
-@c FIXME! This would be a good place for an xref to the GNU linker doc.
-
-@ifset VXWORKS
-On VxWorks, @code{load} links @var{filename} dynamically on the
-current target system as well as adding its symbols in @value{GDBN}.
-@end ifset
-
-@ifset I960
-@cindex download to Nindy-960
-With the Nindy interface to an Intel 960 board, @code{load}
-downloads @var{filename} to the 960 as well as adding its symbols in
-@value{GDBN}.
-@end ifset
-
-@ifset H8
-@cindex download to H8/300 or H8/500
-@cindex H8/300 or H8/500 download
-@cindex download to Hitachi SH
-@cindex Hitachi SH download
-When you select remote debugging to a Hitachi SH, H8/300, or H8/500 board
-(@pxref{Hitachi Remote,,@value{GDBN} and Hitachi Microprocessors}),
-the @code{load} command downloads your program to the Hitachi board and also
-opens it as the current executable target for @value{GDBN} on your host
-(like the @code{file} command).
-@end ifset
-
-@code{load} does not repeat if you press @key{RET} again after using it.
-@ifclear BARETARGET
@kindex add-symbol-file
@cindex dynamic linking
@item add-symbol-file @var{filename} @var{address}
@itemx add-symbol-file @var{filename} @var{address} @r{[} -readnow @r{]} @r{[} -mapped @r{]}
+@itemx add-symbol-file @var{filename} @var{address} @var{data_address} @var{bss_address}
+@itemx add-symbol-file @var{filename} @r{-T}@var{section} @var{address}
The @code{add-symbol-file} command reads additional symbol table information
from the file @var{filename}. You would use this command when @var{filename}
has been dynamically loaded (by some other means) into the program that
is running. @var{address} should be the memory address at which the
file has been loaded; @value{GDBN} cannot figure this out for itself.
-You can specify @var{address} as an expression.
+You can specify up to three addresses, in which case they are taken to be
+the addresses of the text, data, and bss segments respectively.
+For complicated cases, you can specify an arbitrary number of @r{-T}@var{section} @var{address}
+pairs, to give an explicit section name and base address for that section.
+You can specify any @var{address} as an expression.
The symbol table of the file @var{filename} is added to the symbol table
originally read with the @code{symbol-file} command. You can use the
operating system for the Motorola 88k. @value{GDBN} automatically looks for
shared libraries, however if @value{GDBN} does not find yours, you can run
@code{add-shared-symbol-file}. It takes no arguments.
-@end ifclear
@kindex section
@item section
the exec file to ADDR. This can be used if the exec file does not contain
section addresses, (such as in the a.out format), or when the addresses
specified in the file itself are wrong. Each section must be changed
-separately. The ``info files'' command lists all the sections and their
-addresses.
+separately. The @code{info files} command, described below, lists all
+the sections and their addresses.
@kindex info files
@kindex info target
@item info files
@itemx info target
-@code{info files} and @code{info target} are synonymous; both print
-the current target (@pxref{Targets, ,Specifying a Debugging Target}),
-including the
-@ifclear BARETARGET
-names of the executable and core dump files
-@end ifclear
-@ifset BARETARGET
-name of the executable file
-@end ifset
-currently in use by @value{GDBN}, and the files from which symbols were
-loaded. The command @code{help target} lists all possible targets
-rather than current ones.
+@code{info files} and @code{info target} are synonymous; both print the
+current target (@pxref{Targets, ,Specifying a Debugging Target}),
+including the names of the executable and core dump files currently in
+use by @value{GDBN}, and the files from which symbols were loaded. The
+command @code{help target} lists all possible targets rather than
+current ones.
+
@end table
All file-specifying commands allow both absolute and relative file names
as arguments. @value{GDBN} always converts the file name to an absolute file
name and remembers it that way.
-@ifclear BARETARGET
@cindex shared libraries
-@value{GDBN} supports SunOS, SVr4, Irix 5, and IBM RS/6000 shared libraries.
+@value{GDBN} supports HP-UX, SunOS, SVr4, Irix 5, and IBM RS/6000 shared
+libraries.
+
@value{GDBN} automatically loads symbol definitions from shared libraries
when you use the @code{run} command, or when you examine a core file.
(Before you issue the @code{run} command, @value{GDBN} does not understand
references to a function in a shared library, however---unless you are
debugging a core file).
+
+On HP-UX, if the program loads a library explicitly, @value{GDBN}
+automatically loads the symbols at the time of the @code{shl_load} call.
+
@c FIXME: some @value{GDBN} release may permit some refs to undef
@c FIXME...symbols---eg in a break cmd---assuming they are from a shared
@c FIXME...lib; check this from time to time when updating manual
@kindex share
@item sharedlibrary @var{regex}
@itemx share @var{regex}
-
Load shared object library symbols for files matching a
Unix regular expression.
As with files loaded automatically, it only loads shared libraries
@var{regex} is omitted all shared libraries required by your program are
loaded.
@end table
-@end ifclear
+
+On HP-UX systems, @value{GDBN} detects the loading of a shared library
+and automatically reads in symbols from the newly loaded library, up to
+a threshold that is initially set but that you can modify if you wish.
+
+Beyond that threshold, symbols from shared libraries must be explicitly
+loaded. To load these symbols, use the command @code{sharedlibrary
+@var{filename}}. The base address of the shared library is determined
+automatically by @value{GDBN} and need not be specified.
+
+To display or set the threshold, use the commands:
+
+@table @code
+@kindex set auto-solib-add
+@item set auto-solib-add @var{threshold}
+Set the autoloading size threshold, in megabytes. If @var{threshold} is
+nonzero, symbols from all shared object libraries will be loaded
+automatically when the inferior begins execution or when the dynamic
+linker informs @value{GDBN} that a new library has been loaded, until
+the symbol table of the program and libraries exceeds this threshold.
+Otherwise, symbols must be loaded manually, using the
+@code{sharedlibrary} command. The default threshold is 100 megabytes.
+
+@kindex show auto-solib-add
+@item show auto-solib-add
+Display the current autoloading size threshold, in megabytes.
+@end table
@node Symbol Errors
@section Errors reading symbol files
@item unknown symbol type @code{0x@var{nn}}
-The symbol information contains new data types that @value{GDBN} does not yet
-know how to read. @code{0x@var{nn}} is the symbol type of the misunderstood
-information, in hexadecimal.
+The symbol information contains new data types that @value{GDBN} does
+not yet know how to read. @code{0x@var{nn}} is the symbol type of the
+uncomprehended information, in hexadecimal.
-@value{GDBN} circumvents the error by ignoring this symbol information. This
-usually allows you to debug your program, though certain symbols
+@value{GDBN} circumvents the error by ignoring this symbol information.
+This usually allows you to debug your program, though certain symbols
are not accessible. If you encounter such a problem and feel like
-debugging it, you can debug @code{@value{GDBP}} with itself, breakpoint on
-@code{complain}, then go up to the function @code{read_dbx_symtab} and
-examine @code{*bufp} to see the symbol.
+debugging it, you can debug @code{@value{GDBP}} with itself, breakpoint
+on @code{complain}, then go up to the function @code{read_dbx_symtab}
+and examine @code{*bufp} to see the symbol.
@item stub type has NULL name
-@value{GDBN} could not find the full definition for
-@ifclear CONLY
-a struct or class.
-@end ifclear
-@ifset CONLY
-a struct.
-@end ifset
-@ifclear CONLY
-@item const/volatile indicator missing (ok if using g++ v1.x), got@dots{}
+@value{GDBN} could not find the full definition for a struct or class.
+@item const/volatile indicator missing (ok if using g++ v1.x), got@dots{}
The symbol information for a C++ member function is missing some
-information that recent versions of the compiler should have output
-for it.
-@end ifclear
+information that recent versions of the compiler should have output for
+it.
@item info mismatch between compiler and debugger
-@value{GDBN} could not parse a type specification output by the compiler.
-@end table
+@value{GDBN} could not parse a type specification output by the compiler.
+
+@end table
+
+@node Targets
+@chapter Specifying a Debugging Target
+
+@cindex debugging target
+@kindex target
+
+A @dfn{target} is the execution environment occupied by your program.
+
+Often, @value{GDBN} runs in the same host environment as your program;
+in that case, the debugging target is specified as a side effect when
+you use the @code{file} or @code{core} commands. When you need more
+flexibility---for example, running @value{GDBN} on a physically separate
+host, or controlling a standalone system over a serial port or a
+realtime system over a TCP/IP connection---you can use the @code{target}
+command to specify one of the target types configured for @value{GDBN}
+(@pxref{Target Commands, ,Commands for managing targets}).
+
+@menu
+* Active Targets:: Active targets
+* Target Commands:: Commands for managing targets
+* Byte Order:: Choosing target byte order
+* Remote:: Remote debugging
+* KOD:: Kernel Object Display
+
+@end menu
+
+@node Active Targets
+@section Active targets
+
+@cindex stacking targets
+@cindex active targets
+@cindex multiple targets
+
+There are three classes of targets: processes, core files, and
+executable files. @value{GDBN} can work concurrently on up to three
+active targets, one in each class. This allows you to (for example)
+start a process and inspect its activity without abandoning your work on
+a core file.
+
+For example, if you execute @samp{gdb a.out}, then the executable file
+@code{a.out} is the only active target. If you designate a core file as
+well---presumably from a prior run that crashed and coredumped---then
+@value{GDBN} has two active targets and uses them in tandem, looking
+first in the corefile target, then in the executable file, to satisfy
+requests for memory addresses. (Typically, these two classes of target
+are complementary, since core files contain only a program's
+read-write memory---variables and so on---plus machine status, while
+executable files contain only the program text and initialized data.)
+
+When you type @code{run}, your executable file becomes an active process
+target as well. When a process target is active, all @value{GDBN}
+commands requesting memory addresses refer to that target; addresses in
+an active core file or executable file target are obscured while the
+process target is active.
+
+Use the @code{core-file} and @code{exec-file} commands to select a new
+core file or executable target (@pxref{Files, ,Commands to specify
+files}). To specify as a target a process that is already running, use
+the @code{attach} command (@pxref{Attach, ,Debugging an already-running
+process}).
+
+@node Target Commands
+@section Commands for managing targets
+
+@table @code
+@item target @var{type} @var{parameters}
+Connects the @value{GDBN} host environment to a target machine or
+process. A target is typically a protocol for talking to debugging
+facilities. You use the argument @var{type} to specify the type or
+protocol of the target machine.
+
+Further @var{parameters} are interpreted by the target protocol, but
+typically include things like device names or host names to connect
+with, process numbers, and baud rates.
+
+The @code{target} command does not repeat if you press @key{RET} again
+after executing the command.
+
+@kindex help target
+@item help target
+Displays the names of all targets available. To display targets
+currently selected, use either @code{info target} or @code{info files}
+(@pxref{Files, ,Commands to specify files}).
+
+@item help target @var{name}
+Describe a particular target, including any parameters necessary to
+select it.
+
+@kindex set gnutarget
+@item set gnutarget @var{args}
+@value{GDBN} uses its own library BFD to read your files. @value{GDBN}
+knows whether it is reading an @dfn{executable},
+a @dfn{core}, or a @dfn{.o} file; however, you can specify the file format
+with the @code{set gnutarget} command. Unlike most @code{target} commands,
+with @code{gnutarget} the @code{target} refers to a program, not a machine.
+
+@quotation
+@emph{Warning:} To specify a file format with @code{set gnutarget},
+you must know the actual BFD name.
+@end quotation
+
+@noindent
+@xref{Files, , Commands to specify files}.
+
+@kindex show gnutarget
+@item show gnutarget
+Use the @code{show gnutarget} command to display what file format
+@code{gnutarget} is set to read. If you have not set @code{gnutarget},
+@value{GDBN} will determine the file format for each file automatically,
+and @code{show gnutarget} displays @samp{The current BDF target is "auto"}.
+@end table
+
+Here are some common targets (available, or not, depending on the GDB
+configuration):
+
+@table @code
+@kindex target exec
+@item target exec @var{program}
+An executable file. @samp{target exec @var{program}} is the same as
+@samp{exec-file @var{program}}.
+
+@kindex target core
+@item target core @var{filename}
+A core dump file. @samp{target core @var{filename}} is the same as
+@samp{core-file @var{filename}}.
+
+@kindex target remote
+@item target remote @var{dev}
+Remote serial target in GDB-specific protocol. The argument @var{dev}
+specifies what serial device to use for the connection (e.g.
+@file{/dev/ttya}). @xref{Remote, ,Remote debugging}. @code{target remote}
+supports the @code{load} command. This is only useful if you have
+some other way of getting the stub to the target system, and you can put
+it somewhere in memory where it won't get clobbered by the download.
+
+@kindex target sim
+@item target sim
+Builtin CPU simulator. @value{GDBN} includes simulators for most architectures.
+In general,
+@example
+ target sim
+ load
+ run
+@end example
+@noindent
+works; however, you cannot assume that a specific memory map, device
+drivers, or even basic I/O is available, although some simulators do
+provide these. For info about any processor-specific simulator details,
+see the appropriate section in @ref{Embedded Processors, ,Embedded
+Processors}.
+
+@end table
+
+Some configurations may include these targets as well:
+
+@table @code
+
+@kindex target nrom
+@item target nrom @var{dev}
+NetROM ROM emulator. This target only supports downloading.
+
+@end table
+
+Different targets are available on different configurations of @value{GDBN};
+your configuration may have more or fewer targets.
+
+Many remote targets require you to download the executable's code
+once you've successfully established a connection.
+
+@table @code
+
+@kindex load @var{filename}
+@item load @var{filename}
+Depending on what remote debugging facilities are configured into
+@value{GDBN}, the @code{load} command may be available. Where it exists, it
+is meant to make @var{filename} (an executable) available for debugging
+on the remote system---by downloading, or dynamic linking, for example.
+@code{load} also records the @var{filename} symbol table in @value{GDBN}, like
+the @code{add-symbol-file} command.
+
+If your @value{GDBN} does not have a @code{load} command, attempting to
+execute it gets the error message ``@code{You can't do that when your
+target is @dots{}}''
+
+The file is loaded at whatever address is specified in the executable.
+For some object file formats, you can specify the load address when you
+link the program; for other formats, like a.out, the object file format
+specifies a fixed address.
+@c FIXME! This would be a good place for an xref to the GNU linker doc.
+
+@code{load} does not repeat if you press @key{RET} again after using it.
+@end table
+
+@node Byte Order
+@section Choosing target byte order
+
+@cindex choosing target byte order
+@cindex target byte order
+@kindex set endian big
+@kindex set endian little
+@kindex set endian auto
+@kindex show endian
+
+Some types of processors, such as the MIPS, PowerPC, and Hitachi SH,
+offer the ability to run either big-endian or little-endian byte
+orders. Usually the executable or symbol will include a bit to
+designate the endian-ness, and you will not need to worry about
+which to use. However, you may still find it useful to adjust
+@value{GDBN}'s idea of processor endian-ness manually.
+
+@table @code
+@kindex set endian big
+@item set endian big
+Instruct @value{GDBN} to assume the target is big-endian.
+
+@kindex set endian little
+@item set endian little
+Instruct @value{GDBN} to assume the target is little-endian.
+
+@kindex set endian auto
+@item set endian auto
+Instruct @value{GDBN} to use the byte order associated with the
+executable.
+
+@item show endian
+Display @value{GDBN}'s current idea of the target byte order.
+
+@end table
+
+Note that these commands merely adjust interpretation of symbolic
+data on the host, and that they have absolutely no effect on the
+target system.
+
+@node Remote
+@section Remote debugging
+@cindex remote debugging
+
+If you are trying to debug a program running on a machine that cannot run
+@value{GDBN} in the usual way, it is often useful to use remote debugging.
+For example, you might use remote debugging on an operating system kernel,
+or on a small system which does not have a general purpose operating system
+powerful enough to run a full-featured debugger.
+
+Some configurations of @value{GDBN} have special serial or TCP/IP interfaces
+to make this work with particular debugging targets. In addition,
+@value{GDBN} comes with a generic serial protocol (specific to @value{GDBN},
+but not specific to any particular target system) which you can use if you
+write the remote stubs---the code that runs on the remote system to
+communicate with @value{GDBN}.
+
+Other remote targets may be available in your
+configuration of @value{GDBN}; use @code{help target} to list them.
+
+@menu
+* Remote Serial:: @value{GDBN} remote serial protocol
+@end menu
+
+@node Remote Serial
+@subsection The @value{GDBN} remote serial protocol
+
+@cindex remote serial debugging, overview
+To debug a program running on another machine (the debugging
+@dfn{target} machine), you must first arrange for all the usual
+prerequisites for the program to run by itself. For example, for a C
+program, you need:
+
+@enumerate
+@item
+A startup routine to set up the C runtime environment; these usually
+have a name like @file{crt0}. The startup routine may be supplied by
+your hardware supplier, or you may have to write your own.
+
+@item
+A C subroutine library to support your program's
+subroutine calls, notably managing input and output.
+
+@item
+A way of getting your program to the other machine---for example, a
+download program. These are often supplied by the hardware
+manufacturer, but you may have to write your own from hardware
+documentation.
+@end enumerate
+
+The next step is to arrange for your program to use a serial port to
+communicate with the machine where @value{GDBN} is running (the @dfn{host}
+machine). In general terms, the scheme looks like this:
+
+@table @emph
+@item On the host,
+@value{GDBN} already understands how to use this protocol; when everything
+else is set up, you can simply use the @samp{target remote} command
+(@pxref{Targets,,Specifying a Debugging Target}).
+
+@item On the target,
+you must link with your program a few special-purpose subroutines that
+implement the @value{GDBN} remote serial protocol. The file containing these
+subroutines is called a @dfn{debugging stub}.
+
+On certain remote targets, you can use an auxiliary program
+@code{gdbserver} instead of linking a stub into your program.
+@xref{Server,,Using the @code{gdbserver} program}, for details.
+@end table
+
+The debugging stub is specific to the architecture of the remote
+machine; for example, use @file{sparc-stub.c} to debug programs on
+@sc{sparc} boards.
+
+@cindex remote serial stub list
+These working remote stubs are distributed with @value{GDBN}:
+
+@table @code
+
+@item i386-stub.c
+@kindex i386-stub.c
+@cindex Intel
+@cindex i386
+For Intel 386 and compatible architectures.
+
+@item m68k-stub.c
+@kindex m68k-stub.c
+@cindex Motorola 680x0
+@cindex m680x0
+For Motorola 680x0 architectures.
+
+@item sh-stub.c
+@kindex sh-stub.c
+@cindex Hitachi
+@cindex SH
+For Hitachi SH architectures.
+
+@item sparc-stub.c
+@kindex sparc-stub.c
+@cindex Sparc
+For @sc{sparc} architectures.
