Xcode 5 Start to Finish: iOS and OS X Development

Compiler Settings

These settings control how the build system produces executable code. Many of these have the prefix GCC, even though gcc is no longer included in Apple’s developer tools, substituting clang. They carry the prefix over for backward compatibility.

Note

While the build variables expose a great number of clang settings, bear in mind that your scripts will have read-only access to them; any changes you make won’t be visible outside your script. The GCC variables are primarily useful as substitutes into other build settings, including those you might create yourself. You might, for instance, assign a setting string to a preprocessor variable in GCC_PREPROCESSOR_DEFINITIONS so you could experiment with compiler settings and permit ...