properly integrate Python class nodes into type inference

Cython/Compiler/ExprNodes.py

@@ -7163,14 +7163,18 @@ class ClassNode(ExprNode, ModuleNameMixin):
     #  module_name  EncodedString      Name of defining module
 
     subexprs = ['bases', 'doc']
+    type = py_object_type
+    is_temp = True
+
+    def infer_type(self, env):
+        # TODO: could return 'type' in some cases
+        return py_object_type
 
     def analyse_types(self, env):
         self.bases = self.bases.analyse_types(env)
         if self.doc:
             self.doc = self.doc.analyse_types(env)
             self.doc = self.doc.coerce_to_pyobject(env)
-        self.type = py_object_type
-        self.is_temp = 1
         env.use_utility_code(UtilityCode.load_cached("CreateClass", "ObjectHandling.c"))
         return self
 
@@ -7215,10 +7219,14 @@ class Py3ClassNode(ExprNode):
     #  allow_py2_metaclass  bool       should look for Py2 metaclass
 
     subexprs = []
+    type = py_object_type
+    is_temp = True
+
+    def infer_type(self, env):
+        # TODO: could return 'type' in some cases
+        return py_object_type
 
     def analyse_types(self, env):
-        self.type = py_object_type
-        self.is_temp = 1
         return self
 
     def may_be_none(self):

Cython/Compiler/FlowControl.py

@@ -5,8 +5,7 @@ cython.declare(PyrexTypes=object, ExprNodes=object, Nodes=object,
                Builtin=object, InternalError=object,
                error=object, warning=object,
                py_object_type=object, unspecified_type=object,
-               object_expr=object, object_expr_not_none=object,
-               fake_rhs_expr=object, TypedExprNode=object)
+               object_expr=object, fake_rhs_expr=object, TypedExprNode=object)
 
 from . import Builtin
 from . import ExprNodes
@@ -29,7 +28,6 @@ class TypedExprNode(ExprNodes.ExprNode):
         return self._may_be_none != False
 
 object_expr = TypedExprNode(py_object_type, may_be_none=True)
-object_expr_not_none = TypedExprNode(py_object_type, may_be_none=False)
 # Fake rhs to silence "unused variable" warning
 fake_rhs_expr = TypedExprNode(unspecified_type)
 
@@ -1287,7 +1285,7 @@ class ControlFlowAnalysis(CythonTransform):
     def visit_PyClassDefNode(self, node):
         self.visitchildren(node, ('dict', 'metaclass',
                                   'mkw', 'bases', 'class_result'))
-        self.flow.mark_assignment(node.target, object_expr_not_none,
+        self.flow.mark_assignment(node.target, node.classobj,
                                   self.env.lookup(node.name))
         self.env_stack.append(self.env)
         self.env = node.scope