@title Debugging with @value{GDBN}
@subtitle The @sc{gnu} Source-Level Debugger
@sp 1
-@ifclear HPPA
@subtitle @value{EDITION} Edition, for @value{GDBN} version @value{GDBVN}
@subtitle @value{DATE}
@author Richard M. Stallman and Roland H. Pesch
-@end ifclear
-@ifset HPPA
-@subtitle Edition @value{EDITION}, for @value{HPVER} (based on @value{GDBN} @value{GDBVN})
-@subtitle @value{DATE}
-@author Richard M. Stallman and Roland H. Pesch (modified by HP)
-@end ifset
@page
-@ifclear HPPA
-@tex
-{\parskip=0pt
-\hfill (Send bugs and comments on @value{GDBN} to bug-gdb\@prep.ai.mit.edu.)\par
-\hfill {\it Debugging with @value{GDBN}}\par
-\hfill \TeX{}info \texinfoversion\par
-}
-@end tex
-@end ifclear
-@ifset HPPA
@tex
{\parskip=0pt
+\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
}
@end tex
-@end ifset
+
+@c ISBN seems to be wrong...
@vskip 0pt plus 1filll
Copyright @copyright{} 1988-1999 Free Software Foundation, Inc.
@sp 2
-@ifclear HPPA
Published by the Free Software Foundation @*
59 Temple Place - Suite 330, @*
Boston, MA 02111-1307 USA @*
Printed copies are available for $20 each. @*
ISBN 1-882114-11-6 @*
-@end ifclear
Permission is granted to make and distribute verbatim copies of
this manual provided the copyright notice and this permission notice
@page
@ifinfo
-@node Top, Summary, (dir), (dir)
+@node Top
@top Debugging with @value{GDBN}
This file describes @value{GDBN}, the @sc{gnu} symbolic debugger.
* Data:: Examining data
* Languages:: Using @value{GDBN} with different languages
-* C:: C language support
* 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
* Emacs:: Using @value{GDBN} under @sc{gnu} Emacs
* GDB Bugs:: Reporting bugs in @value{GDBN}
-
-@ifclear PRECONFIGURED
-@ifclear HPPA
* Formatting Documentation:: How to format and print @value{GDBN} documentation
-@end ifclear
-
-@end ifclear
* Command Line Editing:: Command Line Editing
* Using History Interactively:: Using History Interactively
* Installing GDB:: Installing GDB
* Index:: Index
-
- --- The Detailed Node Listing ---
-
-Summary of @value{GDBN}
-
-* Free Software:: Freely redistributable software
-* Contributors:: Contributors to GDB
-
-Getting In and Out of @value{GDBN}
-
-* Invoking GDB:: How to start @value{GDBN}
-* Quitting GDB:: How to quit @value{GDBN}
-* Shell Commands:: How to use shell commands inside @value{GDBN}
-
-Invoking @value{GDBN}
-
-* File Options:: Choosing files
-* Mode Options:: Choosing modes
-
-@value{GDBN} Commands
-
-* Command Syntax:: How to give commands to @value{GDBN}
-* Completion:: Command completion
-* Help:: How to ask @value{GDBN} for help
-
-Running Programs Under @value{GDBN}
-
-* Compilation:: Compiling for debugging
-* Starting:: Starting your program
-* 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
-* Processes:: Debugging programs with multiple processes
-
-Stopping and Continuing
-
-* Breakpoints:: Breakpoints, watchpoints, and catchpoints
-* Continuing and Stepping:: Resuming execution
-* Signals:: Signals
-* Thread Stops:: Stopping and starting multi-thread programs
-
-Breakpoints and watchpoints
-
-* Set Breaks:: Setting breakpoints
-* Set Watchpoints:: Setting watchpoints
-* Set Catchpoints:: Setting catchpoints
-* Delete Breaks:: Deleting breakpoints
-* Disabling:: Disabling breakpoints
-* Conditions:: Break conditions
-* Break Commands:: Breakpoint command lists
-* Breakpoint Menus:: Breakpoint menus
-
-Examining the Stack
-
-* Frames:: Stack frames
-* Backtrace:: Backtraces
-* Selection:: Selecting a frame
-* Frame Info:: Information on a frame
-* Alpha/MIPS Stack:: Alpha and MIPS machines and the function stack
-
-Examining Source Files
-
-* List:: Printing source lines
-* Search:: Searching source files
-* Source Path:: Specifying source directories
-* Machine Code:: Source and machine code
-
-Examining Data
-
-* Expressions:: Expressions
-* Variables:: Program variables
-* Arrays:: Artificial arrays
-* Output Formats:: Output formats
-* Memory:: Examining memory
-* Auto Display:: Automatic display
-* Print Settings:: Print settings
-* Value History:: Value history
-* Convenience Vars:: Convenience variables
-* Registers:: Registers
-* Floating Point Hardware:: Floating point hardware
-
-Using @value{GDBN} with Different Languages
-
-* Setting:: Switching between source languages
-* Show:: Displaying the language
-* Checks:: Type and range checks
-* Support:: Supported languages
-
-Switching between source languages
-
-* Filenames:: Filename extensions and languages.
-* Manually:: Setting the working language manually
-* Automatically:: Having @value{GDBN} infer the source language
-
-Type and range checking
-
-* Type Checking:: An overview of type checking
-* Range Checking:: An overview of range checking
-
-Supported languages
-
-C Language Support
-
-* C:: C and C++
-* C Operators:: C and C++ operators
-* C Constants:: C and C++ constants
-* C plus plus expressions:: C++ expressions
-* C Defaults:: Default settings for C and C++
-* C Checks:: C and C++ type and range checks
-* Debugging C:: @value{GDBN} and C
-* Debugging C plus plus:: @value{GDBN} features for C++
-
-Modula-2
-
-* M2 Operators:: Built-in operators
-* 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
-* M2 Checks:: Modula-2 type and range checks
-* M2 Scope:: The scope operators @code{::} and @code{.}
-* GDB/M2:: @value{GDBN} and Modula-2
-
-Altering Execution
-
-* Assignment:: Assignment to variables
-* Jumping:: Continuing at a different address
-* Signaling:: Giving your program a signal
-* Returning:: Returning from a function
-* Calling:: Calling your program's functions
-* Patching:: Patching your program
-
-@value{GDBN} Files
-
-* Files:: Commands to specify files
-* Symbol Errors:: Errors reading symbol files
-
-Specifying a Debugging Target
-
-* Active Targets:: Active targets
-* Target Commands:: Commands for managing targets
-@ifclear HPPA
-* Byte Order:: Choosing target byte order
-* Remote:: Remote debugging
-
-Remote debugging
-@end ifclear
-
-* Remote Serial:: @value{GDBN} remote serial protocol
-
-* i960-Nindy Remote:: @value{GDBN} with a remote i960 (Nindy)
-
-* UDI29K Remote:: The UDI protocol for AMD29K
-
-* EB29K Remote:: The EBMON protocol for AMD29K
-
-* VxWorks Remote:: @value{GDBN} and VxWorks
-
-* ST2000 Remote:: @value{GDBN} with a Tandem ST2000
-
-* Hitachi Remote:: @value{GDBN} and Hitachi Microprocessors
-
-* MIPS Remote:: @value{GDBN} and MIPS boards
-
-* Simulator:: Simulated CPU target
-
-Controlling @value{GDBN}
-
-* Prompt:: Prompt
-* Editing:: Command editing
-* History:: Command history
-* Screen Size:: Screen size
-* Numbers:: Numbers
-* Messages/Warnings:: Optional warnings and messages
-
-Canned Sequences of Commands
-
-* Define:: User-defined commands
-* Hooks:: User-defined command hooks
-* Command Files:: Command files
-* Output:: Commands for controlled output
-
-Reporting Bugs in @value{GDBN}
-
-* Bug Criteria:: Have you found a bug?
-* Bug Reporting:: How to report bugs
-
-Installing @value{GDBN}
-
-* Separate Objdir:: Compiling @value{GDBN} in another directory
-* Config Names:: Specifying names for hosts and targets
-* Configure Options:: Summary of options for configure
@end menu
@end ifinfo
-@node Summary, Sample Session, Top, Top
+@node Summary
@unnumbered Summary of @value{GDBN}
The purpose of a debugger such as @value{GDBN} is to allow you to see what is
effects of one bug and go on to learn about another.
@end itemize
-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.
+You can use @value{GDBN} to debug programs written in C and C++.
