No globals.

dart/frog/leg/ssa/closure.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.
 
 class ClosureFieldElement extends Element {
   ClosureFieldElement(SourceString name, ClassElement enclosing)
       : super(name, ElementKind.FIELD, enclosing);
 
   bool isInstanceMember() => true;
   bool isAssignable() => false;
@@ skipping 61 matching lines @@
               this.callElement,
               this.thisElement)
       : this.freeVariableMapping = new Map<Element, Element>(),
         this.capturedFieldMapping = new Map<Element, Element>(),
         this.capturingScopes = new Map<Node, ClosureScope>(),
         this.usedVariablesInTry = new Set<Element>();
 
   bool isClosure() => closureElement !== null;
 }
 
-Map<Node, ClosureData> _closureDataCache;
-Map<Node, ClosureData> get closureDataCache() {
-  if (_closureDataCache === null) {
-    _closureDataCache = new HashMap<Node, ClosureData>();
-  }
-  return _closureDataCache;
-}
-
 class ClosureTranslator extends AbstractVisitor {
   final Compiler compiler;
   final TreeElements elements;
   int boxCounter = 0;
   bool inTryCatchOrFinally = false;
+  final Map<Node, ClosureData> closureDataCache;
 
   // Map of captured variables. Initially they will map to themselves. If
   // a variable needs to be boxed then the scope declaring the variable
   // will update this mapping.
   Map<Element, Element> capturedVariableMapping;
   // List of encountered closures.
   List<FunctionExpression> closures;
 
   // The variables that have been declared in the current scope.
   List<Element> scopeVariables;
 
   FunctionElement currentFunctionElement;
   // The closureData of the currentFunctionElement.
   ClosureData closureData;
 
   bool insideClosure = false;
 
-  ClosureTranslator(this.compiler, this.elements)
+  ClosureTranslator(Compiler compiler, this.elements)
       : capturedVariableMapping = new Map<Element, Element>(),
-        closures = <FunctionExpression>[];
+        closures = <FunctionExpression>[],
+        this.compiler = compiler,
+        this.closureDataCache = compiler.builder.closureDataCache;
 
   ClosureData translate(Node node) {
     // Closures have already been analyzed when visiting the surrounding
     // method/function. This also shortcuts for bailout functions.
     ClosureData cached = closureDataCache[node];
     if (cached !== null) return cached;
 
     visit(node);
     // When variables need to be boxed their [capturedVariableMapping] is
     // updated, but we delay updating the similar freeVariableMapping in the
@@ skipping 288 matching lines @@
     declareLocal(elements[node]);
   }
 
   visitTryStatement(TryStatement node) {
     // TODO(ngeoffray): implement finer grain state.
     inTryCatchOrFinally = true;
     node.visitChildren(this);
     inTryCatchOrFinally = false;
   }
 }