pg_proc.c

来自「PostgreSQL7.4.6 for Linux」· C语言 代码 · 共 739 行 · 第 1/2 页

					 errmsg("return type mismatch in function declared to return %s",
							format_type_be(rettype)),
			 errdetail("Function's final statement must be a SELECT.")));
		return;
	}

	/* find the final query */
	parse = (Query *) llast(queryTreeList);

	cmd = parse->commandType;
	tlist = parse->targetList;

	/*
	 * The last query must be a SELECT if and only if return type isn't
	 * VOID.
	 */
	if (rettype == VOIDOID)
	{
		if (cmd == CMD_SELECT)
			ereport(ERROR,
					(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
					 errmsg("return type mismatch in function declared to return %s",
							format_type_be(rettype)),
					 errdetail("Function's final statement must not be a SELECT.")));
		return;
	}

	/* by here, the function is declared to return some type */
	if (cmd != CMD_SELECT)
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
		 errmsg("return type mismatch in function declared to return %s",
				format_type_be(rettype)),
			 errdetail("Function's final statement must be a SELECT.")));

	/*
	 * Count the non-junk entries in the result targetlist.
	 */
	tlistlen = ExecCleanTargetListLength(tlist);

	typerelid = typeidTypeRelid(rettype);

	if (fn_typtype == 'b' || fn_typtype == 'd')
	{
		/* Shouldn't have a typerelid */
		Assert(typerelid == InvalidOid);

		/*
		 * For base-type returns, the target list should have exactly one
		 * entry, and its type should agree with what the user declared.
		 * (As of Postgres 7.2, we accept binary-compatible types too.)
		 */
		if (tlistlen != 1)
			ereport(ERROR,
					(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
					 errmsg("return type mismatch in function declared to return %s",
							format_type_be(rettype)),
			 errdetail("Final SELECT must return exactly one column.")));

		restype = ((TargetEntry *) lfirst(tlist))->resdom->restype;
		if (!IsBinaryCoercible(restype, rettype))
			ereport(ERROR,
					(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
					 errmsg("return type mismatch in function declared to return %s",
							format_type_be(rettype)),
					 errdetail("Actual return type is %s.",
							   format_type_be(restype))));
	}
	else if (fn_typtype == 'c')
	{
		/* Must have a typerelid */
		Assert(typerelid != InvalidOid);

		/*
		 * If the target list is of length 1, and the type of the varnode
		 * in the target list matches the declared return type, this is
		 * okay. This can happen, for example, where the body of the
		 * function is 'SELECT func2()', where func2 has the same return
		 * type as the function that's calling it.
		 */
		if (tlistlen == 1)
		{
			restype = ((TargetEntry *) lfirst(tlist))->resdom->restype;
			if (IsBinaryCoercible(restype, rettype))
				return;
		}

		/*
		 * Otherwise verify that the targetlist matches the return tuple
		 * type. This part of the typechecking is a hack. We look up the
		 * relation that is the declared return type, and scan the
		 * non-deleted attributes to ensure that they match the datatypes
		 * of the non-resjunk columns.
		 */
		reln = relation_open(typerelid, AccessShareLock);
		relnatts = reln->rd_rel->relnatts;
		rellogcols = 0;			/* we'll count nondeleted cols as we go */
		colindex = 0;

		foreach(tlistitem, tlist)
		{
			TargetEntry *tle = (TargetEntry *) lfirst(tlistitem);
			Form_pg_attribute attr;
			Oid			tletype;
			Oid			atttype;

			if (tle->resdom->resjunk)
				continue;

			do
			{
				colindex++;
				if (colindex > relnatts)
					ereport(ERROR,
							(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
							 errmsg("return type mismatch in function declared to return %s",
									format_type_be(rettype)),
					errdetail("Final SELECT returns too many columns.")));
				attr = reln->rd_att->attrs[colindex - 1];
			} while (attr->attisdropped);
			rellogcols++;

			tletype = exprType((Node *) tle->expr);
			atttype = attr->atttypid;
			if (!IsBinaryCoercible(tletype, atttype))
				ereport(ERROR,
						(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
						 errmsg("return type mismatch in function declared to return %s",
								format_type_be(rettype)),
						 errdetail("Final SELECT returns %s instead of %s at column %d.",
								   format_type_be(tletype),
								   format_type_be(atttype),
								   rellogcols)));
		}

		for (;;)
		{
			colindex++;
			if (colindex > relnatts)
				break;
			if (!reln->rd_att->attrs[colindex - 1]->attisdropped)
				rellogcols++;
		}

		if (tlistlen != rellogcols)
			ereport(ERROR,
					(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
					 errmsg("return type mismatch in function declared to return %s",
							format_type_be(rettype)),
					 errdetail("Final SELECT returns too few columns.")));

		relation_close(reln, AccessShareLock);
	}
	else if (rettype == RECORDOID)
	{
		/* Shouldn't have a typerelid */
		Assert(typerelid == InvalidOid);

		/*
		 * For RECORD return type, defer this check until we get the first
		 * tuple.
		 */
	}
	else if (rettype == ANYARRAYOID || rettype == ANYELEMENTOID)
	{
		/* This should already have been caught ... */
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
				 errmsg("cannot determine result data type"),
				 errdetail("A function returning \"anyarray\" or \"anyelement\" must have at least one argument of either type.")));
	}
	else
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
			  errmsg("return type %s is not supported for SQL functions",
					 format_type_be(rettype))));
}