For more information, see @ref{Support,,Supported languages}.
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.
@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.
-
-@ifset HPPA
-This version of the manual documents HP Wildebeest (WDB) Version 0.75,
-implemented on HP 9000 systems running Release 10.20, 10.30, or 11.0 of
-the HP-UX operating system. HP WDB 0.75 can be used to debug code
-generated by the HP ANSI C and HP ANSI C++ compilers as well as the
-@sc{gnu} C and C++ compilers. It does not support the debugging of
-Fortran, Modula-2, or Chill programs.
-@end ifset
+it may be necessary to refer to some variables with a trailing
+underscore.
@menu
* Free Software:: Freely redistributable software
* Contributors:: Contributors to GDB
@end menu
-@node Free Software, Contributors, Summary, Summary
+@node Free Software
@unnumberedsec Free software
@value{GDBN} is @dfn{free software}, protected by the @sc{gnu}
you have these freedoms and that you cannot take these freedoms away
from anyone else.
-@node Contributors, , Free Software, Summary
+@node Contributors
@unnumberedsec Contributors to GDB
Richard Stallman was the original author of GDB, and of many other
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, 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, Invocation, Summary, Top
+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
You can use this manual at your leisure to read all about @value{GDBN}.
@noindent
Let us use @value{GDBN} to try to see what is going on.
-@ifclear HPPA
@smallexample
$ @b{@value{GDBP} m4}
@c FIXME: this falsifies the exact text played out, to permit smallbook
@value{GDBN} @value{GDBVN}, Copyright 1999 Free Software Foundation, Inc...
(@value{GDBP})
@end smallexample
-@end ifclear
-@ifset HPPA
-@smallexample
-$ @b{@value{GDBP} m4}
-Wildebeest 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 Wildebeest; type "show warranty"
-for details.
-
-Hewlett-Packard Wildebeest 0.75 (based on GDB 4.16)
-(built for PA-RISC 1.1 or 2.0, HP-UX 10.20)
-Copyright 1996, 1997 Free Software Foundation, Inc.
-(@value{GDBP})
-@end smallexample
-@end ifset
@noindent
@value{GDBN} reads only enough symbol data to know where to find the
(@value{GDBP}) @b{quit}
@end smallexample
-@node Invocation, Commands, Sample Session, Top
+@node Invocation
@chapter Getting In and Out of @value{GDBN}
This chapter discusses how to start @value{GDBN}, and how to get out of it.
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
* Shell Commands:: How to use shell commands inside @value{GDBN}
@end menu
-@node Invoking GDB, Quitting GDB, Invocation, Invocation
+@node Invoking GDB
@section Invoking @value{GDBN}
Invoke @value{GDBN} by running the program @code{@value{GDBP}}. Once started,
would attach @value{GDBN} to process @code{1234} (unless you also have a file
named @file{1234}; @value{GDBN} does check for a core file first).
-@ifclear HPPA
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}:
@itemx -d @var{directory}
Add @var{directory} to the path to search for source files.
-@ifclear HPPA
@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
-@ifclear HPPA
@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 ifclear
+
@end table
-@ifclear HPPA
-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 on @file{.syms} files.) A simple GDB invocation to do
-nothing but build a @file{.syms} file for future use is:
+information. (@xref{Files,,Commands to specify files}, for information
+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, , File Options, Invoking GDB
+@node Mode Options
@subsection Choosing modes
You can run @value{GDBN} in various alternative modes---for example, in
@table @code
@item -nx
@itemx -n
-Do not execute commands from any initialization files (normally called
-@file{.gdbinit}, or @file{gdb.ini} on PCs). 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,
@samp{\032} characters as a signal to display the source code for the
frame.
-@ifclear HPPA
-@item -b @var{bps}
+@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.
-@end ifclear
@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.
-@ifset HPPA
-@item -tui
-Use a Terminal User Interface. For information, use your Web browser to
-read the file @file{TUI.html}, which is usually installed in the
-directory @code{/opt/langtools/wdb/doc} on HP-UX systems. Do not use
-this option if you run @value{GDBN} from Emacs (see @pxref{Emacs, ,Using
-@value{GDBN} under @sc{gnu} Emacs}).
-
-@item -xdb
-Run in XDB compatibility mode, allowing the use of certain XDB commands.
-For information, see the file @file{xdb_trans.html}, which is usually
-installed in the directory @code{/opt/langtools/wdb/doc} on HP-UX
-systems.
-@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, Shell Commands, Invoking GDB, Invocation
+@node Quitting GDB
@section Quitting @value{GDBN}
@cindex exiting @value{GDBN}
@cindex leaving @value{GDBN}
device, you can release it with the @code{detach} command
(@pxref{Attach, ,Debugging an already-running process}).
-@node Shell Commands, , Quitting GDB, Invocation
+@node Shell Commands
@section Shell commands
If you need to execute occasional shell commands during your
@item shell @var{command string}
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}.
+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.
arguments. This is equivalent to @samp{shell make @var{make-args}}.
@end table
-@node Commands, Running, Invocation, Top
+@node Commands
@chapter @value{GDBN} Commands
You can abbreviate a @value{GDBN} command to the first few letters of the command
* Help:: How to ask @value{GDBN} for help
@end menu
-@node Command Syntax, Completion, Commands, Commands
+@node Command Syntax
@section Command syntax
A @value{GDBN} command is a single line of input. There is no limit on
nothing. This is useful mainly in command files (@pxref{Command
Files,,Command files}).
-@node Completion, Help, Command Syntax, Commands
+@node Completion
@section Command completion
@cindex completion
you have not yet started typing the argument list when you ask for
completion on an overloaded symbol.
-For more information about overloaded functions, @pxref{C plus plus
+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;
-@pxref{Debugging C plus plus, ,@value{GDBN} features for C++}.
+see @ref{Debugging C plus plus, ,@value{GDBN} features for C++}.
-@node Help, , Completion, Commands
+@node Help
@section Getting help
@cindex online documentation
@kindex 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.
@smallexample
@group
+if
+ignore
info
inspect
-ignore
@end group
@end smallexample
@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, Stopping, Commands, Top
+@node Running
@chapter Running Programs Under @value{GDBN}
When you run a program under @value{GDBN}, you must first generate
* 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
* Processes:: Debugging programs with multiple processes
@end menu
-@node Compilation, Starting, Running, Running
+@node Compilation
@section Compiling for debugging
In order to debug a program effectively, you need to generate
options together. Using those compilers, you cannot generate optimized
executables containing debugging information.
-@ifclear HPPA
-@value{NGCC}, the @sc{gnu} C compiler, supports @samp{-g} with or without
-@end ifclear
-@ifset HPPA
-The HP ANSI C and C++ compilers, as well as @value{NGCC}, the @sc{gnu} C
-compiler, support @samp{-g} with or without
-@end ifset
-@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
format; if your @sc{gnu} C compiler has this option, do not use it.
@need 2000
-@node Starting, Arguments, Compilation, Running
+@node Starting
@section Starting your program
@cindex starting
@cindex running
table, and reads it again. When it does this, @value{GDBN} tries to retain
your current breakpoints.
-@node Arguments, Environment, Starting, Running
+@node Arguments
@section Your program's arguments
@cindex arguments (to your program)
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}.
+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.
Show the arguments to give your program when it is started.
@end table
-@node Environment, Working Directory, Arguments, Running
+@node Environment
@section Your program's environment
@cindex environment (of your program)
@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
files that are only run when you sign on, such as @file{.login} or
@file{.profile}.
-@node Working Directory, Input/Output, Environment, Running
+@node Working Directory
@section Your program's working directory
@cindex working directory (of your program)
Print the @value{GDBN} working directory.
@end table
-@node Input/Output, Attach, Working Directory, Running
+@node Input/Output
@section Your program's input and output
@cindex redirection
command, only the input @emph{for your program} is affected. The input
for @value{GDBN} still comes from your terminal.
-@node Attach, Kill Process, Input/Output, Running
+@node Attach
@section Debugging an already-running process
@kindex attach
@cindex attach
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
-@ifclear HPPA
-processes with @code{run}. You can insert breakpoints; you can step and
-@end ifclear
-@ifset HPPA
-processes with @code{run}. You can insert breakpoints (except in shared
-libraries); you can step and
-@end ifset
-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
confirm} command (@pxref{Messages/Warnings, ,Optional warnings and
messages}).