+
+@item sparcl-stub.c
+@kindex sparcl-stub.c
+@cindex Fujitsu
+@cindex SparcLite
+For Fujitsu @sc{sparclite} architectures.
+
+@end table
+
+The @file{README} file in the @value{GDBN} distribution may list other
+recently added stubs.
+
+@menu
+* Stub Contents:: What the stub can do for you
+* Bootstrapping:: What you must do for the stub
+* Debug Session:: Putting it all together
+* Protocol:: Definition of the communication protocol
+* Server:: Using the `gdbserver' program
+* NetWare:: Using the `gdbserve.nlm' program
+@end menu
+
+@node Stub Contents
+@subsubsection What the stub can do for you
+
+@cindex remote serial stub
+The debugging stub for your architecture supplies these three
+subroutines:
+
+@table @code
+@item set_debug_traps
+@kindex set_debug_traps
+@cindex remote serial stub, initialization
+This routine arranges for @code{handle_exception} to run when your
+program stops. You must call this subroutine explicitly near the
+beginning of your program.
+
+@item handle_exception
+@kindex handle_exception
+@cindex remote serial stub, main routine
+This is the central workhorse, but your program never calls it
+explicitly---the setup code arranges for @code{handle_exception} to
+run when a trap is triggered.
+
+@code{handle_exception} takes control when your program stops during
+execution (for example, on a breakpoint), and mediates communications
+with @value{GDBN} on the host machine. This is where the communications
+protocol is implemented; @code{handle_exception} acts as the @value{GDBN}
+representative on the target machine. It begins by sending summary
+information on the state of your program, then continues to execute,
+retrieving and transmitting any information @value{GDBN} needs, until you
+execute a @value{GDBN} command that makes your program resume; at that point,
+@code{handle_exception} returns control to your own code on the target
+machine.
+
+@item breakpoint
+@cindex @code{breakpoint} subroutine, remote
+Use this auxiliary subroutine to make your program contain a
+breakpoint. Depending on the particular situation, this may be the only
+way for @value{GDBN} to get control. For instance, if your target
+machine has some sort of interrupt button, you won't need to call this;
+pressing the interrupt button transfers control to
+@code{handle_exception}---in effect, to @value{GDBN}. On some machines,
+simply receiving characters on the serial port may also trigger a trap;
+again, in that situation, you don't need to call @code{breakpoint} from
+your own program---simply running @samp{target remote} from the host
+@value{GDBN} session gets control.
+
+Call @code{breakpoint} if none of these is true, or if you simply want
+to make certain your program stops at a predetermined point for the
+start of your debugging session.
+@end table
+
+@node Bootstrapping
+@subsubsection What you must do for the stub
+
+@cindex remote stub, support routines
+The debugging stubs that come with @value{GDBN} are set up for a particular
+chip architecture, but they have no information about the rest of your
+debugging target machine.
+
+First of all you need to tell the stub how to communicate with the
+serial port.
+
+@table @code
+@item int getDebugChar()
+@kindex getDebugChar
+Write this subroutine to read a single character from the serial port.
+It may be identical to @code{getchar} for your target system; a
+different name is used to allow you to distinguish the two if you wish.
+
+@item void putDebugChar(int)
+@kindex putDebugChar
+Write this subroutine to write a single character to the serial port.
+It may be identical to @code{putchar} for your target system; a
+different name is used to allow you to distinguish the two if you wish.
+@end table
+
+@cindex control C, and remote debugging
+@cindex interrupting remote targets
+If you want @value{GDBN} to be able to stop your program while it is
+running, you need to use an interrupt-driven serial driver, and arrange
+for it to stop when it receives a @code{^C} (@samp{\003}, the control-C
+character). That is the character which @value{GDBN} uses to tell the
+remote system to stop.
+
+Getting the debugging target to return the proper status to @value{GDBN}
+probably requires changes to the standard stub; one quick and dirty way
+is to just execute a breakpoint instruction (the ``dirty'' part is that
+@value{GDBN} reports a @code{SIGTRAP} instead of a @code{SIGINT}).
+
+Other routines you need to supply are:
+
+@table @code
+@item void exceptionHandler (int @var{exception_number}, void *@var{exception_address})
+@kindex exceptionHandler
+Write this function to install @var{exception_address} in the exception
+handling tables. You need to do this because the stub does not have any
+way of knowing what the exception handling tables on your target system
+are like (for example, the processor's table might be in @sc{rom},
+containing entries which point to a table in @sc{ram}).
+@var{exception_number} is the exception number which should be changed;
+its meaning is architecture-dependent (for example, different numbers
+might represent divide by zero, misaligned access, etc). When this
+exception occurs, control should be transferred directly to
+@var{exception_address}, and the processor state (stack, registers,
+and so on) should be just as it is when a processor exception occurs. So if
+you want to use a jump instruction to reach @var{exception_address}, it
+should be a simple jump, not a jump to subroutine.
+
+For the 386, @var{exception_address} should be installed as an interrupt
+gate so that interrupts are masked while the handler runs. The gate
+should be at privilege level 0 (the most privileged level). The
+@sc{sparc} and 68k stubs are able to mask interrupts themselves without
+help from @code{exceptionHandler}.
+
+@item void flush_i_cache()
+@kindex flush_i_cache
+On @sc{sparc} and @sc{sparclite} only, write this subroutine to flush the
+instruction cache, if any, on your target machine. If there is no
+instruction cache, this subroutine may be a no-op.
+
+On target machines that have instruction caches, @value{GDBN} requires this
+function to make certain that the state of your program is stable.
+@end table
+
+@noindent
+You must also make sure this library routine is available:
+
+@table @code
+@item void *memset(void *, int, int)
+@kindex memset
+This is the standard library function @code{memset} that sets an area of
+memory to a known value. If you have one of the free versions of
+@code{libc.a}, @code{memset} can be found there; otherwise, you must
+either obtain it from your hardware manufacturer, or write your own.
+@end table
+
+If you do not use the GNU C compiler, you may need other standard
+library subroutines as well; this varies from one stub to another,
+but in general the stubs are likely to use any of the common library
+subroutines which @code{@value{GCC}} generates as inline code.
+
+
+@node Debug Session
+@subsubsection Putting it all together
+
+@cindex remote serial debugging summary
+In summary, when your program is ready to debug, you must follow these
+steps.
+
+@enumerate
+@item
+Make sure you have the supporting low-level routines
+(@pxref{Bootstrapping,,What you must do for the stub}):
+@display
+@code{getDebugChar}, @code{putDebugChar},
+@code{flush_i_cache}, @code{memset}, @code{exceptionHandler}.
+@end display
+
+@item
+Insert these lines near the top of your program:
+
+@example
+set_debug_traps();
+breakpoint();
+@end example
+
+@item
+For the 680x0 stub only, you need to provide a variable called
+@code{exceptionHook}. Normally you just use:
+
+@example
+void (*exceptionHook)() = 0;
+@end example
+
+@noindent
+but if before calling @code{set_debug_traps}, you set it to point to a
+function in your program; that function is called when
+@code{@value{GDBN}} continues after stopping on a trap (for example, bus
+error). The function indicated by @code{exceptionHook} is called with
+one parameter: an @code{int} which is the exception number.
+
+@item
+Compile and link together: your program, the @value{GDBN} debugging stub for
+your target architecture, and the supporting subroutines.
+
+@item
+Make sure you have a serial connection between your target machine and
+the @value{GDBN} host, and identify the serial port on the host.
+
+@item
+@c The "remote" target now provides a `load' command, so we should
+@c document that. FIXME.
+Download your program to your target machine (or get it there by
+whatever means the manufacturer provides), and start it.
+
+@item
+To start remote debugging, run @value{GDBN} on the host machine, and specify
+as an executable file the program that is running in the remote machine.
+This tells @value{GDBN} how to find your program's symbols and the contents
+of its pure text.
+
+@item
+@cindex serial line, @code{target remote}
+Establish communication using the @code{target remote} command.
+Its argument specifies how to communicate with the target
+machine---either via a devicename attached to a direct serial line, or a
+TCP port (usually to a terminal server which in turn has a serial line
+to the target). For example, to use a serial line connected to the
+device named @file{/dev/ttyb}:
+
+@example
+target remote /dev/ttyb
+@end example
+
+@cindex TCP port, @code{target remote}
+To use a TCP connection, use an argument of the form
+@code{@var{host}:port}. For example, to connect to port 2828 on a
+terminal server named @code{manyfarms}:
+
+@example
+target remote manyfarms:2828
+@end example
+@end enumerate
+
+Now you can use all the usual commands to examine and change data and to
+step and continue the remote program.
+
+To resume the remote program and stop debugging it, use the @code{detach}
+command.
+
+@cindex interrupting remote programs
+@cindex remote programs, interrupting
+Whenever @value{GDBN} is waiting for the remote program, if you type the
+interrupt character (often @key{C-C}), @value{GDBN} attempts to stop the
+program. This may or may not succeed, depending in part on the hardware
+and the serial drivers the remote system uses. If you type the
+interrupt character once again, @value{GDBN} displays this prompt:
+
+@example
+Interrupted while waiting for the program.
+Give up (and stop debugging it)? (y or n)
+@end example
+
+If you type @kbd{y}, @value{GDBN} abandons the remote debugging session.
+(If you decide you want to try again later, you can use @samp{target
+remote} again to connect once more.) If you type @kbd{n}, @value{GDBN}
+goes back to waiting.
+
+@node Protocol
+@subsubsection Communication protocol
+
+@cindex debugging stub, example
+@cindex remote stub, example
+@cindex stub example, remote debugging
+The stub files provided with @value{GDBN} implement the target side of the
+communication protocol, and the @value{GDBN} side is implemented in the
+@value{GDBN} source file @file{remote.c}. Normally, you can simply allow
+these subroutines to communicate, and ignore the details. (If you're
+implementing your own stub file, you can still ignore the details: start
+with one of the existing stub files. @file{sparc-stub.c} is the best
+organized, and therefore the easiest to read.)
+
+However, there may be occasions when you need to know something about
+the protocol---for example, if there is only one serial port to your
+target machine, you might want your program to do something special if
+it recognizes a packet meant for @value{GDBN}.
+
+In the examples below, @samp{<-} and @samp{->} are used to indicate
+transmitted and received data respectfully.
+
+@cindex protocol, @value{GDBN} remote serial
+@cindex serial protocol, @value{GDBN} remote
+@cindex remote serial protocol
+All @value{GDBN} commands and responses (other than acknowledgments)
+are sent as a @var{packet}. A @var{packet} is introduced with the
+character @samp{$}, this is followed by an optional two-digit
+@var{sequence-id} and the character @samp{:}, the actual
+@var{packet-data}, and the terminating character @samp{#} followed by a
+two-digit @var{checksum}:
+
+@example
+@code{$}@var{packet-data}@code{#}@var{checksum}
+@end example
+@noindent
+or, with the optional @var{sequence-id}:
+@example
+@code{$}@var{sequence-id}@code{:}@var{packet-data}@code{#}@var{checksum}
+@end example
+
+@cindex checksum, for @value{GDBN} remote
+@noindent
+The two-digit @var{checksum} is computed as the modulo 256 sum of all
+characters between the leading @samp{$} and the trailing @samp{#} (that
+consisting of both the optional @var{sequence-id}@code{:} and the actual
+@var{packet-data}) (an eight bit unsigned checksum).
+
+@cindex sequence-id, for @value{GDBN} remote
+@noindent
+The two-digit @var{sequence-id}, when present, is returned with the
+acknowledgment. Beyond that its meaning is poorly defined.
+@value{GDBN} is not known to output @var{sequence-id}s.
+
+When either the host or the target machine receives a packet, the first
+response expected is an acknowledgment: either @samp{+} (to indicate
+the package was received correctly) or @samp{-} (to request
+retransmission):
+
+@example
+<- @code{$}@var{packet-data}@code{#}@var{checksum}
+-> @code{+}
+@end example
+@noindent
+If the received packet included a @var{sequence-id} than that is
+appended to a positive acknowledgment:
+
+@example
+<- @code{$}@var{sequence-id}@code{:}@var{packet-data}@code{#}@var{checksum}
+-> @code{+}@var{sequence-id}
+@end example
+
+The host (@value{GDBN}) sends @var{command}s, and the target (the
+debugging stub incorporated in your program) sends a @var{response}. In
+the case of step and continue @var{command}s, the response is only sent
+when the operation has completed (the target has again stopped).
+
+@var{packet-data} consists of a sequence of characters with the
+exception of @samp{#} and @samp{$} (see @samp{X} packet for an
+exception). @samp{:} can not appear as the third character in a packet.
+Fields within the packet should be separated using @samp{,} and @samp{;}
+(unfortunately some packets chose to use @samp{:}). Except where
+otherwise noted all numbers are represented in HEX with leading zeros
+suppressed.
+
+Response @var{data} can be run-length encoded to save space. A @samp{*}
+means that the next character is an @sc{ascii} encoding giving a repeat count
+which stands for that many repetitions of the character preceding the
+@samp{*}. The encoding is @code{n+29}, yielding a printable character
+where @code{n >=3} (which is where rle starts to win). The printable
+characters @samp{$}, @samp{#}, @samp{+} and @samp{-} or with a numeric
+value greater than 126 should not be used.
+
+Some remote systems have used a different run-length encoding mechanism
+loosely refered to as the cisco encoding. Following the @samp{*}
+character are two hex digits that indicate the size of the packet.
+
+So:
+@example
+"@code{0* }"
+@end example
+@noindent
+means the same as "0000".
+
+The error response, returned for some packets includes a two character
+error number. That number is not well defined.
+
+For any @var{command} not supported by the stub, an empty response
+(@samp{$#00}) should be returned. That way it is possible to extend the
+protocol. A newer @value{GDBN} can tell if a packet is supported based
+on that response.
+
+Below is a complete list of all currently defined @var{command}s and
+their corresponding response @var{data}:
+
+@multitable @columnfractions .30 .30 .40
+@item Packet
+@tab Request
+@tab Description
+
+@item extended ops @emph{(optional)}
+@tab @code{!}
+@tab
+Use the extended remote protocol. Sticky---only needs to be set once.
+The extended remote protocol support the @samp{R} packet.
+@item
+@tab reply @samp{}
+@tab
+Stubs that support the extended remote protocol return @samp{} which,
+unfortunately, is identical to the response returned by stubs that do not
+support protocol extensions.
+
+@item last signal
+@tab @code{?}
+@tab
+Indicate the reason the target halted. The reply is the same as for step
+and continue.
+@item
+@tab reply
+@tab see below
+
+
+@item reserved
+@tab @code{a}
+@tab Reserved for future use
+
+@item set program arguments @strong{(reserved)} @emph{(optional)}
+@tab @code{A}@var{arglen}@code{,}@var{argnum}@code{,}@var{arg}@code{,...}
+@tab
+Initialized @samp{argv[]} array passed into program. @var{arglen}
+specifies the number of bytes in the hex encoded byte stream @var{arg}.
+See @file{gdbserver} for more details.
+@item
+@tab reply @code{OK}
+@item
+@tab reply @code{E}@var{NN}
+
+@item set baud @strong{(deprecated)}
+@tab @code{b}@var{baud}
+@tab
+Change the serial line speed to @var{baud}. JTC: @emph{When does the
+transport layer state change? When it's received, or after the ACK is
+transmitted. In either case, there are problems if the command or the
+acknowledgment packet is dropped.} Stan: @emph{If people really wanted
+to add something like this, and get it working for the first time, they
+ought to modify ser-unix.c to send some kind of out-of-band message to a
+specially-setup stub and have the switch happen "in between" packets, so
+that from remote protocol's point of view, nothing actually
+happened.}
+
+@item set breakpoint @strong{(deprecated)}
+@tab @code{B}@var{addr},@var{mode}
+@tab
+Set (@var{mode} is @samp{S}) or clear (@var{mode} is @samp{C}) a
+breakpoint at @var{addr}. @emph{This has been replaced by the @samp{Z} and
+@samp{z} packets.}
+
+@item continue
+@tab @code{c}@var{addr}
+@tab
+@var{addr} is address to resume. If @var{addr} is omitted, resume at
+current address.
+@item
+@tab reply
+@tab see below
+
+@item continue with signal @emph{(optional)}
+@tab @code{C}@var{sig}@code{;}@var{addr}
+@tab
+Continue with signal @var{sig} (hex signal number). If
+@code{;}@var{addr} is omitted, resume at same address.
+@item
+@tab reply
+@tab see below
+
+@item toggle debug @emph{(deprecated)}
+@tab @code{d}
+@tab
+toggle debug flag.
+
+@item detach @emph{(optional)}
+@tab @code{D}
+@tab
+Detach @value{GDBN} from the remote system. Sent to the remote target before
+@value{GDBN} disconnects.
+@item
+@tab reply @emph{no response}
+@tab
+@value{GDBN} does not check for any response after sending this packet
+
+@item reserved
+@tab @code{e}
+@tab Reserved for future use
+
+@item reserved
+@tab @code{E}
+@tab Reserved for future use
+
+@item reserved
+@tab @code{f}
+@tab Reserved for future use
+
+@item reserved
+@tab @code{F}
+@tab Reserved for future use
+
+@item read registers
+@tab @code{g}
+@tab Read general registers.
+@item
+@tab reply @var{XX...}
+@tab
+Each byte of register data is described by two hex digits. The bytes
+with the register are transmitted in target byte order. The size of
+each register and their position within the @samp{g} @var{packet} are
+determined by the @value{GDBN} internal macros @var{REGISTER_RAW_SIZE} and
+@var{REGISTER_NAME} macros. The specification of several standard
+@code{g} packets is specified below.
+@item
+@tab @code{E}@var{NN}
+@tab for an error.
+
+@item write regs
+@tab @code{G}@var{XX...}
+@tab
+See @samp{g} for a description of the @var{XX...} data.
+@item
+@tab reply @code{OK}
+@tab for success
+@item
+@tab reply @code{E}@var{NN}
+@tab for an error
+
+@item reserved
+@tab @code{h}
+@tab Reserved for future use
+
+@item set thread @emph{(optional)}
+@tab @code{H}@var{c}@var{t...}
+@tab
+Set thread for subsequent operations (@samp{m}, @samp{M}, @samp{g},
+@samp{G}, et.al.). @var{c} = @samp{c} for thread used in step and
+continue; @var{t...} can be -1 for all threads. @var{c} = @samp{g} for
+thread used in other operations. If zero, pick a thread, any thread.
