Handler the last native annotations

pkg/compiler/lib/src/constants/evaluation.dart

 // Copyright (c) 2015, 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.
 
 library dart2js.constants.evaluation;
 
+import '../common.dart';
 import '../common/backend_api.dart' show BackendClasses;
 import '../core_types.dart' show CommonElements;
 import '../elements/entities.dart';
 import '../elements/types.dart';
 import '../universe/call_structure.dart' show CallStructure;
 import 'constructors.dart';
 import 'expressions.dart';
 
 /// Environment used for evaluating constant expressions.
 abstract class Environment {
@@ skipping 28 matching lines @@
   final CallStructure callStructure;
   final List<ConstantExpression> arguments;
 
   NormalizedArguments(this.defaultValues, this.callStructure, this.arguments);
 
   /// Returns the normalized named argument [name].
   ConstantExpression getNamedArgument(String name) {
     int index = callStructure.namedArguments.indexOf(name);
     if (index == -1) {
       // The named argument is not provided.
+      invariant(CURRENT_ELEMENT_SPANNABLE, defaultValues[name] != null,
+          message: "No default value for named argument '$name' in $this.");
       return defaultValues[name];
     }
-    return arguments[index + callStructure.positionalArgumentCount];
+    ConstantExpression value =
+        arguments[index + callStructure.positionalArgumentCount];
+    invariant(CURRENT_ELEMENT_SPANNABLE, value != null,
+        message: "No value for named argument '$name' in $this.");
+    return value;
   }
 
   /// Returns the normalized [index]th positional argument.
   ConstantExpression getPositionalArgument(int index) {
     if (index >= callStructure.positionalArgumentCount) {
       // The positional argument is not provided.
+      invariant(CURRENT_ELEMENT_SPANNABLE, defaultValues[index] != null,
+          message: "No default value for positional argument $index in $this.");
       return defaultValues[index];
     }
-    return arguments[index];
+    ConstantExpression value = arguments[index];
+    invariant(CURRENT_ELEMENT_SPANNABLE, value != null,
+        message: "No value for positional argument $index in $this.");
+    return value;
+  }
+
+  String toString() {
+    StringBuffer sb = new StringBuffer();
+    sb.write('NormalizedArguments[');
+    sb.write('defaultValues={');
+    bool needsComma = false;
+    defaultValues.forEach((var key, ConstantExpression value) {
+      if (needsComma) {
+        sb.write(',');
+      }
+      if (key is String) {
+        sb.write('"');
+        sb.write(key);
+        sb.write('"');
+      } else {
+        sb.write(key);
+      }
+      sb.write(':');
+      sb.write(value.toStructuredText());
+      needsComma = true;
+    });
+    sb.write('},callStructure=');
+    sb.write(callStructure);
+    sb.write(',arguments=[');
+    arguments.forEach((ConstantExpression value) {
+      if (needsComma) {
+        sb.write(',');
+      }
+      sb.write(value.toStructuredText());
+      needsComma = true;
+    });
+    sb.write(']]');
+    return sb.toString();
   }
 }