RFC: Start refactoring to provide more than a single backend.

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 {
   SsaCodeGeneratorTask(Compiler compiler) : super(compiler);
   String get name() => 'SSA code generator';
 
 
   String buildJavaScriptFunction(FunctionElement element,
@@ skipping 27 matching lines @@
       String parameters = Strings.join(parameterNames.getValues(), ', ');
       SsaOptimizedCodeGenerator codegen = new SsaOptimizedCodeGenerator(
           compiler, work, parameters, parameterNames);
       codegen.visitGraph(graph);
 
       FunctionElement element = work.element;
       String code;
       if (element.isInstanceMember()
           && element.enclosingElement.isClass()
           && element.enclosingElement.isNative()
-          && native.isOverriddenMethod(element,
-                                       element.enclosingElement,
-                                       compiler.emitter.nativeEmitter)) {
+          && native.isOverriddenMethod(
+              element, element.enclosingElement,
+              compiler.backend.emitter.nativeEmitter)) {
         // Record that this method is overridden. In case of optional
         // arguments, the emitter will generate stubs to handle them,
         // and needs to know if the method is overridden.
-        compiler.emitter.nativeEmitter.overriddenMethods.add(element);
+        compiler.backend.emitter.nativeEmitter.overriddenMethods.add(element);
         StringBuffer buffer = new StringBuffer();
         native.generateMethodWithPrototypeCheckForElement(
             compiler, buffer, element, '${codegen.buffer}', parameters);
         code = buffer.toString();
       } else {
         code = codegen.buffer.toString();
       }
       return buildJavaScriptFunction(element, parameters, code);
     });
   }
@@ skipping 135 matching lines @@
       phiEquivalence = new Equivalence<HPhi>(),
       unsignedShiftPrecedences = JSPrecedence.binary['>>>'] {
 
     for (final name in parameterNames.getValues()) {
       prefixes[name] = 0;
     }
 
     // Create a namespace for temporaries.
     prefixes[TEMPORARY_PREFIX] = 0;
 
-    Interceptors interceptors = compiler.builder.interceptors;
+    Interceptors interceptors = compiler.backend.builder.interceptors;
     equalsNullElement = interceptors.getEqualsNullInterceptor();
     boolifiedEqualsNullElement =
         interceptors.getBoolifiedVersionOf(equalsNullElement);
   }
 
   abstract visitTypeGuard(HTypeGuard node);
 
   abstract beginGraph(HGraph graph);
   abstract endGraph(HGraph graph);
 
@@ skipping 1815 matching lines @@
     beginExpression(JSPrecedence.LOGICAL_AND_PRECEDENCE);
     checkObject(input, '===');
     buffer.add(" && ");
     checkType(input, element);
     endExpression(JSPrecedence.LOGICAL_AND_PRECEDENCE);
     endExpression(JSPrecedence.LOGICAL_OR_PRECEDENCE);
   }
 
   void checkType(HInstruction input, Element element) {
     bool requiresNativeIsCheck =
-        compiler.emitter.nativeEmitter.requiresNativeIsCheck(element);
+        compiler.backend.emitter.nativeEmitter.requiresNativeIsCheck(element);
     if (!requiresNativeIsCheck) buffer.add('!!');
     use(input, JSPrecedence.MEMBER_PRECEDENCE);
     buffer.add('.');
     buffer.add(compiler.namer.operatorIs(element));
     if (requiresNativeIsCheck) buffer.add('()');
   }
 
   void handleStringSupertypeCheck(HInstruction input, Element element) {
     // Make sure List and String don't share supertypes, otherwise we
     // would need to check for List too.
@@ skipping 99 matching lines @@
     }
   }
 
   void visitTypeConversion(HTypeConversion node) {
     if (node.checked) {
       Element element = node.type.computeType(compiler).element;
       compiler.registerIsCheck(element);
       SourceString helper;
       String additionalArgument;
       bool nativeCheck =
-          compiler.emitter.nativeEmitter.requiresNativeIsCheck(element);
+          compiler.backend.emitter.nativeEmitter.requiresNativeIsCheck(element);
       beginExpression(JSPrecedence.CALL_PRECEDENCE);
 
       if (element == compiler.stringClass) {
         helper = const SourceString('stringTypeCheck');
       } else if (element == compiler.doubleClass) {
         helper = const SourceString('doubleTypeCheck');
       } else if (element == compiler.numClass) {
         helper = const SourceString('numTypeCheck');
       } else if (element == compiler.boolClass) {
         helper = const SourceString('boolTypeCheck');
@@ skipping 433 matching lines @@
       startBailoutSwitch();
     }
   }
 
   void endLabeledBlock(HLabeledBlockInformation labeledBlockInfo) {
     if (labeledBlockInfo.body.start.hasGuards()) {
       endBailoutSwitch();
     }
   }
 }