Fix python#307: Method default args can refer to class attributes

mypy/semanal.py

@@ -284,11 +284,11 @@ def analyse_function(self, defn: FuncItem) -> None:
             if isinstance(defn, FuncDef):
                 defn.info = self.type
                 defn.type = set_callable_name(defn.type, defn)
-        self.function_stack.append(defn)
-        self.enter()
         for init in defn.init:
             if init:
                 init.rvalue.accept(self)
+        self.function_stack.append(defn)
+        self.enter()
         for v in defn.args:
             self.add_local(v, defn)
         for init_ in defn.init:
@@ -735,7 +735,7 @@ def analyse_lvalue(self, lval: Node, nested: bool = False,
         Only if add_global is True, add name to globals table. If nested
         is true, the lvalue is within a tuple or list lvalue expression.
         """
-        
+
         if isinstance(lval, NameExpr):
             nested_global = (not self.is_func_scope() and
                              self.block_depth[-1] > 0 and

mypy/test/data/semanal-classes.test

@@ -514,3 +514,29 @@ MypyFile:1(
     Decorators(
       NameExpr(builtinclass [typing.builtinclass]))
     PassStmt:3()))
+
+[case testClassAttributeAsMethodDefaultArgumentValue]
+import typing
+class A:
+    X = 1
+    def f(self, x : int = X) -> None: pass
+[out]
+MypyFile:1(
+  Import:1(typing : typing)
+  ClassDef:2(
+    A
+    AssignmentStmt:3(
+      NameExpr(X* [m])
+      IntExpr(1))
+    FuncDef:4(
+      f
+      Args(
+        Var(self)
+        Var(x))
+      def (self: __main__.A, x: builtins.int =)
+      Init(
+        AssignmentStmt:4(
+          NameExpr(x [l])
+          NameExpr(X [m])))
+      Block:4(
+        PassStmt:4()))))