Serialize metadata

pkg/compiler/lib/src/js_backend/js_interop_analysis.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.
 
 /// Analysis to determine how to generate code for typed JavaScript interop.
 library compiler.src.js_backend.js_interop_analysis;
 
+import '../common.dart';
 import '../constants/values.dart'
     show ConstantValue, ConstructedConstantValue, StringConstantValue;
 import '../diagnostics/messages.dart' show MessageKind;
 import '../elements/elements.dart'
     show
         ClassElement,
         Element,
         FieldElement,
         FunctionElement,
         LibraryElement,
@@ skipping 29 matching lines @@
           .forEach(processJsInteropAnnotationsInLibrary);
     }
   }
 
   void onCodegenStart() {
     _inCodegen = true;
   }
 
   void processJsInteropAnnotation(Element e) {
     for (MetadataAnnotation annotation in e.implementation.metadata) {
+      // TODO(johnniwinther): Avoid processing unresolved elements.
+      if (annotation.constant == null) continue;
       ConstantValue constant =
           backend.compiler.constants.getConstantValue(annotation.constant);
       if (constant == null || constant is! ConstructedConstantValue) continue;
       ConstructedConstantValue constructedConstant = constant;
       if (constructedConstant.type.element == helpers.jsAnnotationClass) {
         ConstantValue value = constructedConstant.fields[nameField];
         if (value.isString) {
           StringConstantValue stringValue = value;
           backend.nativeData
               .setJsInteropName(e, stringValue.primitiveValue.slowToString());
@@ skipping 109 matching lines @@
           var name = backend.namer.invocationName(selector);
           statements.add(js.statement(
               'Function.prototype.# = function(#) { return this(#) }',
               [name, parameters, parameters]));
         }
       });
     });
     return new jsAst.Block(statements);
   }
 }