Fixes to associating existing elements with an AST

pkg/analyzer/lib/src/generated/resolver.dart

Index: pkg/analyzer/lib/src/generated/resolver.dart
diff --git a/pkg/analyzer/lib/src/generated/resolver.dart b/pkg/analyzer/lib/src/generated/resolver.dart
index fd228934ec2b9611519b69df16b1de4136fa7047..479a787c3d1c2bed22d656edaa82bbca9102b379 100644
--- a/pkg/analyzer/lib/src/generated/resolver.dart
+++ b/pkg/analyzer/lib/src/generated/resolver.dart
@@ -36,6 +36,26 @@ import 'package:analyzer/src/task/strong/info.dart'
 export 'package:analyzer/src/generated/type_system.dart';
 
 /**
+ * Throw an [ElementMismatchException] to report that the element model and the
+ * AST do not match. The [message] will have the path to the given [node]
+ * appended to it.
+ */
+void _mismatch(String message, AstNode node) {
+  StringBuffer buffer = new StringBuffer();
+  buffer.writeln(message);
+  buffer.write('Path to root:');
+  String separator = ' ';
+  AstNode parent = node;
+  while (parent != null) {
+    buffer.write(separator);
+    buffer.write(parent.runtimeType.toString());
+    separator = ', ';
+    parent = parent.parent;
+  }
+  throw new ElementMismatchException(buffer.toString());
+}
+
+/**
  * Instances of the class `BestPracticesVerifier` traverse an AST structure looking for
  * violations of Dart best practices.
  */
@@ -2119,6 +2139,11 @@ class DeadCodeVerifier extends RecursiveAstVisitor<Object> {
 /**
  * A visitor that resolves declarations in an AST structure to already built
  * elements.
+ *
+ * The resulting AST must have everything resolved that would have been resolved
+ * by a [CompilationUnitBuilder] (that is, must be a valid [RESOLVED_UNIT1]).
+ * This class must not assume that the [CompilationUnitElement] passed to it is
+ * any more complete than a [COMPILATION_UNIT_ELEMENT].
  */
 class DeclarationResolver extends RecursiveAstVisitor<Object> {
   /**
@@ -2135,7 +2160,7 @@ class DeclarationResolver extends RecursiveAstVisitor<Object> {
   /**
    * The compilation unit containing the AST nodes being visited.
    */
-  CompilationUnitElement _enclosingUnit;
+  CompilationUnitElementImpl _enclosingUnit;
 
   /**
    * The function type alias containing the AST nodes being visited, or `null`
@@ -2200,7 +2225,7 @@ class DeclarationResolver extends RecursiveAstVisitor<Object> {
       SimpleIdentifier className = node.name;
       _enclosingClass = _findIdentifier(_enclosingUnit.types, className);
       super.visitClassDeclaration(node);
-      _resolveMetadata(node.metadata, _enclosingClass);
+      _resolveMetadata(node, node.metadata, _enclosingClass);
       return null;
     } finally {
       _enclosingClass = outerClass;
@@ -2214,7 +2239,7 @@ class DeclarationResolver extends RecursiveAstVisitor<Object> {
       SimpleIdentifier className = node.name;
       _enclosingClass = _findIdentifier(_enclosingUnit.types, className);
       super.visitClassTypeAlias(node);
-      _resolveMetadata(node.metadata, _enclosingClass);
+      _resolveMetadata(node, node.metadata, _enclosingClass);
       return null;
     } finally {
       _enclosingClass = outerClass;
@@ -2244,7 +2269,7 @@ class DeclarationResolver extends RecursiveAstVisitor<Object> {
       _expectedElements.remove(_enclosingExecutable);
       node.element = _enclosingExecutable as ConstructorElement;
       super.visitConstructorDeclaration(node);
-      _resolveMetadata(node.metadata, _enclosingExecutable);
+      _resolveMetadata(node, node.metadata, _enclosingExecutable);
       return null;
     } finally {
       _enclosingExecutable = outerExecutable;
@@ -2257,7 +2282,7 @@ class DeclarationResolver extends RecursiveAstVisitor<Object> {
     Element element =
         _findIdentifier(_enclosingExecutable.localVariables, variableName);
     super.visitDeclaredIdentifier(node);
-    _resolveMetadata(node.metadata, element);
+    _resolveMetadata(node, node.metadata, element);
     return null;
   }
 
