+
+ dnl Check for declarations of anything we want to poison if the
+ dnl corresponding gnulib module is not in use.
+ gl_WARN_ON_USE_PREPARE([[#include <locale.h>
+/* Some systems provide declarations in a non-standard header. */
+#if HAVE_XLOCALE_H
+# include <xlocale.h>
+#endif
+ ]], [duplocale])