-@node Kill Process, Process Information, Attach, Running
+@node Kill Process
@section Killing the child process
@table @code
reads the symbol table again (while trying to preserve your current
breakpoint settings).
-@node Process Information, Threads, Kill Process, Running
-@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}.
-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 Threads, Processes, Process Information, Running
+@node Threads
@section Debugging programs with multiple threads
@cindex threads of execution
@item thread-specific breakpoints
@end itemize
-@ifclear HPPA
@quotation
@emph{Warning:} These facilities are not yet available on every
@value{GDBN} configuration where the operating system supports threads.
@c FIXME to implementors: how hard would it be to say "sorry, this GDB
@c doesn't support threads"?
@end quotation
-@end ifclear
@cindex focus of debugging
@cindex current thread
This thread is called the @dfn{current thread}. Debugging commands show
program information from the perspective of the current thread.
-@ifclear HPPA
@kindex New @var{systag}
@cindex thread identifier (system)
@c FIXME-implementors!! It would be more helpful if the [New...] message
* 1 process 35 thread 13 main (argc=1, argv=0x7ffffff8)
at threadtest.c:68
@end smallexample
-@end ifclear
-@ifset HPPA
+
+On HP-UX systems:
@cindex thread number
@cindex thread identifier (GDB)
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
-@end ifset
@table @code
@kindex thread @var{threadno}
@smallexample
@c FIXME!! This example made up; find a @value{GDBN} w/threads and get real one
(@value{GDBP}) thread 2
-@ifclear HPPA
[Switching to process 35 thread 23]
-@end ifclear
-@ifset HPPA
-[Switching to thread 2 (system thread 26594)]
-@end ifset
0x34e5 in sigpause ()
@end smallexample
@xref{Set Watchpoints,,Setting watchpoints}, for information about
watchpoints in programs with multiple threads.
-@ifclear HPPA
-@node Processes, , Threads, Running
+@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.
-@end ifclear
-@ifset HPPA
-@node Processes, , Threads, Running
-@section Debugging programs with multiple processes
-
-@cindex fork, debugging programs which call
-@cindex multiple processes
-@cindex processes, multiple
-@value{GDBN} provides support for debugging programs that create
-additional processes using the @code{fork} or @code{vfork} function.
+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.
@table @code
@item parent
The original process is debugged after a fork. The child process runs
-unimpeded.
+unimpeded. This is the default.
@item child
The new process is debugged after a fork. The parent process runs
@end table
@item show follow-fork-mode
-Display the current debugger response to a fork or vfork call.
+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
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}.
-@end ifset
-@node Stopping, Stack, Running, Top
+@node Stopping
@chapter Stopping and Continuing
The principal purposes of using a debugger are so that you can stop your
* Thread Stops:: Stopping and starting multi-thread programs
@end menu
-@node Breakpoints, Continuing and Stepping, Stopping, Stopping
+@node Breakpoints
@section Breakpoints, watchpoints, and catchpoints
@cindex breakpoints
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; @pxref{Signals, ,Signals}.)
+@code{handle} command; see @ref{Signals, ,Signals}.)
@cindex breakpoint numbers
@cindex numbers for breakpoints
* Conditions:: Break conditions
* Break Commands:: Breakpoint command lists
* Breakpoint Menus:: Breakpoint menus
-
-@c * Error in Breakpoints:: ``Cannot insert breakpoints''
+* Error in Breakpoints:: ``Cannot insert breakpoints''
@end menu
-@node Set Breaks, Set Watchpoints, Breakpoints, Breakpoints
+@node Set Breaks
@subsection Setting breakpoints
@c FIXME LMB what does GDB do if no code on line of breakpt?
@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}
way, but the breakpoint is automatically deleted after the first time your
program stops there. @xref{Disabling, ,Disabling breakpoints}.
-@ifclear HPPA
@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 data 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 unused 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}.
-@end ifclear
+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.
+@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
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.
@item finish
Temporary internal breakpoint used by the @value{GDBN} @code{finish} command.
-@ifset HPPA
@item shlib events
Shared library events.
-@end ifset
+
@end table
+
@end table
-@node Set Watchpoints, Set Catchpoints, Set Breaks, Breakpoints
+@node Set Watchpoints
@subsection Setting watchpoints
@cindex setting watchpoints
this may happen.
Depending on your system, watchpoints may be implemented in software or
-hardware. GDB does software watchpointing by single-stepping your
+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 and Linux, GDB includes support for
+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.
@kindex rwatch
@item rwatch @var{expr}
Set a watchpoint that will break when watch @var{expr} is read by the program.
-If you use both watchpoints, both must be set with the @code{rwatch}
-command.
@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
@noindent
if it was able to set a hardware watchpoint.
-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.
+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 GDB reaches another
+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
-@ifclear HPPA
@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
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.
-@end ifclear
-@ifset HPPA
-@emph{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 ifset
+
+@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
-@node Set Catchpoints, Delete Breaks, Set Watchpoints, Breakpoints
+@node Set Catchpoints
@subsection Setting catchpoints
-@cindex catchpoints
+@cindex catchpoints, setting
@cindex exception handlers
@cindex event handling
@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
raised.
-@node Delete Breaks, Disabling, Set Catchpoints, Breakpoints
+@node Delete Breaks
@subsection Deleting breakpoints
@cindex clearing breakpoints, watchpoints, catchpoints
confirm off}). You can abbreviate this command as @code{d}.
@end table
-@node Disabling, Conditions, Delete Breaks, Breakpoints
+@node Disabling
@subsection Disabling breakpoints
@kindex disable breakpoints
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,
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
breakpoints; see @ref{Continuing and Stepping, ,Continuing and
stepping}.)
-@node Conditions, Break Commands, Disabling, Breakpoints
+@node Conditions
@subsection Break conditions
@cindex conditional breakpoints
@cindex breakpoint conditions
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}).
@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.
-@ifclear HPPA
-@c The watch command now seems to recognize the if keyword.
-@c catch doesn't, though.
-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.
-@end ifclear
-@ifset HPPA
+
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.
-@end ifset
@table @code
@kindex condition
@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?
+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
Ignore counts apply to breakpoints, watchpoints, and catchpoints.
-@node Break Commands, Breakpoint Menus, Conditions, Breakpoints
+@node Break Commands
@subsection Breakpoint command lists
@cindex breakpoint commands
end
@end example
-@node Breakpoint Menus, , Break Commands, Breakpoints
+@node Breakpoint Menus
@subsection Breakpoint menus
@cindex overloading
@cindex symbol overloading
@end smallexample
@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
+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:
+
+@example
+Cannot insert breakpoints.
+The same program may be running in another process.
+@end example
+
+When this happens, you have three ways to proceed:
+
+@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
-@node Continuing and Stepping, Signals, Breakpoints, Stopping
+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
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
-due to a signal, you may want to use @code{handle}, or use @samp{signal
-0} to resume execution. @xref{Signals, ,Signals}.)
+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
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}
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.
@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
+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
An argument is a repeat count, as in @code{next}.
@end table
-@node Signals, Thread Stops, Continuing and Stepping, Stopping
+@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}
you can continue with @samp{signal 0}. @xref{Signaling, ,Giving your
program a signal}.
-@node Thread Stops, , Signals, Stopping
+@node Thread Stops
@section Stopping and starting multi-thread programs
When your program has multiple threads (@pxref{Threads,, Debugging
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
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 ``next'' over a
+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 ``continue'', ``until'', or ``finish''. However, unless another
+like @samp{continue}, @samp{until}, or @samp{finish}. However, unless another
thread hits a breakpoint during its timeslice, they will never steal the
-GDB prompt away from the thread that you are debugging.
+@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, Source, Stopping, Top
+@node Stack
@chapter Examining the Stack
When your program has stopped, the first thing you need to know is where it
* Backtrace:: Backtraces
* Selection:: Selecting a frame
* Frame Info:: Information on a frame
-* Alpha/MIPS Stack:: Alpha and MIPS machines and the function stack
@end menu
-@node Frames, Backtrace, Stack, Stack
+@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
@code{frame}.
@end table
-@node Backtrace, Selection, Frames, Stack
+@node Backtrace
@section Backtraces
@cindex backtraces
value, indicating that your program has stopped at the beginning of the
code for line @code{993} of @code{builtin.c}.
-@node Selection, Frame Info, Backtrace, Stack
+@node Selection
@section Selecting a frame
Most commands for examining the stack and other data in your program work on
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 HPPA
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}
distracting.
