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

[Kees Cook via lldb-commits]

kees wrote:

Okay, I'm trying to isolate subtopics here.

AFAICT these are resolved:

- type specialization for `_Generic`: yes, `int` is separate from `__ob_trap int`
- type specialization for templates: yes, `int` is separate from `__ob_trap int`

Open, with my proposed outcomes with rationale:

- mangling: Linux wants `int` distinct from `__ob_trap int`. Additionally, follow the type specialization above, so mangling should make them distinct as well.

- instrumentation at function boundaries: Linux wants functions taking `__ob_trap` to trap with a param is out of range. An ABI break is intended and desired. This is also already what the sanitizer does. I don't want a mismatch here. Additionally, if/when we get `__ob_saturate` it will be very very obviously an ABI break.

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