title: Get warning when a variable is shadowed
body: <p>I generally want to avoid code like this:</p>
  
  <pre><code>#include &lt;stdio.h&gt;
  
  int main(int argc, char *argv[]){
  
    int n = 3;
  
    for (int n = 1; n &lt;= 10; n++){
      printf("%d\n", n);
    }
  
    printf("%d\n", n);
  }
  </code></pre>
  
  <p>How can I find such usage of variables? That means, that in the same function a "more local" variable has the same name as a more global variable?</p>
  
  <p>C-Standard : C 99</p>