@end table
-@node Frame Info, Alpha/MIPS Stack, Selection, Stack
+@node Frame Info
@section Information about a frame
There are several other commands to print information about the selected
@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 HPPA
@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{Set Catchpoints, , Setting catchpoints}.
-@end ifclear
-@end table
-
-@node Alpha/MIPS Stack, , Frame Info, Stack
-@section MIPS/Alpha machines and the function stack
-
-@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.
-
-@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} (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.
-@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 Alpha or MIPS processors.
-
-@node Source, Data, Stack, Top
+@node Source
@chapter Examining Source Files
@value{GDBN} can print parts of your program's source, since the debugging
source files by explicit command.
If you use @value{GDBN} through its @sc{gnu} Emacs interface, you may
-prefer to use Emacs facilities to view source; @pxref{Emacs, ,Using
+prefer to use Emacs facilities to view source; see @ref{Emacs, ,Using
@value{GDBN} under @sc{gnu} Emacs}.
@menu
* Machine Code:: Source and machine code
@end menu
-@node List, Search, Source, Source
+@node List
@section Printing source lines
@kindex list
@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
-@node Search, Source Path, List, Source
+@node Search
@section Searching source files
@cindex searching
@kindex reverse-search
this command as @code{rev}.
@end table
-@node Source Path, Machine Code, Search, Source
+@node Source Path
@section Specifying source directories
@cindex source path
@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.
directories in one command.
@end enumerate
-@node Machine Code, , Source Path, Source
+@node Machine Code
@section Source and machine code
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,
mnemonics or other syntax.
@table @code
-@kindex set assembly-language
+@kindex set disassembly-flavor
@cindex assembly instructions
@cindex instructions, assembly
@cindex machine instructions
@cindex listing machine instructions
-@item set assembly-language @var{instruction-set}
+@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{i386} or @code{i8086}.
-The default is @code{i386}.
+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
-@node Data, Languages, Source, Top
+@node Data
@chapter Examining Data
@cindex printing data
Different Languages}).
@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;
+@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
specified format. @xref{Memory, ,Examining memory}.
If you are interested in information about types, or about how the
-fields of a struct or class are declared, use the @code{ptype @var{exp}}
-command rather than @code{print}. @xref{Symbols, ,Examining the Symbol
+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
* Floating Point Hardware:: Floating point hardware
@end menu
-@node Expressions, Variables, Data, Data
+@node Expressions
@section Expressions
@cindex 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.
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
normally supposed to reside at @var{addr}.
@end table
-@node Variables, Arrays, Expressions, Data
+@node Variables
@section Program variables
The most common kind of expression to use is the name of a variable
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 ::
To be sure of always seeing accurate values, turn off all optimization
when compiling.
-@node Arrays, Output Formats, Variables, Data
+@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
@cindex artificial array
@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
@dots{}
@end example
-@node Output Formats, Memory, Arrays, Data
+@node Output Formats
@section Output formats
@cindex formatted output
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
you can use the @code{print} command with just a format and no
expression. For example, @samp{p/x} reprints the last value in hex.
-@node Memory, Auto Display, Output Formats, Data
+@node Memory
@section Examining memory
You can use the command @code{x} (for ``examine'') to examine memory in
(@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
are from the last memory unit printed; this is not the same as the last
address printed if several units were printed on the last line of output.
-@node Auto Display, Print Settings, Memory, Data
+@node Auto Display
@section Automatic display
@cindex automatic display
@cindex display of expressions
@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
automatically. The next time your program stops where @code{last_char}
is meaningful, you can enable the display expression once again.
-@node Print Settings, Value History, Auto Display, Data
+@node Print Settings
@section Print settings
@cindex format options
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
@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
@item gnu
Decode based on the @sc{gnu} C++ compiler (@code{g++}) encoding algorithm.
-@ifclear HPPA
This is the default.
-@end ifclear
@item hp
Decode based on the HP ANSI C++ (@code{aCC}) encoding algorithm.
@item set print vtbl
@itemx set print vtbl on
Pretty print C++ virtual function tables. The default is off.
-@ifset HPPA
(The @code{vtbl} commands do not work on programs compiled with the HP
ANSI C++ compiler (@code{aCC}).)
-@end ifset
@item set print vtbl off
Do not pretty print C++ virtual function tables.
Show whether C++ virtual function tables are pretty printed, or not.
@end table
-@node Value History, Convenience Vars, Print Settings, Data
+@node Value History
@section Value history
@cindex value history
Pressing @key{RET} to repeat @code{show values @var{n}} has exactly the
same effect as @samp{show values +}.
-@node Convenience Vars, Registers, Value History, Data
+@node Convenience Vars
@section Convenience variables
@cindex convenience variables
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 program being debugged terminates.
@end table
-@ifset HPPA
-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.
-@end ifset
+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, Floating Point Hardware, Convenience Vars, Data
+@node Registers
@section Registers
@cindex 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.
-@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
-
-@node Floating Point Hardware, , Registers, Data
+@node Floating Point Hardware
@section Floating point hardware
@cindex floating point
the ARM and x86 machines.
@end table
-@node Languages, Symbols, Data, Top
+@node Languages
@chapter Using @value{GDBN} with Different Languages
@cindex languages
* Support:: Supported languages
@end menu
-@node Setting, Show, Languages, Languages
+@node Setting
@section Switching between source languages
There are two ways to control the working language---either have @value{GDBN}
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
* Automatically:: Having @value{GDBN} infer the source language
@end menu
-@node Filenames, Manually, Setting, Setting
+@node Filenames
@subsection List of filename extensions and languages
If a source file name ends in one of the following extensions, then
@itemx .F
Fortran source file
-@ifclear HPPA
@item .ch
@itemx .c186
@itemx .c286
CHILL source file.
-@end ifclear
@item .mod
Modula-2 source file
In addition, you may set the language associated with a filename
extension. @xref{Show, , Displaying the language}.
-@node Manually, Automatically, Filenames, Setting
+@node Manually
@subsection Setting the working language
If you allow @value{GDBN} to set the language automatically,
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.
-@node Automatically, , Manually, Setting
+@node Automatically
@subsection Having @value{GDBN} infer the source language
To have @value{GDBN} set the working language automatically, use
a different source language. Using @samp{set language auto} in this
case frees you from having to set the working language manually.
-@node Show, Checks, Setting, Languages
+@node Show
@section Displaying the language
The following commands help you find out which language is the
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
List all the filename extensions and the associated languages.
@end table
-@node Checks, Support, Show, Languages
+@node Checks
@section Type and range checking
@quotation
@cindex type checking
@cindex checks, type
-@node Type Checking, Range Checking, Checks, Checks
+@node Type Checking
@subsection An overview of type checking
Some languages, such as Modula-2, are strongly typed, meaning that the
@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
@cindex range checking
@cindex checks, range
-@node Range Checking, , Type Checking, Checks
+@node Range Checking
@subsection An overview of range checking
In some languages (such as Modula-2), it is an error to exceed the
@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,
being set automatically by @value{GDBN}.
@end table
-@node Support, , Checks, Languages
+@node Support
@section Supported languages
-@value{GDBN} supports C, C++, Fortran, Chill, assembly, and Modula-2.
+@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,
@menu
* C:: C and C++
-* Modula-2:: Modula-2
+* Modula-2:: Modula-2
+* Chill:: Chill
@end menu
-@node C, Modula-2, , Support
+@node C
@subsection C and C++
@cindex C and C++
to both languages. Whenever this is the case, we discuss those languages
together.
-@ifclear HPPA
@cindex C++
@kindex g++
@cindex @sc{gnu} C++
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 HPPA
-@cindex C++
-@kindex g++
-@cindex @sc{gnu} C++
-You can use @value{GDBN} to debug C programs compiled with either the HP
-C compiler (@code{cc}) or the GNU C compiler (@code{gcc}), and to debug
-programs compiled with either the HP ANSI C++ compiler (@code{aCC}) or
-the @sc{gnu} C++ compiler (@code{g++}).
-
-If you compile with the @sc{gnu} C++ compiler, use the stabs debugging
-format for best results when debugging. 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 ifset
@menu
* C Operators:: C and C++ operators
* Debugging C plus plus:: @value{GDBN} features for C++
@end menu
-@node C Operators, C Constants, , C
+@node C Operators
@subsubsection C and C++ operators
@cindex C and C++ operators
For the purposes of C and C++, the following definitions hold:
@itemize @bullet
+
@item
-@ifclear HPPA
-@emph{Integral types} include @code{int} with any of its storage-class
-specifiers; @code{char}; and @code{enum}.
