Function get_parse_rowmark

src/backend/parser/parse_relation.c:3710–3723

* Given a Query and rangetable index, return relation's RowMarkClause if any * * Returns NULL if relation is not selected FOR UPDATE/SHARE */

 * Returns NULL if relation is not selected FOR UPDATE/SHARE
 */
RowMarkClause *
get_parse_rowmark(Query *qry, Index rtindex)
{
	ListCell   *l;

	foreach(l, qry->rowMarks)
	{
		RowMarkClause *rc = (RowMarkClause *) lfirst(l);

		if (rc->rti == rtindex)
			return rc;
	}
	return NULL;
}

/*
 *	given relation and att name, return attnum of variable