title: Adding compile flags for multiple targets in XCode
body: <p>I have a app that has multiple targets. Each target has different features. Where and how do I define complier flags so that when I build each target will only have the features that I assign to it.</p>
  
  <p>For instance I like to do something like this.</p>
  
  <pre><code>#ifdef APP1
  
  #define FEATURE_A
  #define FEATURE_B
  
  #elif APP2
  
  #define FEATURE_B
  
  #else
  
  #endif
  </code></pre>
  
  <p>Where would I put <code>#define APP1</code> or <code>#define APP2</code>. APP1 and APP2 are the bundle IDs of the apps. I would like to do it so that the definitions are not defined dynamically when the application runs (i.e. should not be in an if statement), but rather set when I build the application.</p>
  
  <p>Any suggestions?</p>
  
  <p>Thanks.</p>