# error "Must #define __STDC_LIMIT_MACROS before #including Support/DataTypes.h"
#endif
+#if !defined(__STDC_CONSTANT_MACROS)
+# error "Must #define __STDC_CONSTANT_MACROS before " \
+ "#including Support/DataTypes.h"
+#endif
+
// Note that <inttypes.h> includes <stdint.h>, if this is a C99 system.
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>