+@item
+@tab reply @code{OK}
+@tab for success
+@item
+@tab reply @code{E}@var{NN}
+@tab for an error
+
+@c FIXME: JTC:
+@c 'H': How restrictive (or permissive) is the thread model. If a
+@c thread is selected and stopped, are other threads allowed
+@c to continue to execute? As I mentioned above, I think the
+@c semantics of each command when a thread is selected must be
+@c described. For example:
+@c
+@c 'g': If the stub supports threads and a specific thread is
+@c selected, returns the register block from that thread;
+@c otherwise returns current registers.
+@c
+@c 'G' If the stub supports threads and a specific thread is
+@c selected, sets the registers of the register block of
+@c that thread; otherwise sets current registers.
+
+@item cycle step @strong{(draft)} @emph{(optional)}
+@tab @code{i}@var{addr}@code{,}@var{nnn}
+@tab
+Step the remote target by a single clock cycle. If @code{,}@var{nnn} is
+present, cycle step @var{nnn} cycles. If @var{addr} is present, cycle
+step starting at that address.
+
+@item signal then cycle step @strong{(reserved)} @emph{(optional)}
+@tab @code{I}
+@tab
+See @samp{i} and @samp{S} for likely syntax and semantics.
+
+@item reserved
+@tab @code{j}
+@tab Reserved for future use
+
+@item reserved
+@tab @code{J}
+@tab Reserved for future use
+
+@item kill request @emph{(optional)}
+@tab @code{k}
+@tab
+FIXME: @emph{There is no description of how operate when a specific
+thread context has been selected (ie. does 'k' kill only that thread?)}.
+
+@item reserved
+@tab @code{l}
+@tab Reserved for future use
+
+@item reserved
+@tab @code{L}
+@tab Reserved for future use
+
+@item read memory
+@tab @code{m}@var{addr}@code{,}@var{length}
+@tab
+Read @var{length} bytes of memory starting at address @var{addr}.
+Neither @value{GDBN} nor the stub assume that sized memory transfers are assumed
+using word alligned accesses. FIXME: @emph{A word aligned memory
+transfer mechanism is needed.}
+@item
+@tab reply @var{XX...}
+@tab
+@var{XX...} is mem contents. Can be fewer bytes than requested if able
+to read only part of the data. Neither @value{GDBN} nor the stub assume that
+sized memory transfers are assumed using word alligned accesses. FIXME:
+@emph{A word aligned memory transfer mechanism is needed.}
+@item
+@tab reply @code{E}@var{NN}
+@tab @var{NN} is errno
+
+@item write mem
+@tab @code{M}@var{addr},@var{length}@code{:}@var{XX...}
+@tab
+Write @var{length} bytes of memory starting at address @var{addr}.
+@var{XX...} is the data.
+@item
+@tab reply @code{OK}
+@tab for success
+@item
+@tab reply @code{E}@var{NN}
+@tab
+for an error (this includes the case where only part of the data was
+written).
+
+@item reserved
+@tab @code{n}
+@tab Reserved for future use
+
+@item reserved
+@tab @code{N}
+@tab Reserved for future use
+
+@item reserved
+@tab @code{o}
+@tab Reserved for future use
+
+@item reserved
+@tab @code{O}
+@tab Reserved for future use
+
+@item read reg @strong{(reserved)}
+@tab @code{p}@var{n...}
+@tab
+See write register.
+@item
+@tab return @var{r....}
+@tab The hex encoded value of the register in target byte order.
+
+@item write reg @emph{(optional)}
+@tab @code{P}@var{n...}@code{=}@var{r...}
+@tab
+Write register @var{n...} with value @var{r...}, which contains two hex
+digits for each byte in the register (target byte order).
+@item
+@tab reply @code{OK}
+@tab for success
+@item
+@tab reply @code{E}@var{NN}
+@tab for an error
+
+@item general query @emph{(optional)}
+@tab @code{q}@var{query}
+@tab
+Request info about @var{query}. In general @value{GDBN} @var{query}'s
+have a leading upper case letter. Custom vendor queries should use a
+company prefix (in lower case) ex: @samp{qfsf.var}. @var{query} may
+optionally be followed by a @samp{,} or @samp{;} separated list. Stubs
+must ensure that they match the full @var{query} name.
+@item
+@tab reply @code{XX...}
+@tab Hex encoded data from query. The reply can not be empty.
+@item
+@tab reply @code{E}@var{NN}
+@tab error reply
+@item
+@tab reply @samp{}
+@tab Indicating an unrecognized @var{query}.
+
+@item general set @emph{(optional)}
+@tab @code{Q}@var{var}@code{=}@var{val}
+@tab
+Set value of @var{var} to @var{val}. See @samp{q} for a discussing of
+naming conventions.
+
+@item reset @emph{(deprecated)}
+@tab @code{r}
+@tab
+Reset the entire system.
+
+@item remote restart @emph{(optional)}
+@tab @code{R}@var{XX}
+@tab
+Restart the remote server. @var{XX} while needed has no clear
+definition. FIXME: @emph{An example interaction explaining how this
+packet is used in extended-remote mode is needed}.
+
+@item step @emph{(optional)}
+@tab @code{s}@var{addr}
+@tab
+@var{addr} is address to resume. If @var{addr} is omitted, resume at
+same address.
+@item
+@tab reply
+@tab see below
+
+@item step with signal @emph{(optional)}
+@tab @code{S}@var{sig}@code{;}@var{addr}
+@tab
+Like @samp{C} but step not continue.
+@item
+@tab reply
+@tab see below
+
+@item search @emph{(optional)}
+@tab @code{t}@var{addr}@code{:}@var{PP}@code{,}@var{MM}
+@tab
+Search backwards starting at address @var{addr} for a match with pattern
+@var{PP} and mask @var{MM}. @var{PP} and @var{MM} are 4
+bytes. @var{addr} must be at least 3 digits.
+
+@item thread alive @emph{(optional)}
+@tab @code{T}@var{XX}
+@tab Find out if the thread XX is alive.
+@item
+@tab reply @code{OK}
+@tab thread is still alive
+@item
+@tab reply @code{E}@var{NN}
+@tab thread is dead
+
+@item reserved
+@tab @code{u}
+@tab Reserved for future use
+
+@item reserved
+@tab @code{U}
+@tab Reserved for future use
+
+@item reserved
+@tab @code{v}
+@tab Reserved for future use
+
+@item reserved
+@tab @code{V}
+@tab Reserved for future use
+
+@item reserved
+@tab @code{w}
+@tab Reserved for future use
+
+@item reserved
+@tab @code{W}
+@tab Reserved for future use
+
+@item reserved
+@tab @code{x}
+@tab Reserved for future use
+
+@item write mem (binary) @emph{(optional)}
+@tab @code{X}@var{addr}@code{,}@var{length}@var{:}@var{XX...}
+@tab
+@var{addr} is address, @var{length} is number of bytes, @var{XX...} is
+binary data. The characters @code{$}, @code{#}, and @code{0x7d} are
+escaped using @code{0x7d}.
+@item
+@tab reply @code{OK}
+@tab for success
+@item
+@tab reply @code{E}@var{NN}
+@tab for an error
+
+@item reserved
+@tab @code{y}
+@tab Reserved for future use
+
+@item reserved
+@tab @code{Y}
+@tab Reserved for future use
+
+@item remove break or watchpoint @strong{(draft)} @emph{(optional)}
+@tab @code{z}@var{t}@code{,}@var{addr}@code{,}@var{length}
+@tab
+See @samp{Z}.
+
+@item insert break or watchpoint @strong{(draft)} @emph{(optional)}
+@tab @code{Z}@var{t}@code{,}@var{addr}@code{,}@var{length}
+@tab
+@var{t} is type: @samp{0} - software breakpoint, @samp{1} - hardware
+breakpoint, @samp{2} - write watchpoint, @samp{3} - read watchpoint,
+@samp{4} - access watchpoint; @var{addr} is address; @var{length} is in
+bytes. For a software breakpoint, @var{length} specifies the size of
+the instruction to be patched. For hardware breakpoints and watchpoints
+@var{length} specifies the memory region to be monitored. To avoid
+potential problems with duplicate packets, the operations should be
+implemented in an ident-potentent way.
+@item
+@tab reply @code{E}@var{NN}
+@tab for an error
+@item
+@tab reply @code{OK}
+@tab for success
+@item
+@tab @samp{}
+@tab If not supported.
+
+@item reserved
+@tab <other>
+@tab Reserved for future use
+
+@end multitable
+
+The @samp{C}, @samp{c}, @samp{S}, @samp{s} and @samp{?} packets can
+receive any of the below as a reply. In the case of the @samp{C},
+@samp{c}, @samp{S} and @samp{s} packets, that reply is only returned
+when the target halts. In the below the exact meaning of @samp{signal
+number} is poorly defined. In general one of the UNIX signal numbering
+conventions is used.
+
+@multitable @columnfractions .4 .6
+
+@item @code{S}@var{AA}
+@tab @var{AA} is the signal number
+
+@item @code{T}@var{AA}@var{n...}@code{:}@var{r...}@code{;}@var{n...}@code{:}@var{r...}@code{;}@var{n...}@code{:}@var{r...}@code{;}
+@tab
+@var{AA} = two hex digit signal number; @var{n...} = register number
+(hex), @var{r...} = target byte ordered register contents, size defined
+by @code{REGISTER_RAW_SIZE}; @var{n...} = @samp{thread}, @var{r...} =
+thread process ID, this is a hex integer; @var{n...} = other string not
+starting with valid hex digit. @value{GDBN} should ignore this
+@var{n...}, @var{r...} pair and go on to the next. This way we can
+extend the protocol.
+
+@item @code{W}@var{AA}
+@tab
+The process exited, and @var{AA} is the exit status. This is only
+applicable for certains sorts of targets.
+
+@item @code{X}@var{AA}
+@tab
+The process terminated with signal @var{AA}.
+
+@item @code{N}@var{AA}@code{;}@var{tttttttt}@code{;}@var{dddddddd}@code{;}@var{bbbbbbbb} @strong{(obsolete)}
+@tab
+@var{AA} = signal number; @var{tttttttt} = address of symbol "_start";
+@var{dddddddd} = base of data section; @var{bbbbbbbb} = base of bss
+section. @emph{Note: only used by Cisco Systems targets. The difference
+between this reply and the "qOffsets" query is that the 'N' packet may
+arrive spontaneously whereas the 'qOffsets' is a query initiated by the
+host debugger.}
+
+@item @code{O}@var{XX...}
+@tab
+@var{XX...} is hex encoding of @sc{ascii} data. This can happen at any time
+while the program is running and the debugger should continue to wait
+for 'W', 'T', etc.
+
+@end multitable
+
+The following set and query packets have already been defined.
+
+@multitable @columnfractions .2 .2 .6
+
+@item current thread
+@tab @code{q}@code{C}
+@tab Return the current thread id.
+@item
+@tab reply @code{QC}@var{pid}
+@tab
+Where @var{pid} is a HEX encoded 16 bit process id.
+@item
+@tab reply *
+@tab Any other reply implies the old pid.
+
+@item compute CRC of memory block
+@tab @code{q}@code{CRC:}@var{addr}@code{,}@var{length}
+@tab
+@item
+@tab reply @code{E}@var{NN}
+@tab An error (such as memory fault)
+@item
+@tab reply @code{C}@var{CRC32}
+@tab A 32 bit cyclic redundancy check of the specified memory region.
+
+@item query @var{LIST} or @var{threadLIST} @strong{(deprecated)}
+@tab @code{q}@code{L}@var{startflag}@var{threadcount}@var{nextthread}
+@tab
+Obtain thread information from RTOS. Where: @var{startflag} (one hex
+digit) is one to indicate the first query and zero to indicate a
+subsequent query; @var{threadcount} (two hex digits) is the maximum
+number of threads the response packet can contain; and @var{nextthread}
+(eight hex digits), for subsequent queries (@var{startflag} is zero), is
+returned in the response as @var{argthread}.
+@item
+@tab reply @code{q}@code{M}@var{count}@var{done}@var{argthread}@var{thread...}
+@tab
+Where: @var{count} (two hex digits) is the number of threads being
+returned; @var{done} (one hex digit) is zero to indicate more threads
+and one indicates no further threads; @var{argthreadid} (eight hex
+digits) is @var{nextthread} from the request packet; @var{thread...} is
+a sequence of thread IDs from the target. @var{threadid} (eight hex
+digits). See @code{remote.c:parse_threadlist_response()}.
+
+@item query sect offs
+@tab @code{q}@code{Offsets}
+@tab
+Get section offsets that the target used when re-locating the downloaded
+image. @emph{Note: while a @code{Bss} offset is included in the
+response, @value{GDBN} ignores this and instead applies the @code{Data}
+offset to the @code{Bss} section.}
+@item
+@tab reply @code{Text=}@var{xxx}@code{;Data=}@var{yyy}@code{;Bss=}@var{zzz}
+
+@item thread info request
+@tab @code{q}@code{P}@var{mode}@var{threadid}
+@tab
+Returns information on @var{threadid}. Where: @var{mode} is a hex
+encoded 32 bit mode; @var{threadid} is a hex encoded 64 bit thread ID.
+@item
+@tab reply *
+@tab
+See @code{remote.c:remote_unpack_thread_info_response()}.
+
+@item remote command
+@tab @code{q}@code{Rcmd,}@var{COMMAND}
+@tab
+@var{COMMAND} (hex encoded) is passed to the local interpreter for
+execution. Invalid commands should be reported using the output string.
+Before the final result packet, the target may also respond with a
+number of intermediate @code{O}@var{OUTPUT} console output
+packets. @emph{Implementors should note that providing access to a
+stubs's interpreter may have security implications}.
+@item
+@tab reply @code{OK}
+@tab
+A command response with no output.
+@item
+@tab reply @var{OUTPUT}
+@tab
+A command response with the hex encoded output string @var{OUTPUT}.
+@item
+@tab reply @code{E}@var{NN}
+@tab
+Indicate a badly formed request.
+
+@item
+@tab reply @samp{}
+@tab
+When @samp{q}@samp{Rcmd} is not recognized.
+
+@end multitable
+
+The following @samp{g}/@samp{G} packets have previously been defined.
+In the below, some thirty-two bit registers are transferred as sixty-four
+bits. Those registers should be zero/sign extended (which?) to fill the
+space allocated. Register bytes are transfered in target byte order.
+The two nibbles within a register byte are transfered most-significant -
+least-significant.
+
+@multitable @columnfractions .5 .5
+
+@item MIPS32
+@tab
+All registers are transfered as thirty-two bit quantities in the order:
+32 general-purpose; sr; lo; hi; bad; cause; pc; 32 floating-point
+registers; fsr; fir; fp.
+
+@item MIPS64
+@tab
+All registers are transfered as sixty-four bit quantities (including
+thirty-two bit registers such as @code{sr}). The ordering is the same
+as @code{MIPS32}.
+
+@end multitable
+
+Example sequence of a target being re-started. Notice how the restart
+does not get any direct output:
+
+@example
+<- @code{R00}
+-> @code{+}
+@emph{target restarts}
+<- @code{?}
+-> @code{+}
+-> @code{T001:1234123412341234}
+<- @code{+}
+@end example
+
+Example sequence of a target being stepped by a single instruction:
+
+@example
+<- @code{G1445...}
+-> @code{+}
+<- @code{s}
+-> @code{+}
+@emph{time passes}
+-> @code{T001:1234123412341234}
+<- @code{+}
+<- @code{g}
+-> @code{+}
+-> @code{1455...}
+<- @code{+}
+@end example
+
+@kindex set remotedebug@r{, serial protocol}
+@kindex show remotedebug@r{, serial protocol}
+@cindex packets, reporting on stdout
+@cindex serial connections, debugging
+If you have trouble with the serial connection, you can use the command
+@code{set remotedebug}. This makes @value{GDBN} report on all packets sent
+back and forth across the serial line to the remote machine. The
+packet-debugging information is printed on the @value{GDBN} standard output
+stream. @code{set remotedebug off} turns it off, and @code{show
+remotedebug} shows you its current state.
+
+@node Server
+@subsubsection Using the @code{gdbserver} program
+
+@kindex gdbserver
+@cindex remote connection without stubs
+@code{gdbserver} is a control program for Unix-like systems, which
+allows you to connect your program with a remote @value{GDBN} via
+@code{target remote}---but without linking in the usual debugging stub.
+
+@code{gdbserver} is not a complete replacement for the debugging stubs,
+because it requires essentially the same operating-system facilities
+that @value{GDBN} itself does. In fact, a system that can run
+@code{gdbserver} to connect to a remote @value{GDBN} could also run
+@value{GDBN} locally! @code{gdbserver} is sometimes useful nevertheless,
+because it is a much smaller program than @value{GDBN} itself. It is
+also easier to port than all of @value{GDBN}, so you may be able to get
+started more quickly on a new system by using @code{gdbserver}.
+Finally, if you develop code for real-time systems, you may find that
+the tradeoffs involved in real-time operation make it more convenient to
+do as much development work as possible on another system, for example
+by cross-compiling. You can use @code{gdbserver} to make a similar
+choice for debugging.
+
+@value{GDBN} and @code{gdbserver} communicate via either a serial line
+or a TCP connection, using the standard @value{GDBN} remote serial
+protocol.
+
+@table @emph
+@item On the target machine,
+you need to have a copy of the program you want to debug.
+@code{gdbserver} does not need your program's symbol table, so you can
+strip the program if necessary to save space. @value{GDBN} on the host
+system does all the symbol handling.
+
+To use the server, you must tell it how to communicate with @value{GDBN};
+the name of your program; and the arguments for your program. The
+syntax is:
+
+@smallexample
+target> gdbserver @var{comm} @var{program} [ @var{args} @dots{} ]
+@end smallexample
+
+@var{comm} is either a device name (to use a serial line) or a TCP
+hostname and portnumber. For example, to debug Emacs with the argument
+@samp{foo.txt} and communicate with @value{GDBN} over the serial port
+@file{/dev/com1}:
+
+@smallexample
+target> gdbserver /dev/com1 emacs foo.txt
+@end smallexample
+
+@code{gdbserver} waits passively for the host @value{GDBN} to communicate
+with it.
+
+To use a TCP connection instead of a serial line:
+
+@smallexample
+target> gdbserver host:2345 emacs foo.txt
+@end smallexample
+
+The only difference from the previous example is the first argument,
+specifying that you are communicating with the host @value{GDBN} via
+TCP. The @samp{host:2345} argument means that @code{gdbserver} is to
+expect a TCP connection from machine @samp{host} to local TCP port 2345.
+(Currently, the @samp{host} part is ignored.) You can choose any number
+you want for the port number as long as it does not conflict with any
+TCP ports already in use on the target system (for example, @code{23} is
+reserved for @code{telnet}).@footnote{If you choose a port number that
+conflicts with another service, @code{gdbserver} prints an error message
+and exits.} You must use the same port number with the host @value{GDBN}
+@code{target remote} command.
