Index: clang/lib/CodeGen/CGStmt.cpp
===================================================================
--- clang/lib/CodeGen/CGStmt.cpp
+++ clang/lib/CodeGen/CGStmt.cpp
@@ -426,7 +426,7 @@
     llvm_unreachable("target parallel loop directive not supported yet.");
     break;
   case Stmt::OMPParallelMaskedDirectiveClass:
-    llvm_unreachable("parallel masked directive not supported yet.");
+    CGM.ErrorUnsupported(S, "directive");
     break;
   }
 }