Building with CMake

Instructions for building FMS with cmake

1. Environment Variables

For GNU compilers on Linux with the bash shell:

export FC=mpifort
export CC=mpicc

For Intel Compilers on Linux with the bash shell:

export FC=mpiifort
export CC=mpiicc

NetCDF is provided via the nc-config command:

export NetCDF_ROOT=`nc-config --prefix`

If building with yaml parser (-DWITH_YAML)

export LIBYAML_ROOT=<your libyaml install directory>

Setting custom flags with the bash shell

To override the default compiler flags:

export FCFLAGS="<fortran flags>"
export CFLAGS="<c flags>"

In addition, the flag below must be included with the cmake command:

cmake <any other options> -DCMAKE_BUILD_TYPE=Debug ..

2. Build and install FMS with CMake

<prefix> is the full install directory for FMS provided by user

cd FMS
mkdir -p build && cd build
cmake -DCMAKE_INSTALL_PREFIX=<prefix> ..
make -j4
make install

User configurable options:

By default, FMS is built without OpenMP and in single precision (r4)

The 64BIT and 32BIT precision options will build distinct libraries when enabled with the given default real size, libfms_r4 or libfms_r8.

The following build options are available:

-DOPENMP   "Build FMS with OpenMP support"        DEFAULT: OFF
-D32BIT    "Build 32-bit (r4) FMS library"        DEFAULT: ON
-D64BIT    "Build 64-bit (r8) FMS library"        DEFAULT: OFF
-DFPIC     "Build with position independent code" DEFAULT: OFF
 
-DCONSTANTS             "Build with <X> constants parameter definitions"     DEFAULT:GFDL  OPTIONS:GFS|GEOS|GFDL
-DINTERNAL_FILE_NML     "Enable compiler definition -DINTERNAL_FILE_NML"     DEFAULT: ON
-DENABLE_QUAD_PRECISION "Enable compiler definition -DENABLE_QUAD_PRECISION" DEFAULT: ON
-DGFS_PHYS              "Enable compiler definition -DGFS_PHYS"              DEFAULT:OFF
-DLARGEFILE             "Enable compiler definition -Duse_LARGEFILE"         DEFAULT:OFF
-DWITH_YAML             "Enable compiler definition -Duse_yaml"              DEFAULT:OFF

3. Installation structure

When the above command finishes, the <prefix> will have an include_r4 and a lib directory. The lib directory will have these files:

libfms_r4.a
cmake/fms/fms-targets.cmake
cmake/fms/fms-targets-release.cmake
cmake/fms/fms-config.cmake
cmake/fms/fms-config-version.cmake

4. Using FMS in your application

FMS built with cmake provides transient targets with its package configuration. To be able to look for FMS in your application, set the following environment variable:

export FMS_ROOT=<prefix>

where <prefix> is the full path to FMS installation.

To find FMS in your application CMakeLists.txt:

find_package(FMS)

To link your application with FMS library:

target_link_libraries(appName FMS::fms_r4)

If your application does not provide a means to locate the NetCDF installation via cmake, this may help:

-DCMAKE_MODULE_PATH=<FMS_SRC_DIR>/cmake