+
+@item On the @value{GDBN} host machine,
+you need an unstripped copy of your program, since @value{GDBN} needs
+symbols and debugging information. Start up @value{GDBN} as usual,
+using the name of the local copy of your program as the first argument.
+(You may also need the @w{@samp{--baud}} option if the serial line is
+running at anything other than 9600@dmn{bps}.) After that, use @code{target
+remote} to establish communications with @code{gdbserver}. Its argument
+is either a device name (usually a serial device, like
+@file{/dev/ttyb}), or a TCP port descriptor in the form
+@code{@var{host}:@var{PORT}}. For example:
+
+@smallexample
+(@value{GDBP}) target remote /dev/ttyb
+@end smallexample
+
+@noindent
+communicates with the server via serial line @file{/dev/ttyb}, and
+
+@smallexample
+(@value{GDBP}) target remote the-target:2345
+@end smallexample
+
+@noindent
+communicates via a TCP connection to port 2345 on host @w{@file{the-target}}.
+For TCP connections, you must start up @code{gdbserver} prior to using
+the @code{target remote} command. Otherwise you may get an error whose
+text depends on the host system, but which usually looks something like
+@samp{Connection refused}.
+@end table
+
+@node NetWare
+@subsubsection Using the @code{gdbserve.nlm} program
+
+@kindex gdbserve.nlm
+@code{gdbserve.nlm} is a control program for NetWare systems, which
+allows you to connect your program with a remote @value{GDBN} via
+@code{target remote}.
+
+@value{GDBN} and @code{gdbserve.nlm} communicate via a serial line,
+using the standard @value{GDBN} remote serial protocol.
+
+@table @emph
+@item On the target machine,
+you need to have a copy of the program you want to debug.
+@code{gdbserve.nlm} does not need your program's symbol table, so you
+can strip the program if necessary to save space. @value{GDBN} on the
+host system does all the symbol handling.
+
+To use the server, you must tell it how to communicate with
+@value{GDBN}; the name of your program; and the arguments for your
+program. The syntax is:
+
+@smallexample
+load gdbserve [ BOARD=@var{board} ] [ PORT=@var{port} ]
+ [ BAUD=@var{baud} ] @var{program} [ @var{args} @dots{} ]
+@end smallexample
+
+@var{board} and @var{port} specify the serial line; @var{baud} specifies
+the baud rate used by the connection. @var{port} and @var{node} default
+to 0, @var{baud} defaults to 9600@dmn{bps}.
+
+For example, to debug Emacs with the argument @samp{foo.txt}and
+communicate with @value{GDBN} over serial port number 2 or board 1
+using a 19200@dmn{bps} connection:
+
+@smallexample
+load gdbserve BOARD=1 PORT=2 BAUD=19200 emacs foo.txt
+@end smallexample
+
+@item On the @value{GDBN} host machine,
+you need an unstripped copy of your program, since @value{GDBN} needs
+symbols and debugging information. Start up @value{GDBN} as usual,
+using the name of the local copy of your program as the first argument.
+(You may also need the @w{@samp{--baud}} option if the serial line is
+running at anything other than 9600@dmn{bps}. After that, use @code{target
+remote} to establish communications with @code{gdbserve.nlm}. Its
+argument is a device name (usually a serial device, like
+@file{/dev/ttyb}). For example:
+
+@smallexample
+(@value{GDBP}) target remote /dev/ttyb
+@end smallexample
+
+@noindent
+communications with the server via serial line @file{/dev/ttyb}.
+@end table
+
+@node KOD
+@section Kernel Object Display
+
+@cindex kernel object display
+@cindex kernel object
+@cindex KOD
+
+Some targets support kernel object display. Using this facility,
+@value{GDBN} communicates specially with the underlying operating system
+and can display information about operating system-level objects such as
+mutexes and other synchronization objects. Exactly which objects can be
+displayed is determined on a per-OS basis.
+
+Use the @code{set os} command to set the operating system. This tells
+@value{GDBN} which kernel object display module to initialize:
+
+@example
+(@value{GDBP}) set os cisco
+@end example
+
+If @code{set os} succeeds, @value{GDBN} will display some information
+about the operating system, and will create a new @code{info} command
+which can be used to query the target. The @code{info} command is named
+after the operating system:
+
+@example
+(@value{GDBP}) info cisco
+List of Cisco Kernel Objects
+Object Description
+any Any and all objects
+@end example
+
+Further subcommands can be used to query about particular objects known
+by the kernel.
+
+There is currently no way to determine whether a given operating system
+is supported other than to try it.
+
+
+@node Configurations
+@chapter Configuration-Specific Information
+
+While nearly all @value{GDBN} commands are available for all native and
+cross versions of the debugger, there are some exceptions. This chapter
+describes things that are only available in certain configurations.
+
+There are three major categories of configurations: native
+configurations, where the host and target are the same, embedded
+operating system configurations, which are usually the same for several
+different processor architectures, and bare embedded processors, which
+are quite different from each other.
+
+@menu
+* Native::
+* Embedded OS::
+* Embedded Processors::
+* Architectures::
+@end menu
+
+@node Native
+@section Native
+
+This section describes details specific to particular native
+configurations.
+
+@menu
+* HP-UX:: HP-UX
+* SVR4 Process Information:: SVR4 process information
+@end menu
+
+@node HP-UX
+@subsection HP-UX
+
+On HP-UX systems, if you refer to a function or variable name that
+begins with a dollar sign, @value{GDBN} searches for a user or system
+name first, before it searches for a convenience variable.
+
+@node SVR4 Process Information
+@subsection SVR4 process information
+
+@kindex /proc
+@cindex process image
+
+Many versions of SVR4 provide a facility called @samp{/proc} that can be
+used to examine the image of a running process using file-system
+subroutines. If @value{GDBN} is configured for an operating system with
+this facility, the command @code{info proc} is available to report on
+several kinds of information about the process running your program.
+@code{info proc} works only on SVR4 systems that include the
+@code{procfs} code. This includes OSF/1 (Digital Unix), Solaris, Irix,
+and Unixware, but not HP-UX or Linux, for example.
+
+@table @code
+@kindex info proc
+@item info proc
+Summarize available information about the process.
+
+@kindex info proc mappings
+@item info proc mappings
+Report on the address ranges accessible in the program, with information
+on whether your program may read, write, or execute each range.
+
+@kindex info proc times
+@item info proc times
+Starting time, user CPU time, and system CPU time for your program and
+its children.
+
+@kindex info proc id
+@item info proc id
+Report on the process IDs related to your program: its own process ID,
+the ID of its parent, the process group ID, and the session ID.
+
+@kindex info proc status
+@item info proc status
+General information on the state of the process. If the process is
+stopped, this report includes the reason for stopping, and any signal
+received.
+
+@item info proc all
+Show all the above information about the process.
+@end table
+
+@node Embedded OS
+@section Embedded Operating Systems
+
+This section describes configurations involving the debugging of
+embedded operating systems that are available for several different
+architectures.
+
+@menu
+* VxWorks:: Using @value{GDBN} with VxWorks
+@end menu
+
+@value{GDBN} includes the ability to debug programs running on
+various real-time operating systems.
+
+@node VxWorks
+@subsection Using @value{GDBN} with VxWorks
+
+@cindex VxWorks
+
+@table @code
+
+@kindex target vxworks
+@item target vxworks @var{machinename}
+A VxWorks system, attached via TCP/IP. The argument @var{machinename}
+is the target system's machine name or IP address.
+
+@end table
+
+On VxWorks, @code{load} links @var{filename} dynamically on the
+current target system as well as adding its symbols in @value{GDBN}.
+
+@value{GDBN} enables developers to spawn and debug tasks running on networked
+VxWorks targets from a Unix host. Already-running tasks spawned from
+the VxWorks shell can also be debugged. @value{GDBN} uses code that runs on
+both the Unix host and on the VxWorks target. The program
+@code{@value{GDBP}} is installed and executed on the Unix host. (It may be
+installed with the name @code{vxgdb}, to distinguish it from a
+@value{GDB} for debugging programs on the host itself.)
+
+@table @code
+@item VxWorks-timeout @var{args}
+@kindex vxworks-timeout
+All VxWorks-based targets now support the option @code{vxworks-timeout}.
+This option is set by the user, and @var{args} represents the number of
+seconds @value{GDBN} waits for responses to rpc's. You might use this if
+your VxWorks target is a slow software simulator or is on the far side
+of a thin network line.
+@end table
+
+The following information on connecting to VxWorks was current when
+this manual was produced; newer releases of VxWorks may use revised
+procedures.
+
+@kindex INCLUDE_RDB
+To use @value{GDBN} with VxWorks, you must rebuild your VxWorks kernel
+to include the remote debugging interface routines in the VxWorks
+library @file{rdb.a}. To do this, define @code{INCLUDE_RDB} in the
+VxWorks configuration file @file{configAll.h} and rebuild your VxWorks
+kernel. The resulting kernel contains @file{rdb.a}, and spawns the
+source debugging task @code{tRdbTask} when VxWorks is booted. For more
+information on configuring and remaking VxWorks, see the manufacturer's
+manual.
+@c VxWorks, see the @cite{VxWorks Programmer's Guide}.
+
+Once you have included @file{rdb.a} in your VxWorks system image and set
+your Unix execution search path to find @value{GDBN}, you are ready to
+run @value{GDBN}. From your Unix host, run @code{@value{GDBP}} (or @code{vxgdb},
+depending on your installation).
+
+@value{GDBN} comes up showing the prompt:
+
+@example
+(vxgdb)
+@end example
+
+@menu
+* VxWorks Connection:: Connecting to VxWorks
+* VxWorks Download:: VxWorks download
+* VxWorks Attach:: Running tasks
+@end menu
+
+@node VxWorks Connection
+@subsubsection Connecting to VxWorks
+
+The @value{GDBN} command @code{target} lets you connect to a VxWorks target on the
+network. To connect to a target whose host name is ``@code{tt}'', type:
+
+@example
+(vxgdb) target vxworks tt
+@end example
+
+@need 750
+@value{GDBN} displays messages like these:
+
+@smallexample
+Attaching remote machine across net...
+Connected to tt.
+@end smallexample
+
+@need 1000
+@value{GDBN} then attempts to read the symbol tables of any object modules
+loaded into the VxWorks target since it was last booted. @value{GDBN} locates
+these files by searching the directories listed in the command search
+path (@pxref{Environment, ,Your program's environment}); if it fails
+to find an object file, it displays a message such as:
+
+@example
+prog.o: No such file or directory.
+@end example
+
+When this happens, add the appropriate directory to the search path with
+the @value{GDBN} command @code{path}, and execute the @code{target}
+command again.
+
+@node VxWorks Download
+@subsubsection VxWorks download
+
+@cindex download to VxWorks
+If you have connected to the VxWorks target and you want to debug an
+object that has not yet been loaded, you can use the @value{GDBN}
+@code{load} command to download a file from Unix to VxWorks
+incrementally. The object file given as an argument to the @code{load}
+command is actually opened twice: first by the VxWorks target in order
+to download the code, then by @value{GDBN} in order to read the symbol
+table. This can lead to problems if the current working directories on
+the two systems differ. If both systems have NFS mounted the same
+filesystems, you can avoid these problems by using absolute paths.
+Otherwise, it is simplest to set the working directory on both systems
+to the directory in which the object file resides, and then to reference
+the file by its name, without any path. For instance, a program
+@file{prog.o} may reside in @file{@var{vxpath}/vw/demo/rdb} in VxWorks
+and in @file{@var{hostpath}/vw/demo/rdb} on the host. To load this
+program, type this on VxWorks:
+
+@example
+-> cd "@var{vxpath}/vw/demo/rdb"
+@end example
+
+@noindent
+Then, in @value{GDBN}, type:
+
+@example
+(vxgdb) cd @var{hostpath}/vw/demo/rdb
+(vxgdb) load prog.o
+@end example
+
+@value{GDBN} displays a response similar to this:
+
+@smallexample
+Reading symbol data from wherever/vw/demo/rdb/prog.o... done.
+@end smallexample
+
+You can also use the @code{load} command to reload an object module
+after editing and recompiling the corresponding source file. Note that
+this makes @value{GDBN} delete all currently-defined breakpoints,
+auto-displays, and convenience variables, and to clear the value
+history. (This is necessary in order to preserve the integrity of
+debugger's data structures that reference the target system's symbol
+table.)
+
+@node VxWorks Attach
+@subsubsection Running tasks
+
+@cindex running VxWorks tasks
+You can also attach to an existing task using the @code{attach} command as
+follows:
+
+@example
+(vxgdb) attach @var{task}
+@end example
+
+@noindent
+where @var{task} is the VxWorks hexadecimal task ID. The task can be running
+or suspended when you attach to it. Running tasks are suspended at
+the time of attachment.
+
+@node Embedded Processors
+@section Embedded Processors
+
+This section goes into details specific to particular embedded
+configurations.
+
+@menu
+* A29K Embedded:: AMD A29K Embedded
+* ARM:: ARM
+* H8/300:: Hitachi H8/300
+* H8/500:: Hitachi H8/500
+* i960:: Intel i960
+* M32R/D:: Mitsubishi M32R/D
+* M68K:: Motorola M68K
+* M88K:: Motorola M88K
+* MIPS Embedded:: MIPS Embedded
+* PA:: HP PA Embedded
+* PowerPC: PowerPC
+* SH:: Hitachi SH
+* Sparclet:: Tsqware Sparclet
+* Sparclite:: Fujitsu Sparclite
+* ST2000:: Tandem ST2000
+* Z8000:: Zilog Z8000
+@end menu
+
+@node A29K Embedded
+@subsection AMD A29K Embedded
+
+@menu
+* A29K UDI::
+* A29K EB29K::
+* Comms (EB29K):: Communications setup
+* gdb-EB29K:: EB29K cross-debugging
+* Remote Log:: Remote log
+@end menu
+
+@table @code
+
+@kindex target adapt
+@item target adapt @var{dev}
+Adapt monitor for A29K.
+
+@kindex target amd-eb
+@item target amd-eb @var{dev} @var{speed} @var{PROG}
+@cindex AMD EB29K
+Remote PC-resident AMD EB29K board, attached over serial lines.
+@var{dev} is the serial device, as for @code{target remote};
+@var{speed} allows you to specify the linespeed; and @var{PROG} is the
+name of the program to be debugged, as it appears to DOS on the PC.
+@xref{A29K EB29K, ,EBMON protocol for AMD29K}.
+
+@end table
+
+@node A29K UDI
+@subsubsection A29K UDI
+
+@cindex UDI
+@cindex AMD29K via UDI
+
+@value{GDBN} supports AMD's UDI (``Universal Debugger Interface'')
+protocol for debugging the a29k processor family. To use this
+configuration with AMD targets running the MiniMON monitor, you need the
+program @code{MONTIP}, available from AMD at no charge. You can also
+use @value{GDBN} with the UDI-conformant a29k simulator program
+@code{ISSTIP}, also available from AMD.
+
+@table @code
+@item target udi @var{keyword}
+@kindex udi
+Select the UDI interface to a remote a29k board or simulator, where
+@var{keyword} is an entry in the AMD configuration file @file{udi_soc}.
+This file contains keyword entries which specify parameters used to
+connect to a29k targets. If the @file{udi_soc} file is not in your
+working directory, you must set the environment variable @samp{UDICONF}
+to its pathname.
+@end table
+
+@node A29K EB29K
+@subsubsection EBMON protocol for AMD29K
+
+@cindex EB29K board
+@cindex running 29K programs
+
+AMD distributes a 29K development board meant to fit in a PC, together
+with a DOS-hosted monitor program called @code{EBMON}. As a shorthand
+term, this development system is called the ``EB29K''. To use
+@value{GDBN} from a Unix system to run programs on the EB29K board, you
+must first connect a serial cable between the PC (which hosts the EB29K
+board) and a serial port on the Unix system. In the following, we
+assume you've hooked the cable between the PC's @file{COM1} port and
+@file{/dev/ttya} on the Unix system.
+
+@node Comms (EB29K)
+@subsubsection Communications setup
+
+The next step is to set up the PC's port, by doing something like this
+in DOS on the PC:
+
+@example
+C:\> MODE com1:9600,n,8,1,none
+@end example
+
+@noindent
+This example---run on an MS DOS 4.0 system---sets the PC port to 9600
+bps, no parity, eight data bits, one stop bit, and no ``retry'' action;
+you must match the communications parameters when establishing the Unix
+end of the connection as well.
+@c FIXME: Who knows what this "no retry action" crud from the DOS manual may
+@c mean? It's optional; leave it out? ---doc@cygnus.com, 25feb91
+@c
+@c It's optional, but it's unwise to omit it: who knows what is the
+@c default value set when the DOS machines boots? "No retry" means that
+@c the DOS serial device driver won't retry the operation if it fails;
+@c I understand that this is needed because the GDB serial protocol
+@c handles any errors and retransmissions itself. ---Eli Zaretskii, 3sep99
+
+To give control of the PC to the Unix side of the serial line, type
+the following at the DOS console:
+
+@example
+C:\> CTTY com1
+@end example
+
+@noindent
+(Later, if you wish to return control to the DOS console, you can use
+the command @code{CTTY con}---but you must send it over the device that
+had control, in our example over the @file{COM1} serial line).
+
+From the Unix host, use a communications program such as @code{tip} or
+@code{cu} to communicate with the PC; for example,
+
+@example
+cu -s 9600 -l /dev/ttya
+@end example
+
+@noindent
+The @code{cu} options shown specify, respectively, the linespeed and the
+serial port to use. If you use @code{tip} instead, your command line
+may look something like the following:
+
+@example
+tip -9600 /dev/ttya
+@end example
+
+@noindent
+Your system may require a different name where we show
+@file{/dev/ttya} as the argument to @code{tip}. The communications
+parameters, including which port to use, are associated with the
+@code{tip} argument in the ``remote'' descriptions file---normally the
+system table @file{/etc/remote}.
+@c FIXME: What if anything needs doing to match the "n,8,1,none" part of
+@c the DOS side's comms setup? cu can support -o (odd
+@c parity), -e (even parity)---apparently no settings for no parity or
+@c for character size. Taken from stty maybe...? John points out tip
+@c can set these as internal variables, eg ~s parity=none; man stty
+@c suggests that it *might* work to stty these options with stdin or
+@c stdout redirected... ---doc@cygnus.com, 25feb91
+@c
+@c There's nothing to be done for the "none" part of the DOS MODE
+@c command. The rest of the parameters should be matched by the
+@c baudrate, bits, and parity used by the Unix side. ---Eli Zaretskii, 3Sep99
+
+@kindex EBMON
+Using the @code{tip} or @code{cu} connection, change the DOS working
+directory to the directory containing a copy of your 29K program, then
+start the PC program @code{EBMON} (an EB29K control program supplied
+with your board by AMD). You should see an initial display from
+@code{EBMON} similar to the one that follows, ending with the
+@code{EBMON} prompt @samp{#}---
+
+@example
+C:\> G:
+
+G:\> CD \usr\joe\work29k
+
+G:\USR\JOE\WORK29K> EBMON
+Am29000 PC Coprocessor Board Monitor, version 3.0-18
+Copyright 1990 Advanced Micro Devices, Inc.
