Resynthesize import prefixes from Kernel.

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 5747 matching lines @@
     if (offset == 0 && _unlinkedImport != null) {
       if (_unlinkedImport.isImplicit) {
         return -1;
       }
       return _unlinkedImport.offset;
     }
     return offset;
   }
 
   PrefixElement get prefix {
-    if (_unlinkedImport != null) {
-      if (_unlinkedImport.prefixReference != 0 && _prefix == null) {
+    if (_prefix == null) {
+      if (_kernel != null && _kernel.name != null) {
+        LibraryElementImpl library = enclosingElement as LibraryElementImpl;
+        _prefix = new PrefixElementImpl.forKernel(library, _kernel);
+      }
+      if (_unlinkedImport != null && _unlinkedImport.prefixReference != 0) {
         LibraryElementImpl library = enclosingElement as LibraryElementImpl;
         _prefix = new PrefixElementImpl.forSerialized(_unlinkedImport, library);
       }
     }
     return _prefix;
   }
 
   void set prefix(PrefixElement prefix) {
     _assertNotResynthesized(_unlinkedImport);
     _prefix = prefix;
@@ skipping 2532 matching lines @@
 /**
  * A concrete implementation of a [PrefixElement].
  */
 class PrefixElementImpl extends ElementImpl implements PrefixElement {
   /**
    * The unlinked representation of the import in the summary.
    */
   final UnlinkedImport _unlinkedImport;
 
   /**
+   * The kernel of the element.
+   */
+  final kernel.LibraryDependency _kernel;
+
+  /**
    * Initialize a newly created method element to have the given [name] and
    * [nameOffset].
    */
   PrefixElementImpl(String name, int nameOffset)
       : _unlinkedImport = null,
+        _kernel = null,
         super(name, nameOffset);
 
   /**
    * Initialize a newly created prefix element to have the given [name].
    */
   PrefixElementImpl.forNode(Identifier name)
       : _unlinkedImport = null,
+        _kernel = null,
         super.forNode(name);
 
   /**
    * Initialize using the given serialized information.
    */
   PrefixElementImpl.forSerialized(
       this._unlinkedImport, LibraryElementImpl enclosingLibrary)
-      : super.forSerialized(enclosingLibrary);
+      : _kernel = null,
+        super.forSerialized(enclosingLibrary);
+
+  /**
+   * Initialize using the given kernel.
+   */
+  PrefixElementImpl.forKernel(LibraryElementImpl enclosingLibrary, this._kernel)
+      : _unlinkedImport = null,
+        super.forSerialized(enclosingLibrary);
 
   @override
   String get displayName => name;
 
   @override
   LibraryElement get enclosingElement =>
       super.enclosingElement as LibraryElement;
 
   @override
   String get identifier => "_${super.identifier}";
 
   @override
   List<LibraryElement> get importedLibraries => LibraryElement.EMPTY_LIST;
 
   @override
   ElementKind get kind => ElementKind.PREFIX;
 
   @override
   String get name {
+    if (_kernel != null) {
+      return _kernel.name;
+    }
     if (_unlinkedImport != null) {
       if (_name == null) {
         LibraryElementImpl library = enclosingElement as LibraryElementImpl;
         int prefixId = _unlinkedImport.prefixReference;
         return _name = library._unlinkedDefiningUnit.references[prefixId].name;
       }
     }
     return super.name;
   }
 
@@ skipping 1215 matching lines @@
 
   @override
   DartObject computeConstantValue() => null;
 
   @override
   void visitChildren(ElementVisitor visitor) {
     super.visitChildren(visitor);
     _initializer?.accept(visitor);
   }
 }