title: Included files, all or nothing?
body: <p>If I #include a file in C, do I get the <em>entire</em> contents of the file linked in, or just the parts I use?</p>
  <p>If it has 10 functions in it, and I only use one of the functions, does the code for the other nine functions get included in my executable? This is especially relevant for me right now as I am working on a <a href="https://en.wikipedia.org/wiki/Microcontroller" rel="nofollow noreferrer">microcontroller</a> and memory is precious.</p>