Overhaul tree IR visitor and rename IR classes.

pkg/compiler/lib/src/dart_backend/backend.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.
 
 part of dart_backend;
 
 // TODO(ahe): This class is simply wrong.  This backend should use
 // elements when it can, not AST nodes.  Perhaps a [Map<Element,
 // TreeElements>] is what is needed.
 class ElementAst {
@@ skipping 113 matching lines @@
     // Enqueue the methods that the VM might invoke on user objects because
     // we don't trust the resolution to always get these included.
     world.registerInvocation(new Selector.call("toString", null, 0));
     world.registerInvokedGetter(new Selector.getter("hashCode", null));
     world.registerInvocation(new Selector.binaryOperator("=="));
     world.registerInvocation(new Selector.call("compareTo", null, 1));
   }
 
   void codegen(CodegenWorkItem work) { }
 
-  static bool checkTreeIntegrity(tree_ir.ExecutableDefinition node) {
+  static bool checkTreeIntegrity(tree_ir.RootNode node) {
     new CheckTreeIntegrity().check(node);
     return true; // So this can be used from assert().
   }
 
-  static bool checkCpsIntegrity(cps_ir.ExecutableDefinition node) {
+  static bool checkCpsIntegrity(cps_ir.RootNode node) {
     new CheckCpsIntegrity().check(node);
     return true; // So this can be used from assert().
   }
 
   /// Create an [ElementAst] from the CPS IR.
   static ElementAst createElementAst(
        ElementAstCreationContext context,
        Element element,
-       cps_ir.ExecutableDefinition cpsDefinition) {
+       cps_ir.RootNode cpsRoot) {
     context.traceCompilation(element.name);
-    context.traceGraph('CPS builder', cpsDefinition);
-    assert(checkCpsIntegrity(cpsDefinition));
+    context.traceGraph('CPS builder', cpsRoot);
+    assert(checkCpsIntegrity(cpsRoot));
 
     // Transformations on the CPS IR.
     void applyCpsPass(cps_opt.Pass pass) {
-      pass.rewrite(cpsDefinition);
-      context.traceGraph(pass.passName, cpsDefinition);
-      assert(checkCpsIntegrity(cpsDefinition));
+      pass.rewrite(cpsRoot);
+      context.traceGraph(pass.passName, cpsRoot);
+      assert(checkCpsIntegrity(cpsRoot));
     }
 
     // TODO(karlklose): enable type propagation for dart2dart when constant
     // types are correctly marked as instantiated (Issue 21880).
     TypePropagator typePropagator = new TypePropagator(
         context.dartTypes,
         context.constantSystem,
         new UnitTypeSystem(),
         context.internalError);
     applyCpsPass(typePropagator);
     applyCpsPass(new RedundantPhiEliminator());
     applyCpsPass(new ShrinkingReducer());
 
     tree_builder.Builder builder =
         new tree_builder.Builder(context.internalError);
-    tree_ir.ExecutableDefinition treeDefinition = builder.build(cpsDefinition);
-    assert(treeDefinition != null);
-    context.traceGraph('Tree builder', treeDefinition);
-    assert(checkTreeIntegrity(treeDefinition));
+    tree_ir.RootNode treeRoot = builder.build(cpsRoot);
+    assert(treeRoot != null);
+    context.traceGraph('Tree builder', treeRoot);
+    assert(checkTreeIntegrity(treeRoot));
 
     // Transformations on the Tree IR.
     void applyTreePass(tree_opt.Pass pass) {
-      pass.rewrite(treeDefinition);
-      context.traceGraph(pass.passName, treeDefinition);
-      assert(checkTreeIntegrity(treeDefinition));
+      pass.rewrite(treeRoot);
+      context.traceGraph(pass.passName, treeRoot);
+      assert(checkTreeIntegrity(treeRoot));
     }
 
     applyTreePass(new StatementRewriter());
     applyTreePass(new VariableMerger());
     applyTreePass(new LoopRewriter());
     applyTreePass(new LogicalRewriter());
 
     // Backend-specific transformations.
-    new backend_ast_emitter.UnshadowParameters().unshadow(treeDefinition);
-    context.traceGraph('Unshadow parameters', treeDefinition);
+    new backend_ast_emitter.UnshadowParameters().unshadow(treeRoot);
+    context.traceGraph('Unshadow parameters', treeRoot);
 
     TreeElementMapping treeElements = new TreeElementMapping(element);
-    backend_ast.ExecutableDefinition backendAst =
-        backend_ast_emitter.emit(treeDefinition);
+    backend_ast.RootNode backendAst =
+        backend_ast_emitter.emit(treeRoot);
     Node frontend_ast = backend2frontend.emit(treeElements, backendAst);
     return new ElementAst(frontend_ast, treeElements);
 
   }
 
   /**
    * Tells whether we should output given element. Corelib classes like
    * Object should not be in the resulting code.
    */
   @override
   bool shouldOutput(Element element) {
     return (!element.library.isPlatformLibrary &&
             !element.isSynthesized &&
             element is! AbstractFieldElement)
         || mirrorRenamer.isMirrorHelperLibrary(element.library);
   }
 
   int assembleProgram() {
     ElementAstCreationContext context =
         new _ElementAstCreationContext(compiler, constantSystem);
 
     ElementAst computeElementAst(AstElement element) {
       if (!compiler.irBuilder.hasIr(element)) {
         return new ElementAst(element.resolvedAst.node,
                               element.resolvedAst.elements);
       } else {
-        cps_ir.ExecutableDefinition definition =
-            compiler.irBuilder.getIr(element);
-        return createElementAst(context, element, definition);
+        cps_ir.RootNode irNode = compiler.irBuilder.getIr(element);
+        return createElementAst(context, element, irNode);
       }
     }
 
     // TODO(johnniwinther): Remove the need for this method.
     void postProcessElementAst(
         AstElement element, ElementAst elementAst,
         newTypedefElementCallback,
         newClassElementCallback) {
       ReferencedElementCollector collector =
           new ReferencedElementCollector(compiler,
@@ skipping 321 matching lines @@
   }
 
   void traceGraph(String title, var irObject) {
     compiler.tracer.traceGraph(title, irObject);
   }
 
   DartTypes get dartTypes => compiler.types;
 
   InternalErrorFunction get internalError => compiler.internalError;
 }