-@end ifclear
-@ifset HPPA
@emph{Integral types} include @code{int} with any of its storage-class
specifiers; @code{char}; @code{enum}; and, for C++, @code{bool}.
-@end ifset
@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{%}.
pointer based on the stored type information.
Defined on @code{struct} and @code{union} data.
-@ifset HPPA
@item .*@r{, }->*
Dereferences of pointers to members.
-@end ifset
@item []
Array indexing. @code{@var{a}[@var{i}]} is defined as
above.
@end table
-@ifset HPPA
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.
-@end ifset
@menu
* C Constants::
@end menu
-@node C Constants, C plus plus expressions, C Operators, C
+@node C Constants
@subsubsection C and C++ constants
@cindex C and C++ constants
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
* Debugging C::
@end menu
-@node C plus plus expressions, C Defaults, C Constants, C
+@node C plus plus expressions
@subsubsection C++ expressions
@cindex expressions in C++
@value{GDBN} expression handling can interpret most C++ expressions.
-@ifclear HPPA
@cindex C++ support, not in @sc{coff}
@cindex @sc{coff} versus C++
@cindex C++ and object formats
@sc{coff} or @sc{dwarf} in @sc{elf}, on the other hand, most of the C++
support in @value{GDBN} does @emph{not} work.
@end quotation
-@end ifclear
@enumerate
that is, @value{GDBN} allows implicit references to the class instance
pointer @code{this} following the same rules as C++.
-@ifclear HPPA
-@cindex call overloaded functions
-@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.
-@end ifclear
-@ifset HPPA
@cindex call overloaded functions
-@cindex 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 some restrictions. GDB does not
+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
@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
+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;
-@pxref{Completion, ,Command completion}.
-@end ifset
+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
-@ifset HPPA
-In addition, @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.
-@end ifset
+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, C Checks, C plus plus expressions, C
+@node C Defaults
@subsubsection C and C++ defaults
@cindex C and C++ defaults
-@ifclear HPPA
If you allow @value{GDBN} to set type and range checking automatically, they
both default to @code{off} whenever the working language changes to
C or C++. This happens regardless of whether you or @value{GDBN}
selects the working language.
-@end ifclear
If you allow @value{GDBN} to set the language automatically, it
recognizes source files whose names end with @file{.c}, @file{.C}, or
@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. roland 16jul93.
-@node C Checks, Debugging C, C Defaults, C Constants
+@node C Checks
@subsubsection C and C++ type and range checks
@cindex C and C++ checks
indices are not checked, since they are often used to index a pointer
that is not itself an array.
-@node Debugging C, Debugging C plus plus, C Checks, C
+@node Debugging C
@subsubsection @value{GDBN} and C
The @code{set print union} and @code{show print union} commands apply to
* Debugging C plus plus::
@end menu
-@node Debugging C plus plus, , Debugging C, C
+@node Debugging C plus plus
@subsubsection @value{GDBN} features for C++
@cindex commands for C++
@itemx show print vtbl
Control the format for printing virtual function tables.
@xref{Print Settings, ,Print settings}.
-@ifset HPPA
(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
+@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 (@pxref{C plus plus expressions, ,C++
-expressions} for details). If it cannot find a match, it emits a
+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
overloaded functions that are class member functions, @value{GDBN}
searches for a function whose signature @emph{exactly} matches the
argument types.
-@end ifset
@item @r{Overloaded symbol names}
You can specify a particular definition of an overloaded symbol, using
@xref{Completion,, Command completion}, for details on how to do this.
@end table
-@node Modula-2, , C, Support
+@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
* GDB/M2:: @value{GDBN} and Modula-2
@end menu
-@node M2 Operators, Built-In Func/Proc, Modula-2, Modula-2
+@node M2 Operators
@subsubsection Operators
@cindex Modula-2 operators
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}).
@end quotation
@cindex Modula-2 built-ins
-@node Built-In Func/Proc, M2 Constants, M2 Operators, Modula-2
+@node Built-In Func/Proc
@subsubsection Built-in functions and procedures
Modula-2 also makes available several built-in procedures and functions.
@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})
@end quotation
@cindex Modula-2 constants
-@node M2 Constants, M2 Defaults, Built-In Func/Proc, Modula-2
+@node M2 Constants
@subsubsection Constants
@value{GDBN} allows you to express the constants of Modula-2 in the following
@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
Set constants are not yet supported.
@end itemize
-@node M2 Defaults, Deviations, M2 Constants, Modula-2
+@node M2 Defaults
@subsubsection Modula-2 defaults
@cindex Modula-2 defaults
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, M2 Checks, M2 Defaults, Modula-2
+@node Deviations
@subsubsection Deviations from standard Modula-2
@cindex Modula-2, deviations from
All built-in procedures both modify @emph{and} return their argument.
@end itemize
-@node M2 Checks, M2 Scope, Deviations, Modula-2
+@node M2 Checks
@subsubsection Modula-2 type and range checks
@cindex Modula-2 checks
Range checking is done on all mathematical operations, assignment, array
index bounds, and all built-in functions and procedures.
-@node M2 Scope, GDB/M2, M2 Checks, Modula-2
+@node M2 Scope
@subsubsection The scope operators @code{::} and @code{.}
@cindex scope
@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
module @var{module}, or if @var{id} is not an identifier in
@var{module}.
-@node GDB/M2, , M2 Scope, Modula-2
+@node GDB/M2
@subsubsection @value{GDBN} and Modula-2
Some @value{GDBN} commands have little use when debugging Modula-2 programs.
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.
-@node Symbols, Altering, Languages, Top
-@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 @samp{class
-@var{class-name}}, @samp{struct @var{struct-tag}}, @samp{union
-@var{union-tag}} or @samp{enum @var{enum-tag}}.
+@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
-@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.
+@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
-For example, for this variable declaration:
+@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
-@example
-struct complex @{double real; double imag;@} v;
-@end example
+@item @r{@emph{Real Modes:}}
+Real Modes are predefined with @code{REAL} and @code{LONG_REAL}.
-@noindent
-the two commands give this output:
+@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
-@example
-@group
-(@value{GDBP}) whatis v
-type = struct complex
-(@value{GDBP}) ptype v
-type = struct complex @{
- double real;
- double imag;
-@}
-@end group
-@end example
+@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
-@noindent
-As with @code{whatis}, using @code{ptype} without an argument refers to
-the type of @code{$}, the last value in the value history.
+@item @r{@emph{Structure Mode}}
+The Structure mode is displayed by the keyword @code{STRUCT(<field
+list>)}. The @code{<field list>} consists of names and modes of fields
+of the structure. Variant structures have the keyword @code{CASE <field>
+OF <variant fields> ESAC} in their field list. Since the current version
+of the GNU Chill compiler doesn't implement tag processing (no runtime
+checks of variant fields, and therefore no debugging info), the output
+always displays all variant fields.
+@smallexample
+(@value{GDBP}) ptype str
+type = STRUCT (
+ as x,
+ bs x,
+ CASE bs OF
+ (karli):
+ cs a
+ (ott):
+ ds x
+ ESAC
+)
+@end smallexample
+@end table
-@kindex info types
-@item info types @var{regexp}
-@itemx info types
-Print a brief description of all types whose name matches @var{regexp}
-(or all types in your program, if you supply no argument). Each
-complete typename is matched as though it were a complete line; thus,
-@samp{i type value} gives information on all types in your program whose
-name includes the string @code{value}, but @samp{i type ^value$} gives
-information only on types whose complete name is @code{value}.
+@node Locations
+@subsubsection Locations and their accesses
-This command differs from @code{ptype} in two ways: first, like
-@code{whatis}, it does not print a detailed description; second, it
-lists all source files where a type is defined.
+A location in Chill is an object which can contain values.
-@kindex info source
-@item info source
-Show the name of the current source file---that is, the source file for
-the function containing the current point of execution---and the language
-it was written in.
+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}.
-@kindex info sources
-@item info sources
-Print the names of all source files in your program for which there is
-debugging information, organized into two lists: files whose symbols
-have already been read, and files whose symbols will be read when needed.
+The pseudo-location @code{RESULT} (or @code{result}) can be used to
+display or change the result of a currently-active procedure:
-@kindex info functions
-@item info functions
-Print the names and data types of all defined functions.
