title: What does "_" mean in gcc?
body: <p>In some gcc code I came across the following construct. 
     fatal (_("%s: cannot find section %s"), file_name, section_name);
  I have never seen "_" in this context.
  It is some sort of construct to create an entity from the character array, very probably a compiler extension.</p>
  
  <p>Can someone tell me what it is?</p>