A visitor that builds a map from node to "Usage".

lib/compiler/implementation/dart_backend/renamer.dart

Index: lib/compiler/implementation/dart_backend/renamer.dart
diff --git a/lib/compiler/implementation/dart_backend/renamer.dart b/lib/compiler/implementation/dart_backend/renamer.dart
index 5a7f209c76f64ee13d965413726203b6525fe31e..684a212cea9b2a7edc5dc18e5c2a778c89fdeff9 100644
--- a/lib/compiler/implementation/dart_backend/renamer.dart
+++ b/lib/compiler/implementation/dart_backend/renamer.dart
@@ -2,181 +2,41 @@
 // 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 SendRenamer extends ResolvedVisitor<String> {
-  final ConflictingRenamer renamer;
-
-  SendRenamer(this.renamer, elements) : super(elements);
-
-  String visitSuperSend(Send node) => null;
-  String visitOperatorSend(Send node) => null;
-  String visitClosureSend(Send node) => null;
-  String visitForeignSend(Send node) => null;
-
-  String tryRenamePrivateId(Send node) {
-    Identifier selector = node.selector.asIdentifier();
-    assert(selector !== null);
-    String originalName = selector.source.slowToString();
-    if (originalName.startsWith('_')) {
-      String newName = renamer.renamePrivateId(
-          renamer.context.getLibrary(), originalName);
-      if (node.receiver !== null) {
-        // TODO: ugly, should be fixed with new renamer infrastructure.
-        String receiver = new Unparser(renamer).unparse(node.receiver);
-        newName = '$receiver.$newName';
-      }
-      return newName;
-    }
-
-    return null;
-  }
-
-  String visitDynamicSend(Send node) => tryRenamePrivateId(node);
-
-  String visitGetterSend(Send node) {
-    final element = elements[node];
-    if (element === null || !element.isTopLevel()) {
-      return tryRenamePrivateId(node);
-    }
-    return renamer.renameElement(element);
-  }
-
-  String visitStaticSend(Send node) {
-    final element = elements[node];
-
-    if (element.isTopLevel()) return renamer.renameElement(element);
-
-    if (element.isGenerativeConstructor() || element.isFactoryConstructor()) {
-      // Don't want to rename redirects to :this(args) or super calls.
-      if (Initializers.isConstructorRedirect(node)) return null;
-      if (Initializers.isSuperConstructorCall(node)) return null;
-
-      TypeAnnotation typeAnnotation;
-      if (node.selector is TypeAnnotation) {
-        // <simple class name> case.
-        typeAnnotation = node.selector;
-      } else if (node.selector.receiver is TypeAnnotation) {
-        // <complex generic type> case.
-        typeAnnotation = node.selector.receiver;
-      } else {
-        internalError("Don't know how to deduce type", node: node);
-      }
-      final type = new Unparser(renamer).unparse(typeAnnotation);
-
-      final constructor = element.asFunctionElement().cachedNode;
-      final nameAsSend = constructor.name.asSend();
-      if (nameAsSend !== null) {
-        final name = nameAsSend.selector.asIdentifier().source.slowToString();
-        return '$type.$name';
-      }
-      return '$type';
-    }
-
-    return null;
-  }
-
-  void internalError(String reason, [Node node]) {
-    renamer.compiler.cancel(reason: reason, node: node);
-  }
-}
-
 /**
  * Renames only top-level elements that would let to ambiguity if not renamed.
  * TODO(smok): Make sure that top-level fields are correctly renamed.
  */
-class ConflictingRenamer extends Renamer {
+class ConflictingRenamer {
   final Compiler compiler;
   final Map<LibraryElement, Map<String, String>> renamed;
   final Set<String> usedTopLevelIdentifiers;
   final Map<LibraryElement, String> imports;
+  final Map<Node, Placeholder> placeholders;
   int privateNameCounter = 0;
-  TreeElements contextElements;
-  Element context;
 