+@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;
+@end example
+
+@noindent
+the two commands give this output:
+
+@example
+@group
+(@value{GDBP}) whatis v
+type = struct complex
+(@value{GDBP}) ptype v
+type = struct complex @{
+ double real;
+ double imag;
+@}
+@end group
+@end example
+
+@noindent
+As with @code{whatis}, using @code{ptype} without an argument refers to
+the type of @code{$}, the last value in the value history.
+
+@kindex info types
+@item info types @var{regexp}
+@itemx info types
+Print a brief description of all types whose names match @var{regexp}
+(or all types in your program, if you supply no argument). Each
+complete typename is matched as though it were a complete line; thus,
+@samp{i type value} gives information on all types in your program whose
+names include the string @code{value}, but @samp{i type ^value$} gives
+information only on types whose complete name is @code{value}.
+
+This command differs from @code{ptype} in two ways: first, like
+@code{whatis}, it does not print a detailed description; second, it
+lists all source files where a type is defined.
+
+@kindex info source
+@item info source
+Show the name of the current source file---that is, the source file for
+the function containing the current point of execution---and the language
+it was written in.
+
+@kindex info sources
+@item info sources
+Print the names of all source files in your program for which there is
+debugging information, organized into two lists: files whose symbols
+have already been read, and files whose symbols will be read when needed.
+
+@kindex info functions
+@item info functions
+Print the names and data types of all defined functions.
@item info functions @var{regexp}
Print the names and data types of all defined functions
which match the regular-expression @var{regexp}.
@end ignore
-@ifclear HPPA
@cindex reloading symbols
Some systems allow individual object files that make up your program to
be replaced without stopping and restarting your program. For example,
@item show symbol-reloading
Show the current @code{on} or @code{off} setting.
@end table
-@end ifclear
-@ifset HPPA
@kindex set opaque-type-resolution
@item set opaque-type-resolution on
Tell @value{GDBN} to resolve opaque types. An opaque type is a type
@kindex show opaque-type-resolution
@item show opaque-type-resolution
Show whether opaque types are resolved or not.
-@end ifset
@kindex maint print symbols
@cindex symbol dump
@value{GDBN} reads symbols (in the description of @code{symbol-file}).
@end table
-@node Altering, GDB Files, Symbols, Top
+@node Altering
@chapter Altering Execution
Once you think you have found an error in your program, you might want to
* Patching:: Patching your program
@end menu
-@node Assignment, Jumping, Altering, Altering
+@node Assignment
@section Assignment to variables
@cindex assignment
not printed and is not put in the value history (@pxref{Value History,
,Value history}). The expression is evaluated only for its effects.
-@ifclear HPPA
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
@example
(@value{GDBP}) set var width=47
@end example
-@end ifclear
-@ifset HPPA
+
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
(@value{GDBP}) p g
$1 = 1
(@value{GDBP}) set g=4
-(gdb) p g
+(@value{GDBP}) p g
$2 = 1
(@value{GDBP}) r
The program being debugged has been started already.
@example
(@value{GDBP}) set var g=4
@end example
-@end ifset
@value{GDBN} allows more implicit conversions in assignments than C; you can
freely store an integer value into a pointer variable or vice versa,
@noindent
stores the value 4 into that memory location.
-@node Jumping, Signaling, Assignment, Altering
+@node Jumping
@section Continuing at a different address
Ordinarily, when you continue your program, you do so at the place where
Resume execution at the instruction at address @var{address}.
@end table
-@ifclear HPPA
@c Doesn't work on HP-UX; have to set $pcoqh and $pcoqt.
-You can get much the same effect as the @code{jump} command by storing a
-new value into the register @code{$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,
+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
makes the next @code{continue} command or stepping command execute at
address @code{0x485}, rather than at the address where your program stopped.
@xref{Continuing and Stepping, ,Continuing and stepping}.
-@end ifclear
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
detail.
@c @group
-@node Signaling, Returning, Jumping, Altering
+@node Signaling
@section Giving your program a signal
@table @code
passes the signal directly to your program.
-@node Returning, Calling, Signaling, Altering
+@node Returning
@section Returning from a function
@table @code
and Stepping, ,Continuing and stepping}) resumes execution until the
selected stack frame returns naturally.
-@node Calling, Patching, Returning, Altering
+@node Calling
@section Calling program functions
@cindex calling functions
with @code{void} returned values. If the result is not void, it
is printed and saved in the value history.
-@ifclear HPPA
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.
-@end ifclear
-@node Patching, , Calling, Altering
+@node Patching
@section Patching programs
@cindex patching binaries
as well as reading.
@end table
-@node GDB Files, Targets, Altering, Top
+@node GDB Files
@chapter @value{GDBN} Files
@value{GDBN} needs to know the file name of the program to be debugged,
* Symbol Errors:: Errors reading symbol files
@end menu
-@node Files, Symbol Errors, GDB Files, GDB Files
+@node Files
@section Commands to specify files
@cindex symbol table
to run. You can change the value of this variable, for both @value{GDBN}
and your program, using the @code{path} command.
-@ifclear HPPA
On systems with memory-mapped files, an auxiliary file
@file{@var{filename}.syms} may hold symbol table information for
@var{filename}. If so, @value{GDBN} maps in the symbol table from
(available on the command line, and with the commands @code{file},
@code{symbol-file}, or @code{add-symbol-file}, described below),
for more information.
-@end ifclear
@item file
@code{file} with no argument makes @value{GDBN} discard any information 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.
-@ifclear HPPA
Best results are usually obtained from @sc{gnu} compilers; for example,
using @code{@value{GCC}} you can generate debugging information for
optimized code.
-@end ifclear
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
pauses into messages if desired. @xref{Messages/Warnings, ,Optional
warnings and messages}.)
-@ifclear HPPA
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. Note that ``stabs-in-COFF''
tables by using the @samp{-readnow} option with any of the commands that
load symbol table information, if you want to be sure @value{GDBN} has the
entire symbol table available.
-@end ifclear
-@ifclear HPPA
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
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
-@ifclear HPPA
@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
-@ifclear HPPA
@kindex section
@item section
The @code{section} command changes the base address of section SECTION of
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.
-@end ifclear
+separately. The @code{info files} command, described below, lists all
+the sections and their addresses.
@kindex info files
@kindex info target
name and remembers it that way.
@cindex shared libraries
-@ifclear HPPA
-@c added HP-UX -- Kim (HP writer)
@value{GDBN} supports HP-UX, SunOS, SVr4, Irix 5, and IBM RS/6000 shared
libraries.
-@end ifclear
-@ifset HPPA
-@value{GDBN} supports HP-UX shared libraries.
-@end ifset
+
@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).
-@ifset HPPA
-If the program loads a library explicitly, @value{GDBN} automatically
-loads the symbols at the time of the @code{shl_load} call.
-@end ifset
+
+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
loaded.
@end table
-@ifset HPPA
-@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.
+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
+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:
@item show auto-solib-add
Display the current autoloading size threshold, in megabytes.
@end table
-@end ifset
-@node Symbol Errors, , Files, GDB Files
+@node Symbol Errors
@section Errors reading symbol files
While reading a symbol file, @value{GDBN} occasionally encounters problems,
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.
+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
@end table
-@node Targets, Controlling GDB, GDB Files, Top
+@node Targets
@chapter Specifying a Debugging Target
@cindex debugging target
@kindex target
A @dfn{target} is the execution environment occupied by your program.
-@ifclear HPPA
-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
+
+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 HPPA
-On HP-UX systems, @value{GDBN} has been configured to support debugging
-of processes running on the PA-RISC architecture. This means that the
-only possible targets are:
-
-@itemize @bullet
-@item
-An executable that has been compiled and linked to run on HP-UX
-
-@item
-A live HP-UX process, either started by @value{GDBN} (with the
-@code{run} command) or started outside of @value{GDBN} and attached to
-(with the @code{attach} command)
-
-@item
-A core file generated by an HP-UX process that previously aborted
-execution
-@end itemize
-
-@value{GDBN} on HP-UX has not been configured to support remote
-debugging, or to support programs running on other platforms. 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}).
-@end ifset
+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, Target Commands, Targets, Targets
+@node Active Targets
@section Active targets
@cindex stacking targets
the @code{attach} command (@pxref{Attach, ,Debugging an already-running
process}).
-@node Target Commands, Byte Order, Active Targets, Targets
+@node Target Commands
@section Commands for managing targets
@table @code
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}.
