title: warning: ‘struct user_data_s’ declared inside parameter list
body: <p>I'm getting this error:</p>
  
  <pre><code>transform.c:23: warning: ‘struct user_data_s’ declared inside parameter list
  transform.c:23: warning: its scope is only this definition or declaration, which is probably not what you want
  </code></pre>
  
  <p>Which I think is because I have a struct that contains a struct.</p>
  
  <p>This is what I am trying to do:</p>
  
  <pre><code>void f2(struct user_data_s* data) {
    printf("Number %i\n", data-&gt;L);
  }
  
  void f1(struct user_data_s* data) {
    printf("Number %i\n", data-&gt;L);
    f2(data);
  }
  </code></pre>
  
  <p>The printf in f1 works, but the line</p>
  
  <pre><code>void f2(struct user_data_s* data) {
  </code></pre>
  
  <p>gives the error.</p>
  
  <p>Does anyone know how I can fix this?</p>