Fixes to associating existing elements with an AST

pkg/analyzer/lib/src/dart/element/element.dart

Index: pkg/analyzer/lib/src/dart/element/element.dart
diff --git a/pkg/analyzer/lib/src/dart/element/element.dart b/pkg/analyzer/lib/src/dart/element/element.dart
index e3f4dfeeab2c9f4feb4b3fb7b5647c04d8e0d28a..462a95eea6df41288bb2914ebc3ace7986bafe22 100644
--- a/pkg/analyzer/lib/src/dart/element/element.dart
+++ b/pkg/analyzer/lib/src/dart/element/element.dart
@@ -928,6 +928,13 @@ class CompilationUnitElementImpl extends UriReferencedElementImpl
   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.
    */
@@ -1103,6 +1110,18 @@ class CompilationUnitElementImpl extends UriReferencedElementImpl
   @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) {
     //
@@ -1181,6 +1200,17 @@ class CompilationUnitElementImpl extends UriReferencedElementImpl
     _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) {
+    if (annotationMap == null) {

[Paul Berry, 2016/03/04 22:02:11]

Nit: this seems like a premature optimization (there are not very compilation
units and an empty hash map is cheap to create).  I'd recommend making
annotationMap final and initializing it at the declaration site.

(It's possible that that might even be a speed improvement, since making the
annotationMap final and initializing it at the declaration site guarantees to
the VM that it will never be null, so it may be able to eliminate some null
checks).

[Brian Wilkerson, 2016/03/07 16:20:28]

I have almost 3000 CompilationUnitElements in my environment, and I don't have
nearly as much code loaded as some of our users. But you might be right. I'm
leaving it in for now, but we can back it out later if it proves to be
unnecessary.

+      annotationMap = new HashMap<int, List<ElementAnnotation>>();

[scheglov, 2016/03/04 21:49:30]

annotationMap ??= new HashMap<int, List<ElementAnnotation>>(); would be a bit
more compact.

[Brian Wilkerson, 2016/03/07 16:20:28]

Done

+    }
+    annotationMap[offset] = annotations;
+  }
+
   @override
   void visitChildren(ElementVisitor visitor) {
     super.visitChildren(visitor);
@@ -1274,6 +1304,7 @@ class ConstructorElementImpl extends ExecutableElementImpl
   /**
    * The constructor to which this constructor is redirecting.
    */
+  @override

[Paul Berry, 2016/03/04 22:02:11]

Normally I am ok with rolling this sort of clean-up into an unrelated CL like
this, but since we are likely to want to try cherry-picking this CL over to the
stable release candidate, I think we should keep it as small as possible to
reduce the risk of merge conflicts.

[Brian Wilkerson, 2016/03/07 16:20:28]

Not sure it didn't take more time to remove them, but it's done.

   ConstructorElement redirectedConstructor;
 
   /**
@@ -1285,12 +1316,14 @@ class ConstructorElementImpl extends ExecutableElementImpl
   /**
    * The offset of the `.` before this constructor name or `null` if not named.
    */
+  @override
   int periodOffset;
 
   /**
    * Return the offset of the character immediately following the last character
    * of this constructor's name, or `null` if not named.
    */
+  @override
   int nameEnd;
 
   /**
@@ -1594,6 +1627,7 @@ class ElementAnnotationImpl implements ElementAnnotation {
    * The element representing the field, variable, or constructor being used as
    * an annotation.
    */
+  @override
   Element element;
 
   /**
@@ -1679,6 +1713,7 @@ abstract class ElementImpl implements Element {
 
   static int _NEXT_ID = 0;
 
+  @override
   final int id = _NEXT_ID++;
 
   /**
@@ -1706,6 +1741,7 @@ abstract class ElementImpl implements Element {
   /**
    * A list containing all of the metadata associated with this element.
    */
+  @override
   List<ElementAnnotation> metadata = ElementAnnotation.EMPTY_LIST;
 
   /**
@@ -2303,11 +2339,13 @@ abstract class ExecutableElementImpl extends ElementImpl
   /**
    * The return type defined by this executable element.
    */
+  @override
   DartType returnType;
 
   /**
    * The type of function defined by this executable element.
    */
+  @override
   FunctionType type;
 
   /**
@@ -2535,12 +2573,14 @@ class ExportElementImpl extends UriReferencedElementImpl
   /**
    * The library that is exported from this library by this export directive.
    */
+  @override
   LibraryElement exportedLibrary;
 
   /**
    * The combinators that were specified as part of the export directive in the
    * order in which they were specified.
    */
+  @override
   List<NamespaceCombinator> combinators = NamespaceCombinator.EMPTY_LIST;
 
   /**
@@ -2619,6 +2659,7 @@ class FieldFormalParameterElementImpl extends ParameterElementImpl
   /**
    * The field associated with this field formal parameter.
    */
+  @override
   FieldElement field;
 
   /**
@@ -2773,11 +2814,13 @@ class FunctionTypeAliasElementImpl extends ElementImpl
   /**
    * The return type defined by this type alias.
    */
+  @override
   DartType returnType;
 
