[Bug c/107405] enums can be wrongly long in gcc-13 (in gnu99)

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107405

--- Comment #9 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Jiri Slaby from comment #4)
> Another question is why B is affected by A at all? Also sizeof of that enum
> (if one gives it a name) is 8 with gcc-13. That is not allowed by the
> standard, IMO.

C99, C11, and C17 all say:

"The expression that defines the value of an enumeration constant shall be an
integer
constant expression that has a value representable as an int."

So enum { A = 0xffffffff } is a constraint violation and not allowed by the
standard anyway. Such code was always non-conforming and relying on an
(undocumented?) GCC extension, so the standard has nothing to say about the
type.