LLVM API Documentation
This file defines several utility functions used by various ARC optimizations which are IMHO too big to be in a header file.
WARNING: This file knows about certain library functions. It recognizes them by name, and hardwires knowledge of their semantics.
WARNING: This file knows about how certain Objective-C library functions are used. Naive LLVM IR transformations which would otherwise be behavior-preserving may break these assumptions.
Definition in file ObjCARCUtil.cpp.