--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/clang/test/Misc/no-warn-in-system-macro.c	Thu Feb 13 15:10:13 2020 +0900
@@ -0,0 +1,18 @@
+// RUN: %clang_cc1 -isystem %S -Wdouble-promotion -fsyntax-only %s  2>&1 | FileCheck -allow-empty %s
+// CHECK-NOT: warning:
+
+#include <no-warn-in-system-macro.c.inc>
+
+#define MACRO(x) x
+
+int main(void)
+{
+	double foo = 1.0;
+
+	if (isnan(foo))
+		return 1;
+
+        MACRO(isnan(foo));
+
+        return 0;
+}