Function plpgsql_validator

src/pl/plpgsql/src/pl_handler.c:449–559

PG_FUNCTION_INFO_V1(plpgsql_validator);

Datum
plpgsql_validator(PG_FUNCTION_ARGS)
{
	Oid			funcoid = PG_GETARG_OID(0);
	HeapTuple	tuple;
	Form_pg_proc proc;
	char		functyptype;
	int			numargs;
	Oid		   *argtypes;
	char	  **argnames;
	char	   *argmodes;
	bool		is_dml_trigger = false;
	bool		is_event_trigger = false;
	int			i;

	if (!CheckFunctionValidatorAccess(fcinfo->flinfo->fn_oid, funcoid))
		PG_RETURN_VOID();

	/* Get the new function's pg_proc entry */
	tuple = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcoid));
	if (!HeapTupleIsValid(tuple))
		elog(ERROR, "cache lookup failed for function %u", funcoid);
	proc = (Form_pg_proc) GETSTRUCT(tuple);

	functyptype = get_typtype(proc->prorettype);

	/* Disallow pseudotype result */
	/* except for TRIGGER, EVTTRIGGER, RECORD, VOID, or polymorphic */
	if (functyptype == TYPTYPE_PSEUDO)
	{
		if (proc->prorettype == TRIGGEROID)
			is_dml_trigger = true;
		else if (proc->prorettype == EVENT_TRIGGEROID)
			is_event_trigger = true;
		else if (proc->prorettype != RECORDOID &&
				 proc->prorettype != VOIDOID &&
				 !IsPolymorphicType(proc->prorettype))
			ereport(ERROR,
					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
					 errmsg("PL/pgSQL functions cannot return type %s",
							format_type_be(proc->prorettype))));
	}

	/* Disallow pseudotypes in arguments (either IN or OUT) */
	/* except for RECORD and polymorphic */
	numargs = get_func_arg_info(tuple,
								&argtypes, &argnames, &argmodes);
	for (i = 0; i < numargs; i++)
	{
		if (get_typtype(argtypes[i]) == TYPTYPE_PSEUDO)
		{
			if (argtypes[i] != RECORDOID &&
				!IsPolymorphicType(argtypes[i]))
				ereport(ERROR,
						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
						 errmsg("PL/pgSQL functions cannot accept type %s",
								format_type_be(argtypes[i]))));
		}