Function addRangeTableEntryForFunction

src/backend/parser/parse_relation.c:1744–2179

* Add an entry for a function (or functions) to the pstate's range table * (p_rtable). Then, construct and return a ParseNamespaceItem for the new RTE. * * This is much like addRangeTableEntry() except that it makes a function RTE. */

 * This is much like addRangeTableEntry() except that it makes a function RTE.
 */
ParseNamespaceItem *
addRangeTableEntryForFunction(ParseState *pstate,
							  List *funcnames,
							  List *funcexprs,
							  List *coldeflists,
							  RangeFunction *rangefunc,
							  bool lateral,
							  bool inFromCl)
{
	RangeTblEntry *rte = makeNode(RangeTblEntry);
	Oid         funcDescribe = InvalidOid;
	Alias	   *alias = rangefunc->alias;
	Alias	   *eref;
	char	   *aliasname;
	int			nfuncs = list_length(funcexprs);
	TupleDesc  *functupdescs;
	TupleDesc	tupdesc;
	ListCell   *lc1,
			   *lc2,
			   *lc3;
	int			i;
	int			j;
	int			funcno;
	int			natts,
				totalatts;

	Assert(pstate != NULL);

	rte->rtekind = RTE_FUNCTION;
	rte->relid = InvalidOid;
	rte->subquery = NULL;
	rte->functions = NIL;		/* we'll fill this list below */
	rte->funcordinality = rangefunc->ordinality;
	rte->alias = alias;

	/*
	 * Choose the RTE alias name.  We default to using the first function's
	 * name even when there's more than one; which is maybe arguable but beats
	 * using something constant like "table".
	 */
	if (alias)
		aliasname = alias->aliasname;
	else
		aliasname = linitial(funcnames);

	eref = makeAlias(aliasname, NIL);
	rte->eref = eref;

	/* Process each function ... */
	functupdescs = (TupleDesc *) palloc(nfuncs * sizeof(TupleDesc));

	totalatts = 0;
	funcno = 0;
	forthree(lc1, funcexprs, lc2, funcnames, lc3, coldeflists)
	{
		Node	   *funcexpr = (Node *) lfirst(lc1);
		char	   *funcname = (char *) lfirst(lc2);
		List	   *coldeflist = (List *) lfirst(lc3);