As I and others noted below, it is included in Apple's clang version, which is what you get when you install the command line tools for Xcode. Try something lik

As I and others noted below, it is included in Apple's clang version, which is what you get when you install the command line tools for Xcode. Try something like: clang -g -Xclang -fbounds-safety program.c Bounds check failures result in traps; in lldb you get a message like: stop reason = Bounds check failed: Dereferencing above bounds