-echo "# Automatically generated by configure - do not modify" > $config_host_mak
-printf "# Configured with:" >> $config_host_mak
-printf " '%s'" "$0" "$@" >> $config_host_mak
-echo >> $config_host_mak
+##########################################
+# Check whether we have pwritev/preadv
+pwritev="no"
+cat > $TMPC << EOF
+#include <stdio.h>
+#include <sys/uio.h>
+int main(int argc, char **argv)
+{
+ return pwritev(0, NULL, 1, 0) + preadv(0, NULL, 1, 0);
+}
+EOF
+if compile_prog "" "" "pwritev"; then
+ pwritev="yes"
+fi
+echo "pwritev/preadv $pwritev"
+
+##########################################
+# Check whether we have the required functions for ipv6
+ipv6="no"
+cat > $TMPC << EOF
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netdb.h>
+#include <stdio.h>
+int main(int argc, char **argv)
+{
+ struct addrinfo hints;
+ struct in6_addr addr;
+ int ret;
+
+ ret = getaddrinfo(NULL, NULL, &hints, NULL);
+ freeaddrinfo(NULL);
+ printf("%s\n", gai_strerror(ret));
+ addr = in6addr_any;
+ return 0;
+}
+EOF
+if compile_prog "" "" "ipv6"; then
+ ipv6="yes"
+fi
+echo "IPv6 helpers $ipv6"
+
+#############################################################################