Mirror printer test.

dart/sdk/lib/_internal/compiler/implementation/js_backend/backend.dart

 // Copyright (c) 2012, 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 js_backend;
 
 class JavaScriptItemCompilationContext extends ItemCompilationContext {
   final Set<HInstruction> boundsChecked;
 
   JavaScriptItemCompilationContext()
@@ skipping 1420 matching lines @@
       isTreeShakingDisabled = true;
       enqueuer.enqueueEverything();
     } else if (element == preserveNamesMarker) {
       if (mustPreserveNames) return;
       mustPreserveNames = true;
       compiler.log('Preserving names.');
     } else if (element == preserveMetadataMarker) {
       if (mustRetainMetadata) return;
       compiler.log('Retaining metadata.');
       mustRetainMetadata = true;
-      for (LibraryElement library in compiler.libraries.values) {
-        if (retainMetadataOf(library)) {
-          for (Link link = library.metadata; !link.isEmpty; link = link.tail) {
-            link.head.ensureResolved(compiler);
-          }
-        }
-      }
+      compiler.libraries.values.forEach(retainMetadataOf);
       for (Dependency dependency in metadataInstantiatedTypes) {
         registerMetadataInstantiatedType(dependency.type, dependency.user);
       }
       metadataInstantiatedTypes.clear();
       for (Element e in metadataStaticUse) {
         registerMetadataStaticUse(e);
       }
       metadataStaticUse.clear();
       for (Element e in metadataGetOfStaticFunction) {
         registerMetadataGetOfStaticFunction(e);
@@ skipping 23 matching lines @@
     if (name == const SourceString('')) return false;
     return symbolsUsed.contains(name.slowToString());
   }
 
   bool get rememberLazies => isTreeShakingDisabled;
 
   bool retainMetadataOf(Element element) {
     if (mustRetainMetadata) hasRetainedMetadata = true;
     if (mustRetainMetadata && isNeededForReflection(element)) {
       for (MetadataAnnotation metadata in element.metadata) {
-        metadata.value.accept(new ConstantCopier(compiler.constantHandler));
+        metadata.ensureResolved(compiler)
+            .value.accept(new ConstantCopier(compiler.constantHandler));
       }
       return true;
     }
     return false;
   }
 
   void onLibraryLoaded(LibraryElement library, Uri uri) {
     if (uri == Uri.parse('dart:_js_mirrors')) {
       disableTreeShakingMarker =
           library.find(const SourceString('disableTreeShaking'));
@@ skipping 168 matching lines @@
     copy(constant.values);
     copy(constant.protoValue);
     copy(constant);
   }
 
   void visitConstructed(ConstructedConstant constant) {
     copy(constant.fields);
     copy(constant);
   }
 }