Move Index and IndexStore implementations into Engine.

pkg/analyzer/lib/src/index/index.dart

Index: pkg/analyzer/lib/src/index/index.dart
diff --git a/pkg/analyzer/lib/src/index/index.dart b/pkg/analyzer/lib/src/index/index.dart
deleted file mode 100644
index db0e350b52bf7cbf94bc70ecd3dc267247434dd1..0000000000000000000000000000000000000000
--- a/pkg/analyzer/lib/src/index/index.dart
+++ /dev/null
@@ -1,1193 +0,0 @@
-// 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.
-
-// This code was auto-generated, is not intended to be edited, and is subject to
-// significant change. Please see the README file for more information.
-
-library engine.src.index;
-
-import 'dart:collection' show Queue;
-
-import 'package:analyzer/index/index.dart';
-import 'package:analyzer/index/index_store.dart';
-import 'package:analyzer/src/generated/ast.dart';
-import 'package:analyzer/src/generated/element.dart';
-import 'package:analyzer/src/generated/engine.dart';
-import 'package:analyzer/src/generated/html.dart' as ht;
-import 'package:analyzer/src/generated/java_core.dart';
-import 'package:analyzer/src/generated/java_engine.dart';
-import 'package:analyzer/src/generated/resolver.dart';
-import 'package:analyzer/src/generated/scanner.dart';
-import 'package:analyzer/src/generated/source.dart';
-
-
-/**
- * Adds data to [store] based on the resolved Dart [unit].
- */
-void indexDartUnit(IndexStore store, AnalysisContext context,
-    CompilationUnit unit) {
-  CompilationUnitElement unitElement = unit.element;
-  bool mayIndex = store.aboutToIndexDart(context, unitElement);
-  if (!mayIndex) {
-    return;
-  }
-  unit.accept(new _IndexContributor(store));
-  unit.accept(new _AngularDartIndexContributor(store));
-  store.doneIndex();
-}
-
-
-/**
- * Adds data to [store] based on the resolved HTML [unit].
- */
-void indexHtmlUnit(IndexStore store, AnalysisContext context, ht.HtmlUnit unit)
-    {
-  HtmlElement unitElement = unit.element;
-  bool mayIndex = store.aboutToIndexHtml(context, unitElement);
-  if (!mayIndex) {
-    return;
-  }
-  unit.accept(new _AngularHtmlIndexContributor(store));
-  store.doneIndex();
-}
-
-
-/**
- * Visits resolved [CompilationUnit] and adds Angular specific relationships
- * into [IndexStore].
- */
-class _AngularDartIndexContributor extends GeneralizingAstVisitor<Object> {
-  final IndexStore _store;
-
-  _AngularDartIndexContributor(this._store);
-
-  @override
-  Object visitClassDeclaration(ClassDeclaration node) {
-    ClassElement classElement = node.element;
-    if (classElement != null) {
-      List<ToolkitObjectElement> toolkitObjects = classElement.toolkitObjects;
-      for (ToolkitObjectElement object in toolkitObjects) {
-        if (object is AngularComponentElement) {
-          _indexComponent(object);
-        }
-        if (object is AngularDecoratorElement) {
-          AngularDecoratorElement directive = object;
-          _indexDirective(directive);
-        }
-      }
-    }
-    // stop visiting
-    return null;
-  }
-
-  @override
-  Object visitCompilationUnitMember(CompilationUnitMember node) => null;
-
-  void _indexComponent(AngularComponentElement component) {
-    _indexProperties(component.properties);
-  }
-
-  void _indexDirective(AngularDecoratorElement directive) {
-    _indexProperties(directive.properties);
-  }
-
-  /**
-   * Index [FieldElement] references from [AngularPropertyElement]s.
-   */
-  void _indexProperties(List<AngularPropertyElement> properties) {
-    for (AngularPropertyElement property in properties) {
-      FieldElement field = property.field;
-      if (field != null) {
-        int offset = property.fieldNameOffset;
-        if (offset == -1) {
-          continue;
-        }
-        int length = field.name.length;
-        Location location = new Location(property, offset, length);
-        // getter reference
-        if (property.propertyKind.callsGetter()) {
-          PropertyAccessorElement getter = field.getter;
-          if (getter != null) {
-            _store.recordRelationship(getter,
-                IndexConstants.IS_REFERENCED_BY_QUALIFIED, location);
-          }
-        }
-        // setter reference
-        if (property.propertyKind.callsSetter()) {
-          PropertyAccessorElement setter = field.setter;
-          if (setter != null) {
-            _store.recordRelationship(setter,
-                IndexConstants.IS_REFERENCED_BY_QUALIFIED, location);
-          }
-        }
-      }
-    }
-  }
-}
-
-
-/**
- * Visits resolved [HtmlUnit] and adds relationships into [IndexStore].
- */
-class _AngularHtmlIndexContributor extends _ExpressionVisitor {
-  /**
-   * The [IndexStore] to record relations into.
-   */
-  final IndexStore _store;
-
-  /**
-   * The index contributor used to index Dart [Expression]s.
