- AC_CACHE_CHECK([whether wcwidth is declared], ac_cv_have_decl_wcwidth,
- [AC_TRY_COMPILE([
-/* AIX 3.2.5 declares wcwidth in <string.h>. */
-#if HAVE_STRING_H
-# include <string.h>
-#endif
-#if HAVE_WCHAR_H
-# include <wchar.h>
-#endif
-], [
-#ifndef wcwidth
- char *p = (char *) wcwidth;
-#endif
-], ac_cv_have_decl_wcwidth=yes, ac_cv_have_decl_wcwidth=no)])
- if test $ac_cv_have_decl_wcwidth = yes; then
+ dnl UnixWare 7.1.1 <wchar.h> has a declaration of a function mbswidth()
+ dnl that clashes with ours.
+ AC_CACHE_CHECK([whether mbswidth is declared in <wchar.h>],
+ [ac_cv_have_decl_mbswidth],
+ [AC_COMPILE_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[
+/* 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>. */
+#include <stddef.h>
+#include <stdio.h>
+#include <time.h>
+#include <wchar.h>
+ ]],
+ [[
+ char *p = (char *) mbswidth;
+ return !p;
+ ]])],
+ [ac_cv_have_decl_mbswidth=yes],
+ [ac_cv_have_decl_mbswidth=no])])
+ if test $ac_cv_have_decl_mbswidth = yes; then