--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Attr.java	Fri Jun 28 05:29:54 2019 +0800
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Attr.java	Thu Jun 27 10:39:27 2019 +0200
@@ -1447,6 +1447,9 @@
         if (tree.cases.isEmpty()) {
             log.error(tree.pos(),
                       Errors.SwitchExpressionEmpty);
+        } else if (caseTypes.isEmpty()) {
+            log.error(tree.pos(),
+                      Errors.SwitchExpressionNoResultExpressions);
         }
 
         Type owntype = (tree.polyKind == PolyKind.STANDALONE) ? condType(caseTypePositions.toList(), caseTypes.toList()) : pt();