/* * Copyright (C) Internet Systems Consortium, Inc. ("ISC") * * This Source Code Form is subject to the terms of the Mozilla Public * License, v. 2.0. If a copy of the MPL was not distributed with this * file, You can obtain one at http://mozilla.org/MPL/2.0/. * * See the COPYRIGHT file distributed with this work for additional * information regarding copyright ownership. */ #ifndef ISC_MAGIC_H #define ISC_MAGIC_H 1 #include <isc/likely.h> /*! \file isc/magic.h */ typedef struct { unsigned int magic; } isc__magic_t; /*% * To use this macro the magic number MUST be the first thing in the * structure, and MUST be of type "unsigned int". * The intent of this is to allow magic numbers to be checked even though * the object is otherwise opaque. */ #define ISC_MAGIC_VALID(a,b) (ISC_LIKELY((a) != NULL) && \ ISC_LIKELY(((const isc__magic_t *)(a))->magic == (b))) #define ISC_MAGIC(a, b, c, d) ((a) << 24 | (b) << 16 | (c) << 8 | (d)) #endif /* ISC_MAGIC_H */