+@noindent
+@xref{Files, , Commands to specify files}.
@kindex show gnutarget
@item show gnutarget
and @code{show gnutarget} displays @samp{The current BDF target is "auto"}.
@end table
-@ifclear HPPA
Here are some common targets (available, or not, depending on the GDB
configuration):
-@end ifclear
-@ifset HPPA
-These are the valid targets on HP-UX systems:
-@end ifset
@table @code
@kindex target exec
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
+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.
-@ifclear HPPA
@kindex target sim
@item target sim
-CPU simulator. @xref{Simulator,,Simulated CPU Target}.
-@end ifclear
+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
-The following targets are all CPU-specific, and only available for
-specific configurations.
-@c should organize by CPU
+Some configurations may include these targets as well:
@table @code
-@kindex target abug
-@item target abug @var{dev}
-ABug ROM monitor for M68K.
+@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
-@kindex target adapt
-@item target adapt @var{dev}
-Adapt monitor for A29K.
+You can use @code{objdump} to verify that the addresses are what you intended:
-@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}.
+@example
+sparclet-aout-objdump --headers --syms prog
+@end example
-@kindex target array
-@item target array @var{dev}
-Array Tech LSI33K RAID controller board.
+@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).
-@kindex target bug
-@item target bug @var{dev}
-BUG monitor, running on a MVME187 (m88k) board.
+@value{GDBN} comes up showing the prompt:
-@kindex target cpu32bug
-@item target cpu32bug @var{dev}
-CPU32BUG monitor, running on a CPU32 (M68K) board.
+@example
+(gdbslet)
+@end example
-@kindex target dbug
-@item target dbug @var{dev}
-dBUG ROM monitor for Motorola ColdFire.
+@menu
+* Sparclet File:: Setting the file to debug
+* Sparclet Connection:: Connecting to Sparclet
+* Sparclet Download:: Sparclet download
+* Sparclet Execution:: Running and debugging
+@end menu
-@kindex target ddb
-@item target ddb @var{dev}
-NEC's DDB monitor for Mips Vr4300.
+@node Sparclet File
+@subsubsection Setting file to debug
-@kindex target dink32
-@item target dink32 @var{dev}
-DINK32 ROM monitor for PowerPC.
+The @value{GDBN} command @code{file} lets you choose with program to debug.
-@kindex target e7000
-@item target e7000 @var{dev}
-E7000 emulator for Hitachi H8 and SH.
+@example
+(gdbslet) file prog
+@end example
-@kindex target es1800
-@item target es1800 @var{dev}
-ES-1800 emulator for M68K.
+@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:
-@kindex target est
-@item target est @var{dev}
-EST-300 ICE monitor, running on a CPU32 (M68K) board.
+@example
+prog: No such file or directory.
+@end example
-@kindex target hms
-@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.
-@xref{Hitachi Remote,,@value{GDBN} and Hitachi Microprocessors}.
+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.
-@kindex target lsi
-@item target lsi @var{dev}
-LSI ROM monitor for Mips.
+@node Sparclet Connection
+@subsubsection Connecting to Sparclet
-@kindex target m32r
-@item target m32r @var{dev}
-Mitsubishi M32R/D ROM monitor.
+The @value{GDBN} command @code{target} lets you connect to a Sparclet target.
+To connect to a target on serial port ``@code{ttya}'', type:
-@kindex target mips
-@item target mips @var{dev}
-IDT/SIM ROM monitor for Mips.
+@example
+(gdbslet) target sparclet /dev/ttya
+Remote target sparclet connected to /dev/ttya
+main () at ../prog.c:3
+@end example
-@kindex target mon960
-@item target mon960 @var{dev}
-MON960 monitor for Intel i960.
+@need 750
+@value{GDBN} displays messages like these:
-@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)}.
+@example
+Connected to ttya.
+@end example
-@kindex target nrom
-@item target nrom @var{dev}
-NetROM ROM emulator. This target only supports downloading.
+@node Sparclet Download
+@subsubsection Sparclet download
-@kindex target op50n
-@item target op50n @var{dev}
-OP50N monitor, running on an OKI HPPA board.
+@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:
-@kindex target pmon
-@item target pmon @var{dev}
-PMON ROM monitor for Mips.
+@example
+(gdbslet) load prog 0x12010000
+Loading section .text, size 0xdb0 vma 0x12010000
+@end example
-@kindex target ppcbug
-@item target ppcbug @var{dev}
-@kindex target ppcbug1
-@item target ppcbug1 @var{dev}
-PPCBUG ROM monitor for PowerPC.
+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.
-@kindex target r3900
-@item target r3900 @var{dev}
-Densan DVE-R3900 ROM monitor for Toshiba R3900 Mips.
+@node Sparclet Execution
+@subsubsection Running and debugging
-@kindex target rdi
-@item target rdi @var{dev}
-ARM Angel monitor, via RDI library interface.
-
-@kindex target rdp
-@item target rdp @var{dev}
-ARM Demon monitor.
+@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.
-@kindex target rom68k
-@item target rom68k @var{dev}
-ROM 68K monitor, running on an M68K IDP board.
+@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
-@kindex target rombug
-@item target rombug @var{dev}
-ROMBUG ROM monitor for OS/9000.
+@node Sparclite
+@subsection Fujitsu Sparclite
-@kindex target sds
-@item target sds @var{dev}
-SDS monitor, running on a PowerPC board (such as Motorola's ADS).
+@table @code
@kindex target sparclite
@item target sparclite @var{dev}
For example: target remote @var{dev} using @value{GDBN} standard
remote protocol.
-@kindex target sh3
-@kindex target sh3e
-@item target sh3 @var{dev}
-@item target sh3e @var{dev}
-Hitachi SH-3 and SH-3E target systems.
+@end table
-@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}.
+@node ST2000
+@subsection Tandem ST2000
-@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}.
+@value{GDBN} may be used with a Tandem ST2000 phone switch, running Tandem's
+STDBUG protocol.
-@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}.
+To connect your ST2000 to the host system, see the manufacturer's
+manual. Once the ST2000 is physically attached, you can run:
-@kindex target w89k
-@item target w89k @var{dev}
-W89K monitor, running on a Winbond HPPA board.
+@example
+target st2000 @var{dev} @var{speed}
+@end example
+@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:
+
+@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
-Different targets are available on different configurations of @value{GDBN};
-your configuration may have more or fewer targets.
+@node Z8000
+@subsection Zilog Z8000
-Many remote targets require you to download the executable's code
-once you've successfully established a connection.
+@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
+@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
-@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.
+@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.
-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{}}''
+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:
-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.
+@table @code
-On VxWorks, @code{load} links @var{filename} dynamically on the
-current target system as well as adding its symbols in @value{GDBN}.
+@item cycles
+Counts clock-ticks in the simulator.
-@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}.
+@item insts
+Counts instructions run in the simulator.
-@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).
+@item time
+Execution time in 60ths of a second.
-@code{load} does not repeat if you press @key{RET} again after using it.
@end table
-@node Byte Order, Remote, Target Commands, Targets
-@section Choosing target byte order
+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.
-@cindex choosing target byte order
-@cindex target byte order
-@kindex set endian big
-@kindex set endian little
-@kindex set endian auto
-@kindex show endian
+@node Architectures
+@section Architectures
-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
-GDB's idea of processor endian-ness manually.
+This section describes characteristics of architectures that affect
+all uses of @value{GDBN} with the architecture, both native and cross.
-@table @code
-@kindex set endian big
-@item set endian big
-Instruct @value{GDBN} to assume the target is big-endian.
+@menu
+* A29K::
+* Alpha::
+* MIPS::
+@end menu
-@kindex set endian little
-@item set endian little
-Instruct @value{GDBN} to assume the target is little-endian.
+@node A29K
+@subsection A29K
-@kindex set endian auto
-@item set endian auto
-Instruct @value{GDBN} to use the byte order associated with the
-executable.
+@table @code
-@item show endian
-Display @value{GDBN}'s current idea of the target byte order.
+@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 show rstack_high_address
+@item show rstack_high_address
+Display the current limit of the register stack, on AMD 29000 family
+processors.
@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 Alpha
+@subsection Alpha
-@node Remote, , Byte Order, Targets
-@section Remote debugging
-@cindex remote debugging
+See the following section.
-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.
+@node MIPS
+@subsection MIPS
-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}.
+@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.
