Revert "Refactor Library/CompilationUnit and how we define local Scope."

lib/compiler/implementation/elements/elements.dart

Index: lib/compiler/implementation/elements/elements.dart
diff --git a/lib/compiler/implementation/elements/elements.dart b/lib/compiler/implementation/elements/elements.dart
index e45f581338b55bfb3592daf0db7c70d23da1709d..2344018ca6a1811693d957a920efa8c961bbed8d 100644
--- a/lib/compiler/implementation/elements/elements.dart
+++ b/lib/compiler/implementation/elements/elements.dart
@@ -4,8 +4,6 @@
 
 #library('elements');
 
-#import('dart:uri');
-
 #import('../tree/tree.dart');
 #import('../scanner/scannerlib.dart');
 #import('../leg.dart');  // TODO(karlklose): we only need type.
@@ -257,43 +255,10 @@ class Element implements Hashable {
 }
 
 class ContainerElement extends Element {
-  Link<Element> localMembers = const EmptyLink<Element>();
-
-  ContainerElement(name, kind, enclosingElement)
-    : super(name, kind, enclosingElement);
-
-  void addMember(Element element, DiagnosticListener listener) {
-    localMembers = localMembers.prepend(element);
-  }
-}
-
-class ScopeContainerElement extends ContainerElement {
-  final Map<SourceString, Element> localScope;
-
-  ScopeContainerElement(name, kind, enclosingElement)
-    : super(name, kind, enclosingElement),
-      localScope = new Map<SourceString, Element>();
-
-  void addMember(Element element, DiagnosticListener listener) {
-    super.addMember(element, listener);
-    addToScope(element, listener);
-  }
-
-  void addToScope(Element element, DiagnosticListener listener) {
-    if (element.isAccessor()) {
-      addGetterOrSetter(element, localScope[element.name], listener);
-    } else {
-      Element existing = localScope.putIfAbsent(element.name, () => element);
-      if (existing !== element) {
-        listener.cancel('duplicate definition', token: element.position());
-        listener.cancel('existing definition', token: existing.position());
-      }
-    }
-  }
+  ContainerElement(name, kind, enclosingElement) :
+    super(name, kind, enclosingElement);
 
-  Element localLookup(SourceString elementName) {
-    return localScope[elementName];
-  }
+  abstract void addMember(Element element, DiagnosticListener listener);
 
   void addGetterOrSetter(Element element,
                          Element existing,
@@ -333,10 +298,9 @@ class ScopeContainerElement extends ContainerElement {
   }
 }
 
-
-
 class CompilationUnitElement extends ContainerElement {
   final Script script;
+  Link<Element> topLevelElements = const EmptyLink<Element>();
 
   CompilationUnitElement(Script script, Element enclosing)
     : this.script = script,
@@ -344,30 +308,41 @@ class CompilationUnitElement extends ContainerElement {
             ElementKind.COMPILATION_UNIT,
             enclosing);
 
+  CompilationUnitElement.library(Script script)
+    : this.script = script,
+      super(new SourceString(script.name), ElementKind.LIBRARY, null);
+
   void addMember(Element element, DiagnosticListener listener) {
-    // Keep a list of top level members.
-    super.addMember(element, listener);
-    // Provide the member to the library to build scope.
-    getLibrary().addMember(element, listener);
+    LibraryElement library = enclosingElement;
+    library.addMember(element, listener);
+    topLevelElements = topLevelElements.prepend(element);
+  }
+
+  void define(Element element, DiagnosticListener listener) {
+    LibraryElement library = enclosingElement;
+    library.define(element, listener);
+  }
+
+  void addTag(ScriptTag tag, DiagnosticListener listener) {
+    listener.cancel("script tags not allowed here", node: tag);
   }
 }
 
-class LibraryElement extends ScopeContainerElement {
-  CompilationUnitElement entryCompilationUnit;
-  Link<CompilationUnitElement> compilationUnits =
-      const EmptyLink<CompilationUnitElement>();
+class LibraryElement extends CompilationUnitElement {
+  // TODO(ahe): Library element should not be a subclass of
+  // CompilationUnitElement.
 
