Function finalize_primnode

src/backend/optimizer/plan/subselect.c:3410–3468

* finalize_primnode: add IDs of all PARAM_EXEC params appearing in the given * expression tree to the result set. */

 * expression tree to the result set.
 */
static bool
finalize_primnode(Node *node, finalize_primnode_context *context)
{
	if (node == NULL)
		return false;
	if (IsA(node, Param))
	{
		if (((Param *) node)->paramkind == PARAM_EXEC)
		{
			int			paramid = ((Param *) node)->paramid;

			context->paramids = bms_add_member(context->paramids, paramid);
		}
		return false;			/* no more to do here */
	}
	if (IsA(node, SubPlan))
	{
		SubPlan    *subplan = (SubPlan *) node;
		Plan	   *plan = planner_subplan_get_plan(context->root, subplan);
		ListCell   *lc;
		Bitmapset  *subparamids;

		/* Recurse into the testexpr, but not into the Plan */
		finalize_primnode(subplan->testexpr, context);

		/*
		 * Remove any param IDs of output parameters of the subplan that were
		 * referenced in the testexpr.  These are not interesting for
		 * parameter change signaling since we always re-evaluate the subplan.
		 * Note that this wouldn't work too well if there might be uses of the
		 * same param IDs elsewhere in the plan, but that can't happen because
		 * generate_new_exec_param never tries to merge params.
		 */
		foreach(lc, subplan->paramIds)
		{
			context->paramids = bms_del_member(context->paramids,
											   lfirst_int(lc));
		}

		/* Also examine args list */
		finalize_primnode((Node *) subplan->args, context);

		/*
		 * Add params needed by the subplan to paramids, but excluding those
		 * we will pass down to it.  (We assume SS_finalize_plan was run on
		 * the subplan already.)
		 */
		subparamids = bms_copy(plan->extParam);
		foreach(lc, subplan->parParam)
		{
			subparamids = bms_del_member(subparamids, lfirst_int(lc));
		}
		context->paramids = bms_join(context->paramids, subparamids);

		return false;			/* no more to do here */
	}
	return expression_tree_walker(node, finalize_primnode,
								  (void *) context);