Support for AwaitExpression in unlinked expressions.

pkg/analyzer/lib/src/summary/link.dart

Index: pkg/analyzer/lib/src/summary/link.dart
diff --git a/pkg/analyzer/lib/src/summary/link.dart b/pkg/analyzer/lib/src/summary/link.dart
index 7bfbed1de4168e81c39c01b1e95a1538e8de67d5..5c8aff672d2ba7c76eceb4a78d21bfab2083421e 100644
--- a/pkg/analyzer/lib/src/summary/link.dart
+++ b/pkg/analyzer/lib/src/summary/link.dart
@@ -2228,6 +2228,9 @@ class ExprTypeComputer {
         case UnlinkedExprOperation.assignToIndex:
           _doAssignToIndex();
           break;
+        case UnlinkedExprOperation.await:
+          _doAwait();
+          break;
         case UnlinkedExprOperation.extractIndex:
           _doExtractIndex();
           break;
@@ -2363,6 +2366,14 @@ class ExprTypeComputer {
     }
   }
 
+  void _doAwait() {
+    DartType type = stack.removeLast();
+    DartType typeArgument = linker.typeSystem
+        .mostSpecificTypeArgument(type, linker.typeProvider.futureType);
+    typeArgument = _dynamicIfNull(typeArgument);
+    stack.add(typeArgument);

[Paul Berry, 2016/11/29 19:15:57]

Do we need to flatten futures here?  The spec says that the static type of an
await expression is flattened.

[scheglov, 2016/11/29 19:39:13]

Done.

+  }
+
   void _doConditional() {
     DartType elseType = stack.removeLast();
     DartType thenType = stack.removeLast();
@@ -3413,10 +3424,10 @@ abstract class LibraryElementForLink<
       _linkedLibrary.importDependencies.map(_getDependency).toList();
 
   @override
-  bool get isDartAsync => _absoluteUri == 'dart:async';
+  bool get isDartAsync => _absoluteUri.toString() == 'dart:async';
 
   @override
-  bool get isDartCore => _absoluteUri == 'dart:core';
+  bool get isDartCore => _absoluteUri.toString() == 'dart:core';
 
   /**
    * If this library is part of the build unit being linked, return the library