@@ -2279,7 +2304,7 @@ class DeclarationResolver extends RecursiveAstVisitor<Object> {
     try {
       _enclosingParameter = element;
       super.visitDefaultFormalParameter(node);
-      _resolveMetadata(node.metadata, element);
+      _resolveMetadata(node, node.metadata, element);
       return null;
     } finally {
       _enclosingParameter = outerParameter;
@@ -2295,30 +2320,22 @@ class DeclarationResolver extends RecursiveAstVisitor<Object> {
       _findIdentifier(constants, constant.name);
     }
     super.visitEnumDeclaration(node);
-    _resolveMetadata(node.metadata, enclosingEnum);
+    _resolveMetadata(node, node.metadata, enclosingEnum);
     return null;
   }
 
   @override
   Object visitExportDirective(ExportDirective node) {
-    String uri = _getStringValue(node.uri);
-    ExportElement exportElement;
-    if (uri != null) {
-      LibraryElement library = _enclosingUnit.library;
-      Source source = _enclosingUnit.context.sourceFactory
-          .resolveUri(_enclosingUnit.source, uri);
-      exportElement = _findExport(node, library.exports, source);
-      node.element = exportElement;
-    }
     super.visitExportDirective(node);
-    _resolveMetadata(node.metadata, exportElement);
+    _resolveAnnotations(
+        node, node.metadata, _enclosingUnit.getAnnotations(node.offset));
     return null;
   }
 
   @override
   Object visitFieldDeclaration(FieldDeclaration node) {
     super.visitFieldDeclaration(node);
-    _resolveMetadata(node.metadata, node.fields.variables[0].element);
+    _resolveMetadata(node, node.metadata, node.fields.variables[0].element);
     return null;
   }
 
@@ -2331,7 +2348,7 @@ class DeclarationResolver extends RecursiveAstVisitor<Object> {
       try {
         _enclosingParameter = element;
         super.visitFieldFormalParameter(node);
-        _resolveMetadata(node.metadata, element);
+        _resolveMetadata(node, node.metadata, element);
         return null;
       } finally {
         _enclosingParameter = outerParameter;
@@ -2380,7 +2397,7 @@ class DeclarationResolver extends RecursiveAstVisitor<Object> {
       }
       node.functionExpression.element = _enclosingExecutable;
       super.visitFunctionDeclaration(node);
-      _resolveMetadata(node.metadata, _enclosingExecutable);
+      _resolveMetadata(node, node.metadata, _enclosingExecutable);
       return null;
     } finally {
       _enclosingExecutable = outerExecutable;
@@ -2412,7 +2429,7 @@ class DeclarationResolver extends RecursiveAstVisitor<Object> {
       _enclosingAlias =
           _findIdentifier(_enclosingUnit.functionTypeAliases, aliasName);
       super.visitFunctionTypeAlias(node);
-      _resolveMetadata(node.metadata, _enclosingAlias);
+      _resolveMetadata(node, node.metadata, _enclosingAlias);
       return null;
     } finally {
       _enclosingAlias = outerAlias;
@@ -2428,7 +2445,7 @@ class DeclarationResolver extends RecursiveAstVisitor<Object> {
       try {
         _enclosingParameter = element;
         super.visitFunctionTypedFormalParameter(node);
-        _resolveMetadata(node.metadata, _enclosingParameter);
+        _resolveMetadata(node, node.metadata, _enclosingParameter);
         return null;
       } finally {
         _enclosingParameter = outerParameter;
@@ -2440,17 +2457,9 @@ class DeclarationResolver extends RecursiveAstVisitor<Object> {
 
   @override
   Object visitImportDirective(ImportDirective node) {
-    String uri = _getStringValue(node.uri);
-    ImportElement importElement;
-    if (uri != null) {
-      LibraryElement library = _enclosingUnit.library;
-      Source source = _enclosingUnit.context.sourceFactory
-          .resolveUri(_enclosingUnit.source, uri);
-      importElement = _findImport(node, library.imports, source);
-      node.element = importElement;
-    }
     super.visitImportDirective(node);
-    _resolveMetadata(node.metadata, importElement);
+    _resolveAnnotations(
+        node, node.metadata, _enclosingUnit.getAnnotations(node.offset));
     return null;
   }
 
@@ -2465,10 +2474,9 @@ class DeclarationResolver extends RecursiveAstVisitor<Object> {
 
   @override
   Object visitLibraryDirective(LibraryDirective node) {
-    LibraryElement libraryElement = _enclosingUnit.library;
-    node.element = libraryElement;
     super.visitLibraryDirective(node);
-    _resolveMetadata(node.metadata, libraryElement);
+    _resolveAnnotations(
+        node, node.metadata, _enclosingUnit.getAnnotations(node.offset));
     return null;
   }
 
