Automated check for calls to APIs that are not supported in iOS < 4.0?

Question

I'm trying to keep my app compatible with iOS 3.1 while also adding support for some new features of iOS 4, like limited-duration background tasks (beginBackgroundTaskWithExpirationHandler:).

Of course the proper way to do this is to check respondsToSelector: for each appropriate call, but I'm still afraid I'll miss a call here or there. Is there a way to check for any calls I might have missed in an automated fashion—some tool I can run while compiling?

I could simply build with SDK 3.1 as my active SDK, but Apple no longer installs SDK 3.1 and I don't know where to find it any longer.

Answer 1

You can install a second XCode at a different location. So you could open your project with that older xcode for building with SDK 3.1.

I have been trying to integrate the older SDK into my newer XCode so that I'd be able to use SDK 3.0, 3.1, 3.2 and 4.0 all from the same XCode installation but these attempt weren't successful so far.