[PATCH] Reject boolean/enum types in last arg of __builtin_*_overflow_p

[Martin Sebor]

> Here is an untested patch for that.  Except that the middle-end considers
> conversions between BOOLEAN_TYPE and single bit unsigned type as useless,
> so in theory this can't work well, and in practice only if we are lucky
> enough (plus it generates terrible code right now), so we'd probably need
> to come up with a different way of expressing whether the internal fn
> should have a bool/_Bool-ish behavior or not (optional 3rd argument or
> something ugly like that).  Plus add lots of testcases to cover the weirdo
> cases.  Is it really worth it, even when we don't want to support overflow
> into enumeration type and thus will not cover all integral types anyway?

If it's cumbersome to get to work I agree that it's not worth
the effort.  Thanks for taking the time to prototype it.

Martin