+Written by Gibbons and Associates, Inc.
+
+Enter '?' or 'H' for help
+
+PC Coprocessor Type = EB29K
+I/O Base = 0x208
+Memory Base = 0xd0000
+
+Data Memory Size = 2048KB
+Available I-RAM Range = 0x8000 to 0x1fffff
+Available D-RAM Range = 0x80002000 to 0x801fffff
+
+PageSize = 0x400
+Register Stack Size = 0x800
+Memory Stack Size = 0x1800
+
+CPU PRL = 0x3
+Am29027 Available = No
+Byte Write Available = Yes
+
+# ~.
+@end example
+
+Then exit the @code{cu} or @code{tip} program (done in the example by
+typing @code{~.} at the @code{EBMON} prompt). @code{EBMON} keeps
+running, ready for @value{GDBN} to take over.
+
+For this example, we've assumed what is probably the most convenient
+way to make sure the same 29K program is on both the PC and the Unix
+system: a PC/NFS connection that establishes ``drive @file{G:}'' on the
+PC as a file system on the Unix host. If you do not have PC/NFS or
+something similar connecting the two systems, you must arrange some
+other way---perhaps floppy-disk transfer---of getting the 29K program
+from the Unix system to the PC; @value{GDBN} does @emph{not} download it over the
+serial line.
+
+@node gdb-EB29K
+@subsubsection EB29K cross-debugging
+
+Finally, @code{cd} to the directory containing an image of your 29K
+program on the Unix system, and start @value{GDBN}---specifying as argument the
+name of your 29K program:
+
+@example
+cd /usr/joe/work29k
+@value{GDBP} myfoo
+@end example
+
+@need 500
+Now you can use the @code{target} command:
+
+@example
+target amd-eb /dev/ttya 9600 MYFOO
+@c FIXME: test above 'target amd-eb' as spelled, with caps! caps are meant to
+@c emphasize that this is the name as seen by DOS (since I think DOS is
+@c single-minded about case of letters). ---doc@cygnus.com, 25feb91
+@end example
+
+@noindent
+In this example, we've assumed your program is in a file called
+@file{myfoo}. Note that the filename given as the last argument to
+@code{target amd-eb} should be the name of the program as it appears to DOS.
+In our example this is simply @code{MYFOO}, but in general it can include
+a DOS path, and depending on your transfer mechanism may not resemble
+the name on the Unix side.
+
+At this point, you can set any breakpoints you wish; when you are ready
+to see your program run on the 29K board, use the @value{GDBN} command
+@code{run}.
+
+To stop debugging the remote program, use the @value{GDBN} @code{detach}
+command.
+
+To return control of the PC to its console, use @code{tip} or @code{cu}
+once again, after your @value{GDBN} session has concluded, to attach to
+@code{EBMON}. You can then type the command @code{q} to shut down
+@code{EBMON}, returning control to the DOS command-line interpreter.
+Type @kbd{CTTY con} to return command input to the main DOS console,
+and type @kbd{~.} to leave @code{tip} or @code{cu}.
+
+@node Remote Log
+@subsubsection Remote log
+@kindex eb.log
+@cindex log file for EB29K
+
+The @code{target amd-eb} command creates a file @file{eb.log} in the
+current working directory, to help debug problems with the connection.
+@file{eb.log} records all the output from @code{EBMON}, including echoes
+of the commands sent to it. Running @samp{tail -f} on this file in
+another window often helps to understand trouble with @code{EBMON}, or
+unexpected events on the PC side of the connection.
+
+@node ARM
+@subsection ARM
+
+@table @code
+
+@kindex target rdi
+@item target rdi @var{dev}
+ARM Angel monitor, via RDI library interface to ADP protocol. You may
+use this target to communicate with both boards running the Angel
+monitor, or with the EmbeddedICE JTAG debug device.
+
+@kindex target rdp
+@item target rdp @var{dev}
+ARM Demon monitor.
+
+@end table
+
+@node H8/300
+@subsection Hitachi H8/300
+
+@table @code
+
+@kindex target hms@r{, with H8/300}
+@item target hms @var{dev}
+A Hitachi SH, H8/300, or H8/500 board, attached via serial line to your host.
+Use special commands @code{device} and @code{speed} to control the serial
+line and the communications speed used.
+
+@kindex target e7000@r{, with H8/300}
+@item target e7000 @var{dev}
+E7000 emulator for Hitachi H8 and SH.
+
+@kindex target sh3@r{, with H8/300}
+@kindex target sh3e@r{, with H8/300}
+@item target sh3 @var{dev}
+@item target sh3e @var{dev}
+Hitachi SH-3 and SH-3E target systems.
+
+@end table
+
+@cindex download to H8/300 or H8/500
+@cindex H8/300 or H8/500 download
+@cindex download to Hitachi SH
+@cindex Hitachi SH download
+When you select remote debugging to a Hitachi SH, H8/300, or H8/500
+board, the @code{load} command downloads your program to the Hitachi
+board and also opens it as the current executable target for
+@value{GDBN} on your host (like the @code{file} command).
+
+@value{GDBN} needs to know these things to talk to your
+Hitachi SH, H8/300, or H8/500:
+
+@enumerate
+@item
+that you want to use @samp{target hms}, the remote debugging interface
+for Hitachi microprocessors, or @samp{target e7000}, the in-circuit
+emulator for the Hitachi SH and the Hitachi 300H. (@samp{target hms} is
+the default when @value{GDBN} is configured specifically for the Hitachi SH,
+H8/300, or H8/500.)
+
+@item
+what serial device connects your host to your Hitachi board (the first
+serial device available on your host is the default).
+
+@item
+what speed to use over the serial device.
+@end enumerate
+
+@menu
+* Hitachi Boards:: Connecting to Hitachi boards.
+* Hitachi ICE:: Using the E7000 In-Circuit Emulator.
+* Hitachi Special:: Special @value{GDBN} commands for Hitachi micros.
+@end menu
+
+@node Hitachi Boards
+@subsubsection Connecting to Hitachi boards
+
+@c only for Unix hosts
+@kindex device
+@cindex serial device, Hitachi micros
+Use the special @code{@value{GDBP}} command @samp{device @var{port}} if you
+need to explicitly set the serial device. The default @var{port} is the
+first available port on your host. This is only necessary on Unix
+hosts, where it is typically something like @file{/dev/ttya}.
+
+@kindex speed
+@cindex serial line speed, Hitachi micros
+@code{@value{GDBP}} has another special command to set the communications
+speed: @samp{speed @var{bps}}. This command also is only used from Unix
+hosts; on DOS hosts, set the line speed as usual from outside @value{GDBN} with
+the DOS @code{mode} command (for instance,
+@w{@kbd{mode com2:9600,n,8,1,p}} for a 9600@dmn{bps} connection).
+
+The @samp{device} and @samp{speed} commands are available only when you
+use a Unix host to debug your Hitachi microprocessor programs. If you
+use a DOS host,
+@value{GDBN} depends on an auxiliary terminate-and-stay-resident program
+called @code{asynctsr} to communicate with the development board
+through a PC serial port. You must also use the DOS @code{mode} command
+to set up the serial port on the DOS side.
+
+The following sample session illustrates the steps needed to start a
+program under @value{GDBN} control on an H8/300. The example uses a
+sample H8/300 program called @file{t.x}. The procedure is the same for
+the Hitachi SH and the H8/500.
+
+First hook up your development board. In this example, we use a
+board attached to serial port @code{COM2}; if you use a different serial
+port, substitute its name in the argument of the @code{mode} command.
+When you call @code{asynctsr}, the auxiliary comms program used by the
+debugger, you give it just the numeric part of the serial port's name;
+for example, @samp{asyncstr 2} below runs @code{asyncstr} on
+@code{COM2}.
+
+@example
+C:\H8300\TEST> asynctsr 2
+C:\H8300\TEST> mode com2:9600,n,8,1,p
+
+Resident portion of MODE loaded
+
+COM2: 9600, n, 8, 1, p
+
+@end example
+
+@quotation
+@emph{Warning:} We have noticed a bug in PC-NFS that conflicts with
+@code{asynctsr}. If you also run PC-NFS on your DOS host, you may need to
+disable it, or even boot without it, to use @code{asynctsr} to control
+your development board.
+@end quotation
+
+@kindex target hms@r{, and serial protocol}
+Now that serial communications are set up, and the development board is
+connected, you can start up @value{GDBN}. Call @code{@value{GDBP}} with
+the name of your program as the argument. @code{@value{GDBP}} prompts
+you, as usual, with the prompt @samp{(@value{GDBP})}. Use two special
+commands to begin your debugging session: @samp{target hms} to specify
+cross-debugging to the Hitachi board, and the @code{load} command to
+download your program to the board. @code{load} displays the names of
+the program's sections, and a @samp{*} for each 2K of data downloaded.
+(If you want to refresh @value{GDBN} data on symbols or on the
+executable file without downloading, use the @value{GDBN} commands
+@code{file} or @code{symbol-file}. These commands, and @code{load}
+itself, are described in @ref{Files,,Commands to specify files}.)
+
+@smallexample
+(eg-C:\H8300\TEST) @value{GDBP} t.x
+@value{GDBN} is free software and you are welcome to distribute copies
+ of it under certain conditions; type "show copying" to see
+ the conditions.
+There is absolutely no warranty for @value{GDBN}; type "show warranty"
+for details.
+@value{GDBN} @value{GDBVN}, Copyright 1992 Free Software Foundation, Inc...
+(@value{GDBP}) target hms
+Connected to remote H8/300 HMS system.
+(@value{GDBP}) load t.x
+.text : 0x8000 .. 0xabde ***********
+.data : 0xabde .. 0xad30 *
+.stack : 0xf000 .. 0xf014 *
+@end smallexample
+
+At this point, you're ready to run or debug your program. From here on,
+you can use all the usual @value{GDBN} commands. The @code{break} command
+sets breakpoints; the @code{run} command starts your program;
+@code{print} or @code{x} display data; the @code{continue} command
+resumes execution after stopping at a breakpoint. You can use the
+@code{help} command at any time to find out more about @value{GDBN} commands.
+
+Remember, however, that @emph{operating system} facilities aren't
+available on your development board; for example, if your program hangs,
+you can't send an interrupt---but you can press the @sc{reset} switch!
+
+Use the @sc{reset} button on the development board
+@itemize @bullet
+@item
+to interrupt your program (don't use @kbd{ctl-C} on the DOS host---it has
+no way to pass an interrupt signal to the development board); and
+
+@item
+to return to the @value{GDBN} command prompt after your program finishes
+normally. The communications protocol provides no other way for @value{GDBN}
+to detect program completion.
+@end itemize
+
+In either case, @value{GDBN} sees the effect of a @sc{reset} on the
+development board as a ``normal exit'' of your program.
+
+@node Hitachi ICE
+@subsubsection Using the E7000 in-circuit emulator
+
+@kindex target e7000@r{, with Hitachi ICE}
+You can use the E7000 in-circuit emulator to develop code for either the
+Hitachi SH or the H8/300H. Use one of these forms of the @samp{target
+e7000} command to connect @value{GDBN} to your E7000:
+
+@table @code
+@item target e7000 @var{port} @var{speed}
+Use this form if your E7000 is connected to a serial port. The
+@var{port} argument identifies what serial port to use (for example,
+@samp{com2}). The third argument is the line speed in bits per second
+(for example, @samp{9600}).
+
+@item target e7000 @var{hostname}
+If your E7000 is installed as a host on a TCP/IP network, you can just
+specify its hostname; @value{GDBN} uses @code{telnet} to connect.
+@end table
+
+@node Hitachi Special
+@subsubsection Special @value{GDBN} commands for Hitachi micros
+
+Some @value{GDBN} commands are available only for the H8/300:
+
+@table @code
+
+@kindex set machine
+@kindex show machine
+@item set machine h8300
+@itemx set machine h8300h
+Condition @value{GDBN} for one of the two variants of the H8/300
+architecture with @samp{set machine}. You can use @samp{show machine}
+to check which variant is currently in effect.
+
+@end table
+
+@node H8/500
+@subsection H8/500
+
+@table @code
+
+@kindex set memory @var{mod}
+@cindex memory models, H8/500
+@item set memory @var{mod}
+@itemx show memory
+Specify which H8/500 memory model (@var{mod}) you are using with
+@samp{set memory}; check which memory model is in effect with @samp{show
+memory}. The accepted values for @var{mod} are @code{small},
+@code{big}, @code{medium}, and @code{compact}.
+
+@end table
+
+@node i960
+@subsection Intel i960
+
+@table @code
+
+@kindex target mon960
+@item target mon960 @var{dev}
+MON960 monitor for Intel i960.
+
+@item target nindy @var{devicename}
+An Intel 960 board controlled by a Nindy Monitor. @var{devicename} is
+the name of the serial device to use for the connection, e.g.
+@file{/dev/ttya}.
+
+@end table
+
+@cindex Nindy
+@cindex i960
+@dfn{Nindy} is a ROM Monitor program for Intel 960 target systems. When
+@value{GDBN} is configured to control a remote Intel 960 using Nindy, you can
+tell @value{GDBN} how to connect to the 960 in several ways:
+
+@itemize @bullet
+@item
+Through command line options specifying serial port, version of the
+Nindy protocol, and communications speed;
+
+@item
+By responding to a prompt on startup;
+
+@item
+By using the @code{target} command at any point during your @value{GDBN}
+session. @xref{Target Commands, ,Commands for managing targets}.
+
+@kindex target nindy
+@item target nindy @var{devicename}
+An Intel 960 board controlled by a Nindy Monitor. @var{devicename} is
+the name of the serial device to use for the connection, e.g.
+@file{/dev/ttya}.
+
+@end itemize
+
+@cindex download to Nindy-960
+With the Nindy interface to an Intel 960 board, @code{load}
+downloads @var{filename} to the 960 as well as adding its symbols in
+@value{GDBN}.
+
+@menu
+* Nindy Startup:: Startup with Nindy
+* Nindy Options:: Options for Nindy
+* Nindy Reset:: Nindy reset command
+@end menu
+
+@node Nindy Startup
+@subsubsection Startup with Nindy
+
+If you simply start @code{@value{GDBP}} without using any command-line
+options, you are prompted for what serial port to use, @emph{before} you
+reach the ordinary @value{GDBN} prompt:
+
+@example
+Attach /dev/ttyNN -- specify NN, or "quit" to quit:
+@end example
+
+@noindent
+Respond to the prompt with whatever suffix (after @samp{/dev/tty})
+identifies the serial port you want to use. You can, if you choose,
+simply start up with no Nindy connection by responding to the prompt
+with an empty line. If you do this and later wish to attach to Nindy,
+use @code{target} (@pxref{Target Commands, ,Commands for managing targets}).
+
+@node Nindy Options
+@subsubsection Options for Nindy
+
+These are the startup options for beginning your @value{GDBN} session with a
+Nindy-960 board attached:
+
+@table @code
+@item -r @var{port}
+Specify the serial port name of a serial interface to be used to connect
+to the target system. This option is only available when @value{GDBN} is
+configured for the Intel 960 target architecture. You may specify
+@var{port} as any of: a full pathname (e.g. @samp{-r /dev/ttya}), a
+device name in @file{/dev} (e.g. @samp{-r ttya}), or simply the unique
+suffix for a specific @code{tty} (e.g. @samp{-r a}).
+
+@item -O
+(An uppercase letter ``O'', not a zero.) Specify that @value{GDBN} should use
+the ``old'' Nindy monitor protocol to connect to the target system.
+This option is only available when @value{GDBN} is configured for the Intel 960
+target architecture.
+
+@quotation
+@emph{Warning:} if you specify @samp{-O}, but are actually trying to
+connect to a target system that expects the newer protocol, the connection
+fails, appearing to be a speed mismatch. @value{GDBN} repeatedly
+attempts to reconnect at several different line speeds. You can abort
+this process with an interrupt.
+@end quotation
+
+@item -brk
+Specify that @value{GDBN} should first send a @code{BREAK} signal to the target
+system, in an attempt to reset it, before connecting to a Nindy target.
+
+@quotation
+@emph{Warning:} Many target systems do not have the hardware that this
+requires; it only works with a few boards.
+@end quotation
+@end table
+
+The standard @samp{-b} option controls the line speed used on the serial
+port.
+
+@c @group
+@node Nindy Reset
+@subsubsection Nindy reset command
+
+@table @code
+@item reset
+@kindex reset
+For a Nindy target, this command sends a ``break'' to the remote target
+system; this is only useful if the target has been equipped with a
+circuit to perform a hard reset (or some other interesting action) when
+a break is detected.
+@end table
+@c @end group
+
+@node M32R/D
+@subsection Mitsubishi M32R/D
+
+@table @code
+
+@kindex target m32r
+@item target m32r @var{dev}
+Mitsubishi M32R/D ROM monitor.
+
+@end table
+
+@node M68K
+@subsection M68k
+
+The Motorola m68k configuration includes ColdFire support, and
+target command for the following ROM monitors.
+
+@table @code
+
+@kindex target abug
+@item target abug @var{dev}
+ABug ROM monitor for M68K.
+
+@kindex target cpu32bug
+@item target cpu32bug @var{dev}
+CPU32BUG monitor, running on a CPU32 (M68K) board.
+
+@kindex target dbug
+@item target dbug @var{dev}
+dBUG ROM monitor for Motorola ColdFire.
+
+@kindex target est
+@item target est @var{dev}
+EST-300 ICE monitor, running on a CPU32 (M68K) board.
+
+@kindex target rom68k
+@item target rom68k @var{dev}
+ROM 68K monitor, running on an M68K IDP board.
+
+@end table
+
+If @value{GDBN} is configured with @code{m68*-ericsson-*}, it will
+instead have only a single special target command:
+
+@table @code
+
+@kindex target es1800
+@item target es1800 @var{dev}
+ES-1800 emulator for M68K.
+
+@end table
+
+[context?]
+
+@table @code
+
+@kindex target rombug
+@item target rombug @var{dev}
+ROMBUG ROM monitor for OS/9000.
+
+@end table
+
+@node M88K
+@subsection M88K
+
+@table @code
+
+@kindex target bug
+@item target bug @var{dev}
+BUG monitor, running on a MVME187 (m88k) board.
