title: How to prevent `#warning` messages from being treated as an error?
body: <p>I'm trying to compile introduce the <code>-Werror</code> flag in an existing codebase. One of the issues I'm encountering is that at some places <code>#warning</code> is used to display informational messages. These should not be treated as an error. </p>
  
  <p>One solution would be to use <code>#pragma message</code> instead, but this does not seem to be supported by older versions of gcc. (Our build servers use gcc 4.1.2).</p>
  
  <p>Can anyone help me fix this?</p>