AS_IF([test "x$SWIG" != x],
AC_MSG_CHECKING([for $SWIG version])
[SWIG_VERSION=`$SWIG -version 2>&1 | sed -n 's/SWIG Version //p'`]
AS_IF([test "x$SWIG" != x],
AC_MSG_CHECKING([for $SWIG version])
[SWIG_VERSION=`$SWIG -version 2>&1 | sed -n 's/SWIG Version //p'`]