Re: Avoid mix char with bool type in comparisons

Em sex., 7 de out. de 2022 às 14:44, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> escreveu:

> Ranier Vilela <ranier(dot)vf(at)gmail(dot)com> writes:
> > Anyway, it's not *true* that collectMatchesForHeapRow deals
> > only "true" and "false", once that key->entryRes is initialized with
> > GIN_FALSE not false.
>
> Look: GinTernaryValue is carefully designed so that it is
> representation-compatible with bool, including that GIN_FALSE is
> identical to false and GIN_TRUE is identical to true. I'm quite
> uninterested in debating whether that's a good idea or not.
> Moreover, there are a ton of other places besides this one where
> the GIN code relies on that equivalence, so we'd have to do a
> lot more than what's in this patch if we wanted to decouple that.
>
Just now I checked all the places where GinTernaryValue is used and they
all trust using GIN_TRUE, GIN_FALSE and GIN_MAYBE.
The only problematic place I found was at ginget.c and jsonb_gin.c

jsonb_gin.c:
The function execute_jsp_gin_node returns GIN_TRUE if the node->type is
JSP_GIN_ENTRY and the value is GIN_MAYBE.
IMO, it should be GIN_FALSE?

case JSP_GIN_ENTRY:
{
int index = node->val.entryIndex;

if (ternary)
return ((GinTernaryValue *) check)[index];
else
return ((bool *) check)[index] ? GIN_TRUE : GIN_FALSE;
}

The array entryRes is used only in ginget.c and ginscan.c.

The GinTernaryValue is used only in:
File contrib\pg_trgm\trgm_gin.c:
File src\backend\access\gin\ginarrayproc.c:
File src\backend\access\gin\ginget.c:
File src\backend\access\gin\ginlogic.c:
File src\backend\access\gin\ginscan.c:
File src\backend\utils\adt\jsonb_gin.c:
File src\backend\utils\adt\tsginidx.c:

regards,
Ranier Vilela