Introduce CodeBuffer as StringBuffer replacement in compiler.

lib/compiler/implementation/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 {
   final JavaScriptBackend backend;
   SsaCodeGeneratorTask(JavaScriptBackend backend)
       : this.backend = backend,
         super(backend.compiler);
   String get name() => 'SSA code generator';
   NativeEmitter get nativeEmitter() => backend.emitter.nativeEmitter;
 
 
-  CodeBlock buildJavaScriptFunction(FunctionElement element,
-                                    String parameters,
-                                    String body) {
+  CodeBuffer buildJavaScriptFunction(FunctionElement element,
+                                     String parameters,
+                                     String body) {
     String extraSpace = "";
     // Members are emitted inside a JavaScript object literal. To line up the
     // indentation we want the closing curly brace to be indented by one space.
     // Example:
     // defineClass("A", "B", ... , {
     //  foo$1: function(..) {
     //  },  /* <========== indent by 1. */
     //  bar$2: function(..) {
     //  },  /* <========== indent by 1. */
     //
     // For static functions this is not necessary:
     // $.staticFun = function() {
     //   ...
     // };
     if (element.isInstanceMember() ||
         element.kind == ElementKind.GENERATIVE_CONSTRUCTOR_BODY) {
       extraSpace = " ";
     }
 
-    String code = 'function($parameters) {\n$body$extraSpace}';
-    List<SourceMappingEntry> sourceMappings = new List<SourceMappingEntry>();
-    SourceFile sourceFile = element.getCompilationUnit().script.file;
     FunctionExpression expression = element.cachedNode;
-    sourceMappings.add(new SourceMappingEntry(
-      sourceFile, expression.getBeginToken().charOffset, 0));
-    sourceMappings.add(new SourceMappingEntry(
-      sourceFile, expression.getEndToken().charOffset, code.length - 1));
-    return new CodeBlock(code, sourceMappings);
+    CodeBuffer buffer = new CodeBuffer();
+    buffer.setSourceLocation(element, expression.getBeginToken());
+    buffer.add('function($parameters) {\n');
+    buffer.add(body);
+    buffer.add(extraSpace);
+    buffer.setSourceLocation(element, expression.getEndToken());
+    buffer.add('}');
+    return buffer;
   }
 
-  CodeBlock generateMethod(WorkItem work, HGraph graph) {
+  CodeBuffer generateMethod(WorkItem work, HGraph graph) {
     return measure(() {
       compiler.tracer.traceGraph("codegen", graph);
       Map<Element, String> parameterNames = getParameterNames(work);
       parameterNames.forEach((element, name) {
         compiler.enqueuer.codegen.addToWorkList(element);
       });
       String parameters = Strings.join(parameterNames.getValues(), ', ');
       SsaOptimizedCodeGenerator codegen = new SsaOptimizedCodeGenerator(
           backend, work, parameters, parameterNames);
       codegen.visitGraph(graph);
@@ skipping 13 matching lines @@
         native.generateMethodWithPrototypeCheckForElement(
             compiler, buffer, element, '${codegen.buffer}', parameters);
         code = buffer.toString();
       } else {
         code = codegen.buffer.toString();
       }
       return buildJavaScriptFunction(element, parameters, code);
     });
   }
 
-  CodeBlock generateBailoutMethod(WorkItem work, HGraph graph) {
+  CodeBuffer generateBailoutMethod(WorkItem work, HGraph graph) {
     return measure(() {
       compiler.tracer.traceGraph("codegen-bailout", graph);
 
       Map<Element, String> parameterNames = getParameterNames(work);
       String parameters = Strings.join(parameterNames.getValues(), ', ');
       SsaUnoptimizedCodeGenerator codegen = new SsaUnoptimizedCodeGenerator(
           backend, work, parameters, parameterNames);
       codegen.visitGraph(graph);
 
       String body = '${codegen.setup}${codegen.buffer}';
@@ skipping 53 matching lines @@
    * expression, and that it only generates expressions of the form
    *   variable = expression
    * which are also valid as parts of a "var" declaration.
    */
   static final int TYPE_STATEMENT = 0;
   static final int TYPE_EXPRESSION = 1;
   static final int TYPE_DECLARATION = 2;
 
   final JavaScriptBackend backend;
   final WorkItem work;
-  final StringBuffer buffer;
+  final CodeBuffer buffer;
   final String parameters;
 
   final Set<HInstruction> generateAtUseSite;
   final Set<HInstruction> controlFlowOperators;
   final Map<Element, ElementAction> breakAction;
   final Map<Element, ElementAction> continueAction;
   final Map<Element, String> parameterNames;
 
   /**
    * Contains the names of the instructions, as well as the parallel
@@ skipping 78 matching lines @@
     }
     return hasNonBitOpUser(instruction, new Set<HPhi>());
   }
 
   SsaCodeGenerator(this.backend,
                    this.work,
                    this.parameters,
                    this.parameterNames)
     : declaredVariables = new Set<String>(),
       delayedVariableDeclarations = new Set<String>(),
-      buffer = new StringBuffer(),
+      buffer = new CodeBuffer(),
       generateAtUseSite = new Set<HInstruction>(),
       controlFlowOperators = new Set<HInstruction>(),
       breakAction = new Map<Element, ElementAction>(),
       continueAction = new Map<Element, ElementAction>(),
       unsignedShiftPrecedences = JSPrecedence.binary['>>>'] {
   }
 
   abstract visitTypeGuard(HTypeGuard node);
 
   abstract beginGraph(HGraph graph);
@@ skipping 2559 matching lines @@
 
   void startLabeledBlock(HLabeledBlockInformation labeledBlockInfo) {
   }
 
   void endLabeledBlock(HLabeledBlockInformation labeledBlockInfo) {
   }
 }
 
 class SsaUnoptimizedCodeGenerator extends SsaCodeGenerator {
 
-  final StringBuffer setup;
-  final StringBuffer newParameters;
+  final CodeBuffer setup;
+  final CodeBuffer newParameters;
   final List<String> labels;
   int labelId = 0;
 
   SsaBailoutPropagator propagator;
   HInstruction savedFirstInstruction;
 
   SsaUnoptimizedCodeGenerator(backend, work, parameters, parameterNames)
     : super(backend, work, parameters, parameterNames),
-      setup = new StringBuffer(),
-      newParameters = new StringBuffer(),
+      setup = new CodeBuffer(),
+      newParameters = new CodeBuffer(),
       labels = <String>[];
 
   String pushLabel() {
     String label = 'L${labelId++}';
     labels.addLast(label);
     return label;
   }
 
   String popLabel() {
     return labels.removeLast();
@@ skipping 255 matching lines @@
   if (leftType.canBeNull() && rightType.canBeNull()) {
     if (left.isConstantNull() || right.isConstantNull() ||
         (leftType.isPrimitive() && leftType == rightType)) {
       return '==';
     }
     return null;
   } else {
     return '===';
   }
 }