-   */
-  _IndexContributor _indexContributor;
-
-  HtmlElement _htmlUnitElement;
-
-  /**
-   * Initialize a newly created Angular HTML index contributor.
-   *
-   * [store] - the [IndexStore] to record relations into.
-   */
-  _AngularHtmlIndexContributor(this._store) {
-    _indexContributor = new _AngularHtmlIndexContributor_forEmbeddedDart(_store,
-        this);
-  }
-
-  @override
-  void visitExpression(Expression expression) {
-    // Formatter
-    if (expression is SimpleIdentifier) {
-      Element element = expression.bestElement;
-      if (element is AngularElement) {
-        _store.recordRelationship(element, IndexConstants.ANGULAR_REFERENCE,
-            _createLocationForIdentifier(expression));
-        return;
-      }
-    }
-    // index as a normal Dart expression
-    expression.accept(_indexContributor);
-  }
-
-  @override
-  Object visitHtmlUnit(ht.HtmlUnit node) {
-    _htmlUnitElement = node.element;
-    CompilationUnitElement dartUnitElement =
-        _htmlUnitElement.angularCompilationUnit;
-    _indexContributor.enterScope(dartUnitElement);
-    return super.visitHtmlUnit(node);
-  }
-
-  @override
-  Object visitXmlAttributeNode(ht.XmlAttributeNode node) {
-    Element element = node.element;
-    if (element != null) {
-      ht.Token nameToken = node.nameToken;
-      Location location = _createLocationForToken(nameToken);
-      _store.recordRelationship(element, IndexConstants.ANGULAR_REFERENCE,
-          location);
-    }
-    return super.visitXmlAttributeNode(node);
-  }
-
-  @override
-  Object visitXmlTagNode(ht.XmlTagNode node) {
-    Element element = node.element;
-    if (element != null) {
-      // tag
-      {
-        ht.Token tagToken = node.tagToken;
-        Location location = _createLocationForToken(tagToken);
-        _store.recordRelationship(element, IndexConstants.ANGULAR_REFERENCE,
-            location);
-      }
-      // maybe add closing tag range
-      ht.Token closingTag = node.closingTag;
-      if (closingTag != null) {
-        Location location = _createLocationForToken(closingTag);
-        _store.recordRelationship(element,
-            IndexConstants.ANGULAR_CLOSING_TAG_REFERENCE, location);
-      }
-    }
-    return super.visitXmlTagNode(node);
-  }
-
-  Location _createLocationForIdentifier(SimpleIdentifier identifier) =>
-      new Location(_htmlUnitElement, identifier.offset, identifier.length);
-
-  Location _createLocationForToken(ht.Token token) => new Location(
-      _htmlUnitElement, token.offset, token.length);
-}
-
-
-class _AngularHtmlIndexContributor_forEmbeddedDart extends _IndexContributor {
-  final _AngularHtmlIndexContributor angularContributor;
-
-  _AngularHtmlIndexContributor_forEmbeddedDart(IndexStore store,
-      this.angularContributor) : super(store);
-
-  @override
-  Element peekElement() => angularContributor._htmlUnitElement;
-
-  @override
-  void recordRelationship(Element element, Relationship relationship,
-      Location location) {
-    AngularElement angularElement = AngularHtmlUnitResolver.getAngularElement(
-        element);
-    if (angularElement != null) {
-      element = angularElement;
-      relationship = IndexConstants.ANGULAR_REFERENCE;
-    }
-    super.recordRelationship(element, relationship, location);
-  }
-}
-
-
-/**
- * Recursively visits an [HtmlUnit] and every embedded [Expression].
- */
-abstract class _ExpressionVisitor extends ht.RecursiveXmlVisitor<Object> {
-  /**
-   * Visits the given [Expression]s embedded into tag or attribute.
-   *
-   * [expression] - the [Expression] to visit, not `null`
-   */
-  void visitExpression(Expression expression);
-
-  @override
-  Object visitXmlAttributeNode(ht.XmlAttributeNode node) {
-    _visitExpressions(node.expressions);
-    return super.visitXmlAttributeNode(node);
-  }
-
-  @override
-  Object visitXmlTagNode(ht.XmlTagNode node) {
-    _visitExpressions(node.expressions);
-    return super.visitXmlTagNode(node);
-  }
-
-  /**
-   * Visits [Expression]s of the given [XmlExpression]s.
-   */
-  void _visitExpressions(List<ht.XmlExpression> expressions) {
-    for (ht.XmlExpression xmlExpression in expressions) {
-      if (xmlExpression is AngularXmlExpression) {
-        AngularXmlExpression angularXmlExpression = xmlExpression;
-        List<Expression> dartExpressions =
-            angularXmlExpression.expression.expressions;
-        for (Expression dartExpression in dartExpressions) {
-          visitExpression(dartExpression);
-        }
-      }
-      if (xmlExpression is ht.RawXmlExpression) {
-        ht.RawXmlExpression rawXmlExpression = xmlExpression;
-        visitExpression(rawXmlExpression.expression);
-      }
-    }
-  }
-}
-
-
-/**
- * Information about [ImportElement] and place where it is referenced using
- * [PrefixElement].
