I wonder, since LLVM 3.0 is readily available and officially released, is there a way to compile with LLVM 3 when using Xcode 4.1. It would help alot since I used ARC and my app development turned out to be finished sooner than planned. So I don't have to wait until next Xcode 4.2 is released to upload my app to Apple review. Thanks
You can easily compile with any compiler you want with Xcode; see http://mattrajca.com/post/8749868513/llvm-code-coverage-and-xcode-4 , for example. IIRC, you aren't allowed to submit an app that isn't using a compiler bundled with an official Xcode release, though.
来源：https://stackoverflow.com/questions/7361824/is-there-any-way-to-use-llvm-3-in-xcode-4-1