Introduce EnqueuerListener

pkg/compiler/lib/src/enqueue.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.
 
 library dart2js.enqueue;
 
 import 'dart:collection' show Queue;
 
 import 'common/resolution.dart' show Resolution;
 import 'common/tasks.dart' show CompilerTask;
 import 'common/work.dart' show WorkItem;
 import 'common.dart';
 import 'compiler.dart' show Compiler, GlobalDependencyRegistry;
 import 'options.dart';
 import 'elements/elements.dart'
     show
         AnalyzableElement,
         ClassElement,
         ConstructorElement,
         Element,
         MemberElement;
 import 'elements/entities.dart';
 import 'elements/resolution_types.dart'
     show ResolutionDartType, ResolutionInterfaceType;
-import 'js_backend/backend.dart' show JavaScriptBackend;
+import 'elements/types.dart' show InterfaceType;
 import 'native/native.dart' as native;
 import 'universe/world_builder.dart';
 import 'universe/use.dart'
     show DynamicUse, StaticUse, StaticUseKind, TypeUse, TypeUseKind;
 import 'universe/world_impact.dart'
     show ImpactStrategy, ImpactUseCase, WorldImpact, WorldImpactVisitor;
 import 'util/enumset.dart';
 import 'util/util.dart' show Setlet;
 
 class EnqueueTask extends CompilerTask {
   ResolutionEnqueuer _resolution;
   Enqueuer _codegen;
   final Compiler compiler;
 
   String get name => 'Enqueue';
 
   EnqueueTask(Compiler compiler)
       : this.compiler = compiler,
         super(compiler.measurer) {
     _resolution = new ResolutionEnqueuer(
         this,
         compiler.options,
-        compiler.resolution,
+        compiler.reporter,
         compiler.options.analyzeOnly && compiler.options.analyzeMain
             ? const DirectEnqueuerStrategy()
             : const TreeShakingEnqueuerStrategy(),
         compiler.globalDependencies,
-        compiler.backend);
+        compiler.backend,
+        compiler.backend.nativeResolutionEnqueuer(),
+        new ResolutionWorldBuilderImpl(
+            compiler.backend, compiler.resolution, const OpenWorldStrategy()),
+        new ResolutionWorkItemBuilder(compiler.resolution));
     _codegen = compiler.backend.createCodegenEnqueuer(this, compiler);
   }
 
   ResolutionEnqueuer get resolution => _resolution;
   Enqueuer get codegen => _codegen;
 }
 
 abstract class Enqueuer {
   WorldBuilder get worldBuilder;
   native.NativeEnqueuer get nativeEnqueuer;
@@ skipping 29 matching lines @@
   /// if it is no longer needed.
   void applyImpact(WorldImpact worldImpact, {var impactSource});
   bool checkNoEnqueuedInvokedInstanceMethods();
   void logSummary(log(message));
 
   Iterable<Entity> get processedEntities;
 
   Iterable<ClassEntity> get processedClasses;
 }
 
+abstract class EnqueuerListener {
+  /// Called to instruct to the backend that [type] has been instantiated.
+  void registerInstantiatedType(InterfaceType type);
+
+  /// Called to notify to the backend that a class is being instantiated. Any
+  /// backend specific [WorldImpact] of this is returned.
+  WorldImpact registerInstantiatedClass(ClassEntity cls, {bool forResolution});
+
+  /// Called to notify to the backend that a class is implemented by an
+  /// instantiated class. Any backend specific [WorldImpact] of this is
+  /// returned.
+  WorldImpact registerImplementedClass(ClassEntity cls, {bool forResolution});
+
+  /// Called to register that a static function has been closurized. Any backend
+  /// specific [WorldImpact] of this is returned.
+  WorldImpact registerGetOfStaticFunction();
+
+  /// Called to instruct the backend to register that a closure exists for a
+  /// function on an instantiated generic class. Any backend specific
+  /// [WorldImpact] of this is returned.
+  WorldImpact registerClosureWithFreeTypeVariables(MemberEntity member,
+      {bool forResolution});
+
+  /// Called to register that a member has been closurized. Any backend specific
+  /// [WorldImpact] of this is returned.
+  WorldImpact registerBoundClosure();
+
+  /// Called to register that [element] is statically known to be used. Any
+  /// backend specific [WorldImpact] of this is returned.
+  WorldImpact registerUsedElement(MemberEntity member, {bool forResolution});
+
+  /// 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. [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<ClassEntity> recentClasses);
+}
+
 abstract class EnqueuerImpl extends Enqueuer {
   CompilerTask get task;
   EnqueuerStrategy get strategy;
   void checkClass(ClassEntity cls);
   void processStaticUse(StaticUse staticUse);
   void processTypeUse(TypeUse typeUse);
   void processDynamicUse(DynamicUse dynamicUse);
 }
 
