Babel.Compiler.TypeCheckingVisitor.CheckReturnValue C# (CSharp) Method

        protected virtual void CheckReturnValue(ReturnStatement ret)
        {
            if (ret.Value == null) {
                if (!currentRoutine.ReturnType.IsNull) {
                    report.Error(ret.Location,
                                 "return value should be provided");
                    return;
                }
            }
            else {
                if (currentRoutine.ReturnType.IsNull) {
                    report.Error(ret.Location,
                                 "return value should not be provided");
                    return;
                }
                ret.Value.Accept(this);
                if (ret.Value is VoidExpression) {
                    ret.Value.NodeType = currentRoutine.ReturnType.NodeType;
                }
                else {
                    TypeData expectedType = currentRoutine.ReturnType.NodeType;
                    if (!ret.Value.NodeType.IsSubtypeOf(expectedType)) {
                        report.Error(ret.Location,
                                     "the type of the destination: {0} is " +
                                     "not a supertype of {1}",
                                     expectedType.FullName,
                                     ret.Value.NodeType.FullName);
                        return;
                    }
                }
            }
        }