CGBitMapContextCreate方法导致编译器警告Xcode 5而不是Xcode 4

I just updated Xcode from version 4.6.2 to 5.0, and after doing a method in my project (created in Xcode 4.6.2) is suddenly giving a compiler warning. I have tried re-opening the project in both the old and new versions of Xcode, and I have confirmed that the same method gives no warnings in 4.6.2.I just updated Xcode from version 4.6.2 to 5.0,