title: Tools to find included headers which are unused?
body: <p>I know <a href="http://www.gimpel.com/" rel="noreferrer">PC-Lint</a> can tell you about headers which are included but not used.  Are there any other tools that can do this, preferably on linux?</p>
  
  <p>We have a large codebase that through the last 15 years has seen plenty of functionality move around, but rarely do the leftover #include directives get removed when functionality moves from one implementation file to another, leaving us with a pretty good mess by this point.  I can obviously do the painstaking thing of removing all the #include directives and letting the compiler tell me which ones to reinclude, but I'd rather solve the problem in reverse - find the unused ones - rather than rebuilding a list of used ones.</p>