[clang] [lldb] [Clang] Introduce OverflowBehaviorType for fine-grained overflow control (PR #148914)

[Kees Cook via cfe-commits]

kees wrote:

In looking at what's here, I suddenly realize that I think we accidentally deviated a bit on naming, in that the trap behavior got named "no_wrap" which is ambiguous. For example, a future overflow resolution behavior can be added like "saturate", which isn't wrapping either, and suddenly "no_wrap" isn't clear what it's doing. The "no_wrap" runtime overflow resolution is to trap (which is correct here), so I think it should be explicitly named "trap" instead of "no_wrap". (If there was a reason I've forgotten for not naming it "trap", though, please ignore me there -- I don't want to stall this with bikeshedding.)

Additionally, just for some namespace sanity (especially from the perspective of Linux's use of OBTs), can we have the type specifier named "__ob_$behavior": __ob_wrap, __ob_trap ? That would make things a bit cleaner for Linux's resulting macros for OBT usage to de-conflict possible namespace collisions there...

https://github.com/llvm/llvm-project/pull/148914