Disabling ARC in Xcode 4

Description

With Xcode 4.2 (iOS 5) Apple introduce ARC (Automatic Reference Counting) to help with memory management. Basically you no longer need to call retain or release. However current examples/books (and (open source) libraries) are still doing it. This leads to (annoying) errors like:

ARC forbids explicit message send of ‘retain’

To get rid of this error you need to disable ARC, but how? Here is what you need to do in Xcode:

Solution

• Select your project file.
• You should be in the “Build settings” tab. Select the “levels” option (default is “Combined”)
• There’s a search field to the right of “Combined”. Enter “Automatic”
• Second group should be “Apple LLVM Compiler 3.0 – Language”. Second line under that controls ARC.
• Click that line, then in the middle column (where it says “yes”), click and choose “no”.

References

• Lee Silver Blog
• Matthias Wessendorf's Weblog