On 15.06.21 10:17, Kyotaro Horiguchi wrote:
The definitions are not ((type) -1) but ((type) 0xFFFFFFFF) so
actually they might be different if we forget to widen the constant
when widening the types. Regarding to the compiler behavior, I think
we are assuming C99[1] and C99 defines that -1 is converted to
Uxxx_MAX. (6.3.1.3 Singed and unsigned integers)
I'm +0.2 on it. It might be worthwhile as a matter of style.
I think since we have the constants we should use them.
pg_rewind is one special case.
All cases of XLogSegNo (uint64) initialization are zero, but in pg_rewind
was used -1?
I did not find it InvalidXLogSegNo!
I'm not sure whether that is a thinko that the variable is signed or
that it is intentional to assign the maximum value. Anyway, actually
there's no need for initializing the variable at all. So I don't think
it's worth changing the initial value. If any compiler actually
complains about the assignment changing it to zero seems reasonable.
Not tested.
I think this case needs some analysis and explanation what is going on.
I agree that the existing code looks a bit fishy, but we shouldn't just
change it to something else without understanding what is going on.