- */
-class _ImportElementInfo {
-  ImportElement _element;
-
-  int _periodEnd = 0;
-}
-
-
-/**
- * Visits a resolved AST and adds relationships into [IndexStore].
- */
-class _IndexContributor extends GeneralizingAstVisitor<Object> {
-  final IndexStore _store;
-
-  LibraryElement _libraryElement;
-
-  Map<ImportElement, Set<Element>> _importElementsMap = {};
-
-  /**
-   * A stack whose top element (the element with the largest index) is an element representing the
-   * inner-most enclosing scope.
-   */
-  Queue<Element> _elementStack = new Queue();
-
-  _IndexContributor(this._store);
-
-  /**
-   * Enter a new scope represented by the given [Element].
-   */
-  void enterScope(Element element) {
-    _elementStack.addFirst(element);
-  }
-
-  /**
-   * @return the inner-most enclosing [Element], may be `null`.
-   */
-  Element peekElement() {
-    for (Element element in _elementStack) {
-      if (element != null) {
-        return element;
-      }
-    }
-    return null;
-  }
-
-  /**
-   * Record the given relationship between the given [Element] and [Location].
-   */
-  void recordRelationship(Element element, Relationship relationship,
-      Location location) {
-    if (element != null && location != null) {
-      _store.recordRelationship(element, relationship, location);
-    }
-  }
-
-  @override
-  Object visitAssignmentExpression(AssignmentExpression node) {
-    _recordOperatorReference(node.operator, node.bestElement);
-    return super.visitAssignmentExpression(node);
-  }
-
-  @override
-  Object visitBinaryExpression(BinaryExpression node) {
-    _recordOperatorReference(node.operator, node.bestElement);
-    return super.visitBinaryExpression(node);
-  }
-
-  @override
-  Object visitClassDeclaration(ClassDeclaration node) {
-    ClassElement element = node.element;
-    enterScope(element);
-    try {
-      _recordElementDefinition(element, IndexConstants.DEFINES_CLASS);
-      {
-        ExtendsClause extendsClause = node.extendsClause;
-        if (extendsClause != null) {
-          TypeName superclassNode = extendsClause.superclass;
-          _recordSuperType(superclassNode, IndexConstants.IS_EXTENDED_BY);
-        } else {
-          InterfaceType superType = element.supertype;
-          if (superType != null) {
-            ClassElement objectElement = superType.element;
-            recordRelationship(objectElement, IndexConstants.IS_EXTENDED_BY,
-                _createLocationFromOffset(node.name.offset, 0));
-          }
-        }
-      }
-      {
-        WithClause withClause = node.withClause;
-        if (withClause != null) {
-          for (TypeName mixinNode in withClause.mixinTypes) {
-            _recordSuperType(mixinNode, IndexConstants.IS_MIXED_IN_BY);
-          }
-        }
-      }
-      {
-        ImplementsClause implementsClause = node.implementsClause;
-        if (implementsClause != null) {
-          for (TypeName interfaceNode in implementsClause.interfaces) {
-            _recordSuperType(interfaceNode, IndexConstants.IS_IMPLEMENTED_BY);
-          }
-        }
-      }
-      return super.visitClassDeclaration(node);
-    } finally {
-      _exitScope();
-    }
-  }
-
-  @override
-  Object visitClassTypeAlias(ClassTypeAlias node) {
-    ClassElement element = node.element;
-    enterScope(element);
-    try {
-      _recordElementDefinition(element, IndexConstants.DEFINES_CLASS_ALIAS);
-      {
-        TypeName superclassNode = node.superclass;
-        if (superclassNode != null) {
-          _recordSuperType(superclassNode, IndexConstants.IS_EXTENDED_BY);
-        }
-      }
-      {
-        WithClause withClause = node.withClause;
-        if (withClause != null) {
-          for (TypeName mixinNode in withClause.mixinTypes) {
-            _recordSuperType(mixinNode, IndexConstants.IS_MIXED_IN_BY);
-          }
-        }
-      }
-      {
-        ImplementsClause implementsClause = node.implementsClause;
-        if (implementsClause != null) {
-          for (TypeName interfaceNode in implementsClause.interfaces) {
-            _recordSuperType(interfaceNode, IndexConstants.IS_IMPLEMENTED_BY);
-          }
-        }
-      }
-      return super.visitClassTypeAlias(node);
-    } finally {
-      _exitScope();
-    }
-  }
-
-  @override
-  Object visitCompilationUnit(CompilationUnit node) {
-    CompilationUnitElement unitElement = node.element;
-    if (unitElement != null) {
-      _elementStack.add(unitElement);
-      _libraryElement = unitElement.enclosingElement;
-      if (_libraryElement != null) {
-        return super.visitCompilationUnit(node);
-      }
-    }
-    return null;
