title: Complete list of Clang flags
body: <p>Where can I find a complete list of Clang flags?</p>
  <p>There are some, like <code>-include-pch</code>, that don't appear to be even listed in the man page. :(</p>
  <p>I know that GCC uses some of the same flags, but it doesn't include documentation for stuff like <code>-Os</code> which I believe is only available in Clang. Is there a place where I can find a single, consolidated list of all the Clang options ever?</p>