Reverting 7667

lib/compiler/implementation/compiler.dart

Index: lib/compiler/implementation/compiler.dart
===================================================================
--- lib/compiler/implementation/compiler.dart	(revision 7672)
+++ lib/compiler/implementation/compiler.dart	(working copy)
@@ -29,50 +29,6 @@
   }
 }
 
-class Backend {
-  final Compiler compiler;
-
-  Backend(this.compiler);
-
-  abstract String codegen(WorkItem work);
-  abstract void processNativeClasses(libraries);
-  abstract void assembleProgram();
-}
-
-class JavaScriptBackend extends Backend {
-  SsaBuilderTask builder;
-  SsaOptimizerTask optimizer;
-  SsaCodeGeneratorTask generator;
-  CodeEmitterTask emitter;
-
-  JavaScriptBackend(Compiler compiler)
-      : emitter = new CodeEmitterTask(compiler),
-        super(compiler) {
-    builder = new SsaBuilderTask(this);
-    optimizer = new SsaOptimizerTask(this);
-    generator = new SsaCodeGeneratorTask(this);
-  }
-
-  String codegen(WorkItem work) {
-    HGraph graph = builder.build(work);
-    optimizer.optimize(work, graph);
-    if (work.allowSpeculativeOptimization
-        && optimizer.trySpeculativeOptimizations(work, graph)) {
-      String code = generator.generateBailoutMethod(work, graph);
-      compiler.universe.addBailoutCode(work, code);
-      optimizer.prepareForSpeculativeOptimizations(work, graph);
-      optimizer.optimize(work, graph);
-    }
-    return generator.generateMethod(work, graph);
-  }
-
-  void processNativeClasses(libraries) {
-    native.processNativeClasses(emitter, libraries);
-  }
-
-  void assembleProgram() => emitter.assembleProgram();
-}
-
 class Compiler implements DiagnosticListener {
   Queue<WorkItem> codegenQueue;
   Universe universe;
@@ -123,7 +79,10 @@
   TreeValidatorTask validator;
   ResolverTask resolver;
   TypeCheckerTask checker;
-  Backend backend;
+  SsaBuilderTask builder;
+  SsaOptimizerTask optimizer;
+  SsaCodeGeneratorTask generator;
+  CodeEmitterTask emitter;
   ConstantHandler constantHandler;
   EnqueueTask enqueuer;
 
@@ -152,10 +111,14 @@
     validator = new TreeValidatorTask(this);
     resolver = new ResolverTask(this);
     checker = new TypeCheckerTask(this);
-    backend = new JavaScriptBackend(this);
+    builder = new SsaBuilderTask(this);
+    optimizer = new SsaOptimizerTask(this);
+    generator = new SsaCodeGeneratorTask(this);
+    emitter = new CodeEmitterTask(this);
     enqueuer = new EnqueueTask(this);
     tasks = [scanner, dietParser, parser, resolver, checker,
-             constantHandler, enqueuer];
+             builder, optimizer, generator,
+             emitter, constantHandler, enqueuer];
   }
 
   void ensure(bool condition) {
@@ -342,7 +305,7 @@
       });
     }
     Collection<LibraryElement> libraries = universe.libraries.getValues();
-    backend.processNativeClasses(libraries);
+    native.processNativeClasses(this, libraries);
     world.populate(this, libraries);
     addToWorkList(main);
     codegenProgress.reset();
@@ -353,7 +316,7 @@
     codegenQueueIsClosed = true;
     assert(enqueuer.checkNoEnqueuedInvokedInstanceMethods());
     enqueuer.registerFieldClosureInvocations();
-    backend.assembleProgram();
+    emitter.assembleProgram();
     if (!codegenQueue.isEmpty()) {
       internalErrorOnElement(codegenQueue.first().element,
                              "work list is not empty");
@@ -385,9 +348,22 @@
       constantHandler.compileWorkItem(work);
       return null;
     } else {
-      String code = backend.codegen(work);
-      universe.addGeneratedCode(work, code);
-      return code;
+      HGraph graph = builder.build(work);
+      optimizer.optimize(work, graph);
+      if (work.allowSpeculativeOptimization
+          && optimizer.trySpeculativeOptimizations(work, graph)) {
+        String code = generator.generateBailoutMethod(work, graph);
+        universe.addBailoutCode(work, code);
+        optimizer.prepareForSpeculativeOptimizations(work, graph);
+        optimizer.optimize(work, graph);
+        code = generator.generateMethod(work, graph);
+        universe.addGeneratedCode(work, code);
+        return code;
+      } else {
+        String code = generator.generateMethod(work, graph);
+        universe.addGeneratedCode(work, code);
+        return code;
+      }
     }
   }