Remove direct access to enqueuer through use of WorldImpact

pkg/compiler/lib/src/js_backend/enqueuer.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.js.enqueue;
 
 import 'dart:collection' show Queue;
 
 import '../common/backend_api.dart' show Backend;
 import '../common/codegen.dart' show CodegenWorkItem;
@@ skipping 25 matching lines @@
 import '../universe/selector.dart' show Selector;
 import '../universe/world_builder.dart';
 import '../universe/use.dart'
     show DynamicUse, StaticUse, StaticUseKind, TypeUse, TypeUseKind;
 import '../universe/world_impact.dart'
     show ImpactUseCase, ImpactStrategy, WorldImpact, WorldImpactVisitor;
 import '../util/util.dart' show Setlet;
 import '../world.dart';
 
 /// [Enqueuer] which is specific to code generation.
-class CodegenEnqueuer implements Enqueuer {
+class CodegenEnqueuer extends Enqueuer {
   final String name;
   @deprecated
   final Compiler _compiler; // TODO(ahe): Remove this dependency.
   final EnqueuerStrategy strategy;
   final Map<String, Set<Element>> instanceMembersByName =
       new Map<String, Set<Element>>();
   final Map<String, Set<Element>> instanceFunctionsByName =
       new Map<String, Set<Element>>();
   final Set<ClassElement> _processedClasses = new Set<ClassElement>();
   Set<ClassElement> recentClasses = new Setlet<ClassElement>();
@@ skipping 59 matching lines @@
       throw new SpannableAssertionFailure(
           element, "Codegen work list is closed. Trying to add $element");
     }
     queue.add(new CodegenWorkItem(_compiler, element));
     // TODO(sigmund): add other missing dependencies (internals, selectors
     // enqueued after allocations).
     _compiler.dumpInfoTask
         .registerDependency(_compiler.currentElement, element);
   }
 
-  void applyImpact(ImpactStrategy impactStrategy, WorldImpact worldImpact,
-      {Element impactSource}) {
+  void applyImpact(WorldImpact worldImpact, {Element impactSource}) {
+    if (worldImpact.isEmpty) return;
     impactStrategy.visitImpact(
         impactSource, worldImpact, impactVisitor, impactUse);
   }
 
   void registerInstantiatedType(InterfaceType type) {
     _registerInstantiatedType(type);
   }
 
   void _registerInstantiatedType(InterfaceType type,
       {bool mirrorUsage: false, bool nativeUsage: false}) {
     task.measure(() {
       ClassElement cls = type.element;
       bool isNative = backend.isNative(cls);
       _universe.registerTypeInstantiation(type,
           isNative: isNative,
           byMirrors: mirrorUsage, onImplemented: (ClassElement cls) {
-        backend.registerImplementedClass(cls, this);
+        applyImpact(
+            backend.registerImplementedClass(cls, forResolution: false));
       });
       if (nativeUsage) {
         nativeEnqueuer.onInstantiatedType(type);
       }
       backend.registerInstantiatedType(type);
       // TODO(johnniwinther): Share this reasoning with [Universe].
       if (!cls.isAbstract || isNative || mirrorUsage) {
         processInstantiatedClass(cls);
       }
     });
@@ skipping 110 matching lines @@
               message: "Class $superclass has not been "
                        "processed in resolution."));
         */
 
         _processedClasses.add(superclass);
         recentClasses.add(superclass);
         superclass.implementation.forEachMember(processInstantiatedClassMember);
         // We only tell the backend once that [superclass] was instantiated, so
         // any additional dependencies must be treated as global
         // dependencies.
-        backend.registerInstantiatedClass(superclass, this);
+        applyImpact(backend.registerInstantiatedClass(superclass,
+            forResolution: false));
       }
 
       ClassElement superclass = cls;
       while (superclass != null) {
         processClass(superclass);
         superclass = superclass.superclass;
       }
     });
   }
 
@@ skipping 63 matching lines @@
    */
   void registerStaticUse(StaticUse staticUse) {
     strategy.processStaticUse(this, staticUse);
   }
 
   void registerStaticUseInternal(StaticUse staticUse) {
     Element element = staticUse.element;
     assert(invariant(element, element.isDeclaration,
         message: "Element ${element} is not the declaration."));
     _universe.registerStaticUse(staticUse);
-    backend.registerStaticUse(this, element);
+    applyImpact(backend.registerStaticUse(element, forResolution: false));
     bool addElement = true;
     switch (staticUse.kind) {
       case StaticUseKind.STATIC_TEAR_OFF:
-        backend.registerGetOfStaticFunction(this);
+        applyImpact(backend.registerGetOfStaticFunction());
         break;
       case StaticUseKind.FIELD_GET:
       case StaticUseKind.FIELD_SET:
       case StaticUseKind.CLOSURE:
         // TODO(johnniwinther): Avoid this. Currently [FIELD_GET] and
         // [FIELD_SET] contains [BoxFieldElement]s which we cannot enqueue.
         // Also [CLOSURE] contains [LocalFunctionElement] which we cannot
         // enqueue.
         addElement = false;
         break;
@@ skipping 44 matching lines @@
 
   void _registerIsCheck(DartType type) {
     type = _universe.registerIsCheck(type, _compiler.resolution);
     // 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 registerCallMethodWithFreeTypeVariables(Element element) {
-    backend.registerCallMethodWithFreeTypeVariables(element, this);
+    applyImpact(backend.registerCallMethodWithFreeTypeVariables(element,
+        forResolution: false));
   }
 
   void registerClosurizedMember(TypedElement element) {
     assert(element.isInstanceMember);
     if (element.type.containsTypeVariables) {
-      backend.registerClosureWithFreeTypeVariables(element, this);
+      applyImpact(backend.registerClosureWithFreeTypeVariables(element,
+          forResolution: false));
     }
-    backend.registerBoundClosure(this);
+    applyImpact(backend.registerBoundClosure());
   }
 
   void forEach(void f(WorkItem work)) {
     do {
       while (queue.isNotEmpty) {
         // TODO(johnniwinther): Find an optimal process order.
         filter.processWorkItem(f, queue.removeLast());
       }
       List recents = recentClasses.toList(growable: false);
       recentClasses.clear();
@@ skipping 37 matching lines @@
   static const ImpactUseCase IMPACT_USE =
       const ImpactUseCase('CodegenEnqueuer');
 
   ImpactUseCase get impactUse => IMPACT_USE;
 
   bool isProcessed(Element member) =>
       member.isAbstract || generatedCode.containsKey(member);
 
   void registerNoSuchMethod(Element element) {
     if (!enabledNoSuchMethod && backend.enabledNoSuchMethod) {
-      backend.enableNoSuchMethod(this);
+      applyImpact(backend.enableNoSuchMethod());
       enabledNoSuchMethod = true;
     }
   }
 
   void _logSpecificSummary(log(message)) {
     log('Compiled ${generatedCode.length} methods.');
   }
 
   void forgetElement(Element element, Compiler compiler) {
     _forgetElement(element);
@@ skipping 40 matching lines @@
   @override
   void visitStaticUse(StaticUse staticUse) {
     enqueuer.registerStaticUse(staticUse);
   }
 
   @override
   void visitTypeUse(TypeUse typeUse) {
     enqueuer.registerTypeUse(typeUse);
   }
 }