Adding a bit more Mellanox MXM capability to OpenMPI. (#4762)

var/spack/repos/builtin/packages/openmpi/package.py

@@ -52,6 +52,18 @@ def _verbs_dir():
         return None
 
 
+def _mxm_dir():
+    """Look for default directory where the Mellanox package is
+    installed. Return None if not found.
+    """
+    # Only using default directory; make this more flexible in the future
+    path = "/opt/mellanox/mxm"
+    if os.path.isdir(path):
+        return path
+    else:
+        return None
+
+
 class Openmpi(AutotoolsPackage):
     """The Open MPI Project is an open source Message Passing Interface
        implementation that is developed and maintained by a consortium
@@ -251,6 +263,17 @@ def with_or_without_verbs(self, activated):
             line += '={0}'.format(path)
         return line
 
+    def with_or_without_mxm(self, activated):
+        opt = 'mxm'
+        # If the option has not been activated return --without-mxm
+        if not activated:
+            return '--without-{0}'.format(opt)
+        line = '--with-{0}'.format(opt)
+        path = _mxm_dir()
+        if (path is not None):
+            line += '={0}'.format(path)
+        return line
+
     @run_before('autoreconf')
     def die_without_fortran(self):
         # Until we can pass variants such as +fortran through virtual