-  }
-
-  @override
-  Object visitConstructorDeclaration(ConstructorDeclaration node) {
-    ConstructorElement element = node.element;
-    // define
-    {
-      Location location;
-      if (node.name != null) {
-        int start = node.period.offset;
-        int end = node.name.end;
-        location = _createLocationFromOffset(start, end - start);
-      } else {
-        int start = node.returnType.end;
-        location = _createLocationFromOffset(start, 0);
-      }
-      recordRelationship(element, IndexConstants.IS_DEFINED_BY, location);
-    }
-    // visit children
-    enterScope(element);
-    try {
-      return super.visitConstructorDeclaration(node);
-    } finally {
-      _exitScope();
-    }
-  }
-
-  @override
-  Object visitConstructorName(ConstructorName node) {
-    ConstructorElement element = node.staticElement;
-    // in 'class B = A;' actually A constructors are invoked
-    if (element != null && element.isSynthetic && element.redirectedConstructor
-        != null) {
-      element = element.redirectedConstructor;
-    }
-    // prepare location
-    Location location;
-    if (node.name != null) {
-      int start = node.period.offset;
-      int end = node.name.end;
-      location = _createLocationFromOffset(start, end - start);
-    } else {
-      int start = node.type.end;
-      location = _createLocationFromOffset(start, 0);
-    }
-    // record relationship
-    recordRelationship(element, IndexConstants.IS_REFERENCED_BY, location);
-    return super.visitConstructorName(node);
-  }
-
-  @override
-  Object visitExportDirective(ExportDirective node) {
-    ExportElement element = node.element;
-    if (element != null) {
-      LibraryElement expLibrary = element.exportedLibrary;
-      _recordLibraryReference(node, expLibrary);
-    }
-    return super.visitExportDirective(node);
-  }
-
-  @override
-  Object visitFormalParameter(FormalParameter node) {
-    ParameterElement element = node.element;
-    enterScope(element);
-    try {
-      return super.visitFormalParameter(node);
-    } finally {
-      _exitScope();
-    }
-  }
-
-  @override
-  Object visitFunctionDeclaration(FunctionDeclaration node) {
-    Element element = node.element;
-    _recordElementDefinition(element, IndexConstants.DEFINES_FUNCTION);
-    enterScope(element);
-    try {
-      return super.visitFunctionDeclaration(node);
-    } finally {
-      _exitScope();
-    }
-  }
-
-  @override
-  Object visitFunctionTypeAlias(FunctionTypeAlias node) {
-    Element element = node.element;
-    _recordElementDefinition(element, IndexConstants.DEFINES_FUNCTION_TYPE);
-    return super.visitFunctionTypeAlias(node);
-  }
-
-  @override
-  Object visitImportDirective(ImportDirective node) {
-    ImportElement element = node.element;
-    if (element != null) {
-      LibraryElement impLibrary = element.importedLibrary;
-      _recordLibraryReference(node, impLibrary);
-    }
-    return super.visitImportDirective(node);
-  }
-
-  @override
-  Object visitIndexExpression(IndexExpression node) {
-    MethodElement element = node.bestElement;
-    if (element is MethodElement) {
-      Token operator = node.leftBracket;
-      Location location = _createLocationFromToken(operator);
-      recordRelationship(element, IndexConstants.IS_INVOKED_BY_QUALIFIED,
-          location);
-    }
-    return super.visitIndexExpression(node);
-  }
-
-  @override
-  Object visitMethodDeclaration(MethodDeclaration node) {
-    ExecutableElement element = node.element;
-    enterScope(element);
-    try {
-      return super.visitMethodDeclaration(node);
-    } finally {
-      _exitScope();
-    }
-  }
-
-  @override
-  Object visitMethodInvocation(MethodInvocation node) {
-    SimpleIdentifier name = node.methodName;
-    Element element = name.bestElement;
-    if (element is MethodElement || element is PropertyAccessorElement) {
-      Location location = _createLocationFromNode(name);
-      Relationship relationship;
-      if (node.target != null) {
-        relationship = IndexConstants.IS_INVOKED_BY_QUALIFIED;
-      } else {
-        relationship = IndexConstants.IS_INVOKED_BY_UNQUALIFIED;
-      }
-      recordRelationship(element, relationship, location);
-    }
-    if (element is FunctionElement || element is VariableElement) {
-      Location location = _createLocationFromNode(name);
-      recordRelationship(element, IndexConstants.IS_INVOKED_BY, location);
-    }
-    // name invocation
-    {
-      Element nameElement = new NameElement(name.name);
-      Location location = _createLocationFromNode(name);
-      Relationship kind = element != null ?
