At Fri, 11 Jun 2021 23:05:29 -0300, Ranier Vilela <ranier...@gmail.com> wrote in > Hi, > > Removing legitimate warnings can it be worth it?
>From what the warning comes from? And what is the exact message? > -1 CAST can be wrong, when there is an invalid value defined > (InvalidBucket, InvalidBlockNumber). > I think depending on the compiler -1 CAST may be different from > InvalidBucket or InvalidBlockNumber. 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. > 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. > > Trivial patch attached. Please don't quickly update the patch responding to my comments alone. I might be a minority. [1] http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1124.pdf regards. -- Kyotaro Horiguchi NTT Open Source Software Center
