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           README file for the ESMF build_config directory.


 Earth System Modeling Framework
 Copyright 2002-2022, University Corporation for Atmospheric Research,
 Massachusetts Institute of Technology, Geophysical Fluid Dynamics
 Laboratory, University of Michigan, National Centers for Environmental
 Prediction, Los Alamos National Laboratory, Argonne National Laboratory,
 NASA Goddard Space Flight Center.
 Licensed under the University of Illinois-NCSA License.

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The files in this directory contain per-platform makefile information which is 
included by the ESMF build system.

** See the top level README file for more details. **


Naming Conventions
------------------

In $ESMF_DIR/build_config, each compiler/platform combination has
a separate subdirectory which follows a 3-part naming convention:

The first part is the system name as it is automatically set in ESMF_OS.

The second part is the compiler name for those platforms which support
compilers from different vendors.  For those systems which come with a
single vendor-supplied compiler, the compiler name is 'default'.  
The environment variable ESMF_COMPILER is used to select the compiler.

The last part of the name is the site-specific information. The 'default'
directories contain files which are always read for the given 
architecture/compiler combination. Then, in addition, if the environment
variable ESMF_SITE has a value, the corresponding directory will be 
searched after the default directory, for overrides and additional settings 
of directory names, values, flags, and other custom information.

Note that building on the SGI Altix is the same as the other Linux/Intel 
platforms, so set ESMF_COMPILER to 'intel' to use the files in the
Linux.intel.default directory. For Altix set ESMF_COMM to 'mpi' in order to
pick up the vendor MPI library.


File Descriptions
-----------------

Each default directory contains the following files:

 ESMC_Conf.h    : C++ preprocessor definitions needed for this platform.

 ESMF_Conf.inc  : values needed by both preprocessed F90 and C++; contains
                  information in a format parseable by both languages.         

 build_rules.mk : makefile fragment which is included by the main ESMF build
                  system and contains specific settings for this platform.

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 $Id$