Further encapsulate Enqueuer

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 'cache_strategy.dart';
 import 'common/backend_api.dart' show Backend;
@@ skipping 38 matching lines @@
 
   EnqueueTask(Compiler compiler)
       : this.compiler = compiler,
         super(compiler.measurer) {
     _resolution = new ResolutionEnqueuer(
         this,
         compiler.options,
         compiler.resolution,
         compiler.enqueuerFilter,
         compiler.options.analyzeOnly && compiler.options.analyzeMain
-            ? const EnqueuerStrategy()
+            ? const DirectEnqueuerStrategy()
             : const TreeShakingEnqueuerStrategy(),
         compiler.globalDependencies,
         compiler.backend,
         compiler.coreClasses,
         compiler.cacheStrategy);
     _codegen = compiler.backend.createCodegenEnqueuer(this, compiler);
   }
 
   ResolutionEnqueuer get resolution => _resolution;
   Enqueuer get codegen => _codegen;
 
   void forgetElement(Element element) {
     resolution.forgetElement(element, compiler);
     codegen.forgetElement(element, compiler);
   }
 }
 
 abstract class Enqueuer {
-  CompilerTask get task;
   WorldBuilder get universe;
   native.NativeEnqueuer get nativeEnqueuer;
   void forgetElement(Element element, Compiler compiler);
 
   // TODO(johnniwinther): Initialize [_impactStrategy] to `null`.
   ImpactStrategy _impactStrategy = const ImpactStrategy();
 
   ImpactStrategy get impactStrategy => _impactStrategy;
 
   void open(ImpactStrategy impactStrategy) {
     _impactStrategy = impactStrategy;
   }
 
   void close() {
     // TODO(johnniwinther): Set [_impactStrategy] to `null` and [queueIsClosed]
     // to `false` here.
     _impactStrategy = const ImpactStrategy();
   }
 
-  void processInstantiatedClassMembers(ClassElement cls);
-  void processInstantiatedClassMember(ClassElement cls, Element member);
-  void handleUnseenSelectorInternal(DynamicUse dynamicUse);
-  void registerStaticUse(StaticUse staticUse);
-  void registerStaticUseInternal(StaticUse staticUse);
-  void registerDynamicUse(DynamicUse dynamicUse);
-
   /// Returns [:true:] if this enqueuer is the resolution enqueuer.
   bool get isResolutionQueue;
 
   bool queueIsClosed;
 
   bool get queueIsEmpty;
 
   ImpactUseCase get impactUse;
 
-  /**
-   * Documentation wanted -- johnniwinther
-   *
-   * Invariant: [element] must be a declaration element.
-   */
-  void addToWorkList(Element element);
-
-  void enableIsolateSupport();
-
-  void registerInstantiatedType(InterfaceType type);
   void forEach(void f(WorkItem work));
 
-  /// Apply the [worldImpact] to this enqueuer. If the [impactSource] is provided
-  /// the impact strategy will remove it from the element impact cache, if it is
-  /// no longer needed.
+  /// Apply the [worldImpact] to this enqueuer. If the [impactSource] is
+  /// provided the impact strategy will remove it from the element impact cache,
+  /// if it is no longer needed.
   void applyImpact(WorldImpact worldImpact, {Element impactSource});
   bool checkNoEnqueuedInvokedInstanceMethods();
   void logSummary(log(message));
 
   /// Returns [:true:] if [member] has been processed by this enqueuer.
   bool isProcessed(Element member);
 
   Iterable<Entity> get processedEntities;
 
   Iterable<ClassElement> get processedClasses;
 }
 
+abstract class EnqueuerImpl extends Enqueuer {
+  CompilerTask get task;
+  void processInstantiatedClassMembers(ClassElement cls);
+  void processInstantiatedClassMember(ClassElement cls, Element member);
+  void registerStaticUse(StaticUse staticUse);
+  void registerStaticUseInternal(StaticUse staticUse);
+  void registerTypeUse(TypeUse typeUse);
+  void registerTypeUseInternal(TypeUse typeUse);
+  void registerDynamicUse(DynamicUse dynamicUse);
+  void handleUnseenSelectorInternal(DynamicUse dynamicUse);
+}
+
 /// [Enqueuer] which is specific to resolution.
-class ResolutionEnqueuer extends Enqueuer {
+class ResolutionEnqueuer extends EnqueuerImpl {
   final CompilerTask task;
   final String name;
   final Resolution resolution;
   final QueueFilter filter;
   final CompilerOptions options;
   final Backend backend;
   final GlobalDependencyRegistry globalDependencies;
   final CommonElements commonElements;
   final native.NativeEnqueuer nativeEnqueuer;
 
