Deferred loading track type-dependencies for is, as and type-annotations.

pkg/compiler/lib/src/resolution/tree_elements.dart

 // Copyright (c) 2015, 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.
 
 part of resolution;
 
 abstract class TreeElements {
   AnalyzableElement get analyzedElement;
   Iterable<Node> get superUses;
 
   /// Iterables of the dependencies that this [TreeElement] records of
   /// [analyzedElement].
   Iterable<Element> get allElements;
 
+  /// The set of types that this TreeElement depends on.
+  /// This includes instantiated types, types in is-checks and as-expressions
+  /// and in checked mode the types of all type-annotations.
+  Iterable<DartType> get requiredTypes;
+
   void forEachConstantNode(f(Node n, ConstantExpression c));
-  void forEachType(f(Node n, DartType t));
 
   /// A set of additional dependencies.  See [registerDependency] below.
   Iterable<Element> get otherDependencies;
 
   Element operator[](Node node);
 
   SendStructure getSendStructure(Send send);
 
   // TODO(johnniwinther): Investigate whether [Node] could be a [Send].
   Selector getSelector(Node node);
@@ skipping 37 matching lines @@
    */
   bool isTypeLiteral(Send node);
 
   /// Returns the type that the type literal [node] refers to.
   DartType getTypeLiteralType(Send node);
 
   /// Register additional dependencies required by [analyzedElement].
   /// For example, elements that are used by a backend.
   void registerDependency(Element element);
 
+  /// Register a dependency on [type].
+  void addRequiredType(DartType type);
+
   /// Returns a list of nodes that potentially mutate [element] anywhere in its
   /// scope.
   List<Node> getPotentialMutations(VariableElement element);
 
   /// Returns a list of nodes that potentially mutate [element] in [node].
   List<Node> getPotentialMutationsIn(Node node, VariableElement element);
 
   /// Returns a list of nodes that potentially mutate [element] in a closure.
   List<Node> getPotentialMutationsInClosure(VariableElement element);
 
@@ skipping 21 matching lines @@
   Setlet<Node> _superUses;
   Setlet<Element> _otherDependencies;
   Map<Node, ConstantExpression> _constants;
   Map<VariableElement, List<Node>> _potentiallyMutated;
   Map<Node, Map<VariableElement, List<Node>>> _potentiallyMutatedIn;
   Map<VariableElement, List<Node>> _potentiallyMutatedInClosure;
   Map<Node, Map<VariableElement, List<Node>>> _accessedByClosureIn;
   Setlet<Element> _elements;
   Setlet<Send> _asserts;
   Maplet<Send, SendStructure> _sendStructureMap;
+  Setlet<DartType> _requiredTypes;
 
   /// Map from nodes to the targets they define.
   Map<Node, JumpTarget> _definedTargets;
 
   /// Map from goto statements to their targets.
   Map<GotoStatement, JumpTarget> _usedTargets;
 
   /// Map from labels to their label definition.
   Map<Label, LabelDefinition> _definedLabels;
 
@@ skipping 43 matching lines @@
 
   void setType(Node node, DartType type) {
     if (_types == null) {
       _types = new Maplet<Node, DartType>();
     }
     _types[node] = type;
   }
 
   DartType getType(Node node) => _types != null ? _types[node] : null;
 
-  void forEachType(f(Node n, DartType t)) {
-    if (_types != null) {
-      _types.forEach(f);
+  void addRequiredType(DartType type) {
+    if (_requiredTypes == null) _requiredTypes = new Setlet<DartType>();
+    _requiredTypes.add(type);
+  }
+
+  Iterable<DartType> get requiredTypes {
+    if (_requiredTypes == null) {
+      return const <DartType>[];
+    } else {
+      return _requiredTypes;
     }
   }
 
   Iterable<Node> get superUses {
     return _superUses != null ? _superUses : const <Node>[];
   }
 
   void addSuperUse(Node node) {
     if (_superUses == null) {
       _superUses = new Setlet<Node>();
@@ skipping 343 matching lines @@
   TreeElements get treeElements {
     assert(invariant(this, _treeElements !=null,
         message: "TreeElements have not been computed for $this."));
     return _treeElements;
   }
 
   void reuseElement() {
     _treeElements = null;
   }
 }