/*
 * Validator for internal functions
 *
 * Check that the given internal function name (the "prosrc" value) is
 * a known builtin function.
 */
Datum
fmgr_internal_validator(PG_FUNCTION_ARGS)
{
	Oid			funcoid = PG_GETARG_OID(0);
	HeapTuple	tuple;
	Form_pg_proc proc;
	bool		isnull;
	Datum		tmp;
	char	   *prosrc;

	/*
	 * We do not honor check_function_bodies since it's unlikely the
	 * function name will be found later if it isn't there now.
	 */

	tuple = SearchSysCache(PROCOID,
						   ObjectIdGetDatum(funcoid),
						   0, 0, 0);
	if (!HeapTupleIsValid(tuple))
		elog(ERROR, "cache lookup failed for function %u", funcoid);
	proc = (Form_pg_proc) GETSTRUCT(tuple);

	tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosrc, &isnull);
	if (isnull)
		elog(ERROR, "null prosrc");
	prosrc = DatumGetCString(DirectFunctionCall1(textout, tmp));

	if (fmgr_internal_function(prosrc) == InvalidOid)
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_FUNCTION),
				 errmsg("there is no built-in function named \"%s\"",
						prosrc)));

	ReleaseSysCache(tuple);

	PG_RETURN_VOID();
}



/*
 * Validator for C language functions
 *
 * Make sure that the library file exists, is loadable, and contains
 * the specified link symbol. Also check for a valid function
 * information record.
 */
Datum
fmgr_c_validator(PG_FUNCTION_ARGS)
{
	Oid			funcoid = PG_GETARG_OID(0);
	void	   *libraryhandle;
	HeapTuple	tuple;
	Form_pg_proc proc;
	bool		isnull;
	Datum		tmp;
	char	   *prosrc;
	char	   *probin;

	/*
	 * It'd be most consistent to skip the check if !check_function_bodies,
	 * but the purpose of that switch is to be helpful for pg_dump loading,
	 * and for pg_dump loading it's much better if we *do* check.
	 */

	tuple = SearchSysCache(PROCOID,
						   ObjectIdGetDatum(funcoid),
						   0, 0, 0);
	if (!HeapTupleIsValid(tuple))
		elog(ERROR, "cache lookup failed for function %u", funcoid);
	proc = (Form_pg_proc) GETSTRUCT(tuple);

	tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosrc, &isnull);
	if (isnull)
		elog(ERROR, "null prosrc");
	prosrc = DatumGetCString(DirectFunctionCall1(textout, tmp));

	tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_probin, &isnull);
	if (isnull)
		elog(ERROR, "null probin");
	probin = DatumGetCString(DirectFunctionCall1(textout, tmp));

	(void) load_external_function(probin, prosrc, true, &libraryhandle);
	(void) fetch_finfo_record(libraryhandle, prosrc);

	ReleaseSysCache(tuple);

	PG_RETURN_VOID();
}


/*
 * Validator for SQL language functions
 *
 * Parse it here in order to be sure that it contains no syntax errors.
 */
Datum
fmgr_sql_validator(PG_FUNCTION_ARGS)
{
	Oid			funcoid = PG_GETARG_OID(0);
	HeapTuple	tuple;
	Form_pg_proc proc;
	List	   *querytree_list;
	bool		isnull;
	Datum		tmp;
	char	   *prosrc;
	char		functyptype;
	bool		haspolyarg;
	int			i;

	tuple = SearchSysCache(PROCOID,
						   ObjectIdGetDatum(funcoid),
						   0, 0, 0);
	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 RECORD, VOID, ANYARRAY, or ANYELEMENT */
	if (functyptype == 'p' &&
		proc->prorettype != RECORDOID &&
		proc->prorettype != VOIDOID &&
		proc->prorettype != ANYARRAYOID &&
		proc->prorettype != ANYELEMENTOID)
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
				 errmsg("SQL functions cannot return type %s",
						format_type_be(proc->prorettype))));

	/* Disallow pseudotypes in arguments */
	/* except for ANYARRAY or ANYELEMENT */
	haspolyarg = false;
	for (i = 0; i < proc->pronargs; i++)
	{
		if (get_typtype(proc->proargtypes[i]) == 'p')
		{
			if (proc->proargtypes[i] == ANYARRAYOID ||
				proc->proargtypes[i] == ANYELEMENTOID)
				haspolyarg = true;
			else
				ereport(ERROR,
						(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
				 errmsg("SQL functions cannot have arguments of type %s",
						format_type_be(proc->proargtypes[i]))));
		}
	}

	/* Postpone body checks if !check_function_bodies */
	if (check_function_bodies)
	{
		tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosrc, &isnull);
		if (isnull)
			elog(ERROR, "null prosrc");

		prosrc = DatumGetCString(DirectFunctionCall1(textout, tmp));

		/*
		 * We can't do full prechecking of the function definition if there
		 * are any polymorphic input types, because actual datatypes of
		 * expression results will be unresolvable.  The check will be done
		 * at runtime instead.
		 *
		 * We can run the text through the raw parser though; this will at
		 * least catch silly syntactic errors.
		 */
		if (!haspolyarg)
		{
			querytree_list = pg_parse_and_rewrite(prosrc,
												  proc->proargtypes,
												  proc->pronargs);
			check_sql_fn_retval(proc->prorettype, functyptype, querytree_list);
		}
		else
			querytree_list = pg_parse_query(prosrc);
	}

	ReleaseSysCache(tuple);

	PG_RETURN_VOID();
}