Fixes to associating existing elements with an AST

pkg/analyzer/lib/src/dart/element/element.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.
 
 library analyzer.src.dart.element.element;
 
 import 'dart:collection';
 import 'dart:math' show min;
 
 import 'package:analyzer/dart/ast/ast.dart';
@@ skipping 910 matching lines @@
   /**
    * The source of the library containing this compilation unit.
    *
    * This is the same as the source of the containing [LibraryElement],
    * except that it does not require the containing [LibraryElement] to be
    * computed.
    */
   Source librarySource;
 
   /**
+   * A table mapping the offset of a directive to the annotations associated
+   * with that directive, or `null` if none of the annotations in the
+   * compilation unit have annotations.
+   */
+  Map<int, List<ElementAnnotation>> annotationMap = null;
+
+  /**
    * A list containing all of the top-level accessors (getters and setters)
    * contained in this compilation unit.
    */
   List<PropertyAccessorElement> _accessors = PropertyAccessorElement.EMPTY_LIST;
 
   /**
    * A list containing all of the enums contained in this compilation unit.
    */
   List<ClassElement> _enums = ClassElement.EMPTY_LIST;
 
@@ skipping 155 matching lines @@
     if (source == null) {
       buffer.write("{compilation unit}");
     } else {
       buffer.write(source.fullName);
     }
   }
 
   @override
   CompilationUnit computeNode() => unit;
 
+  /**
+   * Return the annotations associated with the directive at the given [offset],
+   * or an empty list if the directive has no annotations or if there is no
+   * directive at the given offset.
+   */
+  List<ElementAnnotation> getAnnotations(int offset) {
+    if (annotationMap == null) {
+      return ElementAnnotation.EMPTY_LIST;
+    }
+    return annotationMap[offset] ?? ElementAnnotation.EMPTY_LIST;
+  }
+
   @override
   ElementImpl getChild(String identifier) {
     //
     // The casts in this method are safe because the set methods would have
     // thrown a CCE if any of the elements in the arrays were not of the
     // expected types.
     //
     for (PropertyAccessorElement accessor in _accessors) {
       if ((accessor as PropertyAccessorElementImpl).identifier == identifier) {
         return accessor as PropertyAccessorElementImpl;
@@ skipping 58 matching lines @@
 
   /**
    * Replace the given [from] top-level variable with [to] in this compilation unit.
    */
   void replaceTopLevelVariable(
       TopLevelVariableElement from, TopLevelVariableElement to) {
     int index = _variables.indexOf(from);
     _variables[index] = to;
   }
 
+  /**
+   * Set the annotations associated with the directive at the given [offset] to
+   * the given list of [annotations].
+   */
+  void setAnnotations(int offset, List<ElementAnnotation> annotations) {
+    annotationMap ??= new HashMap<int, List<ElementAnnotation>>();
+    annotationMap[offset] = annotations;
+  }
+
   @override
   void visitChildren(ElementVisitor visitor) {
     super.visitChildren(visitor);
     safelyVisitChildren(_accessors, visitor);
     safelyVisitChildren(_enums, visitor);
     safelyVisitChildren(_functions, visitor);
     safelyVisitChildren(_typeAliases, visitor);
     safelyVisitChildren(_types, visitor);
     safelyVisitChildren(_variables, visitor);
   }
@@ skipping 3676 matching lines @@
 
   @override
   void visitElement(Element element) {
     int offset = element.nameOffset;
     if (offset != -1) {
       map[offset] = element;
     }
     super.visitElement(element);
   }
 }