-          IndexConstants.NAME_IS_INVOKED_BY_RESOLVED :
-          IndexConstants.NAME_IS_INVOKED_BY_UNRESOLVED;
-      _store.recordRelationship(nameElement, kind, location);
-    }
-    _recordImportElementReferenceWithoutPrefix(name);
-    return super.visitMethodInvocation(node);
-  }
-
-  @override
-  Object visitPartDirective(PartDirective node) {
-    Element element = node.element;
-    Location location = _createLocationFromNode(node.uri);
-    recordRelationship(element, IndexConstants.IS_REFERENCED_BY, location);
-    return super.visitPartDirective(node);
-  }
-
-  @override
-  Object visitPartOfDirective(PartOfDirective node) {
-    Location location = _createLocationFromNode(node.libraryName);
-    recordRelationship(node.element, IndexConstants.IS_REFERENCED_BY, location);
-    return null;
-  }
-
-  @override
-  Object visitPostfixExpression(PostfixExpression node) {
-    _recordOperatorReference(node.operator, node.bestElement);
-    return super.visitPostfixExpression(node);
-  }
-
-  @override
-  Object visitPrefixExpression(PrefixExpression node) {
-    _recordOperatorReference(node.operator, node.bestElement);
-    return super.visitPrefixExpression(node);
-  }
-
-  @override
-  Object visitSimpleIdentifier(SimpleIdentifier node) {
-    Element nameElement = new NameElement(node.name);
-    Location location = _createLocationFromNode(node);
-    // name in declaration
-    if (node.inDeclarationContext()) {
-      recordRelationship(nameElement, IndexConstants.IS_DEFINED_BY, location);
-      return null;
-    }
-    // prepare information
-    Element element = node.bestElement;
-    // qualified name reference
-    _recordQualifiedMemberReference(node, element, nameElement, location);
-    // stop if already handled
-    if (_isAlreadyHandledName(node)) {
-      return null;
-    }
-    // record name read/write
-    {
-      bool inGetterContext = node.inGetterContext();
-      bool inSetterContext = node.inSetterContext();
-      if (inGetterContext && inSetterContext) {
-        Relationship kind = element != null ?
-            IndexConstants.NAME_IS_READ_WRITTEN_BY_RESOLVED :
-            IndexConstants.NAME_IS_READ_WRITTEN_BY_UNRESOLVED;
-        _store.recordRelationship(nameElement, kind, location);
-      } else if (inGetterContext) {
-        Relationship kind = element != null ?
-            IndexConstants.NAME_IS_READ_BY_RESOLVED :
-            IndexConstants.NAME_IS_READ_BY_UNRESOLVED;
-        _store.recordRelationship(nameElement, kind, location);
-      } else if (inSetterContext) {
-        Relationship kind = element != null ?
-            IndexConstants.NAME_IS_WRITTEN_BY_RESOLVED :
-            IndexConstants.NAME_IS_WRITTEN_BY_UNRESOLVED;
-        _store.recordRelationship(nameElement, kind, location);
-      }
-    }
-    // record specific relations
-    if (element is ClassElement || element is FunctionElement || element is
-        FunctionTypeAliasElement || element is LabelElement || element is
-        TypeParameterElement) {
-      recordRelationship(element, IndexConstants.IS_REFERENCED_BY, location);
-    } else if (element is FieldElement) {
-      location = _getLocationWithInitializerType(node, location);
-      recordRelationship(element, IndexConstants.IS_REFERENCED_BY, location);
-    } else if (element is FieldFormalParameterElement) {
-      FieldFormalParameterElement fieldParameter = element;
-      FieldElement field = fieldParameter.field;
-      recordRelationship(field, IndexConstants.IS_REFERENCED_BY_QUALIFIED,
-          location);
-    } else if (element is PrefixElement) {
-      _recordImportElementReferenceWithPrefix(node);
-    } else if (element is PropertyAccessorElement || element is MethodElement) {
-      location = _getLocationWithTypeAssignedToField(node, element, location);
-      if (node.isQualified) {
-        recordRelationship(element, IndexConstants.IS_REFERENCED_BY_QUALIFIED,
-            location);
-      } else {
-        recordRelationship(element, IndexConstants.IS_REFERENCED_BY_UNQUALIFIED,
-            location);
-      }
-    } else if (element is ParameterElement || element is LocalVariableElement) {
-      bool inGetterContext = node.inGetterContext();
-      bool inSetterContext = node.inSetterContext();
-      if (inGetterContext && inSetterContext) {
-        recordRelationship(element, IndexConstants.IS_READ_WRITTEN_BY,
-            location);
-      } else if (inGetterContext) {
-        recordRelationship(element, IndexConstants.IS_READ_BY, location);
-      } else if (inSetterContext) {
-        recordRelationship(element, IndexConstants.IS_WRITTEN_BY, location);
-      } else {
-        recordRelationship(element, IndexConstants.IS_REFERENCED_BY, location);
-      }
-    }
-    _recordImportElementReferenceWithoutPrefix(node);
-    return super.visitSimpleIdentifier(node);
-  }
-
-  @override
-  Object visitSuperConstructorInvocation(SuperConstructorInvocation node) {
-    ConstructorElement element = node.staticElement;
-    Location location;
-    if (node.constructorName != null) {
-      int start = node.period.offset;
-      int end = node.constructorName.end;
-      location = _createLocationFromOffset(start, end - start);
-    } else {
-      int start = node.keyword.end;
-      location = _createLocationFromOffset(start, 0);
-    }
-    recordRelationship(element, IndexConstants.IS_REFERENCED_BY, location);
-    return super.visitSuperConstructorInvocation(node);
