+#if ! HAVE_ISWCNTRL
+
+/* IRIX 5.3 has macros but no functions, its isw* macros refer to an
+ undefined variable _ctmp_ and to <ctype.h> macros like _P, and they
+ refer to system functions like _iswctype that are not in the
+ standard C library. Rather than try to get ancient buggy
+ implementations like this to work, just disable them. */
+# undef iswalnum
+# undef iswalpha
+# undef iswblank
+# undef iswcntrl
+# undef iswdigit
+# undef iswgraph
+# undef iswlower
+# undef iswprint
+# undef iswpunct
+# undef iswspace
+# undef iswupper
+# undef iswxdigit