title: Keep comments in preprocessor i file
body: <p>We want to use the preprocessor output file (<code>.i</code> file ) for further use, especially the comments.<br>
  For that, we use the <code>/PREPRINT</code> (or <code>/PP</code>) command line switch.<br>
  The problem is that the KEIL compiler (C166) deletes any comments.  </p>
  
  <p><strong>Q:</strong> Is it possible to keep comments in the <code>.i</code> file?</p>
  
  <p><strong>Additional research:</strong><br>
  The Microsoft compiler does this with the <code>/P</code> command line switch.<br>
  But they has <code>/C</code> to <em>keep</em> comments.</p>