diff --git a/clang/lib/Headers/__clang_cuda_runtime_wrapper.h b/clang/lib/Headers/__clang_cuda_runtime_wrapper.h
--- a/clang/lib/Headers/__clang_cuda_runtime_wrapper.h
+++ b/clang/lib/Headers/__clang_cuda_runtime_wrapper.h
@@ -208,7 +208,13 @@
 // CUDA-9.2 needs host-side memcpy for some host functions in
 // device_functions.hpp
 #if CUDA_VERSION >= 9020
+// string.h needs __THROW to match the rest of the system includes.
+#pragma pop_macro("__THROW")
 #include <string.h>
+// .. but we still need to undef it in order to include other CUDA headers.
+#pragma push_macro("__THROW")
+#undef __THROW
+#define __THROW
 #endif
 #include "crt/math_functions.hpp"
 #else