Refactored treatment of closure variables in dart2js CPS.

pkg/compiler/lib/src/cps_ir/cps_ir_nodes_sexpr.dart

 // Copyright (c) 2014, 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 dart2js.ir_nodes_sexpr;
 
 import '../util/util.dart';
 import 'cps_ir_nodes.dart';
 
 /// A [Decorator] is a function used by [SExpressionStringifier] to augment the
 /// output produced for a node.  It can be provided to the constructor.
 typedef String Decorator(Node node, String s);
 
 /// Generate a Lisp-like S-expression representation of an IR node as a string.
 class SExpressionStringifier extends Visitor<String> with Indentation {
   final _Namer namer = new _Namer();
 
   String newValueName(Node node) => namer.defineValueName(node);
   String newContinuationName(Node node) => namer.defineContinuationName(node);
   final Decorator decorator;
 
   SExpressionStringifier([this.decorator]);
 
   String access(Reference<Definition> r) => namer.getName(r.definition);
 
   String visitParameter(Parameter node) {
     return namer.useElementName(node);
   }
 
+  String visitClosureVariable(ClosureVariable node) {
+    return namer.getName(node);
+  }
+
   /// Main entry point for creating a [String] from a [Node].  All recursive
   /// calls must go through this method.
   String visit(Node node) {
     String s = super.visit(node);
     return (decorator == null) ? s : decorator(node, s);
   }
 
   String visitFunctionDefinition(FunctionDefinition node) {
     String name = node.element.name;
     namer.useReturnName(node.returnContinuation);
+    String closureVariables = node.closureVariables.isEmpty
+        ? ''
+        : '{${node.closureVariables.map(namer.defineClosureName).join(' ')}} ';
     String parameters = node.parameters.map(visit).join(' ');
     String body = indentBlock(() => visit(node.body));
-    return '$indentation(FunctionDefinition $name ($parameters return)\n'
-           '$body)';
+    return '$indentation(FunctionDefinition $name $closureVariables'
+           '($parameters return)\n$body)';
   }
 
   String visitFieldDefinition(FieldDefinition node) {
     String name = node.element.name;
     if (node.hasInitializer) {
       namer.useReturnName(node.returnContinuation);
       String body = indentBlock(() => visit(node.body));
       return '$indentation(FieldDefinition $name (return)\n'
              '$body)';
     } else {
@@ skipping 108 matching lines @@
     String function = indentBlock(() => visit(node.definition));
     return '(CreateFunction\n$function)';
   }
 
   String visitContinuation(Continuation node) {
     // Continuations are visited directly in visitLetCont.
     return '(Unexpected Continuation)';
   }
 
   String visitGetClosureVariable(GetClosureVariable node) {
-    return '(GetClosureVariable ${node.variable.name})';
+    return '(GetClosureVariable ${visit(node.variable.definition)})';
   }
 
   String visitSetClosureVariable(SetClosureVariable node) {
     String value = access(node.value);
     String body = indentBlock(() => visit(node.body));
-    return '$indentation(SetClosureVariable ${node.variable.name} $value\n'
-           '$body)';
+    return '$indentation(SetClosureVariable ${visit(node.variable.definition)} '
+           '$value\n$body)';
   }
 
   String visitTypeOperator(TypeOperator node) {
     String receiver = access(node.receiver);
     String cont = access(node.continuation);
     String operator = node.isTypeTest ? 'is' : 'as';
     return '$indentation(TypeOperator $operator $receiver ${node.type} $cont)';
   }
 
   String visitLiteralList(LiteralList node) {
     String values = node.values.map(access).join(' ');
     return '(LiteralList ($values))';
   }
 
   String visitLiteralMap(LiteralMap node) {
     String keys = node.entries.map((e) => access(e.key)).join(' ');
     String values = node.entries.map((e) => access(e.value)).join(' ');
     return '(LiteralMap ($keys) ($values))';
   }
 
   String visitDeclareFunction(DeclareFunction node) {
     String function = indentBlock(() => visit(node.definition));
     String body = indentBlock(() => visit(node.body));
-    return '$indentation(DeclareFunction ${node.variable.name} =\n'
+    String name = namer.getName(node.variable.definition);
+    return '$indentation(DeclareFunction $name =\n'
            '$function in\n'
            '$body)';
   }
 
   String visitIsTrue(IsTrue node) {
     String value = access(node.value);
     return '(IsTrue $value)';
   }
 
   String visitIdentical(Identical node) {
     String left = access(node.left);
     String right = access(node.right);
     return '(Identical $left $right)';
   }
 }
 
 class _Namer {
   final Map<Node, String> _names = <Node, String>{};
   int _valueCounter = 0;
   int _continuationCounter = 0;
 
   String useElementName(Parameter parameter) {
     assert(!_names.containsKey(parameter));
     return _names[parameter] = parameter.hint.name;
   }
 
+  String defineClosureName(ClosureVariable variable) {
+    assert(!_names.containsKey(variable));
+    return _names[variable] = variable.hint.name;
+  }
+
   String defineContinuationName(Node node) {
     assert(!_names.containsKey(node));
     return _names[node] = 'k${_continuationCounter++}';
   }
 
   String defineValueName(Node node) {
     assert(!_names.containsKey(node));
     return _names[node] = 'v${_valueCounter++}';
   }
 
   String useReturnName(Continuation node) {
     assert(!_names.containsKey(node) || _names[node] == 'return');
     return _names[node] = 'return';
   }
 
   String getName(Node node) {
     assert(_names.containsKey(node));
     return _names[node];
   }
 }