Initialize unassigned node child attributes to None, clean up ExprNode

Cython/Compiler/ExprNodes.py

@@ -168,16 +168,9 @@ class ExprNode(Node):
     saved_subexpr_nodes = None
     is_temp = 0
 
-    def get_child_attrs(self): return self.subexprs
-    child_attrs = property(fget=get_child_attrs)
-
     def get_child_attrs(self):
-        """Automatically provide the contents of subexprs as children, unless child_attr
-        has been declared. See Nodes.Node.get_child_accessors."""
-        if self.child_attrs is not None:
-            return self.child_attrs
-        elif self.subexprs is not None:
-            return self.subexprs
+        return self.subexprs
+    child_attrs = property(fget=get_child_attrs)
         
     def not_implemented(self, method_name):
         print_call_chain(method_name, "not implemented") ###
@@ -3289,6 +3282,8 @@ class CondExprNode(ExprNode):
     #  false_val   ExprNode
     
     temp_bool = None
+    true_val = None
+    false_val = None
     
     subexprs = ['test', 'true_val', 'false_val']
     

Cython/Compiler/Nodes.py

@@ -2217,6 +2217,7 @@ class CascadedAssignmentNode(AssignmentNode):
     #  coerced_rhs_list   [ExprNode]   RHS coerced to type of each LHS
     
     child_attrs = ["lhs_list", "rhs", "coerced_rhs_list"]
+    coerced_rhs_list = None
 
     def analyse_declarations(self, env):
         for lhs in self.lhs_list:
@@ -2353,6 +2354,7 @@ class InPlaceAssignmentNode(AssignmentNode):
     #  (it must be a NameNode, AttributeNode, or IndexNode).     
     
     child_attrs = ["lhs", "rhs", "dup"]
+    dup = None
 
     def analyse_declarations(self, env):
         self.lhs.analyse_target_declaration(env)
@@ -2987,6 +2989,7 @@ class ForInStatNode(LoopNode, StatNode):
     #  item          NextNode       used internally
     
     child_attrs = ["target", "iterator", "body", "else_clause", "item"]
+    item = None
     
     def analyse_declarations(self, env):
         self.target.analyse_target_declaration(env)
@@ -3103,7 +3106,7 @@ class ForFromStatNode(LoopNode, StatNode):
     #  is_py_target       bool
     #  loopvar_name       string
     #  py_loopvar_node    PyTempNode or None
-    child_attrs = ["target", "bound1", "bound2", "step", "body", "else_clause", "py_loopvar_node"]
+    child_attrs = ["target", "bound1", "bound2", "step", "body", "else_clause"]
     
     def analyse_declarations(self, env):
         self.target.analyse_target_declaration(env)
@@ -3317,6 +3320,7 @@ class ExceptClauseNode(Node):
     #  exc_vars       (string * 3)       local exception variables
     
     child_attrs = ["pattern", "target", "body", "exc_value"]
+    exc_value = None
 
     def analyse_declarations(self, env):
         if self.target: