Re: CAST(... ON DEFAULT) - WIP build on top of Error-Safe User Functions - Mailing list pgsql-hackers

On Mon, Nov 24, 2025 at 11:38 AM Amul Sul <sulamul@gmail.com> wrote:
>
> The change I was suggesting will be as below:
>
> --- a/src/backend/utils/adt/varlena.c
> +++ b/src/backend/utils/adt/varlena.c
> @@ -2684,6 +2684,13 @@ name_text(PG_FUNCTION_ARGS)
>   */
>  List *
>  textToQualifiedNameList(text *textval)
> +{
> +   textToQualifiedNameListSafe(textval, NULL);
> +}
> +
> +/* error safe version of textToQualifiedNameList */
> +List *
> +textToQualifiedNameListSafe(text *textval, Node *escontext)
>  {
>     char       *rawname;
>     List       *result = NIL;
>
>
> We must try to avoid duplication whenever possible, as any bug fixes
> or enhancements would need to be copied to multiple places, which is
> often overlooked.
>
hi.
great idea!

I incorporated all of your ideas into v11.
I replaced all errsave to ereturn.
I aslo simplified T_SafeTypeCastExpr expression initialization, evaluation logic
within execExpr.c, execExprInterp.c.

but one thing I didn't touch: float8_div.

+static inline float8
+float8_div_safe(const float8 val1, const float8 val2, struct Node *escontext)

but we can change float8_div to:

static inline float8
float8_div(const float8 val1, const float8 val2)
{
   return float8_div_safe(val1, val2, NULL);
}
I am worried that entering another function would cause a minor performance
degradation.  And since these simple functions are so simple, keeping them
separated should not be a big problem.  also I placed float8_div,
float8_div_safe together.


--
jian
https://www.enterprisedb.com/