Return null from stringValue and call slowToString() instead of toString().

dart/frog/leg/ssa/codegen.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 SsaCodeGeneratorTask extends CompilerTask {
   SsaCodeGeneratorTask(Compiler compiler) : super(compiler);
   String get name() => 'SSA code generator';
 
   String generate(WorkItem work, HGraph graph) {
     return measure(() {
       FunctionElement function = work.element;
       Map<Element, String> parameterNames =
           new LinkedHashMap<Element, String>();
 
       function.computeParameters(compiler).forEachParameter((Element element) {
-        parameterNames[element] = JsNames.getValid('${element.name}');
+        parameterNames[element] =
+            JsNames.getValid('${element.name.slowToString()}');
       });
 
       String code = generateMethod(parameterNames, work, graph);
       return code;
     });
   }
 
   void preGenerateMethod(HGraph graph, WorkItem work) {
     if (GENERATE_SSA_TRACE) {
       new HTracer.singleton().traceGraph("codegen", graph);
@@ skipping 141 matching lines @@
     Element element = local.element;
     if (element != null && element.kind == ElementKind.PARAMETER) {
       return parameterNames[element];
     }
     int id = local.id;
     String name = names[id];
     if (name !== null) return name;
 
     String prefix;
     if (element !== null) {
-      prefix = element.name.stringValue;
+      prefix = element.name.slowToString();
     } else {
       prefix = 'v';
     }
     if (!prefixes.containsKey(prefix)) {
       prefixes[prefix] = 0;
       return newName(id, prefix);
     } else {
       return newName(id, '${prefix}_${prefixes[prefix]++}');
     }
   }
@@ skipping 211 matching lines @@
       unreachable();
     }
     assert(dominated[0] == currentBlock.successors[0]);
     visitBasicBlock(dominated[0]);
   }
 
   // Used to write the name of labels.
   // The default implementation uses the unmodified Dart label name.
   // Specializations might change this.
   void addLabel(SourceString label) {
-    buffer.add(label.toString());
+    buffer.add(label.slowToString());
   }
 
   visitBreak(HBreak node) {
     assert(currentBlock.successors.length == 1);
     // No block finishing with a 'break' can have more than
     // one dominated block (since it has only one successor).
     // If the successor is dominated by another block, then the other block
     // is responsible for visiting the successor.
     List<HBasicBlock> dominated = currentBlock.dominatedBlocks;
     assert(dominated.isEmpty());
@@ skipping 137 matching lines @@
     String className = compiler.namer.isolatePropertyAccess(superClass);
     String methodName = compiler.namer.instanceMethodName(
         superMethod.name, argumentCount);
     buffer.add('$className.prototype.$methodName.call');
     visitArguments(node.inputs);
     endExpression(JSPrecedence.CALL_PRECEDENCE);
     compiler.registerStaticUse(superMethod);
   }
 
   visitFieldGet(HFieldGet node) {
-    String name = JsNames.getValid('${node.element.name}');
+    String name = JsNames.getValid(node.element.name.slowToString());
     if (node.receiver !== null) {
       beginExpression(JSPrecedence.MEMBER_PRECEDENCE);
       use(node.receiver, JSPrecedence.MEMBER_PRECEDENCE);
       buffer.add('.');
       buffer.add(name);
       beginExpression(JSPrecedence.MEMBER_PRECEDENCE);
     } else {
       buffer.add(name);
     }
   }
 
   visitFieldSet(HFieldSet node) {
     if (node.receiver !== null) {
       beginExpression(JSPrecedence.ASSIGNMENT_PRECEDENCE);
       use(node.receiver, JSPrecedence.MEMBER_PRECEDENCE);
       buffer.add('.');
     } else {
       // TODO(ngeoffray): Remove the 'var' once we don't globally box
       // variables used in a try/catch.
       buffer.add('var ');
     }
-    String name = JsNames.getValid('${node.element.name}');
+    String name = JsNames.getValid(node.element.name.slowToString());
     buffer.add(name);
     buffer.add(' = ');
     use(node.value, JSPrecedence.ASSIGNMENT_PRECEDENCE);
     if (node.receiver !== null) {
       endExpression(JSPrecedence.ASSIGNMENT_PRECEDENCE);
     }
   }
 
   visitForeign(HForeign node) {
     String code = '${node.code}';
@@ skipping 457 matching lines @@
       buffer.add(')) ');
       bailout(node, 'Not a string or array');
     } else {
       unreachable();
     }
   }
 
   void beginLoop(HBasicBlock block) {
     addIndentation();
     for (SourceString label in block.loopInformation.labels) {
-      buffer.add("${label.stringValue}:");
+      buffer.add("${label.slowToString()}:");
     }
     buffer.add('while (true) {\n');
     indent++;
   }
 
   void endLoop(HBasicBlock block) {
     indent--;
     addIndentation();
     buffer.add('}\n');  // Close 'while' loop.
   }
@@ skipping 250 matching lines @@
       startBailoutSwitch();
     }
   }
 
   void endElse(HIf node) {
     if (node.elseBlock.hasBailouts()) {
       endBailoutSwitch();
     }
   }
 }