@@ -2500,7 +2508,7 @@ class DeclarationResolver extends RecursiveAstVisitor<Object> {
         _enclosingExecutable = accessor;
       }
       super.visitMethodDeclaration(node);
-      _resolveMetadata(node.metadata, _enclosingExecutable);
+      _resolveMetadata(node, node.metadata, _enclosingExecutable);
       return null;
     } finally {
       _enclosingExecutable = outerExecutable;
@@ -2509,16 +2517,9 @@ class DeclarationResolver extends RecursiveAstVisitor<Object> {
 
   @override
   Object visitPartDirective(PartDirective node) {
-    String uri = _getStringValue(node.uri);
-    CompilationUnitElement compilationUnitElement;
-    if (uri != null) {
-      Source partSource = _enclosingUnit.context.sourceFactory
-          .resolveUri(_enclosingUnit.source, uri);
-      compilationUnitElement =
-          _findPart(_enclosingUnit.library.parts, node, partSource);
-    }
     super.visitPartDirective(node);
-    _resolveMetadata(node.metadata, compilationUnitElement);
+    _resolveAnnotations(
+        node, node.metadata, _enclosingUnit.getAnnotations(node.offset));
     return null;
   }
 
@@ -2537,7 +2538,7 @@ class DeclarationResolver extends RecursiveAstVisitor<Object> {
       try {
         _enclosingParameter = element;
         super.visitSimpleFormalParameter(node);
-        _resolveMetadata(node.metadata, element);
+        _resolveMetadata(node, node.metadata, element);
         return null;
       } finally {
         _enclosingParameter = outerParameter;
@@ -2567,7 +2568,7 @@ class DeclarationResolver extends RecursiveAstVisitor<Object> {
   @override
   Object visitTopLevelVariableDeclaration(TopLevelVariableDeclaration node) {
     super.visitTopLevelVariableDeclaration(node);
-    _resolveMetadata(node.metadata, node.variables.variables[0].element);
+    _resolveMetadata(node, node.metadata, node.variables.variables[0].element);
     return null;
   }
 
@@ -2596,7 +2597,7 @@ class DeclarationResolver extends RecursiveAstVisitor<Object> {
           'Could not find type parameter with name "$name" at $offset', node);
     }
     super.visitTypeParameter(node);
-    _resolveMetadata(node.metadata, element);
+    _resolveMetadata(node, node.metadata, element);
     return null;
   }
 
@@ -2634,7 +2635,7 @@ class DeclarationResolver extends RecursiveAstVisitor<Object> {
     super.visitVariableDeclarationList(node);
     if (node.parent is! FieldDeclaration &&
         node.parent is! TopLevelVariableDeclaration) {
-      _resolveMetadata(node.metadata, node.variables[0].element);
+      _resolveMetadata(node, node.metadata, node.variables[0].element);
     }
     return null;
   }
@@ -2651,25 +2652,6 @@ class DeclarationResolver extends RecursiveAstVisitor<Object> {
       _findWithNameAndOffset(elements, node, '', offset);
 
   /**
-   * Return the export element from the given list of [exports] whose library
-   * has the given [source]. Throw an [ElementMismatchException] if an element
-   * corresponding to the identifier cannot be found.
-   */
-  ExportElement _findExport(
-      ExportDirective node, List<ExportElement> exports, Source source) {
-    if (source == null || !_context.exists(source)) {
-      return null;
-    }
-    for (ExportElement export in exports) {
-      if (export.exportedLibrary.source == source) {
-        return export;
-      }
-    }
-    _mismatch("Could not find export element for '$source'", node);
-    return null; // Never reached
-  }
-
-  /**
    * Return the element in the given list of [elements] that was created for the
    * declaration with the given [identifier]. As a side-effect, associate the
    * returned element with the identifier. Throw an [ElementMismatchException]
@@ -2687,64 +2669,6 @@ class DeclarationResolver extends RecursiveAstVisitor<Object> {
   }
 
