First steps toward AST-based type inference involving closures.

pkg/analyzer/lib/src/summary/summarize_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.
 
 library serialization.elements;
 
 import 'dart:convert';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart';
@@ skipping 501 matching lines @@
   /**
    * Serialize annotations from the given [element].  If [element] has no
    * annotations, the empty list is returned.
    */
   List<UnlinkedConstBuilder> serializeAnnotations(Element element) {
     if (element.metadata.isEmpty) {
       return const <UnlinkedConstBuilder>[];
     }
     return element.metadata.map((ElementAnnotation a) {
       _ConstExprSerializer serializer =
-          new _ConstExprSerializer(this, element, null);
+          new _ConstExprSerializer(this, element, null, null);
       serializer
           .serializeAnnotation((a as ElementAnnotationImpl).annotationAst);
       return serializer.toBuilder();
     }).toList();
   }
 
   /**
    * Return the index of the entry in the references table
    * ([LinkedLibrary.references]) used for the "bottom" type.  A new entry is
    * added to the table if necessary to satisfy the request.
@@ skipping 124 matching lines @@
       b.end = combinator.end;
     } else if (combinator is HideElementCombinator) {
       b.hides = combinator.hiddenNames;
     }
     return b;
   }
 
   /**
    * Serialize the given [expression], creating an [UnlinkedConstBuilder].
    */
-  UnlinkedConstBuilder serializeConstExpr(
-      Element context, Expression expression,
+  UnlinkedConstBuilder serializeConstExpr(Element context,
+      ExecutableElement executableContext, Expression expression,
       [Set<String> constructorParameterNames]) {
-    _ConstExprSerializer serializer =
-        new _ConstExprSerializer(this, context, constructorParameterNames);
+    _ConstExprSerializer serializer = new _ConstExprSerializer(
+        this, context, executableContext, constructorParameterNames);
     serializer.serialize(expression);
     return serializer.toBuilder();
   }
 
   /**
    * Serialize documentation from the given [element], creating an
    * [UnlinkedDocumentationComment].
    *
    * If [element] has no documentation, `null` is returned.
    */
@@ skipping 94 matching lines @@
       }
       if (executableElement.isConst) {
         b.constCycleSlot = storeConstCycle(!executableElement.isCycleFree);
         if (executableElement.constantInitializers != null) {
           Set<String> constructorParameterNames =
               executableElement.parameters.map((p) => p.name).toSet();
           b.constantInitializers = executableElement.constantInitializers
               .map((ConstructorInitializer initializer) =>
                   serializeConstructorInitializer(
                       initializer,
-                      (expr) => serializeConstExpr(
+                      (expr) => serializeConstExpr(executableElement,
                           executableElement, expr, constructorParameterNames)))
               .toList();
         }
       }
     } else {
       b.kind = UnlinkedExecutableKind.functionOrMethod;
     }
     b.isAbstract = executableElement.isAbstract;
     b.isAsynchronous = executableElement.isAsynchronous;
     b.isGenerator = executableElement.isGenerator;
@@ skipping 119 matching lines @@
             .map((parameter) => serializeParam(parameter, context))
             .toList();
       } else {
         b.type = serializeTypeRef(type, context);
       }
     }
     if (parameter is ConstVariableElement) {
       ConstVariableElement constParameter = parameter as ConstVariableElement;
       Expression initializer = constParameter.constantInitializer;
       if (initializer != null) {
-        b.defaultValue = serializeConstExpr(parameter, initializer);
+        b.defaultValue = serializeConstExpr(
+            parameter,
+            parameter.getAncestor((Element e) => e is ExecutableElement),
+            initializer);
         b.defaultValueCode = parameter.defaultValueCode;
       }
     }
     // TODO(scheglov) VariableMember.initializer is not implemented
     if (parameter is! VariableMember && parameter.initializer != null) {
       b.initializer = serializeExecutable(parameter.initializer);
     }
     {
       SourceRange visibleRange = parameter.visibleRange;
       if (visibleRange != null) {
@@ skipping 190 matching lines @@
     }
     b.isStatic = variable.isStatic && variable.enclosingElement is ClassElement;
     b.isFinal = variable.isFinal;
     b.isConst = variable.isConst;
     b.documentationComment = serializeDocumentation(variable);
     b.annotations = serializeAnnotations(variable);
     if (variable is ConstVariableElement) {
       ConstVariableElement constVariable = variable as ConstVariableElement;
       Expression initializer = constVariable.constantInitializer;
       if (initializer != null) {
-        b.constExpr = serializeConstExpr(variable, initializer);
+        b.constExpr =
+            serializeConstExpr(variable, variable.initializer, initializer);
       }
     }
     if (variable is PropertyInducingElement) {
       if (b.isFinal || b.isConst) {
         b.propagatedTypeSlot =
             storeLinkedType(variable.propagatedType, variable);
       } else {
         // Variable is not propagable.
         assert(variable.propagatedType == null);
       }
@@ skipping 139 matching lines @@
   }
 }
 
 /**
  * Instances of this class keep track of intermediate state during
  * serialization of a single constant [Expression].
  */
 class _ConstExprSerializer extends AbstractConstExprSerializer {
   final _CompilationUnitSerializer serializer;
   final Element context;
+  final ExecutableElement executableContext;
 
   /**
    * If a constructor initializer expression is being serialized, the names of
    * the constructor parameters.  Otherwise `null`.
    */
   final Set<String> constructorParameterNames;
 
-  _ConstExprSerializer(
-      this.serializer, this.context, this.constructorParameterNames);
+  _ConstExprSerializer(this.serializer, this.context, this.executableContext,
+      this.constructorParameterNames);
 
   @override
   bool isConstructorParameterName(String name) {
     return constructorParameterNames?.contains(name) ?? false;
   }
 
   @override
   void serializeAnnotation(Annotation annotation) {
     if (annotation.arguments == null) {
       assert(annotation.constructorName == null);
@@ skipping 40 matching lines @@
           name.staticElement != null
               ? ReferenceKind.constructor
               : ReferenceKind.unresolved,
           prefixReference: typeRef.reference,
           unit: typeLinkedRef.unit);
       return new EntityRefBuilder(
           reference: refId, typeArguments: typeRef.typeArguments);
     }
   }
 
+  @override
+  List<int> serializeFunctionExpression(FunctionExpression functionExpression) {
+    if (executableContext == null) {
+      return null;
+    }
+    ExecutableElement functionElement = functionExpression.element;
+    // TOOD(paulberry): handle the situation where [functionExpression] is not
+    // an immediate child of [executableContext].
+    assert(functionElement.enclosingElement == executableContext);
+    int popCount = 0;
+    int localIndex = executableContext.functions.indexOf(functionElement);
+    assert(localIndex != -1);
+    return <int>[popCount, localIndex];
+  }
+
   EntityRefBuilder serializeIdentifier(Identifier identifier,
       {int prefixReference: 0}) {
     if (identifier is SimpleIdentifier) {
       Element element = identifier.staticElement;
       if (element is TypeParameterElement) {
         int typeParameterIndex =
             serializer.findTypeParameterIndex(element.type, context);
         return new EntityRefBuilder(paramReference: typeParameterIndex);
       } else if (_isPrelinkResolvableElement(element)) {
         int ref = serializer._getElementReferenceId(element);
@@ skipping 279 matching lines @@
       exportNames.add(new LinkedExportNameBuilder(
           name: name,
           dependency: serializeDependency(dependentLibrary),
           unit: unit,
           kind: kind));
     }
     pb.exportNames = exportNames;
     return pb;
   }
 }