Does the UBSan (Undefined Behavior Sanitizer) in Xcode 9 detect issues in Swift code or does it only work with C languages at this point?
Swift + UBSan (Undefined Behavior Sanitizer)
IIRC it's only for C languages.
Since 'Undefined Behavior' is a concept known in C/C++ languages, I'd say yes, only w/C langs.
Apple seems to agree, and says this about that:
"Overview
The Undefined Behavior Sanitizer, or UBSan, is an LLVM tool for C languages that detects undefined behavior at runtime."