Adding e3sm-kernels to Spack (#32341)

* Initial Draft of E3SM-Kernels Spackage

Initial draft of E3SM-Kernels. Currently no support for nested_loops due
to build system limitations

* Style Check and Fixed gfortran Check

Fixed style issues and changed gnu toolchain check to a gfortran check
due to hybrid compilers (e.g. clang+gfortran)

* Fixed Style Issues

var/spack/repos/builtin/packages/e3sm-kernels/package.py

@@ -0,0 +1,57 @@
+# Copyright 2013-2022 Lawrence Livermore National Security, LLC and other
+# Spack Project Developers. See the top-level COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+import os
+
+from spack.package import *
+
+
+class E3smKernels(MakefilePackage):
+    """
+    Climate kernels for Co-design that originate from the Energy
+    Exascale Earth System Model (E3SM).
+    """
+
+    homepage = "https://github.com/e3SM-Project/codesign-kernels"
+    url = "https://github.com/E3SM-Project/codesign-kernels/archive/refs/tags/v1.0.tar.gz"
+    git = "https://github.com/E3SM-Project/codesign-kernels.git"
+
+    maintainers = ["sarats", "philipwjones"]
+
+    version("master", branch="master")
+    version("1.0", sha256="358249785ba9f95616feecbb6f37f7694646568499c11b2094c9233999c6cc95")
+
+    variant(
+        "kernel",
+        default="atmosphere",
+        values=(
+            "atmosphere",
+            "mmf-mpdata-tracer",
+        ),
+        description="Specify E3SM Kernel to Build",
+        multi=False,
+    )
+
+    @property
+    def build_directory(self):
+        return self.spec.variants["kernel"].value
+
+    @property
+    def build_targets(self):
+        # Spack will provide optimization flags
+        # But we still need to pass in fortran flags for gfortran
+        args = []
+        # Test for gfortran specifically due to hybrid compilers like llvm
+        if "gfortran" in self.compiler.fc:
+            args.append("FFLAGS=-ffree-line-length-none")
+        return args
+
+    def install(self, spec, prefix):
+        # Manually copy binaries over
+        mkdir(prefix.bin)
+        if self.spec.variants["kernel"].value == "atmosphere":
+            install(os.path.join("atmosphere", "atm"), prefix.bin.atm)
+        elif self.spec.variants["kernel"].value == "mmf-mpdata-tracer":
+            install(os.path.join("mmf-mpdata-tracer", "advect"), prefix.bin.advect)