-Other remote targets may be available in your
-configuration of @value{GDBN}; use @code{help target} to list them.
+@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:
-@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
-* Remote Serial:: @value{GDBN} remote serial protocol
-* i960-Nindy Remote:: @value{GDBN} with a remote i960 (Nindy)
-* UDI29K Remote:: The UDI protocol for AMD29K
-* EB29K Remote:: The EBMON protocol for AMD29K
-* VxWorks Remote:: @value{GDBN} and VxWorks
-* ST2000 Remote:: @value{GDBN} with a Tandem ST2000
-* Hitachi Remote:: @value{GDBN} and Hitachi Microprocessors
-* MIPS Remote:: @value{GDBN} and MIPS boards
-* Sparclet Remote:: @value{GDBN} and Sparclet boards
-* Simulator:: Simulated CPU target
-@end menu
+@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.
+
+@item show heuristic-fence-post
+Display the current limit.
+@end table
-@include remote.texi
+@noindent
+These commands are available @emph{only} when @value{GDBN} is configured
+for debugging programs on Alpha or MIPS processors.
@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
* Messages/Warnings:: Optional warnings and messages
@end menu
-@node Prompt, Editing, Controlling GDB, Controlling GDB
+@node Prompt
@section Prompt
@cindex 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.
Prints a line of the form: @samp{Gdb's prompt is: @var{your-prompt}}
@end table
-@node Editing, History, Prompt, Controlling GDB
+@node Editing
@section Command editing
@cindex readline
@cindex command line editing
Show whether command line editing is enabled.
@end table
-@node History, Screen Size, Editing, Controlling GDB
+@node History
@section Command history
@value{GDBN} can keep track of the commands you type during your
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
Print ten commands just after the commands last printed.
@end table
-@node Screen Size, Numbers, History, Controlling GDB
+@node Screen Size
@section Screen size
@cindex size of screen
@cindex pauses in output
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:
from wrapping its output.
@end table
-@node Numbers, Messages/Warnings, Screen Size, Controlling GDB
+@node Numbers
@section Numbers
@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
Display the current default base for numeric display.
@end table
-@node Messages/Warnings, , Numbers, Controlling GDB
+@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, Emacs, Controlling GDB, Top
+@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
* Output:: Commands for controlled output
@end menu
-@node Define, Hooks, Sequences, Sequences
+@node Define
@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
commands that normally print messages to say what they are doing omit the
messages when used in a user-defined command.
-@node Hooks, Command Files, Define, Sequences
+@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,
If you try to define a hook which does not match any known command, you
get a warning from the @code{define} command.
-@node Command Files, Output, Hooks, Sequences
+@node Command Files
@section Command files
@cindex command files
@cindex init file
@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{.gdbinit} on Unix, or
@file{gdb.ini} on DOS/Windows. @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}.
+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
normally print messages to say what they are doing omit the messages
when called from command files.
-@node Output, , Command Files, Sequences
+@node Output
@section Commands for controlled output
During the execution of a command file or a user-defined command, normal
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
-@node Emacs, GDB Bugs, Sequences, Top
+@node Emacs
@chapter Using @value{GDBN} under @sc{gnu} Emacs
@cindex 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.
-@ifset HPPA
-(Do not use the @code{-tui} option to run @value{GDBN} from Emacs.)
-@end ifset
+@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.
@end ignore
@node GDB Bugs
-@c links whacked to pacify makeinfo
-@c , Command Line Editing, Emacs, Top
@chapter Reporting Bugs in @value{GDBN}
@cindex bugs in @value{GDBN}
@cindex reporting bugs in @value{GDBN}
* Bug Reporting:: How to report bugs
@end menu
-@node Bug Criteria, Bug Reporting, GDB Bugs, GDB Bugs
+@node Bug Criteria
@section Have you found a bug?
@cindex bug criteria
for improvement of @value{GDBN} are welcome in any case.
@end itemize
-@node Bug Reporting, , Bug Criteria, GDB Bugs
+@node Bug Reporting
@section How to report bugs
@cindex bug reports
@cindex @value{GDBN} bugs, reporting
-@ifclear HPPA
A number of companies and individuals offer support for @sc{gnu} products.
If you obtained @value{GDBN} from a support organization, we recommend you
contact that organization first.
@value{GDBN} to this addresses:
@example
-bug-gdb@@prep.ai.mit.edu
+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
+@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}.
Boston, MA 02111-1307
USA
@end example
-@end ifclear
-
-@ifset HPPA
-If you obtained HP GDB as part of your HP ANSI C or HP ANSI C++ compiler
-kit, report problems to your HP Support Representative.
-
-If you obtained HP GDB from the Hewlett-Packard Web site, report
-problems by electronic mail to @code{wdb-www@@ch.hp.com}.
-@end ifset
The fundamental principle of reporting bugs usefully is this:
@strong{report all the facts}. If you are not sure whether to state a
The type of machine you are using, and the operating system name and
version number.
-@ifclear HPPA
@item
What compiler (and its version) was used to compile @value{GDBN}---e.g.
``@value{GCC}--2.8.1''.
-@end ifclear
@item
What compiler (and its version) was used to compile the program you are
us. If you had not told us to expect a crash, then we would not be able
to draw any conclusion from our observations.
-@ifclear HPPA
@item
If you wish to suggest changes to the @value{GDBN} source, send us context
diffs. If you even discuss something in the @value{GDBN} source, refer to
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 ifclear
+
@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
+@include inc-hist.texinfo
-@ifclear PRECONFIGURED
-@ifclear HPPA
@node Formatting Documentation
-@c links whacked to pacify makeinfo
-@c , Installing GDB, Renamed Commands, Top
@appendix Formatting Documentation
@cindex @value{GDBN} reference card
@end example
Then give @file{gdb.dvi} to your @sc{dvi} printing program.
-@end ifclear
-@node Installing GDB, Index, Using History Interactively, Top
+@node Installing GDB
@appendix Installing @value{GDBN}
@cindex configuring @value{GDBN}
@cindex installation
-@ifset HPPA
-If you obtain @value{GDBN} (HP WDB 0.75) as part of your HP ANSI C or
-HP ANSI C++ Developer's Kit at HP-UX Release 11.0, you do not have to
-take any special action to build or install @value{GDBN}.
-
-If you obtain @value{GDBN} (HP WDB 0.75) from an HP web site, you may
-download either a @code{swinstall}-able package or a source tree, or
-both.
-
-Most customers will want to install the @value{GDBN} binary that is part
-of the @code{swinstall}-able package. To do so, use a command of the
-form
-
-@smallexample
-/usr/sbin/swinstall -s @var{package-name} WDB
-@end smallexample
-
-Alternatively, it is possible to build @value{GDBN} from the source
-distribution. Sophisticated customers who want to modify the debugger
-sources to tailor @value{GDBN} to their their needs may wish to do this.
-The source distribution consists of a @code{tar}'ed source tree rooted
-at @file{gdb-4.16/...}. The instructions that follow describe how to
-build a @file{gdb} executable from this source tree. HP believes that
-these instructions apply to the WDB source tree that it distributes.
-However, HP does not explicitly support building a @file{gdb} for any
-non-HP platform from the WDB source tree. It may work, but HP has not
-tested it for any platforms other than those described in the WDB 0.75
-Release Notes.
-@end ifset
-
@value{GDBN} comes with a @code{configure} script that automates the process
of preparing @value{GDBN} for installation; you can then use @code{make} to
build the @code{gdb} program.
* Configure Options:: Summary of options for configure
@end menu
-@node Separate Objdir, Config Names, Installing GDB, Installing GDB
+@node Separate Objdir
@section Compiling @value{GDBN} in another directory
If you want to run @value{GDBN} versions for several host or target machines,
if they are NFS-mounted on each of the hosts); they will not interfere
with each other.
-@node Config Names, Configure Options, Separate Objdir, Installing GDB
+@node Config Names
@section Specifying names for hosts and targets
The specifications used for hosts and targets in the @code{configure}
@code{config.sub} is also distributed in the @value{GDBN} source
directory (@file{gdb-@value{GDBVN}}, for version @value{GDBVN}).
-@node Configure Options, , Config Names, Installing GDB
+@node Configure Options
@section @code{configure} options
Here is a summary of the @code{configure} options and arguments that
There are many other options available as well, but they are generally
needed for special purposes only.
-@end ifclear
-
-@node Index, , Installing GDB, Top
+@node Index
@unnumbered Index
@printindex cp
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