Refactored treatment of closure variables in dart2js CPS.

pkg/compiler/lib/src/cps_ir/cps_ir_tracer.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_tracer;
 
 import 'dart:async' show EventSink;
 
 import 'cps_ir_nodes.dart' as cps_ir hide Function;
 import '../tracer.dart';
@@ skipping 181 matching lines @@
   visitBranch(cps_ir.Branch node) {
     String dummy = names.name(node);
     String condition = visit(node.condition);
     String trueCont = formatReference(node.trueContinuation);
     String falseCont = formatReference(node.falseContinuation);
     printStmt(dummy, "Branch $condition ($trueCont, $falseCont)");
   }
 
   visitSetClosureVariable(cps_ir.SetClosureVariable node) {
     String dummy = names.name(node);
-    String variable = node.variable.name;
+    String variable = names.name(node.variable.definition);
     String value = formatReference(node.value);
     printStmt(dummy, 'SetClosureVariable $variable = $value');
     visit(node.body);
   }
 
   visitDeclareFunction(cps_ir.DeclareFunction node) {
     String dummy = names.name(node);
-    String variable = node.variable.name;
+    String variable = names.name(node.variable.definition);
     printStmt(dummy, 'DeclareFunction $variable');
     visit(node.body);
   }
 
   String formatReference(cps_ir.Reference ref) {
     cps_ir.Definition target = ref.definition;
     if (target is cps_ir.Continuation && target.isReturnContinuation) {
       return "return"; // Do not generate a name for the return continuation
     } else {
       return names.name(ref.definition);
     }
   }
 
   String formatPrimitive(cps_ir.Primitive p) => visit(p);
 
   visitConstant(cps_ir.Constant node) {
     return "Constant ${node.expression.value.toStructuredString()}";
   }
 
   visitParameter(cps_ir.Parameter node) {
     return "Parameter ${names.name(node)}";
   }
 
+  visitClosureVariable(cps_ir.ClosureVariable node) {
+    return "ClosureVariable ${names.name(node)}";
+  }
+
   visitContinuation(cps_ir.Continuation node) {
     return "Continuation ${names.name(node)}";
   }
 
   visitIsTrue(cps_ir.IsTrue node) {
     return "IsTrue(${names.name(node.value.definition)})";
   }
 
   visitIdentical(cps_ir.Identical node) {
     String left = formatReference(node.left);
     String right = formatReference(node.right);
     return "Identical($left, $right)";
   }
 
   visitThis(cps_ir.This node) {
     return "This";
   }
 
   visitReifyTypeVar(cps_ir.ReifyTypeVar node) {
     return "ReifyTypeVar ${node.typeVariable.name}";
   }
 
   visitCreateFunction(cps_ir.CreateFunction node) {
     return "CreateFunction ${node.definition.element.name}";
   }
 
   visitGetClosureVariable(cps_ir.GetClosureVariable node) {
-    String variable = node.variable.name;
+    String variable = names.name(node.variable.definition);
     return 'GetClosureVariable $variable';
   }
 
 
   visitCondition(cps_ir.Condition c) {}
   visitExpression(cps_ir.Expression e) {}
   visitPrimitive(cps_ir.Primitive p) {}
   visitDefinition(cps_ir.Definition d) {}
   visitNode(cps_ir.Node n) {}
 }
 
 /**
  * Invents (and remembers) names for Continuations, Parameters, etc.
  * The names must match the conventions used by IR Hydra, e.g.
  * Continuations and Functions must have names of form B### since they
  * are visualized as basic blocks.
  */
 class Names {
   final Map<Object, String> names = {};
   final Map<String, int> counters = {
     'r': 0,
     'B': 0,
     'v': 0,
-    'x': 0
+    'x': 0,
+    'c': 0
   };
 
   String prefix(x) {
     if (x is cps_ir.Parameter) return 'r';
     if (x is cps_ir.Continuation || x is cps_ir.FunctionDefinition) return 'B';
     if (x is cps_ir.Primitive) return 'v';
+    if (x is cps_ir.ClosureVariable) return 'c';
     return 'x';
   }
 
   String name(x) {
     String nam = names[x];
     if (nam == null) {
       String pref = prefix(x);
       int id = counters[pref]++;
       nam = names[x] = '${pref}${id}';
     }
@@ skipping 107 matching lines @@
     }
   }
 
   visitContinuation(cps_ir.Continuation c) {
     var old_node = current_block;
     current_block = getBlock(c);
     visit(c.body);
     current_block = old_node;
   }
 }