How to Assign specific compiler flags to specific files

I recently needed to add an ARC file to a non-arc enabled project.  There were compiler warnings saying the -fobjc-arc flag needed to be added for the file.  To do this in Xcode go to Targets -> Build Phases -> Compiler Sources.  Then find the file and add the flag.

http://stackoverflow.com/questions/8768176/how-to-add-arc-for-specific-file