+  Link<CompilationUnitElement> compilationUnits =
+    const EmptyLink<CompilationUnitElement>();
   Link<ScriptTag> tags = const EmptyLink<ScriptTag>();
   ScriptTag libraryTag;
+  Map<SourceString, Element> elements;
   bool canUseNative = false;
   LibraryElement patch = null;
 
   LibraryElement(Script script)
-    : super(new SourceString(script.name), ElementKind.LIBRARY, null) {
-    entryCompilationUnit = new CompilationUnitElement(script, this);
-  }
-
-  Uri get uri() => entryCompilationUnit.script.uri;
+      : elements = new Map<SourceString, Element>(),
+        super.library(script);
 
   bool get isPatched() => patch !== null;
 
@@ -379,27 +354,45 @@ class LibraryElement extends ScopeContainerElement {
     tags = tags.prepend(tag);
   }
 
+  void addMember(Element element, DiagnosticListener listener) {
+    topLevelElements = topLevelElements.prepend(element);
+    define(element, listener);
+  }
+
+  void define(Element element, DiagnosticListener listener) {
+    if (element.kind == ElementKind.GETTER
+        || element.kind == ElementKind.SETTER) {
+      addGetterOrSetter(element, elements[element.name], listener);
+    } else {
+      Element existing = elements.putIfAbsent(element.name, () => element);
+      if (existing !== element) {
+        listener.cancel('duplicate definition', token: element.position());
+        listener.cancel('existing definition', token: existing.position());
+      }
+    }
+  }
+
   /** Look up a top-level element in this library. The element could
     * potentially have been imported from another library. Returns
     * null if no such element exist. */
   Element find(SourceString elementName) {
-    return localScope[elementName];
+    return elements[elementName];
   }
 
   /** Look up a top-level element in this library, but only look for
     * non-imported elements. Returns null if no such element exist. */
   Element findLocal(SourceString elementName) {
-    Element result = localScope[elementName];
+    Element result = elements[elementName];
     if (result === null || result.getLibrary() != this) return null;
     return result;
   }
 
   void forEachExport(f(Element element)) {
-    localMembers.forEach((Element e) {
-      if (e.kind !== ElementKind.PREFIX
-          && e.kind !== ElementKind.FOREIGN
-          && !e.name.isPrivate()) {
-        f(e);
+    elements.forEach((SourceString _, Element e) {
+      if (this === e.getLibrary()
+          && e.kind !== ElementKind.PREFIX
+          && e.kind !== ElementKind.FOREIGN) {
+        if (!e.name.isPrivate()) f(e);
       }
     });
   }
@@ -416,28 +409,26 @@ class LibraryElement extends ScopeContainerElement {
       return libraryTag.argument.dartString.slowToString();
     } else {
       // Use the file name as script name.
-      String path = uri.path;
+      var path = script.uri.path;
       return path.substring(path.lastIndexOf('/') + 1);
     }
   }
 
-  CompilationUnitElement getCompilationUnit() => entryCompilationUnit;
-
   Scope buildEnclosingScope() => new TopScope(this);
 }
 
 class PrefixElement extends Element {
   Map<SourceString, Element> imported;
   Token firstPosition;
-  final CompilationUnitElement patchCompilationUnit;
+  final CompilationUnitElement patchSource;
 
   PrefixElement(SourceString prefix, Element enclosing, this.firstPosition,
-                [this.patchCompilationUnit])
+                [this.patchSource])
     : imported = new Map<SourceString, Element>(),
       super(prefix, ElementKind.PREFIX, enclosing);
 
   CompilationUnitElement getCompilationUnit() {
-    if (patchCompilationUnit !== null) return patchCompilationUnit;
+    if (patchSource !== null) return patchSource;
     return super.getCompilationUnit();
   }
 
@@ -888,12 +879,15 @@ abstract class TypeDeclarationElement implements Element {
   }
 }
 
