s cause error messages but no
       non-local exits. 
  <li> Otherwise, do wrapping: determine output file name(s), define
       some preprocessor symbols and run the preprocessor, initialize
       the interface-definition parser, set up the typemap for handling
       new return strings, and finally do the language-specific parse
       (by calling the language object's <tt>parse()</tt> method), which
       creates output files by side-effect.
  </ul>
Afterwards, remove temporary files, and clean up.  