CGNS: Add option for 64-bit integers (#9990)

* CGNS: Add option for 64-bit integers

Added the `int64` variant which will build the library using 64-bit integers for certain values.  This gives the capability to have models with more than 2 billion cells and/or nodes.  

Beginning with CGNS-3.1.0, two new typedef variables have been introduced to support 64-bit mode. The `cglong_t` typedef is always a 64-bit integer, and `cgsize_t` will be either a 32-bit or 64-bit integer depending on how the library was built. Many of the C functions in the MLL have been changed to to use `cgsize_t` instead of `int` in the arguments. These functions include any that may exceed the 2Gb limit of an` int`, e.g. zone dimensions, element data, boundary conditions, and connectivity. In Fortran, all integer data is taken to be `integer*4` for 32-bit and `integer*8` for 64-bit builds.

1 files changed, 5 insertions, 0 deletions

diff --git a/var/spack/repos/builtin/packages/cgns/package.py b/var/spack/repos/builtin/packages/cgns/package.py
index e101f84c27..7a21848e6b 100644
--- a/var/spack/repos/builtin/packages/cgns/package.py
+++ b/var/spack/repos/builtin/packages/cgns/package.py
@@ -21,6 +21,7 @@ class Cgns(CMakePackage):
     variant('fortran', default=False, description='Enable Fortran interface')
     variant('scoping', default=True, description='Enable scoping')
     variant('mpi', default=True, description='Enable parallel cgns')
+    variant('int64', default=False, description='Build with 64-bit integers')    
 
     depends_on('hdf5', when='+hdf5~mpi')
     depends_on('hdf5+mpi', when='+hdf5+mpi')
@@ -48,6 +49,10 @@ class Cgns(CMakePackage):
                 '-DCMAKE_Fortran_COMPILER=%s' % spec['mpi'].mpifc
             ])
 
+        options.append(
+            '-DCGNS_ENABLE_64BIT:BOOL={0}'.format(
+                'ON' if '+int64' in spec else 'OFF'))
+
         if '+hdf5' in spec:
             options.extend([
                 '-DCGNS_ENABLE_HDF5:BOOL=ON',