--- WebIDL.py
+++ WebIDL.py
@@ -3653,6 +3653,7 @@ class IDLInterfaceMember(IDLObjectWithIdentifier, IDLExposureMixins):
         IDLObjectWithIdentifier.__init__(self, location, None, identifier)
         IDLExposureMixins.__init__(self, location)
         self.tag = tag
+        self.exposed = set()
         if extendedAttrDict is None:
             self._extendedAttrDict = {}
         else:
@@ -3686,12 +3687,16 @@ class IDLInterfaceMember(IDLObjectWithIdentifier, IDLExposureMixins):
     def getExtendedAttribute(self, name):
         return self._extendedAttrDict.get(name, None)

+    def exposedSet(self):
+        return self.exposed
+
     def finish(self, scope):
         # We better be exposed _somewhere_.
         if (len(self._exposureGlobalNames) == 0):
             print self.identifier.name
         assert len(self._exposureGlobalNames) != 0
         IDLExposureMixins.finish(self, scope)
+        globalNameSetToExposureSet(scope, self._exposureGlobalNames, self.exposed)

     def validate(self):
         if self.isAttr() or self.isMethod():