+
+@end table
+
+@node MIPS Embedded
+@subsection MIPS Embedded
+
+@cindex MIPS boards
+@value{GDBN} can use the MIPS remote debugging protocol to talk to a
+MIPS board attached to a serial line. This is available when
+you configure @value{GDBN} with @samp{--target=mips-idt-ecoff}.
+
+@need 1000
+Use these @value{GDBN} commands to specify the connection to your target board:
+
+@table @code
+@item target mips @var{port}
+@kindex target mips @var{port}
+To run a program on the board, start up @code{@value{GDBP}} with the
+name of your program as the argument. To connect to the board, use the
+command @samp{target mips @var{port}}, where @var{port} is the name of
+the serial port connected to the board. If the program has not already
+been downloaded to the board, you may use the @code{load} command to
+download it. You can then use all the usual @value{GDBN} commands.
+
+For example, this sequence connects to the target board through a serial
+port, and loads and runs a program called @var{prog} through the
+debugger:
+
+@example
+host$ @value{GDBP} @var{prog}
+@value{GDBN} is free software and @dots{}
+(@value{GDBP}) target mips /dev/ttyb
+(@value{GDBP}) load @var{prog}
+(@value{GDBP}) run
+@end example
+
+@item target mips @var{hostname}:@var{portnumber}
+On some @value{GDBN} host configurations, you can specify a TCP
+connection (for instance, to a serial line managed by a terminal
+concentrator) instead of a serial port, using the syntax
+@samp{@var{hostname}:@var{portnumber}}.
+
+@item target pmon @var{port}
+@kindex target pmon @var{port}
+PMON ROM monitor.
+
+@item target ddb @var{port}
+@kindex target ddb @var{port}
+NEC's DDB variant of PMON for Vr4300.
+
+@item target lsi @var{port}
+@kindex target lsi @var{port}
+LSI variant of PMON.
+
+@kindex target r3900
+@item target r3900 @var{dev}
+Densan DVE-R3900 ROM monitor for Toshiba R3900 Mips.
+
+@kindex target array
+@item target array @var{dev}
+Array Tech LSI33K RAID controller board.
+
+@end table
+
+
+@noindent
+@value{GDBN} also supports these special commands for MIPS targets:
+
+@table @code
+@item set processor @var{args}
+@itemx show processor
+@kindex set processor @var{args}
+@kindex show processor
+Use the @code{set processor} command to set the type of MIPS
+processor when you want to access processor-type-specific registers.
+For example, @code{set processor @var{r3041}} tells @value{GDBN}
+to use the CPO registers appropriate for the 3041 chip.
+Use the @code{show processor} command to see what MIPS processor @value{GDBN}
+is using. Use the @code{info reg} command to see what registers
+@value{GDBN} is using.
+
+@item set mipsfpu double
+@itemx set mipsfpu single
+@itemx set mipsfpu none
+@itemx show mipsfpu
+@kindex set mipsfpu
+@kindex show mipsfpu
+@cindex MIPS remote floating point
+@cindex floating point, MIPS remote
+If your target board does not support the MIPS floating point
+coprocessor, you should use the command @samp{set mipsfpu none} (if you
+need this, you may wish to put the command in your @value{GDBINIT}
+file). This tells @value{GDBN} how to find the return value of
+functions which return floating point values. It also allows
+@value{GDBN} to avoid saving the floating point registers when calling
+functions on the board. If you are using a floating point coprocessor
+with only single precision floating point support, as on the @sc{r4650}
+processor, use the command @samp{set mipsfpu single}. The default
+double precision floating point coprocessor may be selected using
+@samp{set mipsfpu double}.
+
+In previous versions the only choices were double precision or no
+floating point, so @samp{set mipsfpu on} will select double precision
+and @samp{set mipsfpu off} will select no floating point.
+
+As usual, you can inquire about the @code{mipsfpu} variable with
+@samp{show mipsfpu}.
+
+@item set remotedebug @var{n}
+@itemx show remotedebug
+@kindex set remotedebug@r{, MIPS protocol}
+@kindex show remotedebug@r{, MIPS protocol}
+@cindex @code{remotedebug}, MIPS protocol
+@cindex MIPS @code{remotedebug} protocol
+@c FIXME! For this to be useful, you must know something about the MIPS
+@c FIXME...protocol. Where is it described?
+You can see some debugging information about communications with the board
+by setting the @code{remotedebug} variable. If you set it to @code{1} using
+@samp{set remotedebug 1}, every packet is displayed. If you set it
+to @code{2}, every character is displayed. You can check the current value
+at any time with the command @samp{show remotedebug}.
+
+@item set timeout @var{seconds}
+@itemx set retransmit-timeout @var{seconds}
+@itemx show timeout
+@itemx show retransmit-timeout
+@cindex @code{timeout}, MIPS protocol
+@cindex @code{retransmit-timeout}, MIPS protocol
+@kindex set timeout
+@kindex show timeout
+@kindex set retransmit-timeout
+@kindex show retransmit-timeout
+You can control the timeout used while waiting for a packet, in the MIPS
+remote protocol, with the @code{set timeout @var{seconds}} command. The
+default is 5 seconds. Similarly, you can control the timeout used while
+waiting for an acknowledgement of a packet with the @code{set
+retransmit-timeout @var{seconds}} command. The default is 3 seconds.
+You can inspect both values with @code{show timeout} and @code{show
+retransmit-timeout}. (These commands are @emph{only} available when
+@value{GDBN} is configured for @samp{--target=mips-idt-ecoff}.)
+
+The timeout set by @code{set timeout} does not apply when @value{GDBN}
+is waiting for your program to stop. In that case, @value{GDBN} waits
+forever because it has no way of knowing how long the program is going
+to run before stopping.
+@end table
+
+@node PowerPC
+@subsection PowerPC
+
+@table @code
+
+@kindex target dink32
+@item target dink32 @var{dev}
+DINK32 ROM monitor.
+
+@kindex target ppcbug
+@item target ppcbug @var{dev}
+@kindex target ppcbug1
+@item target ppcbug1 @var{dev}
+PPCBUG ROM monitor for PowerPC.
+
+@kindex target sds
+@item target sds @var{dev}
+SDS monitor, running on a PowerPC board (such as Motorola's ADS).
+
+@end table
+
+@node PA
+@subsection HP PA Embedded
+
+@table @code
+
+@kindex target op50n
+@item target op50n @var{dev}
+OP50N monitor, running on an OKI HPPA board.
+
+@kindex target w89k
+@item target w89k @var{dev}
+W89K monitor, running on a Winbond HPPA board.
+
+@end table
+
+@node SH
+@subsection Hitachi SH
+
+@table @code
+
+@kindex target hms@r{, with Hitachi SH}
+@item target hms @var{dev}
+A Hitachi SH board attached via serial line to your host. Use special
+commands @code{device} and @code{speed} to control the serial line and
+the communications speed used.
+
+@kindex target e7000@r{, with Hitachi SH}
+@item target e7000 @var{dev}
+E7000 emulator for Hitachi SH.
+
+@kindex target sh3@r{, with SH}
+@kindex target sh3e@r{, with SH}
+@item target sh3 @var{dev}
+@item target sh3e @var{dev}
+Hitachi SH-3 and SH-3E target systems.
+
+@end table
+
+@node Sparclet
+@subsection Tsqware Sparclet
+
+@cindex Sparclet
+
+@value{GDBN} enables developers to debug tasks running on
+Sparclet targets from a Unix host.
+@value{GDBN} uses code that runs on
+both the Unix host and on the Sparclet target. The program
+@code{@value{GDBP}} is installed and executed on the Unix host.
+
+@table @code
+@item timeout @var{args}
+@kindex remotetimeout
+@value{GDBN} supports the option @code{remotetimeout}.
+This option is set by the user, and @var{args} represents the number of
+seconds @value{GDBN} waits for responses.
+@end table
+
+@kindex Compiling
+When compiling for debugging, include the options @samp{-g} to get debug
+information and @samp{-Ttext} to relocate the program to where you wish to
+load it on the target. You may also want to add the options @samp{-n} or
+@samp{-N} in order to reduce the size of the sections. Example:
+
+@example
+sparclet-aout-gcc prog.c -Ttext 0x12010000 -g -o prog -N
+@end example
+
+You can use @code{objdump} to verify that the addresses are what you intended:
+
+@example
+sparclet-aout-objdump --headers --syms prog
+@end example
+
+@kindex Running
+Once you have set
+your Unix execution search path to find @value{GDBN}, you are ready to
+run @value{GDBN}. From your Unix host, run @code{@value{GDBP}}
+(or @code{sparclet-aout-gdb}, depending on your installation).
+
+@value{GDBN} comes up showing the prompt:
+
+@example
+(gdbslet)
+@end example
+
+@menu
+* Sparclet File:: Setting the file to debug
+* Sparclet Connection:: Connecting to Sparclet
+* Sparclet Download:: Sparclet download
+* Sparclet Execution:: Running and debugging
+@end menu
+
+@node Sparclet File
+@subsubsection Setting file to debug
+
+The @value{GDBN} command @code{file} lets you choose with program to debug.
+
+@example
+(gdbslet) file prog
+@end example
+
+@need 1000
+@value{GDBN} then attempts to read the symbol table of @file{prog}.
+@value{GDBN} locates
+the file by searching the directories listed in the command search
+path.
+If the file was compiled with debug information (option "-g"), source
+files will be searched as well.
+@value{GDBN} locates
+the source files by searching the directories listed in the directory search
+path (@pxref{Environment, ,Your program's environment}).
+If it fails
+to find a file, it displays a message such as:
+
+@example
+prog: No such file or directory.
+@end example
+
+When this happens, add the appropriate directories to the search paths with
+the @value{GDBN} commands @code{path} and @code{dir}, and execute the
+@code{target} command again.
+
+@node Sparclet Connection
+@subsubsection Connecting to Sparclet
+
+The @value{GDBN} command @code{target} lets you connect to a Sparclet target.
+To connect to a target on serial port ``@code{ttya}'', type:
+
+@example
+(gdbslet) target sparclet /dev/ttya
+Remote target sparclet connected to /dev/ttya
+main () at ../prog.c:3
+@end example
+
+@need 750
+@value{GDBN} displays messages like these:
+
+@example
+Connected to ttya.
+@end example
-@node Targets
-@chapter Specifying a Debugging Target
-@cindex debugging target
-@kindex target
+@node Sparclet Download
+@subsubsection Sparclet download
-A @dfn{target} is the execution environment occupied by your program.
-@ifclear BARETARGET
-Often, @value{GDBN} runs in the same host environment as your program; in
-that case, the debugging target is specified as a side effect when you
-use the @code{file} or @code{core} commands. When you need more
-flexibility---for example, running @value{GDBN} on a physically separate
-host, or controlling a standalone system over a serial port or a
-realtime system over a TCP/IP connection---you
-@end ifclear
-@ifset BARETARGET
-You
-@end ifset
-can use the @code{target} command to specify one of the target types
-configured for @value{GDBN} (@pxref{Target Commands, ,Commands for managing
-targets}).
+@cindex download to Sparclet
+Once connected to the Sparclet target,
+you can use the @value{GDBN}
+@code{load} command to download the file from the host to the target.
+The file name and load offset should be given as arguments to the @code{load}
+command.
+Since the file format is aout, the program must be loaded to the starting
+address. You can use @code{objdump} to find out what this value is. The load
+offset is an offset which is added to the VMA (virtual memory address)
+of each of the file's sections.
+For instance, if the program
+@file{prog} was linked to text address 0x1201000, with data at 0x12010160
+and bss at 0x12010170, in @value{GDBN}, type:
-@menu
-* Active Targets:: Active targets
-* Target Commands:: Commands for managing targets
-* Remote:: Remote debugging
-@end menu
+@example
+(gdbslet) load prog 0x12010000
+Loading section .text, size 0xdb0 vma 0x12010000
+@end example
-@node Active Targets
-@section Active targets
-@cindex stacking targets
-@cindex active targets
-@cindex multiple targets
+If the code is loaded at a different address then what the program was linked
+to, you may need to use the @code{section} and @code{add-symbol-file} commands
+to tell @value{GDBN} where to map the symbol table.
-@ifclear BARETARGET
-There are three classes of targets: processes, core files, and
-executable files. @value{GDBN} can work concurrently on up to three active
-targets, one in each class. This allows you to (for example) start a
-process and inspect its activity without abandoning your work on a core
-file.
+@node Sparclet Execution
+@subsubsection Running and debugging
-For example, if you execute @samp{gdb a.out}, then the executable file
-@code{a.out} is the only active target. If you designate a core file as
-well---presumably from a prior run that crashed and coredumped---then
-@value{GDBN} has two active targets and uses them in tandem, looking
-first in the corefile target, then in the executable file, to satisfy
-requests for memory addresses. (Typically, these two classes of target
-are complementary, since core files contain only a program's
-read-write memory---variables and so on---plus machine status, while
-executable files contain only the program text and initialized data.)
-@end ifclear
+@cindex running and debugging Sparclet programs
+You can now begin debugging the task using @value{GDBN}'s execution control
+commands, @code{b}, @code{step}, @code{run}, etc. See the @value{GDBN}
+manual for the list of commands.
-When you type @code{run}, your executable file becomes an active process
-target as well. When a process target is active, all @value{GDBN} commands
-requesting memory addresses refer to that target; addresses in an
-@ifclear BARETARGET
-active core file or
-@end ifclear
-executable file target are obscured while the process
-target is active.
-
-@ifset BARETARGET
-Use the @code{exec-file} command to select a
-new executable target (@pxref{Files, ,Commands to specify
-files}).
-@end ifset
-@ifclear BARETARGET
-Use the @code{core-file} and @code{exec-file} commands to select a
-new core file or executable target (@pxref{Files, ,Commands to specify
-files}). To specify as a target a process that is already running, use
-the @code{attach} command (@pxref{Attach, ,Debugging an
-already-running process}).
-@end ifclear
+@example
+(gdbslet) b main
+Breakpoint 1 at 0x12010000: file prog.c, line 3.
+(gdbslet) run
+Starting program: prog
+Breakpoint 1, main (argc=1, argv=0xeffff21c) at prog.c:3
+3 char *symarg = 0;
+(gdbslet) step
+4 char *execarg = "hello!";
+(gdbslet)
+@end example
-@node Target Commands
-@section Commands for managing targets
+@node Sparclite
+@subsection Fujitsu Sparclite
@table @code
-@item target @var{type} @var{parameters}
-Connects the @value{GDBN} host environment to a target
-@ifset BARETARGET
-machine.
-@end ifset
-@ifclear BARETARGET
-machine or process. A target is typically a protocol for talking to
-debugging facilities. You use the argument @var{type} to specify the
-type or protocol of the target machine.
-Further @var{parameters} are interpreted by the target protocol, but
-typically include things like device names or host names to connect
-with, process numbers, and baud rates.
-@end ifclear
+@kindex target sparclite
+@item target sparclite @var{dev}
+Fujitsu sparclite boards, used only for the purpose of loading.
+You must use an additional command to debug the program.
+For example: target remote @var{dev} using @value{GDBN} standard
+remote protocol.
-The @code{target} command does not repeat if you press @key{RET} again
-after executing the command.
+@end table
-@kindex help target
-@item help target
-Displays the names of all targets available. To display targets
-currently selected, use either @code{info target} or @code{info files}
-(@pxref{Files, ,Commands to specify files}).
+@node ST2000
+@subsection Tandem ST2000
-@item help target @var{name}
-Describe a particular target, including any parameters necessary to
-select it.
+@value{GDBN} may be used with a Tandem ST2000 phone switch, running Tandem's
+STDBUG protocol.
-@kindex set gnutarget
-@item set gnutarget @var{args}
-@value{GDBN}uses its own library BFD to read your files. @value{GDBN}
-knows whether it is reading an @dfn{executable},
-a @dfn{core}, or a @dfn{.o} file, however you can specify the file format
-with the @code{set gnutarget} command. Unlike most @code{target} commands,
-with @code{gnutarget} the @code{target} refers to a program, not a machine.
+To connect your ST2000 to the host system, see the manufacturer's
+manual. Once the ST2000 is physically attached, you can run:
-@emph{Warning:} To specify a file format with @code{set gnutarget},
-you must know the actual BFD name.
+@example
+target st2000 @var{dev} @var{speed}
+@end example
-@noindent @xref{Files, , Commands to specify files}.
+@noindent
+to establish it as your debugging environment. @var{dev} is normally
+the name of a serial device, such as @file{/dev/ttya}, connected to the
+ST2000 via a serial line. You can instead specify @var{dev} as a TCP
+connection (for example, to a serial line attached via a terminal
+concentrator) using the syntax @code{@var{hostname}:@var{portnumber}}.
+
+The @code{load} and @code{attach} commands are @emph{not} defined for
+this target; you must load your program into the ST2000 as you normally
+would for standalone operation. @value{GDBN} reads debugging information
+(such as symbols) from a separate, debugging version of the program
+available on your host computer.
+@c FIXME!! This is terribly vague; what little content is here is
+@c basically hearsay.
+
+@cindex ST2000 auxiliary commands
+These auxiliary @value{GDBN} commands are available to help you with the ST2000
+environment:
-@kindex show gnutarget
-@item show gnutarget
-Use the @code{show gnutarget} command to display what file format
-@code{gnutarget} is set to read. If you have not set @code{gnutarget},
-@value{GDBN} will determine the file format for each file automatically
-and @code{show gnutarget} displays @code{The current BDF target is "auto"}.
+@table @code
+@item st2000 @var{command}
+@kindex st2000 @var{cmd}
+@cindex STDBUG commands (ST2000)
+@cindex commands to STDBUG (ST2000)
+Send a @var{command} to the STDBUG monitor. See the manufacturer's
+manual for available commands.
+
+@item connect
+@cindex connect (to STDBUG)
+Connect the controlling terminal to the STDBUG command monitor. When
+you are done interacting with STDBUG, typing either of two character
+sequences gets you back to the @value{GDBN} command prompt:
+@kbd{@key{RET}~.} (Return, followed by tilde and period) or
+@kbd{@key{RET}~@key{C-d}} (Return, followed by tilde and control-D).
@end table
-Here are some common targets (available, or not, depending on the GDB
-configuration):
+@node Z8000
+@subsection Zilog Z8000
+
+@cindex Z8000
+@cindex simulator, Z8000
+@cindex Zilog Z8000 simulator
+
+When configured for debugging Zilog Z8000 targets, @value{GDBN} includes
+a Z8000 simulator.
+
+For the Z8000 family, @samp{target sim} simulates either the Z8002 (the
+unsegmented variant of the Z8000 architecture) or the Z8001 (the
+segmented variant). The simulator recognizes which architecture is
+appropriate by inspecting the object code.
@table @code
-@kindex target exec
-@item target exec @var{program}
-An executable file. @samp{target exec @var{program}} is the same as
-@samp{exec-file @var{program}}.
