Channelflow installation instructions. Tue Feb 14 15:05:17 EST 2006

In four parts
(1) Installation of channelflow libraries
(2) Compiling channelflow programs and linking to the channelflow libraries
(3) Debugging channelflow programs
(4) Generic GNU install instructions

-------------------------------------------------------------------------
(1) Installation of channelflow libraries

For the most part you can follow the generic GNU installation instructions 
listed in (4) below, which boil down to

  tar xzpfz channeflow-0.9.22.tar.gz  # maybe change release number
  cd channelflow
  ./configure [--prefix=/alternate/installation/dir]
  make
  make -s check                       # skippable
  make install

where the square brackets [...] indicate an optional argument and # marks off
comments. The --prefix option specifies the directory where the channelflow 
headers and libraries will ultimately be installed. The default installtion 

The above installation sequence will install optimized libraries with neither 
debugging symbols nor run-time checks for index bounds, etc. To compile 
and install debugging libraries in addition to the optimized libraries, run 
these commands, too:

  make clean
  ./configure --enable-debug --prefix=/alternate/installation/dir
  cp channelflow/libchlflow.a /alternate/installation/dir/lib/libchflowdebug.a

or if you used the default install directory,

  make clean
  ./configure --enable-debug 
  cp channelflow/libchflow.a /usr/local/lib/libchflowdebug.a 

Be warned: It's not hard to let the debugging library get out of sync with
the headers and the optimized library, since you have to remember to perform
these steps. I intend to figure out how compile both optimized and debugging 
libraries in with a single "./configure; make". Maybe I'll have more luck on 
my second try.


-------------------------------------------------------------------------
(2) Compiling channelflow programs and linking to the channelflow libraries

The channelflow/examples directory has several examples of simple channelflow
programs and a rudimentary Makefile. If channelflow was installed in the 
default directory /usr/local, you can probably compile, link and run the 
example programs with direct calls to the compiler

  cd examples
  g++ -o channel channel.cpp -lchflow -lfftw3 -lm
  ./channel

-------------------------------------------------------------------------
(3) Debugging channelflow programs

The Channelflow debugging libraries have quite a few run-time checks for 
things like out-of-bounds errors on indices and discretization compatibility 
between fields in algebraic operations. Hitting such an error will produce 
a run-time error message. With the optimized libraries, the error will
produce a seg fault, or in the worse case, keep running without complaining.

The examples directory has a simple Makefile that shows how you can build 
debugging versus optimized executables. You might need to edit the Makefile
to redefine the CHANNELDIR variable, if you installed channelflow in an 
alternate installtion directory. To compile an optimized executable,
run "make <program>.x". E.g.
  
  make channel.x
  ./channel.x

To compile a debugging executable, run "make <program>.dx". E.g.

  make channel.dx
  ./channel.dx     

The program errorexamples.cpp illustrates the consequences of programming 
errors with optimized versus debugging executables. To wit,

  make ./errorexamples.x
  g++ -Wall -O2 -DNDEBUG -I/usr/local/include  -c errorexamples.cpp
  g++ -o errorexamples.x errorexamples.o  -L/usr/local/lib -lchflow -lfftw3 -lm
  rm errorexamples.o

  ./errorexamples.x
  Deliberately causing an index-out-of-bounds error...
  Deliberately causing a field-state error...
  Deliberately causing a field incompatibility error...
  Segmentation fault

  make ./errorexamples.dx
  g++ -Wall -g -O1  -I/usr/local/include  -o errorexamples.do -c errorexamples.cpp
  g++ -g -o errorexamples.dx errorexamples.do  -L/usr/local/lib -lchflowdebug -lfftw3 -lm
  rm errorexamples.do
  ./errorexamples.dx
  Deliberately causing an index-out-of-bounds error...
  errorexamples.dx: /usr/local/include/channelflow/flowfield.h:347: 
    int FlowField::flatten(int, int, int, int) const: 
    Assertion `ny>=0 && ny<Ny_' failed.
  Aborted

It is often helpful to run debugging executables within a debugger. E.g.
"gdb errorexamples.dx". See gdb documentation for more information.


