xcode 5 does not have gcc

https://developer.apple.com/library/ios/releasenotes/developertools/rn-xcode/xc5_release_notes/xc5_release_notes.html#//apple_ref/doc/uid/TP40001051-CH2-SW2

Note: LLVM-GCC is not included in Xcode 5.

Deprecation and Removal Notice

Important: Xcode 5 does not support use of the LLVM-GCC compiler and the GDB debugger. Existing projects configured to use LLVM-GCC and GDB will be reconfigured to use the LLVM compiler and LLDB debugger when opened by Xcode 5. Please file a bug using bugreporter.apple.com for any issues that prevent you from moving to Xcode 5 for this reason.