   /**
-   * Return the import element from the given list of [imports] whose library
-   * has the given [source]. Throw an [ElementMismatchException] if an element
-   * corresponding to the [source] cannot be found.
-   */
-  ImportElement _findImport(
-      ImportDirective node, List<ImportElement> imports, Source source) {
-    if (source == null || !_context.exists(source)) {
-      return null;
-    }
-    SimpleIdentifier prefix = node.prefix;
-    bool foundSource = false;
-    for (ImportElement element in imports) {
-      if (element.importedLibrary.source == source) {
-        foundSource = true;
-        PrefixElement prefixElement = element.prefix;
-        if (prefix == null) {
-          if (prefixElement == null) {
-            return element;
-          }
-        } else {
-          if (prefixElement != null &&
-              prefix.name == prefixElement.displayName) {
-            return element;
-          }
-        }
-      }
-    }
-    if (foundSource) {
-      if (prefix == null) {
-        _mismatch(
-            "Could not find import element for '$source' with no prefix", node);
-      }
-      _mismatch(
-          "Could not find import element for '$source' with prefix ${prefix.name}",
-          node);
-    }
-    _mismatch("Could not find import element for '$source'", node);
-    return null; // Never reached
-  }
-
-  /**
-   * Return the element in the given list of [parts] that was created for the
-   * part with the given [source]. Throw an [ElementMismatchException] if an
-   * element corresponding to the source cannot be found.
-   */
-  CompilationUnitElement _findPart(List<CompilationUnitElement> parts,
-      PartDirective directive, Source source) {
-    for (CompilationUnitElement part in parts) {
-      if (part.source == source) {
-        return part;
-      }
-    }
-    _mismatch(
-        'Could not find compilation unit element for "$source"', directive);
-    return null; // Never reached
-  }
-
-  /**
    * Return the element in the given list of [elements] that was created for the
    * declaration with the given [name] at the given [offset]. Throw an
    * [ElementMismatchException] if an element corresponding to the identifier
@@ -2811,51 +2735,37 @@ class DeclarationResolver extends RecursiveAstVisitor<Object> {
   }
 
   /**
-   * Return the value of the given string [literal], or `null` if the string is
-   * not a constant string without any string interpolation.
+   * Associate each of the annotation [nodes] with the corresponding
+   * [ElementAnnotation] in [annotations]. If there is a problem, report it
+   * against the given [parent] node.
    */
-  String _getStringValue(StringLiteral literal) {
-    if (literal is StringInterpolation) {
-      return null;
+  void _resolveAnnotations(AstNode parent, NodeList<Annotation> nodes,
+      List<ElementAnnotation> annotations) {
+    int nodeCount = nodes.length;
+    if (nodeCount != annotations.length) {
+      _mismatch(
+          'Found $nodeCount annotation nodes and '
+          '${annotations.length} element annotations',
+          parent);
     }
-    return literal.stringValue;
-  }
-
-  /**
-   * Throw an [ElementMismatchException] to report that the element model and
-   * the AST do not match. The [message] will have the path to the given [node]
-   * appended to it.
-   */
-  void _mismatch(String message, AstNode node) {
-    StringBuffer buffer = new StringBuffer();
-    buffer.writeln(message);
-    buffer.write('Path to root:');
-    String separator = ' ';
-    AstNode parent = node;
-    while (parent != null) {
-      buffer.write(separator);
-      buffer.write(parent.runtimeType.toString());
-      separator = ', ';
-      parent = parent.parent;
+    for (int i = 0; i < nodeCount; i++) {
+      nodes[i].elementAnnotation = annotations[i];
     }
-    throw new ElementMismatchException(buffer.toString());
   }
 
   /**
-   * If [element] is not `null`, associate each [Annotation] in [astMetadata]
-   * with the corresponding [ElementAnnotation] in [element.metadata].
+   * If [element] is not `null`, associate each of the annotation [nodes] with
+   * the corresponding [ElementAnnotation] in [element.metadata]. If there is a
+   * problem, report it against the given [parent] node.
    *
    * If [element] is `null`, do nothing--this allows us to be robust in the
    * case where we are operating on an element model that hasn't been fully
    * built.
    */
-  void _resolveMetadata(NodeList<Annotation> astMetadata, Element element) {
+  void _resolveMetadata(
+      AstNode parent, NodeList<Annotation> nodes, Element element) {
     if (element != null) {
-      List<ElementAnnotation> elementMetadata = element.metadata;
-      assert(astMetadata.length == elementMetadata.length);
-      for (int i = 0; i < astMetadata.length; i++) {
-        astMetadata[i].elementAnnotation = elementMetadata[i];
-      }
+      _resolveAnnotations(parent, nodes, element.metadata);
     }
   }
 
@@ -2878,6 +2788,129 @@ class DeclarationResolver extends RecursiveAstVisitor<Object> {
 }
 