-------------------------------------------------------------------------
(4) Generic GNU Installtion instructions

This file is the generic INSTALL document distributed with autoconf.
It is intended as a basic guide for all autoconf-generated configure
scripts.  See the file INSTALL.OCTAVE for information specific to
installing Octave.

========================================================================

Copyright (C) 1994, 1995, 1996, 1999, 2000, 2001, 2002 Free Software
Foundation, Inc.

   This file is free documentation; the Free Software Foundation gives
unlimited permission to copy, distribute and modify it.

Basic Installation
==================

   These are generic installation instructions.

   The `configure' shell script attempts to guess correct values for
various system-dependent variables used during compilation.  It uses
those values to create a `Makefile' in each directory of the package.
It may also create one or more `.h' files containing system-dependent
definitions.  Finally, it creates a shell script `config.status' that
you can run in the future to recreate the current configuration, and a
file `config.log' containing compiler output (useful mainly for
debugging `configure').

   It can also use an optional file (typically called `config.cache'
and enabled with `--cache-file=config.cache' or simply `-C') that saves
the results of its tests to speed up reconfiguring.  (Caching is
disabled by default to prevent problems with accidental use of stale
cache files.)

   If you need to do unusual things to compile the package, please try
to figure out how `configure' could check whether to do them, and mail
diffs or instructions to the address given in the `README' so they can
be considered for the next release.  If you are using the cache, and at
some point `config.cache' contains results you don't want to keep, you
may remove or edit it.

   The file `configure.ac' (or `configure.in') is used to create
`configure' by a program called `autoconf'.  You only need
`configure.ac' if you want to change it or regenerate `configure' using
a newer version of `autoconf'.

The simplest way to compile this package is:

  1. `cd' to the directory containing the package's source code and type
     `./configure' to configure the package for your system.  If you're
     using `csh' on an old version of System V, you might need to type
     `sh ./configure' instead to prevent `csh' from trying to execute
     `configure' itself.

     Running `configure' takes awhile.  While running, it prints some
     messages telling which features it is checking for.

  2. Type `make' to compile the package.

  3. Optionally, type `make check' to run any self-tests that come with
     the package.

  4. Type `make install' to install the programs and any data files and
     documentation.

  5. You can remove the program binaries and object files from the
     source code directory by typing `make clean'.  To also remove the
     files that `configure' created (so you can compile the package for
     a different kind of computer), type `make distclean'.  There is
     also a `make maintainer-clean' target, but that is intended mainly
     for the package's developers.  If you use it, you may have to get
     all sorts of other programs in order to regenerate files that came
     with the distribution.

Compilers and Options
=====================

   Some systems require unusual options for compilation or linking that
the `configure' script does not know about.  Run `./configure --help'
for details on some of the pertinent environment variables.

   You can give `configure' initial values for configuration parameters
by setting variables in the command line or in the environment.  Here
is an example:

     ./configure CC=c89 CFLAGS=-O2 LIBS=-lposix

   *Note Defining Variables::, for more details.

Compiling For Multiple Architectures
====================================

   You can compile the package for more than one kind of computer at the
same time, by placing the object files for each architecture in their
own directory.  To do this, you must use a version of `make' that
supports the `VPATH' variable, such as GNU `make'.  `cd' to the
directory where you want the object files and executables to go and run
the `configure' script.  `configure' automatically checks for the
source code in the directory that `configure' is in and in `..'.

   If you have to use a `make' that does not support the `VPATH'
variable, you have to compile the package for one architecture at a
time in the source code directory.  After you have installed the
package for one architecture, use `make distclean' before reconfiguring
for another architecture.

Installation Names
==================

   By default, `make install' will install the package's files in
`/usr/local/bin', `/usr/local/man', etc.  You can specify an
installation prefix other than `/usr/local' by giving `configure' the
option `--prefix=PATH'.

