Fix module support for oneapi compilers (#28901)

Updates to improve Spack-generated modules for Intel oneAPI compilers:

* intel-oneapi-compilers set CC etc.
* Add a new package intel-oneapi-compilers-classic which can be used to
  generate a module which sets CC etc. to older compilers (e.g. icc)
* lmod module logic now updated to treat the intel-oneapi-compilers*
  packages as compilers

lib/spack/spack/modules/lmod.py

@@ -196,6 +196,14 @@ def provides(self):
         if self.spec.name == 'llvm-amdgpu':
             provides['compiler'] = spack.spec.CompilerSpec(str(self.spec))
             provides['compiler'].name = 'rocmcc'
+        # Special case for oneapi
+        if self.spec.name == 'intel-oneapi-compilers':
+            provides['compiler'] = spack.spec.CompilerSpec(str(self.spec))
+            provides['compiler'].name = 'oneapi'
+        # Special case for oneapi classic
+        if self.spec.name == 'intel-oneapi-compilers-classic':
+            provides['compiler'] = spack.spec.CompilerSpec(str(self.spec))
+            provides['compiler'].name = 'intel'
 
         # All the other tokens in the hierarchy must be virtual dependencies
         for x in self.hierarchy_tokens:

var/spack/repos/builtin/packages/intel-oneapi-compilers-classic/package.py

@@ -0,0 +1,50 @@
+# 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)
+
+from spack import *
+
+
+@IntelOneApiPackage.update_description
+class IntelOneapiCompilersClassic(Package):
+    """Relies on intel-oneapi-compilers to install the compilers, and
+    configures modules for icc/icpc/ifort.
+
+    """
+
+    maintainers = ['rscohn2']
+
+    homepage = "https://software.intel.com/content/www/us/en/develop/tools/oneapi.html"
+
+    has_code = False
+
+    phases = []
+
+    for ver in ['2022.1.0',
+                '2022.0.2',
+                '2022.0.1',
+                '2021.4.0',
+                '2021.3.0',
+                '2021.2.0',
+                '2021.1.2']:
+        version(ver)
+        depends_on('intel-oneapi-compilers@' + ver, when='@' + ver, type='run')
+
+    def setup_run_environment(self, env):
+        """Adds environment variables to the generated module file.
+
+        These environment variables come from running:
+
+        .. code-block:: console
+
+           $ source {prefix}/{component}/{version}/env/vars.sh
+
+        and from setting CC/CXX/F77/FC
+        """
+        bin = join_path(self.spec['intel-oneapi-compilers'].prefix,
+                        'compile', 'linux', 'bin', 'intel64')
+        env.set('CC', join_path(bin, 'icc'))
+        env.set('CXX', join_path(bin, 'icpc'))
+        env.set('F77', join_path(bin, 'ifort'))
+        env.set('FC', join_path(bin, 'ifort'))

var/spack/repos/builtin/packages/intel-oneapi-compilers/package.py

@@ -143,3 +143,22 @@ def install(self, spec, prefix):
                 # Try to patch all files, patchelf will do nothing if
                 # file should not be patched
                 subprocess.call(['patchelf', '--set-rpath', rpath, file])
+
+    def setup_run_environment(self, env):
+        """Adds environment variables to the generated module file.
+
+        These environment variables come from running:
+
+        .. code-block:: console
+
+           $ source {prefix}/{component}/{version}/env/vars.sh
+
+        and from setting CC/CXX/F77/FC
+        """
+        super(IntelOneapiCompilers, self).setup_run_environment(env)
+
+        bin = join_path(self.component_path, 'linux', 'bin')
+        env.set('CC', join_path(bin, 'icx'))
+        env.set('CXX', join_path(bin, 'icpx'))
+        env.set('F77', join_path(bin, 'ifx'))
+        env.set('FC', join_path(bin, 'ifx'))