Index: wasm/WriterUtils.cpp
===================================================================
--- wasm/WriterUtils.cpp
+++ wasm/WriterUtils.cpp
@@ -174,6 +174,8 @@
     return "F32";
   case ValType::F64:
     return "F64";
+  case ValType::EXCEPT_REF:
+    return "except_ref";
   }
   llvm_unreachable("Invalid wasm::ValType");
 }