-  }
-
-  @override
-  Object visitTopLevelVariableDeclaration(TopLevelVariableDeclaration node) {
-    VariableDeclarationList variables = node.variables;
-    for (VariableDeclaration variableDeclaration in variables.variables) {
-      Element element = variableDeclaration.element;
-      _recordElementDefinition(element, IndexConstants.DEFINES_VARIABLE);
-    }
-    return super.visitTopLevelVariableDeclaration(node);
-  }
-
-  @override
-  Object visitTypeParameter(TypeParameter node) {
-    TypeParameterElement element = node.element;
-    enterScope(element);
-    try {
-      return super.visitTypeParameter(node);
-    } finally {
-      _exitScope();
-    }
-  }
-
-  @override
-  Object visitVariableDeclaration(VariableDeclaration node) {
-    VariableElement element = node.element;
-    // record declaration
-    {
-      SimpleIdentifier name = node.name;
-      Location location = _createLocationFromNode(name);
-      location = _getLocationWithExpressionType(location, node.initializer);
-      recordRelationship(element, IndexConstants.IS_DEFINED_BY, location);
-    }
-    // visit
-    enterScope(element);
-    try {
-      return super.visitVariableDeclaration(node);
-    } finally {
-      _exitScope();
-    }
-  }
-
-  @override
-  Object visitVariableDeclarationList(VariableDeclarationList node) {
-    NodeList<VariableDeclaration> variables = node.variables;
-    if (variables != null) {
-      // use first VariableDeclaration as Element for Location(s) in type
-      {
-        TypeName type = node.type;
-        if (type != null) {
-          for (VariableDeclaration variableDeclaration in variables) {
-            enterScope(variableDeclaration.element);
-            try {
-              type.accept(this);
-            } finally {
-              _exitScope();
-            }
-            // only one iteration
-            break;
-          }
-        }
-      }
-      // visit variables
-      variables.accept(this);
-    }
-    return null;
-  }
-
-  /**
-   * @return the [Location] representing location of the [AstNode].
-   */
-  Location _createLocationFromNode(AstNode node) => _createLocationFromOffset(
-      node.offset, node.length);
-
-  /**
-   * [offset] - the offset of the location within [Source].
-   * [length] - the length of the location.
-   *
-   * Returns the [Location] representing the given offset and length within the
-   * inner-most [Element].
-   */
-  Location _createLocationFromOffset(int offset, int length) {
-    Element element = peekElement();
-    return new Location(element, offset, length);
-  }
-
-  /**
-   * @return the [Location] representing location of the [Token].
-   */
-  Location _createLocationFromToken(Token token) => _createLocationFromOffset(
-      token.offset, token.length);
-
-  /**
-   * Exit the current scope.
-   */
-  void _exitScope() {
-    _elementStack.removeFirst();
-  }
-
-  /**
-   * @return `true` if given node already indexed as more interesting reference, so it should
-   *         not be indexed again.
-   */
-  bool _isAlreadyHandledName(SimpleIdentifier node) {
-    AstNode parent = node.parent;
-    if (parent is MethodInvocation) {
-      return identical(parent.methodName, node);
-    }
-    return false;
-  }
-
-  /**
-   * Records the [Element] definition in the library and universe.
-   */
-  void _recordElementDefinition(Element element, Relationship relationship) {
-    Location location = createLocation(element);
-    recordRelationship(_libraryElement, relationship, location);
-    recordRelationship(IndexConstants.UNIVERSE, relationship, location);
-  }
-
-  /**
-   * Records [ImportElement] that declares given prefix and imports library with element used
-   * with given prefix node.
-   */
-  void _recordImportElementReferenceWithPrefix(SimpleIdentifier prefixNode) {
-    _ImportElementInfo info = getImportElementInfo(prefixNode);
-    if (info != null) {
-      int offset = prefixNode.offset;
-      int length = info._periodEnd - offset;
-      Location location = _createLocationFromOffset(offset, length);
-      recordRelationship(info._element, IndexConstants.IS_REFERENCED_BY,
-          location);
-    }
-  }
-
-  /**
-   * Records [ImportElement] reference if given [SimpleIdentifier] references some
-   * top-level element and not qualified with import prefix.
-   */
-  void _recordImportElementReferenceWithoutPrefix(SimpleIdentifier node) {
-    if (_isIdentifierInImportCombinator(node)) {
-      return;
-    }
-    if (_isIdentifierInPrefixedIdentifier(node)) {
-      return;
-    }
-    Element element = node.staticElement;
-    ImportElement importElement = _internalGetImportElement(_libraryElement,
-        null, element, _importElementsMap);
-    if (importElement != null) {
-      Location location = _createLocationFromOffset(node.offset, 0);
-      recordRelationship(importElement, IndexConstants.IS_REFERENCED_BY,
-          location);
-    }
-  }
-
-  /**
-   * Records reference to defining [CompilationUnitElement] of the given
-   * [LibraryElement].
-   */
-  void _recordLibraryReference(UriBasedDirective node, LibraryElement library) {
-    if (library != null) {
-      Location location = _createLocationFromNode(node.uri);
-      recordRelationship(library.definingCompilationUnit,
-          IndexConstants.IS_REFERENCED_BY, location);
-    }
-  }
-
-  /**
-   * Record reference to the given operator [Element] and name.
