Building from the Command Line with Xcode
New features in Xcode make it easier than ever for command line developers to manage powerful build configurations in both Terminal and the Xcode IDE. Discover how to adapt your makefile-based projects to use the latest LLVM compilers, switch effortlessly between installed toolsets, and learn best practices for building from the command line.
WWDC 2012 - Session 404 - iOS, macOS