+ # Some of these niche implementations use copy/paste, double-check...
+ test -n "$verbose" && echo " checking if _POSIX_C_SOURCE inteferes" 1>&6
+
+echo "${as_me:-configure}:5373: testing checking if _POSIX_C_SOURCE inteferes ..." 1>&5
+
+ cat >"conftest.$ac_ext" <<_ACEOF
+#line 5376 "configure"
+#include "confdefs.h"
+
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+
+int
+main (void)
+{
+
+#ifndef _XOPEN_SOURCE
+make an error
+#endif
+
+ ;
+ return 0;
+}
+_ACEOF
+rm -f "conftest.$ac_objext"
+if { (eval echo "$as_me:5396: \"$ac_compile\"") >&5
+ (eval $ac_compile) 2>&5
+ ac_status=$?
+ echo "$as_me:5399: \$? = $ac_status" >&5
+ (exit "$ac_status"); } &&
+ { ac_try='test -s "conftest.$ac_objext"'
+ { (eval echo "$as_me:5402: \"$ac_try\"") >&5
+ (eval $ac_try) 2>&5
+ ac_status=$?
+ echo "$as_me:5405: \$? = $ac_status" >&5
+ (exit "$ac_status"); }; }; then
+ :
+else
+ echo "$as_me: failed program was:" >&5
+cat "conftest.$ac_ext" >&5
+
+ { echo "$as_me:5412: WARNING: _POSIX_C_SOURCE definition is not usable" >&5
+echo "$as_me: WARNING: _POSIX_C_SOURCE definition is not usable" >&2;}
+ CPPFLAGS="$cf_save_xopen_cppflags"
+fi
+rm -f "conftest.$ac_objext" "conftest.$ac_ext"