Propertly summarize LUB function types.

pkg/analyzer/lib/src/summary/resynthesize.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 summary_resynthesizer;
 
 import 'dart:collection';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
@@ skipping 1638 matching lines @@
       element.setVisibleRange(
           serializedVariable.visibleOffset, serializedVariable.visibleLength);
     }
     buildVariableCommonParts(element, serializedVariable);
     return element;
   }
 
   /**
    * Resynthesize a [ParameterElement].
    */
-  ParameterElement buildParameter(UnlinkedParam serializedParameter) {
+  ParameterElement buildParameter(UnlinkedParam serializedParameter,
+      {bool synthetic: false}) {
     ParameterElementImpl parameterElement;
+    int nameOffset = synthetic ? -1 : serializedParameter.nameOffset;
     if (serializedParameter.isInitializingFormal) {
       FieldFormalParameterElementImpl initializingParameter;
       if (serializedParameter.kind == UnlinkedParamKind.required) {
         initializingParameter = new FieldFormalParameterElementImpl(
-            serializedParameter.name, serializedParameter.nameOffset);
+            serializedParameter.name, nameOffset);
       } else {
         DefaultFieldFormalParameterElementImpl defaultParameter =
             new DefaultFieldFormalParameterElementImpl(
-                serializedParameter.name, serializedParameter.nameOffset);
+                serializedParameter.name, nameOffset);
         initializingParameter = defaultParameter;
         if (serializedParameter.defaultValue != null) {
           defaultParameter.constantInitializer =
               _buildConstExpression(serializedParameter.defaultValue);
           defaultParameter.defaultValueCode =
               serializedParameter.defaultValueCode;
         }
       }
       parameterElement = initializingParameter;
       initializingParameter.field = fields[serializedParameter.name];
     } else {
       if (serializedParameter.kind == UnlinkedParamKind.required) {
-        parameterElement = new ParameterElementImpl(
-            serializedParameter.name, serializedParameter.nameOffset);
+        parameterElement =
+            new ParameterElementImpl(serializedParameter.name, nameOffset);
       } else {
         DefaultParameterElementImpl defaultParameter =
             new DefaultParameterElementImpl(
-                serializedParameter.name, serializedParameter.nameOffset);
+                serializedParameter.name, nameOffset);
         parameterElement = defaultParameter;
         if (serializedParameter.defaultValue != null) {
           defaultParameter.constantInitializer =
               _buildConstExpression(serializedParameter.defaultValue);
           defaultParameter.defaultValueCode =
               serializedParameter.defaultValueCode;
         }
       }
     }
+    parameterElement.synthetic = synthetic;
     buildAnnotations(parameterElement, serializedParameter.annotations);
     if (serializedParameter.isFunctionTyped) {
       FunctionElementImpl parameterTypeElement =
           new FunctionElementImpl('', -1);
       parameterTypeElement.synthetic = true;
       parameterElement.parameters =
           serializedParameter.parameters.map(buildParameter).toList();
       parameterTypeElement.enclosingElement = parameterElement;
       parameterTypeElement.shareParameters(parameterElement.parameters);
       parameterTypeElement.returnType = buildType(serializedParameter.type);
@@ skipping 70 matching lines @@
   DartType buildType(EntityRef type, {bool defaultVoid: false}) {
     if (type == null) {
       if (defaultVoid) {
         return VoidTypeImpl.instance;
       } else {
         return summaryResynthesizer.typeProvider.dynamicType;
       }
     }
     if (type.paramReference != 0) {
       return getTypeParameterFromScope(type.paramReference);
+    } else if (type.syntheticReturnType != null) {
+      FunctionElementImpl element = new FunctionElementImpl('', -1);
+      element.synthetic = true;
+      element.parameters = type.syntheticParams
+          .map((UnlinkedParam param) => buildParameter(param, synthetic: true))
+          .toList();
+      element.returnType = buildType(type.syntheticReturnType);
+      FunctionTypeImpl result = new FunctionTypeImpl.elementWithNameAndArgs(
+          element, null, null, false);
+      element.type = result;
+      return result;
     } else {
       DartType getTypeArgument(int i) {
         if (i < type.typeArguments.length) {
           return buildType(type.typeArguments[i]);
         } else {
           return summaryResynthesizer.typeProvider.dynamicType;
         }
       }
       _ReferenceInfo referenceInfo = referenceInfos[type.reference];
       return referenceInfo.buildType(
@@ skipping 635 matching lines @@
     List<DartType> typeArguments = const <DartType>[];
     if (numTypeArguments != 0) {
       typeArguments = <DartType>[];
       for (int i = 0; i < numTypeArguments; i++) {
         typeArguments.add(getTypeArgument(i));
       }
     }
     return typeArguments;
   }
 }