@@ skipping 22 matching lines @@
       CacheStrategy cacheStrategy,
       [this.name = 'resolution enqueuer'])
       : this.backend = backend,
         this.commonElements = commonElements,
         this.nativeEnqueuer = backend.nativeResolutionEnqueuer(),
         processedElements = new Set<AstElement>(),
         queue = new Queue<ResolutionWorkItem>(),
         deferredQueue = new Queue<_DeferredAction>(),
         _universe = new ResolutionWorldBuilderImpl(
             backend, commonElements, cacheStrategy, const TypeMaskStrategy()) {
-    impactVisitor = new _EnqueuerImpactVisitor(this);
+    impactVisitor = new EnqueuerImplImpactVisitor(this);
   }
 
   ResolutionWorldBuilder get universe => _universe;
 
   OpenWorld get openWorld => universe.openWorld;
 
   bool get queueIsEmpty => queue.isEmpty;
 
   DiagnosticReporter get reporter => resolution.reporter;
 
@@ skipping 266 matching lines @@
         // enqueue.
         LocalFunctionElement closure = staticUse.element;
         if (closure.type.containsTypeVariables) {
           universe.closuresWithFreeTypeVariables.add(closure);
         }
         addElement = false;
         break;
       case StaticUseKind.SUPER_FIELD_SET:
       case StaticUseKind.SUPER_TEAR_OFF:
       case StaticUseKind.GENERAL:
+      case StaticUseKind.DIRECT_USE:
         break;
       case StaticUseKind.CONSTRUCTOR_INVOKE:
       case StaticUseKind.CONST_CONSTRUCTOR_INVOKE:
         _registerInstantiatedType(staticUse.type,
             constructor: staticUse.element, globalDependency: false);
         break;
       case StaticUseKind.REDIRECTION:
         _registerInstantiatedType(staticUse.type,
             constructor: staticUse.element,
             globalDependency: false,
             isRedirection: true);
         break;
       case StaticUseKind.DIRECT_INVOKE:
         invariant(
             element, 'Direct static use is not supported for resolution.');
         break;
     }
     if (addElement) {
       addToWorkList(element);
     }
   }
 
-  void _registerTypeUse(TypeUse typeUse) {
+  void registerTypeUse(TypeUse typeUse) {
+    strategy.processTypeUse(this, typeUse);
+  }
+
+  void registerTypeUseInternal(TypeUse typeUse) {
     DartType type = typeUse.type;
     switch (typeUse.kind) {
       case TypeUseKind.INSTANTIATION:
         _registerInstantiatedType(type, globalDependency: false);
         break;
       case TypeUseKind.MIRROR_INSTANTIATION:
         _registerInstantiatedType(type,
             mirrorUsage: true, globalDependency: false);
         break;
       case TypeUseKind.NATIVE_INSTANTIATION:
@@ skipping 196 matching lines @@
     _universe.forgetElement(element, compiler);
     _processedClasses.remove(element);
     instanceMembersByName[element.name]?.remove(element);
     instanceFunctionsByName[element.name]?.remove(element);
     processedElements.remove(element);
   }
 }
 
 /// Parameterizes filtering of which work items are enqueued.
 class QueueFilter {
-  bool checkNoEnqueuedInvokedInstanceMethods(Enqueuer enqueuer) {
+  bool checkNoEnqueuedInvokedInstanceMethods(EnqueuerImpl enqueuer) {
     enqueuer.task.measure(() {
       // Run through the classes and see if we need to compile methods.
       for (ClassElement classElement
           in enqueuer.universe.directlyInstantiatedClasses) {
         for (ClassElement currentClass = classElement;
             currentClass != null;
             currentClass = currentClass.superclass) {
           enqueuer.processInstantiatedClassMembers(currentClass);
         }
       }
@@ skipping 11 matching lines @@
   if (set == null) return;
   set.remove(element);
 }
 
