objective c - Adding compile flags for multiple targets in XCode -

I have an app that has multiple targets, each target has different attributes, where and how I define the inferior flag When I create each goal, it will only feature features I provide them. For example, I like doing something like this.

  #ifdef APP1 #define FEATURE_A #define FEATURE_B #elif APP2 #define FEATURE_B #else #endif   
 Where do I  # APP1  Or  define # app2 . There are bundle IDs for APP1 and APP2 apps; I would like to do this so that the definitions are not dynamically defined when the application runs (i.e. should not be in the statement), but when I create the application I set it.  
 Any suggestions?  
 Thank you.  
 
 
 
 Define definitions in the settings of the target, the 'Preprocessor macro' section.