title: How to make gcc ignore functions never called?
body: <pre><code>#include &lt;stdio.h&gt;
  
  void func(){
    printf("123\n");
  }
  
  int main(){
    printf("hi\n");
  }
  </code></pre>
  
  <p>It seems no matter how I compile it,<code>func</code> always exists in the binary target?</p>