+@item target sim @var{args}
+@kindex sim
+@kindex target sim@r{, with Z8000}
+Debug programs on a simulated CPU. If the simulator supports setup
+options, specify them via @var{args}.
+@end table
-@ifclear BARETARGET
-@kindex target core
-@item target core @var{filename}
-A core dump file. @samp{target core @var{filename}} is the same as
-@samp{core-file @var{filename}}.
-@end ifclear
+@noindent
+After specifying this target, you can debug programs for the simulated
+CPU in the same style as programs for your host computer; use the
+@code{file} command to load a new program image, the @code{run} command
+to run your program, and so on.
-@ifset REMOTESTUB
-@kindex target remote
-@item target remote @var{dev}
-Remote serial target in GDB-specific protocol. The argument @var{dev}
-specifies what serial device to use for the connection (e.g.
-@file{/dev/ttya}). @xref{Remote, ,Remote debugging}. @code{target remote}
-now supports the @code{load} command. This is only useful if you have
-some other way of getting the stub to the target system, and you can put
-it somewhere in memory where it won't get clobbered by the download.
-@end ifset
+As well as making available all the usual machine registers
+(@pxref{Registers, ,Registers}), the Z8000 simulator provides three
+additional items of information as specially named registers:
-@ifset SIMS
-@kindex target sim
-@item target sim
-CPU simulator. @xref{Simulator,,Simulated CPU Target}.
-@end ifset
+@table @code
-@ifset AMD29K
-@kindex target udi
-@item target udi @var{keyword}
-Remote AMD29K target, using the AMD UDI protocol. The @var{keyword}
-argument specifies which 29K board or simulator to use. @xref{UDI29K
-Remote,,The UDI protocol for AMD29K}.
+@item cycles
+Counts clock-ticks in the simulator.
-@kindex target amd-eb
-@item target amd-eb @var{dev} @var{speed} @var{PROG}
-@cindex AMD EB29K
-Remote PC-resident AMD EB29K board, attached over serial lines.
-@var{dev} is the serial device, as for @code{target remote};
-@var{speed} allows you to specify the linespeed; and @var{PROG} is the
-name of the program to be debugged, as it appears to DOS on the PC.
-@xref{EB29K Remote, ,The EBMON protocol for AMD29K}.
+@item insts
+Counts instructions run in the simulator.
-@end ifset
-@ifset H8
-@kindex target hms
-@item target hms @var{dev}
-A Hitachi SH, H8/300, or H8/500 board, attached via serial line to your host.
-@ifclear H8EXCLUSIVE
-Use special commands @code{device} and @code{speed} to control the serial
-line and the communications speed used.
-@end ifclear
-@xref{Hitachi Remote,,@value{GDBN} and Hitachi Microprocessors}.
+@item time
+Execution time in 60ths of a second.
-@end ifset
-@ifset I960
-@kindex target nindy
-@item target nindy @var{devicename}
-An Intel 960 board controlled by a Nindy Monitor. @var{devicename} is
-the name of the serial device to use for the connection, e.g.
-@file{/dev/ttya}. @xref{i960-Nindy Remote, ,@value{GDBN} with a remote i960 (Nindy)}.
+@end table
-@end ifset
-@ifset ST2000
-@kindex target st2000
-@item target st2000 @var{dev} @var{speed}
-A Tandem ST2000 phone switch, running Tandem's STDBUG protocol. @var{dev}
-is the name of the device attached to the ST2000 serial line;
-@var{speed} is the communication line speed. The arguments are not used
-if @value{GDBN} is configured to connect to the ST2000 using TCP or Telnet.
-@xref{ST2000 Remote,,@value{GDBN} with a Tandem ST2000}.
-@end ifset
+You can refer to these values in @value{GDBN} expressions with the usual
+conventions; for example, @w{@samp{b fputc if $cycles>5000}} sets a
+conditional breakpoint that suspends only after at least 5000
+simulated clock ticks.
-@ifset VXWORKS
-@kindex target vxworks
-@item target vxworks @var{machinename}
-A VxWorks system, attached via TCP/IP. The argument @var{machinename}
-is the target system's machine name or IP address.
-@xref{VxWorks Remote, ,@value{GDBN} and VxWorks}.
-@end ifset
+@node Architectures
+@section Architectures
-@kindex target cpu32bug
-@item target cpu32bug @var{dev}
-CPU32BUG monitor, running on a CPU32 (M68K) board.
+This section describes characteristics of architectures that affect
+all uses of @value{GDBN} with the architecture, both native and cross.
-@kindex target op50n
-@item target op50n @var{dev}
-OP50N monitor, running on an OKI HPPA board.
+@menu
+* A29K::
+* Alpha::
+* MIPS::
+@end menu
-@kindex target w89k
-@item target w89k @var{dev}
-W89K monitor, running on a Winbond HPPA board.
+@node A29K
+@subsection A29K
-@kindex target est
-@item target est @var{dev}
-EST-300 ICE monitor, running on a CPU32 (M68K) board.
+@table @code
-@kindex target rom68k
-@item target rom68k @var{dev}
-ROM 68K monitor, running on an IDP board.
+@kindex set rstack_high_address
+@cindex AMD 29K register stack
+@cindex register stack, AMD29K
+@item set rstack_high_address @var{address}
+On AMD 29000 family processors, registers are saved in a separate
+@dfn{register stack}. There is no way for @value{GDBN} to determine the
+extent of this stack. Normally, @value{GDBN} just assumes that the
+stack is ``large enough''. This may result in @value{GDBN} referencing
+memory locations that do not exist. If necessary, you can get around
+this problem by specifying the ending address of the register stack with
+the @code{set rstack_high_address} command. The argument should be an
+address, which you probably want to precede with @samp{0x} to specify in
+hexadecimal.
-@kindex target array
-@item target array @var{dev}
-Array Tech LSI33K RAID controller board.
+@kindex show rstack_high_address
+@item show rstack_high_address
+Display the current limit of the register stack, on AMD 29000 family
+processors.
-@kindex target sparclite
-@item target sparclite @var{dev}
-Fujitsu sparclite boards, used only for the purpose of loading.
-You must use an additional command to debug the program.
-For example: target remote @var{dev} using @value{GDBN} standard
-remote protocol.
@end table
-@ifset GENERIC
-Different targets are available on different configurations of @value{GDBN};
-your configuration may have more or fewer targets.
-@end ifset
+@node Alpha
+@subsection Alpha
-@section Choosing target byte order
-@cindex choosing target byte order
-@cindex target byte order
-@kindex set endian big
-@kindex set endian little
-@kindex set endian auto
-@kindex show endian
+See the following section.
-You can now choose which byte order to use with a target system.
-Use the @code{set endian big} and @code{set endian little} commands.
-Use the @code{set endian auto} command to instruct
-@value{GDBN} to use the byte order associated with the executable.
-You can see the current setting for byte order with the @code{show endian}
-command.
-
-@emph{Warning:} Currently, only embedded MIPS configurations support
-dynamic selection of target byte order.
+@node MIPS
+@subsection MIPS
-@node Remote
-@section Remote debugging
-@cindex remote debugging
+@cindex stack on Alpha
+@cindex stack on MIPS
+@cindex Alpha stack
+@cindex MIPS stack
+Alpha- and MIPS-based computers use an unusual stack frame, which
+sometimes requires @value{GDBN} to search backward in the object code to
+find the beginning of a function.
-If you are trying to debug a program running on a machine that cannot run
-@value{GDBN} in the usual way, it is often useful to use remote debugging.
-For example, you might use remote debugging on an operating system kernel,
-or on a small system which does not have a general purpose operating system
-powerful enough to run a full-featured debugger.
+@cindex response time, MIPS debugging
+To improve response time (especially for embedded applications, where
+@value{GDBN} may be restricted to a slow serial line for this search)
+you may want to limit the size of this search, using one of these
+commands:
-Some configurations of @value{GDBN} have special serial or TCP/IP interfaces
-to make this work with particular debugging targets. In addition,
-@value{GDBN} comes with a generic serial protocol (specific to @value{GDBN},
-but not specific to any particular target system) which you can use if you
-write the remote stubs---the code that runs on the remote system to
-communicate with @value{GDBN}.
+@table @code
+@cindex @code{heuristic-fence-post} (Alpha,MIPS)
+@item set heuristic-fence-post @var{limit}
+Restrict @value{GDBN} to examining at most @var{limit} bytes in its
+search for the beginning of a function. A value of @var{0} (the
+default) means there is no limit. However, except for @var{0}, the
+larger the limit the more bytes @code{heuristic-fence-post} must search
+and therefore the longer it takes to run.
-Other remote targets may be available in your
-configuration of @value{GDBN}; use @code{help target} to list them.
+@item show heuristic-fence-post
+Display the current limit.
+@end table
-@ifset GENERIC
-@c Text on starting up GDB in various specific cases; it goes up front
-@c in manuals configured for any of those particular situations, here
-@c otherwise.
-@menu
-@ifset REMOTESTUB
-* Remote Serial:: @value{GDBN} remote serial protocol
-@end ifset
-@ifset I960
-* i960-Nindy Remote:: @value{GDBN} with a remote i960 (Nindy)
-@end ifset
-@ifset AMD29K
-* UDI29K Remote:: The UDI protocol for AMD29K
-* EB29K Remote:: The EBMON protocol for AMD29K
-@end ifset
-@ifset VXWORKS
-* VxWorks Remote:: @value{GDBN} and VxWorks
-@end ifset
-@ifset ST2000
-* ST2000 Remote:: @value{GDBN} with a Tandem ST2000
-@end ifset
-@ifset H8
-* Hitachi Remote:: @value{GDBN} and Hitachi Microprocessors
-@end ifset
-@ifset MIPS
-* MIPS Remote:: @value{GDBN} and MIPS boards
-@end ifset
-@ifset SIMS
-* Simulator:: Simulated CPU target
-@end ifset
-@end menu
+@noindent
+These commands are available @emph{only} when @value{GDBN} is configured
+for debugging programs on Alpha or MIPS processors.
-@include remote.texi
-@end ifset
@node Controlling GDB
@chapter Controlling @value{GDBN}
-You can alter the way @value{GDBN} interacts with you by using
-the @code{set} command. For commands controlling how @value{GDBN} displays
-data, @pxref{Print Settings, ,Print settings}; other settings are described
-here.
+You can alter the way @value{GDBN} interacts with you by using the
+@code{set} command. For commands controlling how @value{GDBN} displays
+data, see @ref{Print Settings, ,Print settings}. Other settings are
+described here.
@menu
* Prompt:: Prompt
the prompt in one of the @value{GDBN} sessions so that you can always tell
which one you are talking to.
-@emph{Note:} @code{set prompt} no longer adds a space for you after the
+@emph{Note:} @code{set prompt} does not add a space for you after the
prompt you set. This allows you to set a prompt which ends in a space
or a prompt that does not.
exits. You can access this list through history expansion or through
the history command editing characters listed below. This file defaults
to the value of the environment variable @code{GDBHISTFILE}, or to
-@file{./.gdb_history} if this variable is not set.
+@file{./.gdb_history} (@file{./_gdb_history} on MS-DOS) if this variable
+is not set.
@cindex history save
@kindex set history save
printed, @value{GDBN} tries to break the line at a readable place,
rather than simply letting it overflow onto the following line.
-Normally @value{GDBN} knows the size of the screen from the termcap data base
+Normally @value{GDBN} knows the size of the screen from the terminal
+driver software. For example, on Unix @value{GDBN} uses the termcap data base
together with the value of the @code{TERM} environment variable and the
-@code{stty rows} and @code{stty cols} settings. If this is not correct,
+@code{stty rows} and @code{stty cols} settings. If this is not correct,
you can override it with the @code{set height} and @code{set
width} commands:
@cindex number representation
@cindex entering numbers
-You can always enter numbers in octal, decimal, or hexadecimal in @value{GDBN} by
-the usual conventions: octal numbers begin with @samp{0}, decimal
-numbers end with @samp{.}, and hexadecimal numbers begin with @samp{0x}.
-Numbers that begin with none of these are, by default, entered in base
-10; likewise, the default display for numbers---when no particular
-format is specified---is base 10. You can change the default base for
-both input and output with the @code{set radix} command.
+You can always enter numbers in octal, decimal, or hexadecimal in
+@value{GDBN} by the usual conventions: octal numbers begin with
+@samp{0}, decimal numbers end with @samp{.}, and hexadecimal numbers
+begin with @samp{0x}. Numbers that begin with none of these are, by
+default, entered in base 10; likewise, the default display for
+numbers---when no particular format is specified---is base 10. You can
+change the default base for both input and output with the @code{set
+radix} command.
@table @code
@kindex set input-radix
@node Messages/Warnings
@section Optional warnings and messages
-By default, @value{GDBN} is silent about its inner workings. If you are running
-on a slow machine, you may want to use the @code{set verbose} command.
-This makes @value{GDBN} tell you when it does a lengthy internal operation, so
-you will not think it has crashed.
+By default, @value{GDBN} is silent about its inner workings. If you are
+running on a slow machine, you may want to use the @code{set verbose}
+command. This makes @value{GDBN} tell you when it does a lengthy
+internal operation, so you will not think it has crashed.
Currently, the messages controlled by @code{set verbose} are those
which announce that the symbol table for a source file is being read;
Displays whether @code{set verbose} is on or off.
@end table
-By default, if @value{GDBN} encounters bugs in the symbol table of an object
-file, it is silent; but if you are debugging a compiler, you may find
-this information useful (@pxref{Symbol Errors, ,Errors reading symbol files}).
+By default, if @value{GDBN} encounters bugs in the symbol table of an
+object file, it is silent; but if you are debugging a compiler, you may
+find this information useful (@pxref{Symbol Errors, ,Errors reading
+symbol files}).
@table @code
+
@kindex set complaints
@item set complaints @var{limit}
-Permits @value{GDBN} to output @var{limit} complaints about each type of unusual
-symbols before becoming silent about the problem. Set @var{limit} to
-zero to suppress all complaints; set it to a large number to prevent
-complaints from being suppressed.
+Permits @value{GDBN} to output @var{limit} complaints about each type of
+unusual symbols before becoming silent about the problem. Set
+@var{limit} to zero to suppress all complaints; set it to a large number
+to prevent complaints from being suppressed.
@kindex show complaints
@item show complaints
Displays how many symbol complaints @value{GDBN} is permitted to produce.
+
@end table
By default, @value{GDBN} is cautious, and asks what sometimes seems to be a
commands, you can disable this ``feature'':
@table @code
+
@kindex set confirm
@cindex flinching
@cindex confirmation
@kindex show confirm
@item show confirm
Displays state of confirmation requests.
+
@end table
@node Sequences
@chapter Canned Sequences of Commands
Aside from breakpoint commands (@pxref{Break Commands, ,Breakpoint
-command lists}), @value{GDBN} provides two ways to store sequences of commands
-for execution as a unit: user-defined commands and command files.
+command lists}), @value{GDBN} provides two ways to store sequences of
+commands for execution as a unit: user-defined commands and command
+files.
@menu
* Define:: User-defined commands
-* Hooks:: User-defined command hooks
+* Hooks:: User-defined command hooks
* Command Files:: Command files
* Output:: Commands for controlled output
@end menu
@section User-defined commands
@cindex user-defined command
-A @dfn{user-defined command} is a sequence of @value{GDBN} commands to which
-you assign a new name as a command. This is done with the @code{define}
-command. User commands may accept up to 10 arguments separated by whitespace.
-Arguments are accessed within the user command via @var{$arg0@dots{}$arg9}.
-A trivial example:
+A @dfn{user-defined command} is a sequence of @value{GDBN} commands to
+which you assign a new name as a command. This is done with the
+@code{define} command. User commands may accept up to 10 arguments
+separated by whitespace. Arguments are accessed within the user command
+via @var{$arg0@dots{}$arg9}. A trivial example:
@smallexample
define adder
print $arg0 + $arg1 + $arg2
@end smallexample
-@noindent To execute the command use:
+@noindent
+To execute the command use:
@smallexample
adder 1 2 3
@end smallexample
-@noindent This defines the command @code{adder}, which prints the sum of
+@noindent
+This defines the command @code{adder}, which prints the sum of
its three arguments. Note the arguments are text substitutions, so they may
reference variables, use complex expressions, or even perform inferior
functions calls.
@table @code
+
@kindex define
@item define @var{commandname}
Define a command named @var{commandname}. If there is already a command
@kindex show user
@item show user
@itemx show user @var{commandname}
-Display the @value{GDBN} commands used to define @var{commandname} (but not its
-documentation). If no @var{commandname} is given, display the
+Display the @value{GDBN} commands used to define @var{commandname} (but
+not its documentation). If no @var{commandname} is given, display the
definitions for all user-defined commands.
+
@end table
When user-defined commands are executed, the
@node Hooks
@section User-defined command hooks
-@cindex command files
+@cindex command hooks
+@cindex hooks, for commands
You may define @emph{hooks}, which are a special kind of user-defined
command. Whenever you run the command @samp{foo}, if the user-defined
command @samp{hook-foo} exists, it is executed (with no arguments)
before that command.
+@kindex stop@r{, a pseudo-command}
In addition, a pseudo-command, @samp{stop} exists. Defining
(@samp{hook-stop}) makes the associated commands execute every time
execution stops in your program: before breakpoint commands are run,
displays are printed, or the stack frame is printed.
-@ifclear BARETARGET
For example, to ignore @code{SIGALRM} signals while
single-stepping, but treat them normally during normal execution,
you could define:
handle SIGLARM pass
end
@end example
-@end ifclear
You can define a hook for any single-word command in @value{GDBN}, but
not for command aliases; you should define a hook for the basic command
the last command, as it would from the terminal.
@cindex init file
-@cindex @file{@value{GDBINIT}}
+@cindex @file{.gdbinit}
+@cindex @file{gdb.ini}
When you start @value{GDBN}, it automatically executes commands from its
-@dfn{init files}. These are files named @file{@value{GDBINIT}}.
-@value{GDBN} reads the init file (if any) in your home directory, then
-processes command line options and operands, and then reads the init
-file (if any) in the current working directory. This is so the init
-file in your home directory can set options (such as @code{set
-complaints}) which affect the processing of the command line options and
-operands. The init files are not executed if you use the @samp{-nx}
-option; @pxref{Mode Options, ,Choosing modes}.
-
-@ifset GENERIC
+@dfn{init files}. These are files named @file{.gdbinit} on Unix, or
+@file{gdb.ini} on DOS/Windows. @value{GDBN} reads the init file (if
+any) in your home directory@footnote{On DOS/Windows systems, the home
+directory is the one pointed to by the @code{HOME} environment
+variable.}, then processes command line options and operands, and then
+reads the init file (if any) in the current working directory. This is
+so the init file in your home directory can set options (such as
+@code{set complaints}) which affect the processing of the command line
+options and operands. The init files are not executed if you use the
+@samp{-nx} option; @pxref{Mode Options, ,Choosing modes}.
