On 15.04.26 13:06, Heikki Linnakangas wrote:
On 14/04/2026 10:02, David Geier wrote:
I didn't do it for performance, but because I find the function easier
to read that way. We could change it back.
It's a pretty scary thought that a compiler might misoptimize that
though. In the same function we have 'nullFlags', too, as a local
variable, even before this commit. Not sure why Coverity doesn't
complain about that.
/*
* PointerGetDatum
* Returns datum representation for a pointer.
*/
static inline Datum
PointerGetDatum(const void *X)
{
return (Datum) (uintptr_t) X;
}
Hmm, is that 'const' incorrect? This function doesn't modify *X, but the
resulting address will be used to modify it. Maybe changing it to non-
const "void *X" would give Coverity a hint.
This was briefly discussed when PointerGetDatum() was changed from a
macro to a static inline function [1]. On that email, Peter pointed out
that the compiler was doing the same deduction that Coverity did now,
i.e. that if you pass the Datum returned by PointerGetDatum(&foo) to a
function, it cannot change *foo. I'm surprised we dismissed that worry
so quickly. If the compiler optimizes based on that assumption, you can
get incorrect code.
I don't think this is in evidence. AFAICT, it's just Coverity that is
complaining here, which is its right, but the code is not incorrect.