 /// [Enqueuer] which is specific to resolution.
 class ResolutionEnqueuer extends EnqueuerImpl {
   static const ImpactUseCase IMPACT_USE =
       const ImpactUseCase('ResolutionEnqueuer');
 
   final CompilerTask task;
   final String name;
-  final Resolution _resolution;
   final CompilerOptions _options;
-  final JavaScriptBackend backend;
+  final EnqueuerListener _listener;
   final GlobalDependencyRegistry _globalDependencies;
   final native.NativeEnqueuer nativeEnqueuer;
 
   final EnqueuerStrategy strategy;
   final Set<ClassEntity> _recentClasses = new Setlet<ClassEntity>();
   final ResolutionWorldBuilderImpl _universe;
   final WorkItemBuilder _workItemBuilder;
+  final DiagnosticReporter _reporter;
 
   bool queueIsClosed = false;
 
   WorldImpactVisitor _impactVisitor;
 
   /// All declaration elements that have been processed by the resolver.
   final Set<Entity> _processedEntities = new Set<Entity>();
 
   final Queue<WorkItem> _queue = new Queue<WorkItem>();
 
   /// Queue of deferred resolution actions to execute when the resolution queue
   /// has been emptied.
   final Queue<_DeferredAction> _deferredQueue = new Queue<_DeferredAction>();
 
-  ResolutionEnqueuer(this.task, this._options, Resolution resolution,
-      this.strategy, this._globalDependencies, JavaScriptBackend backend,
-      [this.name = 'resolution enqueuer'])
-      : this.backend = backend,
-        this._resolution = resolution,
-        this.nativeEnqueuer = backend.nativeResolutionEnqueuer(),
-        _universe = new ResolutionWorldBuilderImpl(
-            backend, resolution, const OpenWorldStrategy()),
-        _workItemBuilder = new ResolutionWorkItemBuilder(resolution) {
+  ResolutionEnqueuer(
+      this.task,
+      this._options,
+      this._reporter,
+      this.strategy,
+      this._globalDependencies,
+      this._listener,
+      this.nativeEnqueuer,
+      this._universe,
+      this._workItemBuilder,
+      [this.name = 'resolution enqueuer']) {
     _impactVisitor = new EnqueuerImplImpactVisitor(this);
   }
 
   ResolutionWorldBuilder get worldBuilder => _universe;
 
   bool get queueIsEmpty => _queue.isEmpty;
 
-  DiagnosticReporter get _reporter => _resolution.reporter;
-
   Iterable<ClassEntity> get processedClasses => _universe.processedClasses;
 
   void applyImpact(WorldImpact worldImpact, {var impactSource}) {
     if (worldImpact.isEmpty) return;
     impactStrategy.visitImpact(
         impactSource, worldImpact, _impactVisitor, impactUse);
   }
 
   void _registerInstantiatedType(ResolutionInterfaceType type,
       {ConstructorElement constructor,
       bool mirrorUsage: false,
       bool nativeUsage: false,
       bool globalDependency: false,
       bool isRedirection: false}) {
     task.measure(() {
       _universe.registerTypeInstantiation(type, _applyClassUse,
           constructor: constructor,
           byMirrors: mirrorUsage,
           isRedirection: isRedirection);
       if (globalDependency && !mirrorUsage) {
         _globalDependencies.registerDependency(type.element);
       }
       if (nativeUsage) {
         nativeEnqueuer.onInstantiatedType(type);
       }
-      backend.registerInstantiatedType(type);
+      _listener.registerInstantiatedType(type);
     });
   }
 
   bool checkNoEnqueuedInvokedInstanceMethods() {
     return strategy.checkEnqueuerConsistency(this);
   }
 
   void checkClass(ClassEntity cls) {
     _universe.processClassMembers(cls,
         (MemberEntity member, EnumSet<MemberUse> useSet) {
       if (useSet.isNotEmpty) {
         _reporter.internalError(member,
             'Unenqueued use of $member: ${useSet.iterable(MemberUse.values)}');
       }
     });
   }
 
   /// Callback for applying the use of a [member].
   void _applyMemberUse(Entity member, EnumSet<MemberUse> useSet) {
     if (useSet.contains(MemberUse.NORMAL)) {
       _addToWorkList(member);
     }
     if (useSet.contains(MemberUse.CLOSURIZE_INSTANCE)) {
       _registerClosurizedMember(member);
     }
     if (useSet.contains(MemberUse.CLOSURIZE_STATIC)) {
-      applyImpact(backend.registerGetOfStaticFunction());
+      applyImpact(_listener.registerGetOfStaticFunction());
     }
   }
 
