title: List of Xcode compiler flags
body: <p>I know there are many compiler flags and how to use them. At times while seeing a third-party code we encounter a new flag and fail to understand why the hell this flag is used? How no warnings are shown even though there is retain-cycle in an existing code.</p>
  
  <p>So I tried to find if I can find all the compiler flags with description. That would help to understand about its usage and other flags to replace it.</p>
  
  <p>Please provide me some link or list of all the flags.</p>