-   */
-  void _recordOperatorReference(Token operator, Element element) {
-    // prepare location
-    Location location = _createLocationFromToken(operator);
-    // record name reference
-    {
-      String name = operator.lexeme;
-      if (name == "++") {
-        name = "+";
-      }
-      if (name == "--") {
-        name = "-";
-      }
-      if (StringUtilities.endsWithChar(name, 0x3D) && name != "==") {
-        name = name.substring(0, name.length - 1);
-      }
-      Element nameElement = new NameElement(name);
-      Relationship relationship = element != null ?
-          IndexConstants.IS_REFERENCED_BY_QUALIFIED_RESOLVED :
-          IndexConstants.IS_REFERENCED_BY_QUALIFIED_UNRESOLVED;
-      recordRelationship(nameElement, relationship, location);
-    }
-    // record element reference
-    if (element != null) {
-      recordRelationship(element, IndexConstants.IS_INVOKED_BY_QUALIFIED,
-          location);
-    }
-  }
-
-  /**
-   * Records reference if the given [SimpleIdentifier] looks like a qualified property access
-   * or method invocation.
-   */
-  void _recordQualifiedMemberReference(SimpleIdentifier node, Element element,
-      Element nameElement, Location location) {
-    if (node.isQualified) {
-      Relationship relationship = element != null ?
-          IndexConstants.IS_REFERENCED_BY_QUALIFIED_RESOLVED :
-          IndexConstants.IS_REFERENCED_BY_QUALIFIED_UNRESOLVED;
-      recordRelationship(nameElement, relationship, location);
-    }
-  }
-
-  /**
-   * Records extends/implements relationships between given [ClassElement] and [Type] of
-   * "superNode".
-   */
-  void _recordSuperType(TypeName superNode, Relationship relationship) {
-    if (superNode != null) {
-      Identifier superName = superNode.name;
-      if (superName != null) {
-        Element superElement = superName.staticElement;
-        recordRelationship(superElement, relationship, _createLocationFromNode(
-            superNode));
-      }
-    }
-  }
-
-  /**
-   * @return the [Location] representing location of the [Element].
-   */
-  static Location createLocation(Element element) {
-    if (element != null) {
-      int offset = element.nameOffset;
-      int length = element.displayName.length;
-      return new Location(element, offset, length);
-    }
-    return null;
-  }
-
-  /**
-   * @return the [ImportElement] that is referenced by this node with [PrefixElement],
-   *         may be `null`.
-   */
-  static ImportElement getImportElement(SimpleIdentifier prefixNode) {
-    _ImportElementInfo info = getImportElementInfo(prefixNode);
-    return info != null ? info._element : null;
-  }
-
-  /**
-   * @return the [ImportElementInfo] with [ImportElement] that is referenced by this
-   *         node with [PrefixElement], may be `null`.
-   */
-  static _ImportElementInfo getImportElementInfo(SimpleIdentifier prefixNode) {
-    _ImportElementInfo info = new _ImportElementInfo();
-    // prepare environment
-    AstNode parent = prefixNode.parent;
-    CompilationUnit unit = prefixNode.getAncestor((node) => node is
-        CompilationUnit);
-    LibraryElement libraryElement = unit.element.library;
-    // prepare used element
-    Element usedElement = null;
-    if (parent is PrefixedIdentifier) {
-      PrefixedIdentifier prefixed = parent;
-      if (identical(prefixed.prefix, prefixNode)) {
-        usedElement = prefixed.staticElement;
-        info._periodEnd = prefixed.period.end;
-      }
-    }
-    if (parent is MethodInvocation) {
-      MethodInvocation invocation = parent;
-      if (identical(invocation.target, prefixNode)) {
-        usedElement = invocation.methodName.staticElement;
-        info._periodEnd = invocation.period.end;
-      }
-    }
-    // we need used Element
-    if (usedElement == null) {
-      return null;
-    }
-    // find ImportElement
-    String prefix = prefixNode.name;
-    Map<ImportElement, Set<Element>> importElementsMap = {};
-    info._element = _internalGetImportElement(libraryElement, prefix,
-        usedElement, importElementsMap);
-    if (info._element == null) {
-      return null;
-    }
-    return info;
-  }
-
-  /**
-   * If the given expression has resolved type, returns the new location with this type.
-   *
-   * [location] - the base location
-   * [expression] - the expression assigned at the given location
-   */
-  static Location _getLocationWithExpressionType(Location location,
-      Expression expression) {
-    if (expression != null) {
-      return new LocationWithData<DartType>(location, expression.bestType);
-    }
-    return location;
-  }
-
-  /**
-   * If the given node is the part of the [ConstructorFieldInitializer], returns location with
-   * type of the initializer expression.
