+(linux*|uclinux*|gnu*|mint*|k*bsd*-gnu|cygwin)
+
+cf_gnu_xopen_source=$cf_XOPEN_SOURCE
+
+echo "$as_me:11016: checking if this is the GNU C library" >&5
+echo $ECHO_N "checking if this is the GNU C library... $ECHO_C" >&6
+if test "${cf_cv_gnu_library+set}" = set; then
+ echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+
+cat >conftest.$ac_ext <<_ACEOF
+#line 11023 "configure"
+#include "confdefs.h"
+#include <sys/types.h>
+int
+main (void)
+{
+
+ #if __GLIBC__ > 0 && __GLIBC_MINOR__ >= 0
+ return 0;
+ #elif __NEWLIB__ > 0 && __NEWLIB_MINOR__ >= 0
+ return 0;
+ #else
+ # error not GNU C library
+ #endif
+ ;
+ return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext
+if { (eval echo "$as_me:11042: \"$ac_compile\"") >&5
+ (eval $ac_compile) 2>&5
+ ac_status=$?
+ echo "$as_me:11045: \$? = $ac_status" >&5
+ (exit $ac_status); } &&
+ { ac_try='test -s conftest.$ac_objext'
+ { (eval echo "$as_me:11048: \"$ac_try\"") >&5
+ (eval $ac_try) 2>&5
+ ac_status=$?
+ echo "$as_me:11051: \$? = $ac_status" >&5
+ (exit $ac_status); }; }; then
+ cf_cv_gnu_library=yes
+else
+ echo "$as_me: failed program was:" >&5
+cat conftest.$ac_ext >&5
+cf_cv_gnu_library=no
+fi
+rm -f conftest.$ac_objext conftest.$ac_ext
+
+fi
+echo "$as_me:11062: result: $cf_cv_gnu_library" >&5
+echo "${ECHO_T}$cf_cv_gnu_library" >&6
+
+if test x$cf_cv_gnu_library = xyes; then
+
+ # With glibc 2.19 (13 years after this check was begun), _DEFAULT_SOURCE
+ # was changed to help a little. newlib incorporated the change about 4
+ # years later.
+ echo "$as_me:11070: checking if _DEFAULT_SOURCE can be used as a basis" >&5
+echo $ECHO_N "checking if _DEFAULT_SOURCE can be used as a basis... $ECHO_C" >&6
+if test "${cf_cv_gnu_library_219+set}" = set; then
+ echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+
+ cf_save="$CPPFLAGS"
+
+ test -n "$CPPFLAGS" && CPPFLAGS="$CPPFLAGS "
+ CPPFLAGS="${CPPFLAGS}-D_DEFAULT_SOURCE"
+
+ cat >conftest.$ac_ext <<_ACEOF
+#line 11082 "configure"
+#include "confdefs.h"
+#include <sys/types.h>
+int
+main (void)
+{
+
+ #if (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 19) || (__GLIBC__ > 2)
+ return 0;
+ #elif (__NEWLIB__ == 2 && __NEWLIB_MINOR__ >= 4) || (__GLIBC__ > 3)
+ return 0;
+ #else
+ # error GNU C library __GLIBC__.__GLIBC_MINOR__ is too old
+ #endif
+ ;
+ return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext
+if { (eval echo "$as_me:11101: \"$ac_compile\"") >&5
+ (eval $ac_compile) 2>&5
+ ac_status=$?
+ echo "$as_me:11104: \$? = $ac_status" >&5
+ (exit $ac_status); } &&
+ { ac_try='test -s conftest.$ac_objext'
+ { (eval echo "$as_me:11107: \"$ac_try\"") >&5
+ (eval $ac_try) 2>&5
+ ac_status=$?
+ echo "$as_me:11110: \$? = $ac_status" >&5
+ (exit $ac_status); }; }; then
+ cf_cv_gnu_library_219=yes
+else
+ echo "$as_me: failed program was:" >&5
+cat conftest.$ac_ext >&5
+cf_cv_gnu_library_219=no
+fi
+rm -f conftest.$ac_objext conftest.$ac_ext
+ CPPFLAGS="$cf_save"
+
+fi
+echo "$as_me:11122: result: $cf_cv_gnu_library_219" >&5
+echo "${ECHO_T}$cf_cv_gnu_library_219" >&6
+
+ if test "x$cf_cv_gnu_library_219" = xyes; then
+ cf_save="$CPPFLAGS"
+ echo "$as_me:11127: checking if _XOPEN_SOURCE=$cf_gnu_xopen_source works with _DEFAULT_SOURCE" >&5
+echo $ECHO_N "checking if _XOPEN_SOURCE=$cf_gnu_xopen_source works with _DEFAULT_SOURCE... $ECHO_C" >&6
+if test "${cf_cv_gnu_dftsrc_219+set}" = set; then
+ echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+
+cf_fix_cppflags=no