   You can specify separate installation prefixes for
architecture-specific files and architecture-independent files.  If you
give `configure' the option `--exec-prefix=PATH', the package will use
PATH as the prefix for installing programs and libraries.
Documentation and other data files will still use the regular prefix.

   In addition, if you use an unusual directory layout you can give
options like `--bindir=PATH' to specify different values for particular
kinds of files.  Run `configure --help' for a list of the directories
you can set and what kinds of files go in them.

   If the package supports it, you can cause programs to be installed
with an extra prefix or suffix on their names by giving `configure' the
option `--program-prefix=PREFIX' or `--program-suffix=SUFFIX'.

Optional Features
=================

   Some packages pay attention to `--enable-FEATURE' options to
`configure', where FEATURE indicates an optional part of the package.
They may also pay attention to `--with-PACKAGE' options, where PACKAGE
is something like `gnu-as' or `x' (for the X Window System).  The
`README' should mention any `--enable-' and `--with-' options that the
package recognizes.

   For packages that use the X Window System, `configure' can usually
find the X include and library files automatically, but if it doesn't,
you can use the `configure' options `--x-includes=DIR' and
`--x-libraries=DIR' to specify their locations.

Specifying the System Type
==========================

   There may be some features `configure' cannot figure out
automatically, but needs to determine by the type of machine the package
will run on.  Usually, assuming the package is built to be run on the
_same_ architectures, `configure' can figure that out, but if it prints
a message saying it cannot guess the machine type, give it the
`--build=TYPE' option.  TYPE can either be a short name for the system
type, such as `sun4', or a canonical name which has the form:

     CPU-COMPANY-SYSTEM

where SYSTEM can have one of these forms:

     OS KERNEL-OS

   See the file `config.sub' for the possible values of each field.  If
`config.sub' isn't included in this package, then this package doesn't
need to know the machine type.

   If you are _building_ compiler tools for cross-compiling, you should
use the `--target=TYPE' option to select the type of system they will
produce code for.

   If you want to _use_ a cross compiler, that generates code for a
platform different from the build platform, you should specify the
"host" platform (i.e., that on which the generated programs will
eventually be run) with `--host=TYPE'.

Sharing Defaults
================

   If you want to set default values for `configure' scripts to share,
you can create a site shell script called `config.site' that gives
default values for variables like `CC', `cache_file', and `prefix'.
`configure' looks for `PREFIX/share/config.site' if it exists, then
`PREFIX/etc/config.site' if it exists.  Or, you can set the
`CONFIG_SITE' environment variable to the location of the site script.
A warning: not all `configure' scripts look for a site script.

Defining Variables
==================

   Variables not defined in a site shell script can be set in the
environment passed to `configure'.  However, some packages may run
configure again during the build, and the customized values of these
variables may be lost.  In order to avoid this problem, you should set
them in the `configure' command line, using `VAR=value'.  For example:

     ./configure CC=/usr/local2/bin/gcc

will cause the specified gcc to be used as the C compiler (unless it is
overridden in the site shell script).

`configure' Invocation
======================

   `configure' recognizes the following options to control how it
operates.

`--help'
`-h'
     Print a summary of the options to `configure', and exit.

`--version'
`-V'
     Print the version of Autoconf used to generate the `configure'
     script, and exit.

`--cache-file=FILE'
     Enable the cache: use and save the results of the tests in FILE,
     traditionally `config.cache'.  FILE defaults to `/dev/null' to
     disable caching.

`--config-cache'
`-C'
     Alias for `--cache-file=config.cache'.

`--quiet'
`--silent'
`-q'
     Do not print messages saying which checks are being made.  To
     suppress all normal output, redirect it to `/dev/null' (any error
     messages will still be shown).

`--srcdir=DIR'
     Look for the package's source code in directory DIR.  Usually
     `configure' can determine that directory automatically.

`configure' also accepts some other, not widely useful, options.  Run
`configure --help' for more details.