-class ClassElement extends ScopeContainerElement
+class ClassElement extends ContainerElement
     implements TypeDeclarationElement {
   final int id;
   InterfaceType type;
   Type supertype;
   Type defaultClass;
+  Link<Element> members = const EmptyLink<Element>();
+  Map<SourceString, Element> localMembers;
+  Map<SourceString, Element> constructors;
   Link<Type> interfaces = const EmptyLink<Type>();
   bool isResolved = false;
   bool isBeingResolved = false;
@@ -905,7 +899,22 @@ class ClassElement extends ScopeContainerElement
   ClassElement patch = null;
 
   ClassElement(SourceString name, CompilationUnitElement enclosing, this.id)
-    : super(name, ElementKind.CLASS, enclosing);
+    : localMembers = new Map<SourceString, Element>(),
+      constructors = new Map<SourceString, Element>(),
+      super(name, ElementKind.CLASS, enclosing);
+
+  void addMember(Element element, DiagnosticListener listener) {
+    members = members.prepend(element);
+    if (element.kind == ElementKind.GENERATIVE_CONSTRUCTOR ||
+        element.modifiers.isFactory()) {
+      constructors[element.name] = element;
+    } else if (element.kind == ElementKind.GETTER
+               || element.kind == ElementKind.SETTER) {
+      addGetterOrSetter(element, localMembers[element.name], listener);
+    } else {
+      localMembers[element.name] = element;
+    }
+  }
 
   InterfaceType computeType(compiler) {
     if (type == null) {
@@ -924,18 +933,10 @@ class ClassElement extends ScopeContainerElement
     return this;
   }
 
-  /**
-   * Lookup local members in the class. This will ignore constructors.
-   */
   Element lookupLocalMember(SourceString memberName) {
-    var result = localLookup(memberName);
-    if (result !== null && result.isConstructor()) return null;
-    return result;
+    return localMembers[memberName];
   }
 
-  /**
-  * Lookup super members for the class. This will ignore constructors.
-   */
   Element lookupSuperMember(SourceString memberName) {
     bool isPrivate = memberName.isPrivate();
     for (ClassElement s = superclass; s != null; s = s.superclass) {
@@ -957,7 +958,7 @@ class ClassElement extends ScopeContainerElement
    * rules, where library scope comes before superclass scope.
    */
   Element lookupMember(SourceString memberName) {
-    Element localMember = lookupLocalMember(memberName);
+    Element localMember = localMembers[memberName];
     return localMember === null ? lookupSuperMember(memberName) : localMember;
   }
 
@@ -1002,31 +1003,13 @@ class ClassElement extends ScopeContainerElement
     } else {
       normalizedName = className;
     }
-    Element result = localLookup(normalizedName);
-    if (result === null || !result.isConstructor()) {
-      result = noMatch !== null ? noMatch(result) : null;
+    Element result = constructors[normalizedName];
+    if (result === null && noMatch !== null) {
+      result = noMatch(lookupLocalMember(constructorName));
     }
     return result;
   }
 
-  bool get hasConstructor() {
-    // Search in scope to be sure we search patched constructors.
-    for (var element in localScope.getValues()) {
-      if (element.isConstructor()) return true;
-    }
-    return false;
-  }
-
-  Collection<Element> get constructors() {
-    // TODO(ajohnsen): See if we can avoid this method at some point.
-    List<Element> result = <Element>[];
-    // Search in scope to be sure we search patched constructors.
-    localScope.forEach((_, Element value) {
-      if (value.isConstructor()) result.add(value);
-    });
-    return result;
-  }
-
   /**
    * Returns the super class, if any.
    *
@@ -1051,7 +1034,7 @@ class ClassElement extends ScopeContainerElement
     do {
       if (seen.contains(classElement)) return;
       seen.add(classElement);
-      for (Element element in classElement.localMembers) {
+      for (Element element in classElement.members) {
         f(classElement, element);
       }
       if (includeBackendMembers) {