Improve 'length' instance property reference encoding.

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

Index: pkg/analyzer/lib/src/summary/summarize_const_expr.dart
diff --git a/pkg/analyzer/lib/src/summary/summarize_const_expr.dart b/pkg/analyzer/lib/src/summary/summarize_const_expr.dart
index 771dac90b84f242de15f7f772218944283e3528c..b238fdf6328f4c6d53ff62df599fe837767b576b 100644
--- a/pkg/analyzer/lib/src/summary/summarize_const_expr.dart
+++ b/pkg/analyzer/lib/src/summary/summarize_const_expr.dart
@@ -93,9 +93,7 @@ abstract class AbstractConstExprSerializer {
     } else if (expr is PrefixExpression) {
       _serializePrefixExpression(expr);
     } else if (expr is PropertyAccess) {
-      // TODO(scheglov) solve ambiguity of `a.b.length` where `a` and `b` are
-      // identifiers
-      if (expr.propertyName.name == 'length') {
+      if (expr.target is StringLiteral && expr.propertyName.name == 'length') {

[Paul Berry, 2016/01/27 16:48:59]

I think this should be:

    if (expr.target is! PrefixedIdentifier && expr.propertyName.name ==
'length')

That way we correctly handle cases like:

    const x = ('abc' + 'def').length;

and:

    const x = ('abc').length;

[scheglov, 2016/01/27 17:55:10]

Done.

         serialize(expr.target);
         operations.add(UnlinkedConstOperation.length);
       } else {
@@ -110,6 +108,11 @@ abstract class AbstractConstExprSerializer {
   }
 
   /**
+   * Return [EntityRefBuilder] that corresponds to the given [constructor].
+   */
+  EntityRefBuilder serializeConstructorName(ConstructorName constructor);
+
+  /**
    * Return [EntityRefBuilder] that corresponds to the given [identifier].
    */
   EntityRefBuilder serializeIdentifier(Identifier identifier);
@@ -125,11 +128,6 @@ abstract class AbstractConstExprSerializer {
   EntityRefBuilder serializeType(TypeName type);
 
   /**
-   * Return [EntityRefBuilder] that corresponds to the given [constructor].
-   */
-  EntityRefBuilder serializeConstructorName(ConstructorName constructor);
-
-  /**
    * Return the [UnlinkedConstBuilder] that corresponds to the state of this
    * serializer.
    */