-  Map<Element, TreeElements> get resolvedElements() =>
-      compiler.enqueuer.resolution.resolvedElements;
-
-  ConflictingRenamer(this.compiler) :
+  ConflictingRenamer(this.compiler, this.placeholders) :
       renamed = new Map<LibraryElement, Map<String, String>>(),
       usedTopLevelIdentifiers = new Set<String>(),
-      imports = new Map<LibraryElement, String>();
-
-  void setContext(Element element) {
-    this.context = element;
-    contextElements = resolvedElements[element];
+      imports = new Map<LibraryElement, String>() {
+    // Rename main() right now so that nobody takes its place.
+    renameElement(compiler.mainApp.find(Compiler.MAIN));
   }
 
-  String renameSendMethod(Send send) =>
-      new SendRenamer(this, contextElements).visitSend(send);
-
-  String renameTypeName(TypeAnnotation typeAnnotation) {
-    Type type;
-    if (context.isClass()) {
-      // This only happens if we're unparsing class declaration.
-      type = new TypeResolver(compiler)
-          .resolveTypeAnnotation(typeAnnotation, null, context);
-    } else {
-      type = compiler.resolveTypeAnnotation(context, typeAnnotation);
-    }
-    return renameType(type);
-  }
-
-  String renameType(Type type) => renameElement(type.element);
-
-  String renameIdentifier(Identifier node) {
-    if (context.isGenerativeConstructor() || context.isFactoryConstructor()) {
-      // Two complicated cases for class/interface renaming:
-      // 1) class which implements constructors of other interfaces, but not
-      //    implements interfaces themselves:
-      //      0.dart: class C { I(); }
-      //      1.dart and 2.dart: interface I default C { I(); }
-      //    now we have to duplicate our I() constructor in C class with
-      //    proper names.
-      // 2) (even worse for us):
-      //      0.dart: class C { C(); }
-      //      1.dart: interface C default p0.C { C(); }
-      //    the second case is just a bug now.
-      final enclosingClass = context.getEnclosingClass();
-      if (node.token.slowToString() == enclosingClass.name.slowToString()) {
-        // TODO: distinguish the case of constructor vs. nested named closure
-        // (see function_syntax_test).
-        // TODO: fix the bugs above and turn if into the assert.
-        return renameElement(enclosingClass);
-      }
-    }
-    if (context.isFunction() && context.isTopLevel() &&
-        context.cachedNode.name == node) {
-      return renameElement(context);
-    }
-    // TODO: as the rest of renameIdentifier should go closer to
-    // Emitter.outputElement.
-    // Note: this code should only rename private identifiers for class'
-    // fields/getters/setters/methods.  Top-level identifiers are renamed
-    // just to escape conflicts and that should be enough as we shouldn't
-    // be able to resolve private identifiers for other libraries.
-    final originalName = node.source.slowToString();
-    if (originalName.startsWith('_')) {
-      return '${renamePrivateId(context.getLibrary(), originalName)}';
-    }
-    return null;
+  // Renamer implementation.
+  String rename(Node node) {
+    Placeholder placeholder = placeholders[node];
+    return (placeholder !== null) ? placeholder.rename(this) : null;
   }
 
   String getName(LibraryElement library, String originalName, renamer) =>
       renamed.putIfAbsent(library, () => <String>{})
           .putIfAbsent(originalName, renamer);
 
-  String renamePrivateId(LibraryElement library, String originalName) =>
-      getName(library, originalName,
-              () => '_${privateNameCounter++}${originalName}');
+  String renamePrivateIdentifier(LibraryElement library, String id) =>
+      getName(library, id, () => '_${privateNameCounter++}${id}');
 
   String renameElement(Element element) {
-    // TODO: investigate what went wrong here.
-    if (!element.isTopLevel()) return null;
-
-    // This comes from currently buggy TypeAnnotation renamer.
-    // It should be solved in there and it will be solved with
-    // new fancy renamer. TODO: remove this cruft.
-    if (element === compiler.types.voidType.element) return null;
-
+    assert(element.isTopLevel());
     // TODO(smok): Make sure that the new name does not conflict with existing
     // local identifiers.
     generateUniqueName(name) {