Re: Portability concerns over pq_sendbyte?

>>>>> "Andres" == Andres Freund <andres(at)anarazel(dot)de> writes:

>> unsigned char x = 128;
>> pq_sendbyte(&buf, x);
>>
>> which I believe is not well-defined since pq_sendbyte takes an int8,
>> and conversions of unrepresentable values to _signed_ integer types
>> are (iirc) implementation-dependent.

Andres> It's not implementation defined in postgres' dialect of C - we
Andres> rely on accurate signed->unsigned conversions in a number of
Andres> places.

Converting signed integer to unsigned is ok as I understand it - what's
happening here is the reverse, converting an unrepresentable unsigned
value to a signed type.

>> There are also some cases where pq_sendint16 is being called for an
>> unsigned value or a value that might exceed 32767.

Andres> Hm, which case were you thinking of here? The calls usually are
Andres> exactly the types that the wire protocol expects, no?

There are cases where it's not actually clear what the wire protocol
expects - I'm thinking in particular of the number of entries in a list
of parameter types/formats.

--
Andrew (irc:RhodiumToad)