Re: xcode project settings ex****t?

If you create an external build system project, you can build a project
from Xcode using a makefile.

To set compiler options and build settings, you must first open the
project's information panel. Select the project name from the Groups
and Files List and click the Info button in the project window toolbar
to open the information panel. Click the Build tab in the project's
information panel to modify your project's build settings. You would go
to the Preprocessing build settings collection to set the -DFOO
prerprocessor macros.

Mark Szymczyk
Author, Xcode Tools Sensei
<http://www.meandmark.com>