Adding a Conditional Build Setting
Customize the build process by choosing conditions under which particular build setting specifications apply.
Select a project or target in the project editor.
Click Build Settings.
Select the build setting to which you want to add a conditional definition.
In the screenshot, the Debug setting for the Generate Profiling Code build option is selected.
Click the Add button (+) for the build setting.
Choose a condition from the pop-up menu in the left column.
Choose a value from the pop-up menu in the right column.
Conditional build setting definitions allow you to add build setting values that apply only when one or more conditions are met. You can add a conditional build setting at the project level and target level.
You can remove a conditional build setting by selecting it and clicking the Remove button (-).