 /**
+ * A visitor that resolves directives in an AST structure to already built
+ * elements.
+ *
+ * The resulting AST must have everything resolved that would have been resolved
+ * by a [DirectiveElementBuilder].
+ */
+class DirectiveResolver extends SimpleAstVisitor {
+  CompilationUnitElementImpl _enclosingUnit;
+
+  @override
+  void visitCompilationUnit(CompilationUnit node) {
+    _enclosingUnit = node.element;
+    for (Directive directive in node.directives) {
+      directive.accept(this);
+    }
+  }
+
+  @override
+  void visitExportDirective(ExportDirective node) {
+    String uri = _getStringValue(node.uri);
+    if (uri != null) {
+      LibraryElement library = _enclosingUnit.library;
+      Source source = _enclosingUnit.context.sourceFactory
+          .resolveUri(_enclosingUnit.source, uri);
+      ExportElement exportElement = _findExport(node, library.exports, source);
+      node.element = exportElement;
+    } else {
+      node.element = null;
+    }
+  }
+
+  @override
+  void visitImportDirective(ImportDirective node) {
+    String uri = _getStringValue(node.uri);
+    if (uri != null) {
+      LibraryElement library = _enclosingUnit.library;
+      Source source = _enclosingUnit.context.sourceFactory
+          .resolveUri(_enclosingUnit.source, uri);
+      ImportElement importElement = _findImport(node, library.imports, source);
+      node.element = importElement;
+    } else {
+      node.element = null;
+    }
+  }
+
+  @override
+  void visitLibraryDirective(LibraryDirective node) {
+    node.element = _enclosingUnit.library;
+  }
+
+  /**
+   * Return the export element from the given list of [exports] whose library
+   * has the given [source]. Throw an [ElementMismatchException] if an element
+   * corresponding to the identifier cannot be found.
+   */
+  ExportElement _findExport(
+      ExportDirective node, List<ExportElement> exports, Source source) {
+    if (source == null || !_enclosingUnit.context.exists(source)) {
+      return null;
+    }
+    for (ExportElement export in exports) {
+      if (export.exportedLibrary.source == source) {
+        return export;
+      }
+    }
+    _mismatch("Could not find export element for '$source'", node);
+    return null; // Never reached
+  }
+
+  /**
+   * Return the import element from the given list of [imports] whose library
+   * has the given [source]. Throw an [ElementMismatchException] if an element
+   * corresponding to the [source] cannot be found.
+   */
+  ImportElement _findImport(
+      ImportDirective node, List<ImportElement> imports, Source source) {
+    if (source == null || !_enclosingUnit.context.exists(source)) {
+      return null;
+    }
+    SimpleIdentifier prefix = node.prefix;
+    bool foundSource = false;
+    for (ImportElement element in imports) {
+      if (element.importedLibrary.source == source) {
+        foundSource = true;
+        PrefixElement prefixElement = element.prefix;
+        if (prefix == null) {
+          if (prefixElement == null) {
+            return element;
+          }
+        } else {
+          if (prefixElement != null &&
+              prefix.name == prefixElement.displayName) {
+            return element;
+          }
+        }
+      }
+    }
+    if (foundSource) {
+      if (prefix == null) {
+        _mismatch(
+            "Could not find import element for '$source' with no prefix", node);
+      }
+      _mismatch(
+          "Could not find import element for '$source' with prefix ${prefix.name}",
+          node);
+    }
+    _mismatch("Could not find any import element for '$source'", node);
+    return null; // Never reached
+  }
+
+  /**
+   * Return the value of the given string [literal], or `null` if the string is
+   * not a constant string without any string interpolation.
+   */
+  String _getStringValue(StringLiteral literal) {
+    if (literal is StringInterpolation) {
+      return null;
+    }
+    return literal.stringValue;
+  }
+}
+
+/**
  * Instances of the class `ElementHolder` hold on to elements created while traversing an AST
  * structure so that they can be accessed when creating their enclosing element.
  */
@@ -3255,6 +3288,7 @@ class EnclosedScope extends Scope {
   /**
    * The scope in which this scope is lexically enclosed.
    */
+  @override
   final Scope enclosingScope;
 
   /**
@@ -6046,6 +6080,7 @@ class LibraryImportScope extends Scope {
   /**
    * The listener that is to be informed when an error is encountered.
    */
+  @override
   final AnalysisErrorListener errorListener;
 
   /**
@@ -7243,6 +7278,7 @@ class ResolverVisitor extends ScopedVisitor {
    * The class element representing the class containing the current node,
    * or `null` if the current node is not contained in a class.
    */
+  @override
   ClassElement enclosingClass = null;
 
   /**