Fix issue 21379

pkg/analyzer/lib/src/generated/engine.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.
 
 // 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;
 
 import 'dart:collection';
@@ skipping 8019 matching lines @@
     if (getState(PARSED_UNIT) == CacheState.VALID) {
       CompilationUnit unit = getValue(PARSED_UNIT);
       setState(PARSED_UNIT, CacheState.FLUSHED);
       return unit;
     }
     ResolutionState state = _resolutionState;
     while (state != null) {
       if (state.getState(BUILT_UNIT) == CacheState.VALID) {
         // TODO(brianwilkerson) We're cloning the structure to remove any
         // previous resolution data, but I'm not sure that's necessary.
-        return state.getValue(BUILT_UNIT).accept(new AstCloner()) as CompilationUnit;
+        return state.getValue(BUILT_UNIT).accept(new AstCloner());
       }
       if (state.getState(RESOLVED_UNIT) == CacheState.VALID) {
-        return state.getValue(RESOLVED_UNIT).accept(new AstCloner()) as CompilationUnit;
+        return state.getValue(RESOLVED_UNIT).accept(new AstCloner());
       }
       state = state._nextState;
     }
     return null;
   }
 
   /**
    * Return the state of the data represented by the given [descriptor] in the
    * context of the given [librarySource].
    */
@@ skipping 86 matching lines @@
   /**
    * Invalidate all of the resolution information associated with the
    * compilation unit. The flag [invalidateUris] should be `true` if the cached
    * results of converting URIs to source files should also be invalidated.
    */
   void invalidateAllResolutionInformation(bool invalidateUris) {
     if (getState(PARSED_UNIT) == CacheState.FLUSHED) {
       ResolutionState state = _resolutionState;
       while (state != null) {
         if (state.getState(BUILT_UNIT) == CacheState.VALID) {
-          setValue(PARSED_UNIT, state.getValue(BUILT_UNIT));
+          CompilationUnit unit = state.getValue(BUILT_UNIT);
+          ResolutionEraser.erase(unit);
+          setValue(PARSED_UNIT, unit);
           break;
         } else if (state.getState(RESOLVED_UNIT) == CacheState.VALID) {
-          setValue(PARSED_UNIT, state.getValue(RESOLVED_UNIT));
+          CompilationUnit unit = state.getValue(RESOLVED_UNIT);
+          ResolutionEraser.erase(unit);
+          setValue(PARSED_UNIT, unit);
           break;
         }
         state = state._nextState;
       }
     }
     _discardCachedResolutionInformation(invalidateUris);
   }
 
   /**
    * Return `true` if this data is safe to use in refactoring.
@@ skipping 3627 matching lines @@
   Object visitHtmlScriptTagNode(ht.HtmlScriptTagNode node) {
     CompilationUnit script = node.script;
     if (script != null) {
       GenerateDartErrorsTask.validateDirectives(ResolveHtmlTask_this.context, ResolveHtmlTask_this.source, script, errorListener);
     }
     return null;
   }
 }
 
 /**
- * Instances of the class `ResolutionEraser` remove any resolution information from an AST
+ * A `ResolutionEraser` removes any resolution information from an AST
  * structure when used to visit that structure.
  */
 class ResolutionEraser extends GeneralizingAstVisitor<Object> {
+  /**
+   * Remove any resolution information from the given AST structure.
+   */
+  static void erase(AstNode node) {
+    node.accept(new ResolutionEraser());
+  }
+
   @override
   Object visitAssignmentExpression(AssignmentExpression node) {
     node.staticElement = null;
     node.propagatedElement = null;
     return super.visitAssignmentExpression(node);
   }
 
   @override
   Object visitBinaryExpression(BinaryExpression node) {
     node.staticElement = null;
@@ skipping 162 matching lines @@
     }
     return false;
   }
 
   /**
    * Invalidate all of the resolution information associated with the compilation unit.
    */
   void invalidateAllResolutionInformation() {
     _nextState = null;
     _librarySource = null;
+    setState(DartEntry.BUILT_UNIT, CacheState.INVALID);
+    setState(DartEntry.BUILT_ELEMENT, CacheState.INVALID);
+    setState(DartEntry.HINTS, CacheState.INVALID);
     setState(DartEntry.RESOLVED_UNIT, CacheState.INVALID);
     setState(DartEntry.RESOLUTION_ERRORS, CacheState.INVALID);
     setState(DartEntry.VERIFICATION_ERRORS, CacheState.INVALID);
-    setState(DartEntry.HINTS, CacheState.INVALID);
   }
 
   /**
    * Record that an exception occurred while attempting to build the element
    * model for the source associated with this state.
    */
   void recordBuildElementError() {
     setState(DartEntry.BUILT_UNIT, CacheState.ERROR);
     setState(DartEntry.BUILT_ELEMENT, CacheState.ERROR);
     recordResolutionError();
@@ skipping 1032 matching lines @@
     _validateStateChange(descriptor, state);
     if (state == CacheState.INVALID) {
       resultMap.remove(descriptor);
     } else {
       CachedResult result = resultMap.putIfAbsent(
           descriptor,
           () => new CachedResult(descriptor));
       result.state = state;
       if (state != CacheState.IN_PROCESS) {
         //
-        // If the state is in-process, we can leave the current value in the cache
-        // for any 'get' methods to access.
+        // If the state is in-process, we can leave the current value in the
+        // cache for any 'get' methods to access.
         //
         result.value = descriptor.defaultValue;
       }
     }
   }
 
   /**
    * Set the value of the data represented by the given [descriptor] to the
    * given [value].
    */
@@ skipping 447 matching lines @@
     _index++;
     if (_index >= _manager._workQueues[_queueIndex].length) {
       _index = 0;
       _queueIndex++;
       while (_queueIndex < _manager._workQueues.length && _manager._workQueues[_queueIndex].isEmpty) {
         _queueIndex++;
       }
     }
   }
 }