+#include "verify.h"
+
+/* Check that EXIT_SUCCESS is 0, per POSIX. */
+static int exitcode = EXIT_SUCCESS;
+#if EXIT_SUCCESS
+"oops"
+#endif
+
+/* Check for GNU value (not guaranteed by POSIX, but is guaranteed by
+ gnulib). */
+#if EXIT_FAILURE != 1
+"oops"
+#endif
+
+/* Check that NULL can be passed through varargs as a pointer type,
+ per POSIX 2008. */
+verify (sizeof NULL == sizeof (void *));
+
+#if GNULIB_TEST_SYSTEM_POSIX
+# include "test-sys_wait.h"
+#else
+# define test_sys_wait_macros() 0
+#endif