--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/clang/test/Sema/pragma-pack-2.c	Thu Feb 13 15:10:13 2020 +0900
@@ -0,0 +1,60 @@
+// RUN: %clang_cc1 -triple i686-apple-darwin9 %s -fsyntax-only -verify
+// expected-no-diagnostics
+
+#include <stddef.h>
+
+#pragma pack(4)
+
+// Baseline
+struct s0 {
+  char f0;
+  int  f1;
+};
+extern int a0[offsetof(struct s0, f1) == 4 ? 1 : -1];
+
+#pragma pack(push, 2)
+struct s1 {
+  char f0;
+  int  f1;
+};
+extern int a1[offsetof(struct s1, f1) == 2 ? 1 : -1];
+#pragma pack(pop)
+
+#pragma pack(1)
+struct s3_0 {
+  char f0;
+  int f1;
+};
+#pragma pack()
+struct s3_1 {
+  char f0;
+  int f1;
+};
+extern int a3_0[offsetof(struct s3_0, f1) == 1 ? 1 : -1];
+extern int a3_1[offsetof(struct s3_1, f1) == 4 ? 1 : -1];
+
+// pack(0) is like pack()
+#pragma pack(1)
+struct s4_0 {
+  char f0;
+  int f1;
+};
+#pragma pack(0)
+struct s4_1 {
+  char f0;
+  int f1;
+};
+extern int a4_0[offsetof(struct s4_0, f1) == 1 ? 1 : -1];
+extern int a4_1[offsetof(struct s4_1, f1) == 4 ? 1 : -1];
+
+void f() {
+  #pragma pack(push, 2)
+  struct s5_0 {
+    char f0;
+    struct s2_4_0 { 
+      int f0;
+    } f1;
+  };
+  #pragma pack(pop)
+  extern int s5_0[offsetof(struct s5_0, f1) == 2 ? 1 : -1];
+}