Implement reflection on annotations of parameters.

sdk/lib/_internal/compiler/implementation/js_emitter/container_builder.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.
 
 part of dart2js.js_emitter;
 
 /// This class should morph into something that makes it easy to build
 /// JavaScript representations of libraries, class-sides, and instance-sides.
 /// Initially, it is just a placeholder for code that is moved from
 /// [CodeEmitterTask].
@@ skipping 468 matching lines @@
         ..add((tearOffName == null || member.isAccessor())
               ? js("null") : js.string(tearOffName))
         ..add(requiredParameterCount)
         ..add(optionalParameterCount)
         ..add(memberTypeExpression)
         ..addAll(task.metadataEmitter.reifyDefaultArguments(member));
 
     if (canBeReflected || canBeApplied) {
       parameters.orderedForEachParameter((Element parameter) {
         expressions.add(task.metadataEmitter.reifyName(parameter.name));
+        List<MetadataAnnotation> annotations = parameter.metadata.toList();
+        Iterable<int> metadataIndices = annotations.map((MetadataAnnotation a) {
+          compiler.constantHandler.addCompileTimeConstantForEmission(a.value);
+          return task.metadataEmitter.reifyMetadata(a);
+        });
+        // TODO(karlklose): store metadata on elements in correct source order.
+        metadataIndices = metadataIndices.toList().reversed.toList();
+        expressions.add(metadataIndices.isNotEmpty ? metadataIndices
+                                                   : js('[]'));
       });
     }
     if (canBeReflected) {
       jsAst.LiteralString reflectionName;
       if (member.isConstructor()) {
         String reflectionNameString = task.getReflectionName(member, name);
         reflectionName =
             new jsAst.LiteralString(
                 '"new ${Elements.reconstructConstructorName(member)}"'
                 ' /* $reflectionNameString */');
       } else {
         reflectionName = js.string(member.name);
       }
       expressions
           ..add(reflectionName)
           ..addAll(task.metadataEmitter.computeMetadata(member));
     } else if (isClosure && canBeApplied) {
       expressions.add(js.string(member.name));
     }
 
     builder.addProperty(name, js.toExpression(expressions));
   }
 
   void addMemberField(VariableElement member, ClassBuilder builder) {
     // For now, do nothing.
   }
 }