--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/clang/test/PCH/pragma-optimize.c	Thu Feb 13 15:10:13 2020 +0900
@@ -0,0 +1,33 @@
+// Test this without pch.
+// RUN: %clang_cc1 %s -include %s -verify -fsyntax-only
+
+// Test with pch.
+// RUN: %clang_cc1 %s -emit-pch -o %t
+// RUN: %clang_cc1 %s -emit-llvm -include-pch %t -o - | FileCheck %s
+
+// The first run line creates a pch, and since at that point HEADER is not
+// defined, the only thing contained in the pch is the pragma. The second line
+// then includes that pch, so HEADER is defined and the actual code is compiled.
+// The check then makes sure that the pragma is in effect in the file that
+// includes the pch.
+
+// expected-no-diagnostics
+
+#ifndef HEADER
+#define HEADER
+#pragma clang optimize off
+
+#else
+
+int a;
+
+void f() {
+  a = 12345;
+}
+
+// Check that the function is decorated with optnone
+
+// CHECK-DAG: @f() [[ATTRF:#[0-9]+]]
+// CHECK-DAG: attributes [[ATTRF]] = { {{.*}}noinline{{.*}}optnone{{.*}} }
+
+#endif