Add NAG Fortran Compiler support

lib/spack/env/cc

@@ -94,11 +94,11 @@ case "$command" in
         command="$SPACK_CXX"
         language="C++"
         ;;
-    f90|fc|f95|gfortran|ifort|pgf90|xlf90)
+    f90|fc|f95|gfortran|ifort|pgf90|xlf90|nagfor)
         command="$SPACK_FC"
         language="Fortran 90"
         ;;
-    f77|gfortran|ifort|pgf77|xlf)
+    f77|gfortran|ifort|pgf77|xlf|nagfor)
         command="$SPACK_F77"
         language="Fortran 77"
         ;;

lib/spack/spack/compilers/__init__.py

@@ -45,7 +45,7 @@
 _imported_compilers_module = 'spack.compilers'
 _required_instance_vars = ['cc', 'cxx', 'f77', 'fc']
 
-_default_order = ['gcc', 'intel', 'pgi', 'clang', 'xlc']
+_default_order = ['gcc', 'intel', 'pgi', 'clang', 'xlc', 'nag']
 
 def _auto_compiler_spec(function):
     def converter(cspec_like):

lib/spack/spack/compilers/nag.py

@@ -0,0 +1,24 @@
+class Nag(Compiler):
+    # Subclasses use possible names of C compiler
+    cc_names = []
+
+    # Subclasses use possible names of C++ compiler
+    cxx_names = []
+
+    # Subclasses use possible names of Fortran 77 compiler
+    f77_names = ['nagfor']
+
+    # Subclasses use possible names of Fortran 90 compiler
+    fc_names = ['nagfor']
+
+    @classmethod
+    def default_version(self, comp):
+        """The '-V' option works for nag compilers.
+           Output looks like this::
+
+               NAG Fortran Compiler Release 6.0(Hibiya) Build 1037
+               Product NPL6A60NA for x86-64 Linux
+               Copyright 1990-2015 The Numerical Algorithms Group Ltd., Oxford, U.K.
+        """
+        return get_compiler_version(
+            comp, '-V', r'NAG Fortran Compiler Release ([0-9.]+)')