title: How to detect shell used in GNU make?
body: <p>How can I detect shell that will be used by gnu make? I want my make to be running on following platforms: </p>
  
  <ul>
  <li>linux </li>
  <li>windows  </li>
  <li>windows with cygwin (Note that on windows with cygwin the make uses cygwin shell) </li>
  </ul>
  
  <p>Then I would like to detect if gcc is present on the system independently on OS.</p>