+AC_ARG_ENABLE(gsharing, [ --enable-gsharing Enable gsharing], enable_gsharing=$enableval, enable_gsharing=no)
+if test x$enable_gsharing = xyes; then
+ AC_DEFINE(ENABLE_GSHAREDVT,1,[Gsharing])
+fi
+
+AC_ARG_ENABLE(native-types, [ --enable-native-types Enable native types], enable_native_types=$enableval, enable_native_types=no)
+if test x$enable_native_types = xyes; then
+ AC_DEFINE(MONO_NATIVE_TYPES,1,[native types])
+fi