Implement tracing for function expressions and statements, and infer types of parameters of these c…

tests/compiler/dart2js/closure_tracer_test.dart

+// Copyright (c) 2013, 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 'compiler_helper.dart';
+import 'parser_helper.dart';
+
+const String TEST = '''
+testFunctionStatement() {
+  var res;
+  closure(a) => res = a;
+  closure(42);
+  return res;
+}
+
+testFunctionExpression() {
+  var res;
+  var closure = (a) => res = a;
+  closure(42);
+  return res;
+}
+
+var staticField;
+
+testStoredInStatic() {
+  var res;
+  closure(a) => res = a;
+  staticField = closure;
+  staticField(42);
+  return res;
+}
+
+class A {
+  var field;
+  A(this.field);
+}
+
+testStoredInInstance() {
+  var res;
+  closure(a) => res = a;
+  var a = new A(closure);
+  a.field(42);
+  return res;
+}
+
+foo(closure) {
+  closure(42);
+}
+
+testPassedInParameter() {
+  var res;
+  closure(a) => res = a;
+  foo(closure);
+  return res;
+}
+
+main() {
+  testFunctionStatement();
+  testFunctionExpression();
+  testStoredInStatic();
+  testStoredInInstance();
+  testPassedInParameter();
+}
+''';
+
+void main() {
+  Uri uri = new Uri(scheme: 'source');
+  var compiler = compilerFor(TEST, uri);
+  asyncTest(() => compiler.runCompiler(uri).then((_) {
+    var typesTask = compiler.typesTask;
+    var typesInferrer = typesTask.typesInferrer;
+
+    checkType(String name, type) {
+      var element = findElement(compiler, name);
+      var mask = typesInferrer.getReturnTypeOfElement(element);
+      Expect.equals(type.nullable(), mask.simplify(compiler), name);
+    }
+
+    checkType('testFunctionStatement', typesTask.uint31Type);
+    checkType('testFunctionExpression', typesTask.uint31Type);
+    checkType('testStoredInInstance', typesTask.uint31Type);
+    checkType('testStoredInStatic', typesTask.uint31Type);
+    checkType('testPassedInParameter', typesTask.uint31Type);
+  }));
+}