Snap for 4485699 from 247b304cfa05df0252fef1932b6fde8cc7aff9eb to oc-m2-release

Change-Id: Ic2de4a29bdd58a07f5c658d163f2ac014ed38147
diff --git a/generateCpp.cpp b/generateCpp.cpp
index eee5412..158402f 100644
--- a/generateCpp.cpp
+++ b/generateCpp.cpp
@@ -1672,6 +1672,10 @@
 
         out.indent();
 
+        out << "bool _hidl_is_oneway = _hidl_flags & ::android::hardware::IBinder::FLAG_ONEWAY;\n";
+        out << "if (_hidl_is_oneway != " << (method->isOneway() ? "true" : "false") << ") ";
+        out.block([&] { out << "return ::android::UNKNOWN_ERROR;\n"; }).endl().endl();
+
         status_t err = generateStubSourceForMethod(out, method, superInterface);
 
         if (err != OK) {