Take inheritance into account when computing the elements accessible by mirrors.

sdk/lib/_internal/compiler/implementation/compiler.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 dart2js;
 
 /**
  * If true, print a warning for each method that was resolved, but not
  * compiled.
  */
@@ skipping 203 matching lines @@
   /// constants.
   BackendConstantEnvironment get constants;
 
   /// The compiler task responsible for the compilation of constants for both
   /// the frontend and the backend.
   ConstantCompilerTask get constantCompilerTask;
 
   /// Backend callback methods for the resolution phase.
   ResolutionCallbacks get resolutionCallbacks;
 
+  /// Set of classes that need to be considered for reflection although not
+  /// otherwise visible during resolution.
+  Iterable<ClassElement> classesRequiredForReflection = const [];
+
   // Given a [FunctionElement], return a buffer with the code generated for it
   // or null if no code was generated.
   CodeBuffer codeOf(Element element) => null;
 
   void initializeHelperClasses() {}
 
   void enqueueHelpers(ResolutionEnqueuer world, Registry registry);
   void codegen(CodegenWorkItem work);
 
   // The backend determines the native resolution enqueuer, with a no-op
@@ skipping 161 matching lines @@
     return new Future.value();
   }
 
   /// Called by [MirrorUsageAnalyzerTask] after it has merged all @MirrorsUsed
   /// annotations. The arguments corresponds to the unions of the corresponding
   /// fields of the annotations.
   void registerMirrorUsage(Set<String> symbols,
                            Set<Element> targets,
                            Set<Element> metaTargets) {}
 
-  /// Returns true if this element should be retained for reflection even if it
-  /// would normally be tree-shaken away.
-  bool isNeededForReflection(Element element) => false;
+  /// Returns true if this element needs reflection information at runtime.
+  bool isAccessibleByReflection(Element element) => true;
+
+  /// Returns true if this element is covered by a mirrorsUsed annotation.
+  ///
+  /// Note that it might still be ok to tree shake the element away if no
+  /// reflection is used in the program (and thus [isTreeShakingDisabled] is
+  /// still false). Therefore _do not_ use this predicate to decide inclusion
+  /// in the tree, use [requiredByMirrorSystem] instead.
+  bool referencedFromMirrorSystem(Element element, [recursive]) => false;
+
+  /// Returns true if this element has to be enqueued due to
+  /// mirror usage. Might be a subset of [referencedFromMirrorSystem] if
+  /// normal tree shaking is still active ([isTreeShakingDisabled] is false).
+  bool requiredByMirrorSystem(Element element) => false;
 
   /// Returns true if global optimizations such as type inferencing
   /// can apply to this element. One category of elements that do not
   /// apply is runtime helpers that the backend calls, but the
   /// optimizations don't see those calls.
   bool canBeUsedForGlobalOptimizations(Element element) => true;
 
   /// Called when [enqueuer]'s queue is empty, but before it is closed.
   /// This is used, for example, by the JS backend to enqueue additional
-  /// elements needed for reflection.
-  void onQueueEmpty(Enqueuer enqueuer) {}
+  /// elements needed for reflection. [recentClasses] is a collection of
+  /// all classes seen for the first time by the [enqueuer] since the last call
+  /// to [onQueueEmpty].
+  ///
+  /// A return value of [:true:] indicates that [recentClasses] has been
+  /// processed and its elements do not need to be seen in the next round. When
+  /// [:false:] is returned, [onQueueEmpty] will be called again once the
+  /// resolution queue has drained and [recentClasses] will be a superset of the
+  /// current value.
+  ///
+  /// There is no guarantee that a class is only present once in
+  /// [recentClasses], but every class seen by the [enqueuer] will be present in
+  /// [recentClasses] at least once.
+  bool onQueueEmpty(Enqueuer enqueuer, Iterable<ClassElement> recentClasses) {
+    return true;
+  }
 
   /// Called after [element] has been resolved.
   // TODO(johnniwinther): Change [TreeElements] to [Registry] or a dependency
   // node. [elements] is currently unused by the implementation.
   void onElementResolved(Element element, TreeElements elements) {}
 
   // Does this element belong in the output
   bool shouldOutput(Element element) => true;
 }
 
@@ skipping 1556 matching lines @@
   static NullSink outputProvider(String name, String extension) {
     return new NullSink('$name.$extension');
   }
 }
 
 /// Information about suppressed warnings and hints for a given library.
 class SuppressionInfo {
   int warnings = 0;
   int hints = 0;
 }