dart2js cps: Clean up in type propagation.

pkg/compiler/lib/src/js_backend/codegen/task.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.
 
 /// Generate code using the cps-based IR pipeline.
 library code_generator_task;
 
 import 'glue.dart';
 import 'codegen.dart';
 import 'unsugar.dart';
@@ skipping 21 matching lines @@
 import '../../tree_ir/tree_ir_integrity.dart';
 import '../../cps_ir/cps_ir_nodes_sexpr.dart';
 import 'js_tree_builder.dart';
 
 class CpsFunctionCompiler implements FunctionCompiler {
   final ConstantSystem constantSystem;
   final Compiler compiler;
   final Glue glue;
   final SourceInformationFactory sourceInformationFactory;
 
-  TypeSystem types;
-
   // TODO(karlklose,sigurm): remove and update dart-doc of [compile].
   final FunctionCompiler fallbackCompiler;
 
   Tracer get tracer => compiler.tracer;
 
   IrBuilderTask get irBuilderTask => compiler.irBuilder;
 
   CpsFunctionCompiler(Compiler compiler, JavaScriptBackend backend,
                       SourceInformationFactory sourceInformationFactory)
       : fallbackCompiler =
             new ssa.SsaFunctionCompiler(backend, sourceInformationFactory),
         this.sourceInformationFactory = sourceInformationFactory,
         constantSystem = backend.constantSystem,
         compiler = compiler,
         glue = new Glue(compiler);
 
   String get name => 'CPS Ir pipeline';
 
   /// Generates JavaScript code for `work.element`. First tries to use the
   /// Cps Ir -> tree ir -> js pipeline, and if that fails due to language
   /// features not implemented it will fall back to the ssa pipeline (for
   /// platform code) or will cancel compilation (for user code).
   js.Fun compile(CodegenWorkItem work) {
-    types = new TypeMaskSystem(compiler);
     AstElement element = work.element;
     JavaScriptBackend backend = compiler.backend;
     return compiler.withCurrentElement(element, () {
       if (element.library.isPlatformLibrary ||
           element.library == backend.interceptorsLibrary) {
         compiler.log('Using SSA compiler for platform element $element');
         return fallbackCompiler.compile(work);
       }
       try {
         if (tracer != null) {
@@ skipping 53 matching lines @@
       }
       String suffix = (type.isExact ? "" : "+") + (type.isNullable ? "?" : "!");
       return '${type.base.name}$suffix';
     } else if (type is ForwardingTypeMask) {
       return formatTypeMask(type.forwardTo);
     }
     throw 'unsupported: $type';
   }
 
   void dumpTypedIR(cps.FunctionDefinition cpsNode,
-                   TypePropagator<TypeMask> typePropagator) {
+                   TypePropagator typePropagator) {
     if (PRINT_TYPED_IR_FILTER != null &&
         PRINT_TYPED_IR_FILTER.matchAsPrefix(cpsNode.element.name) != null) {
       String printType(nodeOrRef, String s) {
         cps.Node node = nodeOrRef is cps.Reference
             ? nodeOrRef.definition
             : nodeOrRef;
         var type = typePropagator.getType(node);
         return type == null ? s : "$s:${formatTypeMask(type.type)}";
       }
       DEBUG_MODE = true;
       print(new SExpressionStringifier(printType).visit(cpsNode));
     }
   }
 
   static bool checkCpsIntegrity(cps.FunctionDefinition node) {
     new CheckCpsIntegrity().check(node);
     return true; // So this can be used from assert().
   }
 
   cps.FunctionDefinition optimizeCpsIR(cps.FunctionDefinition cpsNode) {
     // Transformations on the CPS IR.
     void applyCpsPass(cps_opt.Pass pass) {
       pass.rewrite(cpsNode);
       traceGraph(pass.passName, cpsNode);
       assert(checkCpsIntegrity(cpsNode));
     }
 
-    TypePropagator typePropagator = new TypePropagator<TypeMask>(
-        compiler.types,
-        constantSystem,
-        new TypeMaskSystem(compiler),
-        compiler.internalError);
+    TypePropagator typePropagator = new TypePropagator(compiler);
     applyCpsPass(typePropagator);
     dumpTypedIR(cpsNode, typePropagator);
     applyCpsPass(new RedundantPhiEliminator());
     applyCpsPass(new ShrinkingReducer());
 
     return cpsNode;
   }
 
   tree_ir.FunctionDefinition compileToTreeIR(cps.FunctionDefinition cpsNode) {
     tree_builder.Builder builder = new JsTreeBuilder(
@@ skipping 36 matching lines @@
     // TODO(sigurdm): Make a better list of tasks.
     return <CompilerTask>[irBuilderTask]..addAll(fallbackCompiler.tasks);
   }
 
   js.Node attachPosition(js.Node node, AstElement element) {
     return node.withSourceInformation(
         sourceInformationFactory.forContext(element)
             .buildDeclaration(element));
   }
 }