Apple LLVM compiler 3.1 - Warnings Objective-C++ Automatic Reference Counting

Question

I am converting a non ARC project to arc, using xcode 4.3.1. I am wondering what the

Build Setting Objective C++ Automatic Reference Counting

in the

Apple LLVM compiler 3.1 - Warnings

section means. Presumable it turns some kind of warning related to ARC on or off, but I'm not exactly sure what it means.

Answer 1

If you select that warning, open the right most tab in Xcode 4, and select the second icon at the top (the wavy lines), you will see the Apple Help for that item, which says:

Objective-C++ Automatic Reference Counting ABI incompatibilities

CLANG_WARN_OBJCPP_ARC_ABI

When compiling Objective-C++ code that uses Automatic Reference Counting, report code that may cause ABI issues when linking ARC code with traditional manual reference counting code.

Also, I do NOT believe in using the "fno-objc-arc" flag to just avoid having to deal with ARC. People who do this believe they have perfect leak free code that adheres in all aspects to the ARC naming heuristics. I wish I could be that confident in my old retain/release/autorelease code! Also, ARC code is often smaller and faster.