Function build_aggregate_serialfn_expr

src/backend/parser/parse_agg.c:2140–2157

* Like build_aggregate_transfn_expr, but creates an expression tree for the * serialization function of an aggregate. */

 * serialization function of an aggregate.
 */
void
build_aggregate_serialfn_expr(Oid serialfn_oid,
							  Expr **serialfnexpr)
{
	List	   *args;
	FuncExpr   *fexpr;

	/* serialfn always takes INTERNAL and returns BYTEA */
	args = list_make1(make_agg_arg(INTERNALOID, InvalidOid));

	fexpr = makeFuncExpr(serialfn_oid,
						 BYTEAOID,
						 args,
						 InvalidOid,
						 InvalidOid,
						 COERCE_EXPLICIT_CALL);
	*serialfnexpr = (Expr *) fexpr;
}

/*
 * Like build_aggregate_transfn_expr, but creates an expression tree for the