AM_CONDITIONAL([USE_AS504],[test x"$AS504_CHECK" = x"yes"])
AM_CONDITIONAL([USE_AS51],[test x"$ASEM51_CHECK" = x"yes"])
+dnl zlib required for its crc32 function
+ac_have_zlib=no
+
+PKG_CHECK_MODULES([zlib], [zlib > 1.2.1],
+ [AC_CHECK_LIB([z], [crc32],
+ [ac_have_zlib=yes],
+ [ac_have_zlib=no])])
+
+if test x"$ac_have_zlib" = x"yes" ; then
+ ZLIB_LIBS='-lz'
+ AC_SUBST(ZLIB_LIBS)
+else
+ AC_MSG_ERROR([Please install zlib and zlib-devel packages])
+fi
+
AC_SUBST(WARNINGCFLAGS)
AC_SUBST(LIBS)
AC_SUBST(ac_aux_dir)