   /// Callback for applying the use of a [cls].
   void _applyClassUse(ClassEntity cls, EnumSet<ClassUse> useSet) {
     if (useSet.contains(ClassUse.INSTANTIATED)) {
       _recentClasses.add(cls);
       _universe.processClassMembers(cls, _applyMemberUse);
       // We only tell the backend once that [cls] was instantiated, so
       // any additional dependencies must be treated as global
       // dependencies.
-      applyImpact(backend.registerInstantiatedClass(cls, forResolution: true));
+      applyImpact(
+          _listener.registerInstantiatedClass(cls, forResolution: true));
     }
     if (useSet.contains(ClassUse.IMPLEMENTED)) {
-      applyImpact(backend.registerImplementedClass(cls, forResolution: true));
+      applyImpact(_listener.registerImplementedClass(cls, forResolution: true));
     }
   }
 
   void processDynamicUse(DynamicUse dynamicUse) {
     task.measure(() {
       _universe.registerDynamicUse(dynamicUse, _applyMemberUse);
     });
   }
 
   void processStaticUse(StaticUse staticUse) {
@@ skipping 53 matching lines @@
     type = _universe.registerIsCheck(type);
     // Even in checked mode, type annotations for return type and argument
     // types do not imply type checks, so there should never be a check
     // against the type variable of a typedef.
     assert(!type.isTypeVariable || !type.element.enclosingElement.isTypedef);
   }
 
   void _registerClosurizedMember(MemberElement element) {
     assert(element.isInstanceMember);
     if (element.type.containsTypeVariables) {
-      applyImpact(backend.registerClosureWithFreeTypeVariables(element,
+      applyImpact(_listener.registerClosureWithFreeTypeVariables(element,
           forResolution: true));
       _universe.closuresWithFreeTypeVariables.add(element);
     }
-    applyImpact(backend.registerBoundClosure());
+    applyImpact(_listener.registerBoundClosure());
     _universe.closurizedMembers.add(element);
   }
 
   void forEach(void f(WorkItem work)) {
     do {
       while (_queue.isNotEmpty) {
         // TODO(johnniwinther): Find an optimal process order.
         WorkItem work = _queue.removeLast();
         if (!_processedEntities.contains(work.element)) {
           strategy.processWorkItem(f, work);
@@ skipping 40 matching lines @@
   void _addToWorkList(MemberEntity entity) {
     if (hasBeenProcessed(entity)) return;
     WorkItem workItem = _workItemBuilder.createWorkItem(entity);
     if (workItem == null) return;
 
     if (queueIsClosed) {
       throw new SpannableAssertionFailure(
           entity, "Resolution work list is closed. Trying to add $entity.");
     }
 
-    applyImpact(backend.registerUsedElement(entity, forResolution: true));
+    applyImpact(_listener.registerUsedElement(entity, forResolution: true));
     _universe.registerUsedElement(entity);
     _queue.add(workItem);
   }
 
   /// Adds an action to the deferred task queue.
   /// The action is performed the next time the resolution queue has been
   /// emptied.
   ///
   /// The queue is processed in FIFO order.
   void addDeferredAction(Entity entity, void action()) {
     if (queueIsClosed) {
       throw new SpannableAssertionFailure(
           entity,
           "Resolution work list is closed. "
           "Trying to add deferred action for $entity");
     }
     _deferredQueue.add(new _DeferredAction(entity, action));
   }
 
   /// [_onQueueEmpty] is called whenever the queue is drained. [recentClasses]
   /// contains the set of all classes seen for the first time since
   /// [_onQueueEmpty] was called last. A return value of [true] indicates that
   /// the [recentClasses] have been processed and may be cleared. If [false] is
   /// returned, [_onQueueEmpty] will be called once the queue is empty again (or
   /// still empty) and [recentClasses] will be a superset of the current value.
   bool _onQueueEmpty(Iterable<ClassEntity> recentClasses) {
     _emptyDeferredQueue();
 
-    return backend.onQueueEmpty(this, recentClasses);
+    return _listener.onQueueEmpty(this, recentClasses);
   }
 
   void emptyDeferredQueueForTesting() => _emptyDeferredQueue();
 
   void _emptyDeferredQueue() {
     while (!_deferredQueue.isEmpty) {
       _DeferredAction task = _deferredQueue.removeFirst();
       _reporter.withCurrentElement(task.element, task.action);
     }
   }
@@ skipping 112 matching lines @@
   @override
   WorkItem createWorkItem(MemberElement element) {
     assert(invariant(element, element.isDeclaration));
     if (element.isMalformed) return null;
 
     assert(invariant(element, element is AnalyzableElement,
         message: 'Element $element is not analyzable.'));
     return _resolution.createWorkItem(element);
   }
 }