--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/clang/test/Sema/mms-bitfields.c	Thu Feb 13 15:10:13 2020 +0900
@@ -0,0 +1,28 @@
+// RUN: %clang_cc1 -mms-bitfields -fsyntax-only -verify -triple x86_64-apple-darwin9 %s
+// expected-no-diagnostics
+
+// The -mms-bitfields commandline parameter should behave the same
+// as the ms_struct attribute.
+struct
+{
+   int a : 1;
+   short b : 1;
+} t;
+
+// MS pads out bitfields between different types.
+static int arr[(sizeof(t) == 8) ? 1 : -1];
+
+#pragma pack (push,1)
+
+typedef unsigned int UINT32;
+
+struct Inner {
+  UINT32    A    :  1;
+  UINT32    B    :  1;
+  UINT32    C    :  1;
+  UINT32    D    : 30;
+} Inner;
+
+#pragma pack (pop)
+
+static int arr2[(sizeof(Inner) == 8) ? 1 : -1];