问题
I have new changed the Snow leopard with Lion OS x and Xcode 4.0.1 with 4.1. The iPhone code was working fine on Xcode 4.0.1. Now in Xcode 4.1 it giving errors mostly related to LLVM GCC 4.2. I have tried with changing the compiler's different options available. Can body know the issue and help me out of this.
回答1:
I think you want to change the compiler version on the target and double click it then you have to change it from there.Try it,i may solve your problem. http://useyourloaf.com/blog/2011/3/21/compiler-options-in-xcode-gcc-or-llvm.html check this url
回答2:
I know that when I upgraded to Lion and Xcode 4.1, the update via App Store removed iOS SDK 4.0, 4.1 and 4.2, leaving only 4.3.
This gave me compile errors because my base SDK was 4.0, it required the 4.0 SDK files to compile, I was lucky enough to have everything backed up and I copied my SDKs back over to Lion into
/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs
This was the only issue I had with the upgrade, hope this helps.
来源：https://stackoverflow.com/questions/7145001/upgrading-xcode-4-0-1-to-4-1-giving-compilation-error-for-iphone-sdk