-   */
-  static Location _getLocationWithInitializerType(SimpleIdentifier node,
-      Location location) {
-    if (node.parent is ConstructorFieldInitializer) {
-      ConstructorFieldInitializer initializer = node.parent as
-          ConstructorFieldInitializer;
-      if (identical(initializer.fieldName, node)) {
-        location = _getLocationWithExpressionType(location,
-            initializer.expression);
-      }
-    }
-    return location;
-  }
-
-  /**
-   * If the given identifier has a synthetic [PropertyAccessorElement], i.e.
-   * accessor for normal field, and it is LHS of assignment, then include [Type]
-   * of the assigned value into the [Location].
-   *
-   * [identifier] - the identifier to record location.
-   * [element] - the [Element] of the identifier.
-   * [location] - the raw location
-   *
-   * Returns the [Location] with the type of the assigned value
-   */
-  static Location
-      _getLocationWithTypeAssignedToField(SimpleIdentifier identifier,
-      Element element, Location location) {
-    // we need accessor
-    if (element is! PropertyAccessorElement) {
-      return location;
-    }
-    PropertyAccessorElement accessor = element as PropertyAccessorElement;
-    // should be setter
-    if (!accessor.isSetter) {
-      return location;
-    }
-    // accessor should be synthetic, i.e. field normal
-    if (!accessor.isSynthetic) {
-      return location;
-    }
-    // should be LHS of assignment
-    AstNode parent;
-    {
-      AstNode node = identifier;
-      parent = node.parent;
-      // new T().field = x;
-      if (parent is PropertyAccess) {
-        PropertyAccess propertyAccess = parent as PropertyAccess;
-        if (identical(propertyAccess.propertyName, node)) {
-          node = propertyAccess;
-          parent = propertyAccess.parent;
-        }
-      }
-      // obj.field = x;
-      if (parent is PrefixedIdentifier) {
-        PrefixedIdentifier prefixedIdentifier = parent as PrefixedIdentifier;
-        if (identical(prefixedIdentifier.identifier, node)) {
-          node = prefixedIdentifier;
-          parent = prefixedIdentifier.parent;
-        }
-      }
-    }
-    // OK, remember the type
-    if (parent is AssignmentExpression) {
-      AssignmentExpression assignment = parent as AssignmentExpression;
-      Expression rhs = assignment.rightHandSide;
-      location = _getLocationWithExpressionType(location, rhs);
-    }
-    // done
-    return location;
-  }
-
-  /**
-   * @return the [ImportElement] that declares given [PrefixElement] and imports library
-   *         with given "usedElement".
-   */
-  static ImportElement _internalGetImportElement(LibraryElement libraryElement,
-      String prefix, Element usedElement, Map<ImportElement,
-      Set<Element>> importElementsMap) {
-    // validate Element
-    if (usedElement == null) {
-      return null;
-    }
-    if (usedElement.enclosingElement is! CompilationUnitElement) {
-      return null;
-    }
-    LibraryElement usedLibrary = usedElement.library;
-    // find ImportElement that imports used library with used prefix
-    List<ImportElement> candidates = null;
-    for (ImportElement importElement in libraryElement.imports) {
-      // required library
-      if (importElement.importedLibrary != usedLibrary) {
-        continue;
-      }
-      // required prefix
-      PrefixElement prefixElement = importElement.prefix;
-      if (prefix == null) {
-        if (prefixElement != null) {
-          continue;
-        }
-      } else {
-        if (prefixElement == null) {
-          continue;
-        }
-        if (prefix != prefixElement.name) {
-          continue;
-        }
-      }
-      // no combinators => only possible candidate
-      if (importElement.combinators.length == 0) {
-        return importElement;
-      }
-      // OK, we have candidate
-      if (candidates == null) {
-        candidates = [];
-      }
-      candidates.add(importElement);
-    }
-    // no candidates, probably element is defined in this library
-    if (candidates == null) {
-      return null;
-    }
-    // one candidate
-    if (candidates.length == 1) {
-      return candidates[0];
-    }
-    // ensure that each ImportElement has set of elements
-    for (ImportElement importElement in candidates) {
-      if (importElementsMap.containsKey(importElement)) {
-        continue;
-      }
-      Namespace namespace = new NamespaceBuilder(
-          ).createImportNamespaceForDirective(importElement);
-      Set<Element> elements = new Set();
-      importElementsMap[importElement] = elements;
-    }
-    // use import namespace to choose correct one
-    for (MapEntry<ImportElement, Set<Element>> entry in getMapEntrySet(
-        importElementsMap)) {
-      if (entry.getValue().contains(usedElement)) {
-        return entry.getKey();
-      }
-    }
-    // not found
-    return null;
-  }
-
-  /**
-   * @return `true` if given "node" is part of an import [Combinator].
-   */
-  static bool _isIdentifierInImportCombinator(SimpleIdentifier node) {
-    AstNode parent = node.parent;
-    return parent is Combinator;
-  }
-
-  /**
-   * @return `true` if given "node" is part of [PrefixedIdentifier] "prefix.node".
-   */
-  static bool _isIdentifierInPrefixedIdentifier(SimpleIdentifier node) {
-    AstNode parent = node.parent;
-    return parent is PrefixedIdentifier && identical(parent.identifier, node);
-  }
-}