   /**
    * The type of function defined by this type alias.
    */
+  @override
   FunctionType type;
 
   /**
@@ -2908,6 +2951,7 @@ class HideElementCombinatorImpl implements HideElementCombinator {
    * The names that are not to be made visible in the importing library even if
    * they are defined in the imported library.
    */
+  @override
   List<String> hiddenNames = StringUtilities.EMPTY_ARRAY;
 
   @override
@@ -2934,23 +2978,27 @@ class ImportElementImpl extends UriReferencedElementImpl
    * The offset of the prefix of this import in the file that contains the this
    * import directive, or `-1` if this import is synthetic.
    */
+  @override
   int prefixOffset = 0;
 
   /**
    * The library that is imported into this library by this import directive.
    */
+  @override
   LibraryElement importedLibrary;
 
   /**
    * The combinators that were specified as part of the import directive in the
    * order in which they were specified.
    */
+  @override
   List<NamespaceCombinator> combinators = NamespaceCombinator.EMPTY_LIST;
 
   /**
    * The prefix that was specified as part of the import directive, or `null` if
    * there was no prefix specified.
    */
+  @override
   PrefixElement prefix;
 
   /**
@@ -3058,6 +3106,7 @@ class LibraryElementImpl extends ElementImpl implements LibraryElement {
   /**
    * The analysis context in which this library is defined.
    */
+  @override
   final AnalysisContext context;
 
   /**
@@ -3069,6 +3118,7 @@ class LibraryElementImpl extends ElementImpl implements LibraryElement {
    * The entry point for this library, or `null` if this library does not have
    * an entry point.
    */
+  @override
   FunctionElement entryPoint;
 
   /**
@@ -3939,11 +3989,13 @@ class MultiplyDefinedElementImpl implements MultiplyDefinedElement {
   /**
    * The unique integer identifier of this element.
    */
+  @override
   final int id = ElementImpl._NEXT_ID++;
 
   /**
    * The analysis context in which the multiply defined elements are defined.
    */
+  @override
   final AnalysisContext context;
 
   /**
@@ -3954,6 +4006,7 @@ class MultiplyDefinedElementImpl implements MultiplyDefinedElement {
   /**
    * A list containing all of the elements that conflict.
    */
+  @override
   final List<Element> conflictingElements;
 
   /**
@@ -4201,6 +4254,7 @@ class ParameterElementImpl extends VariableElementImpl
   /**
    * The kind of this parameter.
    */
+  @override
   ParameterKind parameterKind;
 
   /**
@@ -4420,6 +4474,7 @@ class PropertyAccessorElementImpl extends ExecutableElementImpl
   /**
    * The variable associated with this accessor.
    */
+  @override
   PropertyInducingElement variable;
 
   /**
@@ -4562,6 +4617,7 @@ abstract class PropertyInducingElementImpl extends VariableElementImpl
   /**
    * The getter associated with this element.
    */
+  @override
   PropertyAccessorElement getter;
 
   /**
@@ -4569,12 +4625,14 @@ abstract class PropertyInducingElementImpl extends VariableElementImpl
    * effectively `final` and therefore does not have a setter associated with
    * it.
    */
+  @override
   PropertyAccessorElement setter;
 
   /**
    * The propagated type of this variable, or `null` if type propagation has not
    * been performed.
    */
+  @override
   DartType propagatedType;
 
   /**
@@ -4597,17 +4655,20 @@ class ShowElementCombinatorImpl implements ShowElementCombinator {
    * The names that are to be made visible in the importing library if they are
    * defined in the imported library.
    */
+  @override
   List<String> shownNames = StringUtilities.EMPTY_ARRAY;
 
   /**
    * The offset of the character immediately following the last character of
    * this node.
    */
+  @override
   int end = -1;
 
   /**
    * The offset of the 'show' keyword of this element.
    */
+  @override
   int offset = 0;
 
   @override
@@ -4664,12 +4725,14 @@ class TypeParameterElementImpl extends ElementImpl
   /**
    * The type defined by this type parameter.
    */
+  @override
   TypeParameterType type;
 
   /**
    * The type representing the bound associated with this parameter, or `null`
    * if this parameter does not have an explicit bound.
    */
+  @override
   DartType bound;
 
   /**
@@ -4715,17 +4778,20 @@ abstract class UriReferencedElementImpl extends ElementImpl
   /**
    * The offset of the URI in the file, may be `-1` if synthetic.
    */
+  @override
   int uriOffset = -1;
 
   /**
    * The offset of the character immediately following the last character of
    * this node's URI, may be `-1` if synthetic.
    */
+  @override
   int uriEnd = -1;
 
   /**
    * The URI that is specified by this directive.
    */
+  @override
   String uri;
 
   /**
@@ -4743,6 +4809,7 @@ abstract class VariableElementImpl extends ElementImpl
   /**
    * The declared type of this variable.
    */
+  @override
   DartType type;
 
   /**