Don't generate forwarding hooks if all noSuchMethod implementations

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.
 
 part of dart2js;
 
 typedef ItemCompilationContext ItemCompilationContextCreator();
 
 class EnqueueTask extends CompilerTask {
   final ResolutionEnqueuer resolution;
@@ skipping 144 matching lines @@
         // All field initializers must be resolved as they could
         // have an observable side-effect (and cannot be tree-shaken
         // away).
         addToWorkList(member);
         return;
       }
     } else if (member.kind == ElementKind.FUNCTION) {
       FunctionElement function = member;
       function.computeSignature(compiler);
       if (function.name == Compiler.NO_SUCH_METHOD) {
-        enableNoSuchMethod(function);
+        registerNoSuchMethod(function);
       }
       if (function.name == Compiler.CALL_OPERATOR_NAME &&
           !cls.typeVariables.isEmpty) {
         registerCallMethodWithFreeTypeVariables(
             function, compiler.globalDependencies);
       }
       // If there is a property access with the same name as a method we
       // need to emit the method.
       if (universe.hasInvokedGetter(function, compiler.world)) {
         registerClosurizedMember(function, compiler.globalDependencies);
@@ skipping 29 matching lines @@
         return;
       }
     }
 
     // The element is not yet used. Add it to the list of instance
     // members to still be processed.
     instanceMembersByName.putIfAbsent(memberName, () => new Set<Element>())
         .add(member);
   }
 
-  void enableNoSuchMethod(Element element) {}
+  void registerNoSuchMethod(Element noSuchMethod);
+
   void enableIsolateSupport() {}
 
   void processInstantiatedClass(ClassElement cls) {
     task.measure(() {
       if (_processedClasses.contains(cls)) return;
       // The class must be resolved to compute the set of all
       // supertypes.
       cls.ensureResolved(compiler);
 
       void processClass(ClassElement cls) {
@@ skipping 503 matching lines @@
       // TODO(ahe): Record precise dependency here.
       compiler.backend.registerRuntimeType(this, compiler.globalDependencies);
     } else if (element == compiler.functionApplyMethod) {
       compiler.enabledFunctionApply = true;
     }
 
     nativeEnqueuer.registerElement(element);
     return true;
   }
 
+  void registerNoSuchMethod(Element element) {
+    compiler.backend.registerNoSuchMethod(element);
+  }
+
   void enableIsolateSupport() {
     compiler.hasIsolateSupport = true;
     compiler.backend.enableIsolateSupport(this);
   }
 
-  void enableNoSuchMethod(Element element) {
-    if (compiler.enabledNoSuchMethod) return;
-    if (compiler.backend.isDefaultNoSuchMethodImplementation(element)) return;
-
-    compiler.enabledNoSuchMethod = true;
-    compiler.backend.enableNoSuchMethod(element, this);
-  }
-
   /**
    * 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(Element element, DeferredAction action) {
     if (queueIsClosed) {
@@ skipping 37 matching lines @@
 /// [Enqueuer] which is specific to code generation.
 class CodegenEnqueuer extends Enqueuer {
   final Queue<CodegenWorkItem> queue;
   final Map<Element, js.Expression> generatedCode =
       new Map<Element, js.Expression>();
 
   final Set<Element> newlyEnqueuedElements;
 
   final Set<Selector> newlySeenSelectors;
 
+  bool enabledNoSuchMethod = false;
+
   CodegenEnqueuer(Compiler compiler,
                   ItemCompilationContext itemCompilationContextCreator())
       : queue = new Queue<CodegenWorkItem>(),
         newlyEnqueuedElements = compiler.cacheStrategy.newSet(),
         newlySeenSelectors = compiler.cacheStrategy.newSet(),
         super('codegen enqueuer', compiler, itemCompilationContextCreator);
 
   bool isProcessed(Element member) =>
       member.isAbstract || generatedCode.containsKey(member);
 
@@ skipping 29 matching lines @@
     if (queueIsClosed) {
       throw new SpannableAssertionFailure(element,
           "Codegen work list is closed. Trying to add $element");
     }
     CodegenWorkItem workItem = new CodegenWorkItem(
         element, itemCompilationContextCreator());
     queue.add(workItem);
     return true;
   }
 
+  void registerNoSuchMethod(Element element) {
+    if (!enabledNoSuchMethod && compiler.backend.enabledNoSuchMethod) {
+      compiler.backend.enableNoSuchMethod(this);
+      enabledNoSuchMethod = true;
+    }
+  }
+
   void _logSpecificSummary(log(message)) {
     log('Compiled ${generatedCode.length} methods.');
   }
 
   void forgetElement(Element element) {
     super.forgetElement(element);
     generatedCode.remove(element);
     if (element is MemberElement) {
       for (Element closure in element.nestedClosures) {
         generatedCode.remove(closure);
@@ skipping 31 matching lines @@
   void processWorkItem(void f(WorkItem work), WorkItem work) {
     f(work);
   }
 }
 
 void removeFromSet(Map<String, Set<Element>> map, Element element) {
   Set<Element> set = map[element.name];
   if (set == null) return;
   set.remove(element);
 }