Dummy receiver optimization

sdk/lib/_internal/compiler/implementation/js_backend/backend.dart

Index: sdk/lib/_internal/compiler/implementation/js_backend/backend.dart
diff --git a/sdk/lib/_internal/compiler/implementation/js_backend/backend.dart b/sdk/lib/_internal/compiler/implementation/js_backend/backend.dart
index 9151b71b64d9c5716c39bb68541acdd54f0cf6f0..34a7e16739ed51e1ac18320e1dfc8e35233e6b8d 100644
--- a/sdk/lib/_internal/compiler/implementation/js_backend/backend.dart
+++ b/sdk/lib/_internal/compiler/implementation/js_backend/backend.dart
@@ -171,6 +171,17 @@ class JavaScriptBackend extends Backend {
   // explicit receiver.  https://code.google.com/p/dart/issues/detail?id=8942

[floitsch, 2013/12/18 19:20:12]

Update comment.

[sra1, 2013/12/19 03:28:15]

Done.

 
   /**
+   * The members of mixin classes that are mixed into an instantiated
+   * interceptor class.  This is a cached subset of [interceptedElements].
+   * These members must be invoked with a correct explicit receiver even when
+   * the receiver is not an intercepted class because the function uses the
+   * explicit interceptor parameter since it may be called on an intercepted
+   * class.
+   */
+  final Map<SourceString, Set<Element>> interceptedMixinElements =
+      new Map<SourceString, Set<Element>>();
+
+  /**
    * A map of specialized versions of the [getInterceptorMethod].
    * Since [getInterceptorMethod] is a hot method at runtime, we're
    * always specializing it based on the incoming type. The keys in
@@ -367,6 +378,29 @@ class JavaScriptBackend extends Backend {
     return interceptedElements[selector.name] != null;
   }
 
+  /**
+   * Returns `true` iff [selector] matches an element defined in a class mixed
+   * into an intercepted class.  These selectors are not eligible for the 'dummy
+   * explicit receiver' optimization.
+   */
+  bool isInterceptedMixinSelector(Selector selector) {
+    Set<Element> elements = interceptedMixinElements.putIfAbsent(
+        selector.name,
+        () {
+          Set<Element> elements = interceptedElements[selector.name];
+          if (elements == null) return null;
+          return elements
+              .where((element) =>
+                  classesMixedIntoNativeClasses.contains(
+                      element.getEnclosingClass()))
+              .toSet();
+        });
+
+    if (elements == null) return false;
+    if (elements.isEmpty) return false;
+    return elements.any((element) => selector.applies(element, compiler));
+  }
+
   final Map<String, Set<ClassElement>> interceptedClassesCache =
       new Map<String, Set<ClassElement>>();