Insert checks before deferred calls and accesses.

tests/language/deferred_not_loaded_check_test.dart

+// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'package:expect/expect.dart';
+import 'package:async_helper/async_helper.dart';
+
+import "deferred_not_loaded_check_lib.dart" deferred as lib;
+
+// Test that we give appropriate errors when accessing an element that is not
+// yet loaded.
+
+var c;
+
+expectNoSideEffect(test) {
+  c = 0;
+  test();
+  Expect.isTrue(c == 0);
+}
+
+expectThrowsNotLoaded(test){
+  Expect.throws(test, (e) => e is Error);
+}
+
+int sideEffect() {
+  c = 1;
+  return 10;
+}
+
+void main() {
+  expectNoSideEffect(() {
+    expectThrowsNotLoaded(() {
+      print("Calling toplevel ${lib.foo(sideEffect())}");
+    });
+  });
+  expectNoSideEffect(() {
+    expectThrowsNotLoaded(() {
+      print("Calling static ${lib.C.foo(sideEffect())}");
+    });
+  });
+  expectNoSideEffect(() {
+    expectThrowsNotLoaded(() {
+      print("New-expression ${new lib.C(sideEffect())}");
+    });
+  });
+  expectThrowsNotLoaded(() {
+    print("Getting var ${lib.a}");
+  });
+  expectNoSideEffect(() {
+    expectThrowsNotLoaded(() {
+      print("Setting var ${lib.a = sideEffect()}");
+    });
+  });
+  expectThrowsNotLoaded(() {
+    print("Getter ${lib.getter}");
+  });
+  expectNoSideEffect(() {
+    expectThrowsNotLoaded(() {
+      print("Setter ${lib.setter = sideEffect()}");
+    });
+  });
+  expectNoSideEffect(() {
+    expectThrowsNotLoaded(() {
+      print("Setter ${lib.list[sideEffect()] = sideEffect()}");
+    });
+  });
+  expectNoSideEffect(() {
+    expectThrowsNotLoaded(() {
+      print("Non-function static call ${lib.closure(sideEffect())}");
+    });
+  });
+}