XCode 4 - using GCC 4.0 to compile?

Code coverage for xcode 4 only works on GCC 4.0. How 开发者_运维技巧can I set my compiler to use GCC 4.0 instead of GCC 4.2. Do i need to download 4.0 ?

GCC 4.0 is not installed with Xcode 4. You can get it back by following the directions in this question about adding support for 10.4 and 10.5 SDKs to Xcode 4.