dart2js: keep track of non-final static fields.

pkg/compiler/lib/src/universe/universe.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 universe;
 
 import '../elements/elements.dart';
 import '../dart2jslib.dart';
 import '../dart_types.dart';
 import '../types/types.dart';
@@ skipping 19 matching lines @@
   ///
   /// See [_directlyInstantiatedClasses].
   final Set<DartType> _instantiatedTypes = new Set<DartType>();
 
   /// The set of all instantiated classes, either directly, as superclasses or
   /// as supertypes.
   ///
   /// Invariant: Elements are declaration elements.
   final Set<ClassElement> _allInstantiatedClasses = new Set<ClassElement>();
 
+  /// The set of all referenced static fields.
+  ///
+  /// Invariant: Elements are declaration elements.
+  final Set<FieldElement> allReferencedStaticFields = new Set<FieldElement>();
+
   /**
    * Documentation wanted -- johnniwinther
    *
    * Invariant: Elements are declaration elements.
    */
   final Set<FunctionElement> staticFunctionsNeedingGetter =
       new Set<FunctionElement>();
   final Set<FunctionElement> methodsNeedingSuperGetter =
       new Set<FunctionElement>();
   final Map<String, Set<Selector>> invokedNames =
@@ skipping 128 matching lines @@
 
   DartType registerIsCheck(DartType type, Compiler compiler) {
     type = type.unalias(compiler);
     // 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.
     isChecks.add(type);
     return type;
   }
 
+  void registerStaticFieldUse(FieldElement staticField) {
+    assert(Elements.isStaticOrTopLevel(staticField) && staticField.isField);
+    assert(staticField.isDeclaration);
+
+    allReferencedStaticFields.add(staticField);
+  }
+
   void forgetElement(Element element, Compiler compiler) {
     allClosures.remove(element);
     slowDirectlyNestedClosures(element).forEach(compiler.forgetElement);
     closurizedMembers.remove(element);
     fieldSetters.remove(element);
     fieldGetters.remove(element);
     _directlyInstantiatedClasses.remove(element);
     _allInstantiatedClasses.remove(element);
     if (element is ClassElement) {
       assert(invariant(
@@ skipping 649 matching lines @@
 
   Selector extendIfReachesAll(Compiler compiler) {
     bool canReachAll = compiler.enabledInvokeOn
         && mask.needsNoSuchMethodHandling(this, compiler.world);
     return canReachAll
         ? new TypedSelector(
             compiler.typesTask.dynamicType, this, compiler.world)
         : this;
   }
 }