title: #ifdef inside #define
body: <p>I am trying to write something like this:</p>
  
  <pre><code>#define COV_ON(x) \
                  #ifdef COVERAGE_TOOL \
                      _Pragma (COVERAGE #x)
                  #endif
  </code></pre>
  
  <p>Is there any way to define <code>COV_ON</code> like this? I know what I have done above is wrong as I can't have <code>#ifdef</code> inside #define. (<code>#</code> is not an allowed character in <code>#define</code>). 
  So is there any solution?</p>