Cache const-or-volatile-propagated entries from scope of const or volatile object"

Cython/Compiler/Symtab.py

@@ -3246,13 +3246,18 @@ class CConstOrVolatileScope(Scope):
         self.base_type_scope = base_type_scope
         self.is_const = is_const
         self.is_volatile = is_volatile
+        self.cached_const_or_volatile_entries = {}
 
     def lookup_here(self, name):
-        entry = self.base_type_scope.lookup_here(name)
-        if entry is not None:
-            entry = copy.copy(entry)
-            entry.type = PyrexTypes.c_const_or_volatile_type(
-                    entry.type, self.is_const, self.is_volatile)
+        try:
+            return self.cached_const_or_volatile_entries[name]
+        except KeyError:
+            entry = self.base_type_scope.lookup_here(name)
+            if entry is not None:
+                entry = copy.copy(entry)
+                entry.type = PyrexTypes.c_const_or_volatile_type(
+                        entry.type, self.is_const, self.is_volatile)
+            self.cached_const_or_volatile_entries[name] = entry
             return entry