 /// Strategy used by the enqueuer to populate the world.
 // TODO(johnniwinther): Merge this interface with [QueueFilter].
 class EnqueuerStrategy {
   const EnqueuerStrategy();
 
   /// Process a class instantiated in live code.
-  void processInstantiatedClass(Enqueuer enqueuer, ClassElement cls) {}
+  void processInstantiatedClass(EnqueuerImpl enqueuer, ClassElement cls) {}
 
   /// Process a static use of and element in live code.
-  void processStaticUse(Enqueuer enqueuer, StaticUse staticUse) {}
+  void processStaticUse(EnqueuerImpl enqueuer, StaticUse staticUse) {}
+
+  /// Process a type use in live code.
+  void processTypeUse(EnqueuerImpl enqueuer, TypeUse typeUse) {}
 
   /// Process a dynamic use for a call site in live code.
-  void processDynamicUse(Enqueuer enqueuer, DynamicUse dynamicUse) {}
+  void processDynamicUse(EnqueuerImpl enqueuer, DynamicUse dynamicUse) {}
 }
 
+/// Strategy that only enqueues directly used elements.
+class DirectEnqueuerStrategy extends EnqueuerStrategy {
+  const DirectEnqueuerStrategy();
+  void processStaticUse(EnqueuerImpl enqueuer, StaticUse staticUse) {
+    if (staticUse.kind == StaticUseKind.DIRECT_USE) {
+      enqueuer.registerStaticUseInternal(staticUse);
+    }
+  }
+}
+
+/// Strategy used for tree-shaking.
 class TreeShakingEnqueuerStrategy implements EnqueuerStrategy {
   const TreeShakingEnqueuerStrategy();
 
   @override
-  void processInstantiatedClass(Enqueuer enqueuer, ClassElement cls) {
+  void processInstantiatedClass(EnqueuerImpl enqueuer, ClassElement cls) {
     cls.implementation.forEachMember(enqueuer.processInstantiatedClassMember);
   }
 
   @override
-  void processStaticUse(Enqueuer enqueuer, StaticUse staticUse) {
+  void processStaticUse(EnqueuerImpl enqueuer, StaticUse staticUse) {
     enqueuer.registerStaticUseInternal(staticUse);
   }
 
   @override
-  void processDynamicUse(Enqueuer enqueuer, DynamicUse dynamicUse) {
+  void processTypeUse(EnqueuerImpl enqueuer, TypeUse typeUse) {
+    enqueuer.registerTypeUseInternal(typeUse);
+  }
+
+  @override
+  void processDynamicUse(EnqueuerImpl enqueuer, DynamicUse dynamicUse) {
     enqueuer.handleUnseenSelectorInternal(dynamicUse);
   }
 }
 
-class _EnqueuerImpactVisitor implements WorldImpactVisitor {
-  final ResolutionEnqueuer enqueuer;
+class EnqueuerImplImpactVisitor implements WorldImpactVisitor {
+  final EnqueuerImpl enqueuer;
 
-  _EnqueuerImpactVisitor(this.enqueuer);
+  EnqueuerImplImpactVisitor(this.enqueuer);
 
   @override
   void visitDynamicUse(DynamicUse dynamicUse) {
     enqueuer.registerDynamicUse(dynamicUse);
   }
 
   @override
   void visitStaticUse(StaticUse staticUse) {
     enqueuer.registerStaticUse(staticUse);
   }
 
   @override
   void visitTypeUse(TypeUse typeUse) {
-    enqueuer._registerTypeUse(typeUse);
+    enqueuer.registerTypeUse(typeUse);
   }
 }
 
 typedef void _DeferredActionFunction();
 
 class _DeferredAction {
   final Element element;
   final _DeferredActionFunction action;
 
   _DeferredAction(this.element, this.action);
 }