+
@cindex init file name
On some configurations of @value{GDBN}, the init file is known by a
different name (these are typically environments where a specialized
-form of @value{GDBN} may need to coexist with other forms,
-hence a different name
-for the specialized version's init file). These are the environments
-with special init file names:
+form of @value{GDBN} may need to coexist with other forms, hence a
+different name for the specialized version's init file). These are the
+environments with special init file names:
@kindex .vxgdbinit
@itemize @bullet
@item
ES-1800 (Ericsson Telecom AB M68000 emulator): @samp{.esgdbinit}
@end itemize
-@end ifset
You can also request the execution of a command file with the
@code{source} command:
either numbers or pointers. Their values are printed as specified by
@var{string}, exactly as if your program were to execute the C
subroutine
+@c FIXME: the above implies that at least all ANSI C formats are
+@c supported, but it isn't true: %E and %G don't work (or so it seems).
+@c Either this is a bug, or the manual should document what formats are
+@c supported.
@example
printf (@var{string}, @var{expressions}@dots{});
letter.
@end table
-@ifclear DOSHOST
@node Emacs
@chapter Using @value{GDBN} under @sc{gnu} Emacs
executable file you want to debug as an argument. This command starts
@value{GDBN} as a subprocess of Emacs, with input and output through a newly
created Emacs buffer.
+@c (Do not use the @code{-tui} option to run @value{GDBN} from Emacs.)
Using @value{GDBN} under Emacs is just like using @value{GDBN} normally except for two
things:
@end example
@noindent
-(preceded by @kbd{ESC ESC}, or typed in the @code{*scratch*} buffer, or
+(preceded by @kbd{M-:} or @kbd{ESC :}, or typed in the @code{*scratch*} buffer, or
in your @file{.emacs} file) makes Emacs call the program named
``@code{mygdb}'' instead.
to correspond properly with the code.
@c The following dropped because Epoch is nonstandard. Reactivate
-@c if/when v19 does something similar. ---pesch@cygnus.com 19dec1990
+@c if/when v19 does something similar. ---doc@cygnus.com 19dec1990
@ignore
@kindex Emacs Epoch environment
@kindex Epoch
@code{inspect} which performs identically to @code{print} except that
each value is printed in its own window.
@end ignore
-@end ifclear
-
-@ifset LUCID
-@node Energize
-@chapter Using @value{GDBN} with Energize
-
-@cindex Energize
-The Energize Programming System is an integrated development environment
-that includes a point-and-click interface to many programming tools.
-When you use @value{GDBN} in this environment, you can use the standard
-Energize graphical interface to drive @value{GDBN}; you can also, if you
-choose, type @value{GDBN} commands as usual in a debugging window. Even if
-you use the graphical interface, the debugging window (which uses Emacs,
-and resembles the standard @sc{gnu} Emacs interface to
-@value{GDBN}) displays the
-equivalent commands, so that the history of your debugging session is
-properly reflected.
-
-When Energize starts up a @value{GDBN} session, it uses one of the
-command-line options @samp{-energize} or @samp{-cadillac} (``cadillac''
-is the name of the communications protocol used by the Energize system).
-This option makes @value{GDBN} run as one of the tools in the Energize Tool
-Set: it sends all output to the Energize kernel, and accept input from
-it as well.
-
-See the user manual for the Energize Programming System for
-information on how to use the Energize graphical interface and the other
-development tools that Energize integrates with @value{GDBN}.
-
-@end ifset
@node GDB Bugs
@chapter Reporting Bugs in @value{GDBN}
@cindex error on valid input
@item
-If @value{GDBN} produces an error message for valid input, that is a bug.
+If @value{GDBN} produces an error message for valid input, that is a
+bug. (Note that if you're cross debugging, the problem may also be
+somewhere in the connection to the target.)
@cindex invalid input
@item
You can find contact information for many support companies and
individuals in the file @file{etc/SERVICE} in the @sc{gnu} Emacs
distribution.
+@c should add a web page ref...
-In any event, we also recommend that you send bug reports for @value{GDBN} to one
-of these addresses:
+In any event, we also recommend that you send bug reports for
+@value{GDBN} to this addresses:
@example
-bug-gdb@@prep.ai.mit.edu
-@{ucbvax|mit-eddie|uunet@}!prep.ai.mit.edu!bug-gdb
+bug-gdb@@gnu.org
@end example
@strong{Do not send bug reports to @samp{info-gdb}, or to
-@samp{help-gdb}, or to any newsgroups.} Most users of @value{GDBN} do not want to
-receive bug reports. Those that do have arranged to receive @samp{bug-gdb}.
+@samp{help-gdb}, or to any newsgroups.} Most users of @value{GDBN} do
+not want to receive bug reports. Those that do have arranged to receive
+@samp{bug-gdb}.
The mailing list @samp{bug-gdb} has a newsgroup @samp{gnu.gdb.bug} which
serves as a repeater. The mailing list and the newsgroup carry exactly
@example
@sc{gnu} Debugger Bugs
-Free Software Foundation
-545 Tech Square
-Cambridge, MA 02139
+Free Software Foundation Inc.
+59 Temple Place - Suite 330
+Boston, MA 02111-1307
+USA
@end example
The fundamental principle of reporting bugs usefully is this:
the bug. Play it safe and give a specific, complete example. That is the
easiest thing for you to do, and the most helpful.
-Keep in mind that the purpose of a bug report is to enable us to fix
-the bug if it is new to us.
-@c
-@c FIX ME!!--What the heck does the following sentence mean,
-@c in the context of the one above?
-@c
-@c It is not as important as what happens if the bug is already known.
-@c
-Therefore, always write your bug reports on
-the assumption that the bug has not been reported previously.
+Keep in mind that the purpose of a bug report is to enable us to fix the
+bug. It may be that the bug has been reported previously, but neither
+you nor we can know that unless your bug report is complete and
+self-contained.
Sometimes people give a few sketchy facts and ask, ``Does this ring a
bell?'' Those bug reports are useless, and we urge everyone to
@itemize @bullet
@item
-The version of @value{GDBN}. @value{GDBN} announces it if you start with no
-arguments; you can also print it at any time using @code{show version}.
+The version of @value{GDBN}. @value{GDBN} announces it if you start
+with no arguments; you can also print it at any time using @code{show
+version}.
Without this, we will not know whether there is any point in looking for
the bug in the current version of @value{GDBN}.
@item
What compiler (and its version) was used to compile @value{GDBN}---e.g.
-``@value{GCC}--2.0''.
+``@value{GCC}--2.8.1''.
@item
-What compiler (and its version) was used to compile the program you
-are debugging---e.g. ``@value{GCC}--2.0''.
+What compiler (and its version) was used to compile the program you are
+debugging---e.g. ``@value{GCC}--2.8.1'', or ``HP92453-01 A.10.32.03 HP
+C Compiler''. For GCC, you can say @code{gcc --version} to get this
+information; for other compilers, see the documentation for those
+compilers.
@item
The command arguments you gave the compiler to compile your example and
A description of what behavior you observe that you believe is
incorrect. For example, ``It gets a fatal signal.''
-Of course, if the bug is that @value{GDBN} gets a fatal signal, then we will
-certainly notice it. But if the bug is incorrect output, we might not
-notice unless it is glaringly wrong. You might as well not give us a
-chance to make a mistake.
+Of course, if the bug is that @value{GDBN} gets a fatal signal, then we
+will certainly notice it. But if the bug is incorrect output, we might
+not notice unless it is glaringly wrong. You might as well not give us
+a chance to make a mistake.
Even if the problem you experience is a fatal signal, you should still
-say so explicitly. Suppose something strange is going on, such as,
-your copy of @value{GDBN} is out of synch, or you have encountered a
-bug in the C library on your system. (This has happened!) Your copy
-might crash and ours would not. If you told us to expect a crash,
-then when ours fails to crash, we would know that the bug was not
-happening for us. If you had not told us to expect a crash, then we
-would not be able to draw any conclusion from our observations.
+say so explicitly. Suppose something strange is going on, such as, your
+copy of @value{GDBN} is out of synch, or you have encountered a bug in
+the C library on your system. (This has happened!) Your copy might
+crash and ours would not. If you told us to expect a crash, then when
+ours fails to crash, we would know that the bug was not happening for
+us. If you had not told us to expect a crash, then we would not be able
+to draw any conclusion from our observations.
@item
If you wish to suggest changes to the @value{GDBN} source, send us context
The line numbers in our development sources will not match those in your
sources. Your line numbers would convey no useful information to us.
+
@end itemize
Here are some things that are not necessary:
@c The readline documentation is distributed with the readline code
@c and consists of the two following files:
@c rluser.texinfo
-@c inc-hist.texi
+@c inc-hist.texinfo
@c Use -I with makeinfo to point to the appropriate directory,
@c environment var TEXINPUTS with TeX.
@include rluser.texinfo
-@include inc-hist.texi
-
-@ifset NOVEL
-@ifset RENAMED
-@node Renamed Commands
-@appendix Renamed Commands
-
-The following commands were renamed in @value{GDBN} 4, in order to make the
-command set as a whole more consistent and easier to use and remember:
-
-@kindex add-syms
-@kindex delete environment
-@kindex info copying
-@kindex info convenience
-@kindex info directories
-@kindex info editing
-@kindex info history
-@kindex info targets
-@kindex info values
-@kindex info version
-@kindex info warranty
-@kindex set addressprint
-@kindex set arrayprint
-@kindex set prettyprint
-@kindex set screen-height
-@kindex set screen-width
-@kindex set unionprint
-@kindex set vtblprint
-@kindex set demangle
-@kindex set asm-demangle
-@kindex set sevenbit-strings
-@kindex set array-max
-@kindex set caution
-@kindex set history write
-@kindex show addressprint
-@kindex show arrayprint
-@kindex show prettyprint
-@kindex show screen-height
-@kindex show screen-width
-@kindex show unionprint
-@kindex show vtblprint
-@kindex show demangle
-@kindex show asm-demangle
-@kindex show sevenbit-strings
-@kindex show array-max
-@kindex show caution
-@kindex show history write
-@kindex unset
-
-@c TEXI2ROFF-KILL
-@ifinfo
-@c END TEXI2ROFF-KILL
-@example
-OLD COMMAND NEW COMMAND
-@c TEXI2ROFF-KILL
---------------- -------------------------------
-@c END TEXI2ROFF-KILL
-add-syms add-symbol-file
-delete environment unset environment
-info convenience show convenience
-info copying show copying
-info directories show directories
-info editing show commands
-info history show values
-info targets help target
-info values show values
-info version show version
-info warranty show warranty
-set/show addressprint set/show print address
-set/show array-max set/show print elements
-set/show arrayprint set/show print array
-set/show asm-demangle set/show print asm-demangle
-set/show caution set/show confirm
-set/show demangle set/show print demangle
-set/show history write set/show history save
-set/show prettyprint set/show print pretty
-set/show screen-height set/show height
-set/show screen-width set/show width
-set/show sevenbit-strings set/show print sevenbit-strings
-set/show unionprint set/show print union
-set/show vtblprint set/show print vtbl
-
-unset [No longer an alias for delete]
-@end example
-@c TEXI2ROFF-KILL
-@end ifinfo
+@include inc-hist.texinfo
-@tex
-\vskip \parskip\vskip \baselineskip
-\halign{\tt #\hfil &\qquad#&\tt #\hfil\cr
-{\bf Old Command} &&{\bf New Command}\cr
-add-syms &&add-symbol-file\cr
-delete environment &&unset environment\cr
-info convenience &&show convenience\cr
-info copying &&show copying\cr
-info directories &&show directories \cr
-info editing &&show commands\cr
-info history &&show values\cr
-info targets &&help target\cr
-info values &&show values\cr
-info version &&show version\cr
-info warranty &&show warranty\cr
-set{\rm / }show addressprint &&set{\rm / }show print address\cr
-set{\rm / }show array-max &&set{\rm / }show print elements\cr
-set{\rm / }show arrayprint &&set{\rm / }show print array\cr
-set{\rm / }show asm-demangle &&set{\rm / }show print asm-demangle\cr
-set{\rm / }show caution &&set{\rm / }show confirm\cr
-set{\rm / }show demangle &&set{\rm / }show print demangle\cr
-set{\rm / }show history write &&set{\rm / }show history save\cr
-set{\rm / }show prettyprint &&set{\rm / }show print pretty\cr
-set{\rm / }show screen-height &&set{\rm / }show height\cr
-set{\rm / }show screen-width &&set{\rm / }show width\cr
-set{\rm / }show sevenbit-strings &&set{\rm / }show print sevenbit-strings\cr
-set{\rm / }show unionprint &&set{\rm / }show print union\cr
-set{\rm / }show vtblprint &&set{\rm / }show print vtbl\cr
-\cr
-unset &&\rm(No longer an alias for delete)\cr
-}
-@end tex
-@c END TEXI2ROFF-KILL
-@end ifset
-@end ifset
-@ifclear PRECONFIGURED
@node Formatting Documentation
@appendix Formatting Documentation
formatting commands to create the on-line version of the documentation
and @TeX{} (or @code{texi2roff}) to typeset the printed version.
-@value{GDBN} includes an already formatted copy of the on-line Info version of
-this manual in the @file{gdb} subdirectory. The main Info file is
-@file{gdb-@r{version-number}/gdb/gdb.info}, and it refers to
+@value{GDBN} includes an already formatted copy of the on-line Info
+version of this manual in the @file{gdb} subdirectory. The main Info
+file is @file{gdb-@value{GDBVN}/gdb/gdb.info}, and it refers to
subordinate files matching @samp{gdb.info*} in the same directory. If
necessary, you can print out these files, or read them with any editor;
-but they are easier to read using the @code{info} subsystem in @sc{gnu} Emacs
-or the standalone @code{info} program, available as part of the @sc{gnu}
-Texinfo distribution.
+but they are easier to read using the @code{info} subsystem in @sc{gnu}
+Emacs or the standalone @code{info} program, available as part of the
+@sc{gnu} Texinfo distribution.
If you want to format these Info files yourself, you need one of the
Info formatting programs, such as @code{texinfo-format-buffer} or
@code{makeinfo}.
-If you have @code{makeinfo} installed, and are in the top level @value{GDBN}
-source directory (@file{gdb-@value{GDBVN}}, in the case of version @value{GDBVN}), you can
-make the Info file by typing:
+If you have @code{makeinfo} installed, and are in the top level
+@value{GDBN} source directory (@file{gdb-@value{GDBVN}}, in the case of
+version @value{GDBVN}), you can make the Info file by typing:
@example
cd gdb
If you have @TeX{} and a @sc{dvi} printer program installed, you can
typeset and print this manual. First switch to the the @file{gdb}
subdirectory of the main source directory (for example, to
-@file{gdb-@value{GDBVN}/gdb}) and then type:
+@file{gdb-@value{GDBVN}/gdb}) and type:
@example
make gdb.dvi
@end example
+Then give @file{gdb.dvi} to your @sc{dvi} printing program.
+
@node Installing GDB
@appendix Installing @value{GDBN}
@cindex configuring @value{GDBN}
@menu
* Separate Objdir:: Compiling @value{GDBN} in another directory
* Config Names:: Specifying names for hosts and targets
-* configure Options:: Summary of options for configure
+* Configure Options:: Summary of options for configure
@end menu
@node Separate Objdir
abbreviations---for example:
@smallexample
+% sh config.sub i386-linux
+i386-pc-linux-gnu
+% sh config.sub alpha-linux
+alpha-unknown-linux-gnu
+% sh config.sub hp9k700
+hppa1.1-hp-hpux
% sh config.sub sun4
sparc-sun-sunos4.1.1
% sh config.sub sun3
m68k-sun-sunos4.1.1
-% sh config.sub decstation
-mips-dec-ultrix4.2
-% sh config.sub hp300bsd
-m68k-hp-bsd
-% sh config.sub i386v
-i386-unknown-sysv
-% sh config.sub i786v
-Invalid configuration `i786v': machine `i786v' not recognized
+% sh config.sub i986v
+Invalid configuration `i986v': machine `i986v' not recognized
@end smallexample
@noindent
@code{config.sub} is also distributed in the @value{GDBN} source
directory (@file{gdb-@value{GDBVN}}, for version @value{GDBVN}).
-@node configure Options
+@node Configure Options
@section @code{configure} options
Here is a summary of the @code{configure} options and arguments that
@example
configure @r{[}--help@r{]}
@r{[}--prefix=@var{dir}@r{]}
+ @r{[}--exec-prefix=@var{dir}@r{]}
@r{[}--srcdir=@var{dirname}@r{]}
@r{[}--norecursion@r{]} @r{[}--rm@r{]}
- @r{[}--target=@var{target}@r{]} @var{host}
+ @r{[}--target=@var{target}@r{]}
+ @var{host}
@end example
@noindent
@item --help
Display a quick summary of how to invoke @code{configure}.
-@item -prefix=@var{dir}
+@item --prefix=@var{dir}
Configure the source to install programs and files under directory
@file{@var{dir}}.
+@item --exec-prefix=@var{dir}
+Configure the source to install programs under directory
+@file{@var{dir}}.
+
@c avoid splitting the warning from the explanation:
@need 2000
@item --srcdir=@var{dirname}
Configure only the directory level where @code{configure} is executed; do not
propagate configuration to subdirectories.
-@item --rm
-@emph{Remove} files otherwise built during configuration.
-
-@c This does not work (yet if ever). FIXME.
-@c @item --parse=@var{lang} @dots{}
-@c Configure the @value{GDBN} expression parser to parse the listed languages.
-@c @samp{all} configures @value{GDBN} for all supported languages. To get a
-@c list of all supported languages, omit the argument. Without this
-@c option, @value{GDBN} is configured to parse all supported languages.
-
@item --target=@var{target}
Configure @value{GDBN} for cross-debugging programs running on the specified
@var{target}. Without this option, @value{GDBN} is configured to debug
There is no convenient way to generate a list of all available hosts.
@end table
-@noindent
-@code{configure} accepts other options, for compatibility with
-configuring other @sc{gnu} tools recursively; but these are the only
-options that affect @value{GDBN} or its supporting libraries.
-@end ifclear
-
+There are many other options available as well, but they are generally
+needed for special purposes only.
+
@node Index
@unnumbered Index
\centerline{{\sl\fontname\tensl\/}}
\centerline{are used for emphasis.}\vfill}
\page\colophon
-% Blame: pesch@cygnus.com, 1991.
+% Blame: doc@cygnus.com, 1991.
@end tex
@contents
projects / thirdparty / binutils-gdb.git / blobdiff