+cf_new_cflags=
+cf_new_cppflags=
+cf_new_extra_cppflags=
+
+for cf_add_cflags in -D_DEFAULT_SOURCE -D_XOPEN_SOURCE=$cf_gnu_xopen_source
+do
+case $cf_fix_cppflags in
+(no)
+ case $cf_add_cflags in
+ (-undef|-nostdinc*|-I*|-D*|-U*|-E|-P|-C)
+ case $cf_add_cflags in
+ (-D*)
+ cf_tst_cflags=`echo ${cf_add_cflags} |sed -e 's/^-D[^=]*='\''\"[^"]*//'`
+
+ test "x${cf_add_cflags}" != "x${cf_tst_cflags}" \
+ && test -z "${cf_tst_cflags}" \
+ && cf_fix_cppflags=yes
+
+ if test $cf_fix_cppflags = yes ; then
+
+ test -n "$cf_new_extra_cppflags" && cf_new_extra_cppflags="$cf_new_extra_cppflags "
+ cf_new_extra_cppflags="${cf_new_extra_cppflags}$cf_add_cflags"
+
+ continue
+ elif test "${cf_tst_cflags}" = "\"'" ; then
+
+ test -n "$cf_new_extra_cppflags" && cf_new_extra_cppflags="$cf_new_extra_cppflags "
+ cf_new_extra_cppflags="${cf_new_extra_cppflags}$cf_add_cflags"
+
+ continue
+ fi
+ ;;
+ esac
+ case "$CPPFLAGS" in
+ (*$cf_add_cflags)
+ ;;
+ (*)
+ case $cf_add_cflags in
+ (-D*)
+ cf_tst_cppflags=`echo "x$cf_add_cflags" | sed -e 's/^...//' -e 's/=.*//'`
+
+CPPFLAGS=`echo "$CPPFLAGS" | \
+ sed -e 's/-[UD]'"$cf_tst_cppflags"'\(=[^ ]*\)\?[ ]/ /g' \
+ -e 's/-[UD]'"$cf_tst_cppflags"'\(=[^ ]*\)\?$//g'`
+
+ ;;
+ esac
+
+ test -n "$cf_new_cppflags" && cf_new_cppflags="$cf_new_cppflags "
+ cf_new_cppflags="${cf_new_cppflags}$cf_add_cflags"
+
+ ;;
+ esac
+ ;;
+ (*)
+
+ test -n "$cf_new_cflags" && cf_new_cflags="$cf_new_cflags "
+ cf_new_cflags="${cf_new_cflags}$cf_add_cflags"
+
+ ;;
+ esac
+ ;;
+(yes)
+
+ test -n "$cf_new_extra_cppflags" && cf_new_extra_cppflags="$cf_new_extra_cppflags "
+ cf_new_extra_cppflags="${cf_new_extra_cppflags}$cf_add_cflags"
+
+ cf_tst_cflags=`echo ${cf_add_cflags} |sed -e 's/^[^"]*"'\''//'`
+
+ test "x${cf_add_cflags}" != "x${cf_tst_cflags}" \
+ && test -z "${cf_tst_cflags}" \
+ && cf_fix_cppflags=no
+ ;;
+esac
+done
+
+if test -n "$cf_new_cflags" ; then
+
+ test -n "$CFLAGS" && CFLAGS="$CFLAGS "
+ CFLAGS="${CFLAGS}$cf_new_cflags"
+
+fi
+
+if test -n "$cf_new_cppflags" ; then
+
+ test -n "$CPPFLAGS" && CPPFLAGS="$CPPFLAGS "
+ CPPFLAGS="${CPPFLAGS}$cf_new_cppflags"
+
+fi
+
+if test -n "$cf_new_extra_cppflags" ; then
+
+ test -n "$EXTRA_CPPFLAGS" && EXTRA_CPPFLAGS="$EXTRA_CPPFLAGS "
+ EXTRA_CPPFLAGS="${EXTRA_CPPFLAGS}$cf_new_extra_cppflags"
+
+fi
+
+ cat >conftest.$ac_ext <<_ACEOF
+#line 11232 "configure"
+#include "confdefs.h"
+
+ #include <limits.h>
+ #include <sys/types.h>
+
+int
+main (void)
+{
+
+ #if (_XOPEN_SOURCE >= $cf_gnu_xopen_source) && (MB_LEN_MAX > 1)
+ return 0;
+ #else
+ # error GNU C library is too old
+ #endif
+ ;
+ return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext
+if { (eval echo "$as_me:11252: \"$ac_compile\"") >&5
+ (eval $ac_compile) 2>&5
+ ac_status=$?
+ echo "$as_me:11255: \$? = $ac_status" >&5
+ (exit $ac_status); } &&
+ { ac_try='test -s conftest.$ac_objext'
+ { (eval echo "$as_me:11258: \"$ac_try\"") >&5
+ (eval $ac_try) 2>&5
+ ac_status=$?
+ echo "$as_me:11261: \$? = $ac_status" >&5
+ (exit $ac_status); }; }; then
+ cf_cv_gnu_dftsrc_219=yes
+else
+ echo "$as_me: failed program was:" >&5
+cat conftest.$ac_ext >&5
+cf_cv_gnu_dftsrc_219=no
+fi
+rm -f conftest.$ac_objext conftest.$ac_ext
+
+fi
+echo "$as_me:11272: result: $cf_cv_gnu_dftsrc_219" >&5
+echo "${ECHO_T}$cf_cv_gnu_dftsrc_219" >&6
+ test "x$cf_cv_gnu_dftsrc_219" = "xyes" || CPPFLAGS="$cf_save"
+ else
+ cf_cv_gnu_dftsrc_219=maybe
+ fi
+
+ if test "x$cf_cv_gnu_dftsrc_219" != xyes; then