Prepare for decoupling analyzer ASTs from element model.

pkg/analysis_server/lib/src/services/index/index.dart

 // Copyright (c) 2016, 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.
 
 import 'dart:async';
 
 import 'package:analysis_server/src/services/index/index_unit.dart';
 import 'package:analyzer/dart/ast/ast.dart';
+import 'package:analyzer/dart/ast/resolution_accessors.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/src/generated/engine.dart' show AnalysisContext;
 import 'package:analyzer/src/generated/source.dart';
 import 'package:analyzer/src/summary/format.dart';
 import 'package:analyzer/src/summary/idl.dart';
 import 'package:collection/collection.dart';
 
 /**
  * Return a new [Index] instance that keeps information in memory.
  */
@@ skipping 54 matching lines @@
   Future<List<Location>> getUnresolvedMemberReferences(String name) {
     return _mergeLocations((_ContextIndex index) {
       return index.getUnresolvedMemberReferences(name);
     });
   }
 
   /**
    * Index declarations in the given partially resolved [unit].
    */
   void indexDeclarations(CompilationUnit unit) {
-    if (unit?.element?.library == null) {
+    if (unit == null) {
       return;
     }
-    AnalysisContext context = unit.element.context;
+    CompilationUnitElement compilationUnitElement =
+        elementForCompilationUnit(unit);
+    if (compilationUnitElement?.library == null) {
+      return;
+    }
+    AnalysisContext context = compilationUnitElement.context;
     _getContextIndex(context).indexDeclarations(unit);
   }
 
   /**
    * Index the given fully resolved [unit].
    */
   void indexUnit(CompilationUnit unit) {
-    if (unit?.element?.library == null) {
+    if (unit == null) {
       return;
     }
-    AnalysisContext context = unit.element.context;
+    CompilationUnitElement compilationUnitElement =
+        elementForCompilationUnit(unit);
+    if (compilationUnitElement?.library == null) {
+      return;
+    }
+    AnalysisContext context = compilationUnitElement.context;
     _getContextIndex(context).indexUnit(unit);
   }
 
   /**
    * Remove all index information for the given [context].
    */
   void removeContext(AnalysisContext context) {
     _contextIndexMap.remove(context);
   }
 
@@ skipping 522 matching lines @@
           unitUnitUri,
           unitIndex.usedNameKinds[i],
           unitIndex.usedNameOffsets[i],
           name.length,
           unitIndex.usedNameIsQualifiedFlags[i],
           false));
     }
     return locations;
   }
 }