Lazy implementation of final variables.

lib/compiler/implementation/namer.dart

 // Copyright (c) 2011, 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.
 
 /**
  * Assigns JavaScript identifiers to Dart variables, class-names and members.
  */
 class Namer {
   final Compiler compiler;
 
@@ skipping 17 matching lines @@
         usedGlobals = new Map<String, int>(),
         usedPrivateNames = new Map<String, Set<LibraryElement>>(),
         shortPrivateNameOwners = new Map<String, LibraryElement>();
 
   final String CURRENT_ISOLATE = @'$';
   final String ISOLATE = 'Isolate';
   final String ISOLATE_PROPERTIES = @"$isolateProperties";
   /** Some closures must contain their name. The name is stored in
     * [STATIC_CLOSURE_NAME_NAME]. */
   final String STATIC_CLOSURE_NAME_NAME = @'$name';
+  // TODO(floitsch): make sure the sentinel can't clash with other fields.
+  final String LAZY_INITIALIZATION_SENTINEL = @"$lazySentinel";
   static final SourceString CLOSURE_INVOCATION_NAME =
       Compiler.CALL_OPERATOR_NAME;
 
 
   String closureInvocationName(Selector selector) {
     // TODO(floitsch): mangle, while not conflicting with instance names.
     return instanceMethodInvocationName(null, CLOSURE_INVOCATION_NAME,
                                         selector);
   }
 
@@ skipping 226 matching lines @@
           kind === ElementKind.LIBRARY) {
         String result = getFreshGlobalName(guess);
         globals[element] = result;
         return result;
       }
       compiler.internalError('getName for unknown kind: ${element.kind}',
                               node: element.parseNode(compiler));
     }
   }
 
+  String getLazyInitializerName(Element element) {
+    // TODO(floitsch): mangle while not conflicting with other statics.
+    assert(Elements.isStaticOrTopLevelField(element));
+    return "get\$${getName(element)}";
+  }
+
+  String getLazyInitializerBailoutName(Element element) {
+    return "${getLazyInitializerName}\$bailout";
+  }
+
   String isolatePropertiesAccess(Element element) {
     return "$ISOLATE.$ISOLATE_PROPERTIES.${getName(element)}";
   }
 
   String isolatePropertiesAccessForConstant(String constantName) {
     return "$ISOLATE.$ISOLATE_PROPERTIES.$constantName";
   }
 
   String isolateAccess(Element element) {
     return "$CURRENT_ISOLATE.${getName(element)}";
   }
 
   String isolateBailoutAccess(Element element) {
     return '${isolateAccess(element)}\$bailout';
   }
 
+  String isolateLazyInitializerAccess(Element element) {
+    return "$CURRENT_ISOLATE.${getLazyInitializerName(element)}";
+  }
+
+  String isolateLazyInitializerBailoutAccess(Element element) {
+    return "$CURRENT_ISOLATE.${getLazyInitializerName(element)}\$bailout";
+  }
+
   String operatorIs(Element element) {
     return 'is\$${getName(element)}';
   }
 
   String safeName(String name) {
     if (jsReserved.contains(name) || name.startsWith('\$')) {
       name = "\$$name";
       assert(!jsReserved.contains(name));
     }
     return name;
   }
 }