+
+ 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([[
+/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be included before
+ <wchar.h>.
+ BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h> must be
+ included before <wchar.h>. */
+#if !(defined __GLIBC__ && !defined __UCLIBC__)
+# include <stddef.h>
+# include <stdio.h>
+# include <time.h>
+# include <wchar.h>
+#endif
+#include <wctype.h>
+ ]],
+ [wctype iswctype wctrans towctrans
+ ])