[mirror_ovs.git] / lib / compiler.h

/*
 * Copyright (c) 2008, 2009, 2010, 2011, 2012 Nicira, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef COMPILER_H
#define COMPILER_H 1

#if __GNUC__ && !__CHECKER__
#define NO_RETURN __attribute__((__noreturn__))
#define OVS_UNUSED __attribute__((__unused__))
#define PRINTF_FORMAT(FMT, ARG1) __attribute__((__format__(printf, FMT, ARG1)))
#define STRFTIME_FORMAT(FMT) __attribute__((__format__(__strftime__, FMT, 0)))
#define MALLOC_LIKE __attribute__((__malloc__))
#define ALWAYS_INLINE __attribute__((always_inline))
#define WARN_UNUSED_RESULT __attribute__((__warn_unused_result__))
#define SENTINEL(N) __attribute__((sentinel(N)))
#define OVS_LIKELY(CONDITION) __builtin_expect(!!(CONDITION), 1)
#define OVS_UNLIKELY(CONDITION) __builtin_expect(!!(CONDITION), 0)
#else
#define NO_RETURN
#define OVS_UNUSED
#define PRINTF_FORMAT(FMT, ARG1)
#define STRFTIME_FORMAT(FMT)
#define MALLOC_LIKE
#define ALWAYS_INLINE
#define WARN_UNUSED_RESULT
#define SENTINEL(N)
#define OVS_LIKELY(CONDITION) (!!(CONDITION))
#define OVS_UNLIKELY(CONDITION) (!!(CONDITION))
#endif

/* ISO C says that a C implementation may choose any integer type for an enum
 * that is sufficient to hold all of its values.  Common ABIs (such as the
 * System V ABI used on i386 GNU/Linux) always use a full-sized "int", even
 * when a smaller type would suffice.
 *
 * In GNU C, "enum __attribute__((packed)) name { ... }" defines 'name' as an
 * enum compatible with a type that is no bigger than necessary.  This is the
 * intended use of OVS_PACKED_ENUM.
 *
 * OVS_PACKED_ENUM is intended for use only as a space optimization, since it
 * only works with GCC.  That means that it must not be used in wire protocols
 * or otherwise exposed outside of a single process. */
#if __GNUC__ && !__CHECKER__
#define OVS_PACKED_ENUM __attribute__((__packed__))
#else
#define OVS_PACKED_ENUM
#endif

#endif /* compiler.h */
Commit	Line	Data
064af421	1	/*
f25d0cf3	2	* Copyright (c) 2008, 2009, 2010, 2011, 2012 Nicira, Inc.
064af421	3	*
a14bc59f BP	4	* Licensed under the Apache License, Version 2.0 (the "License");
	5	* you may not use this file except in compliance with the License.
	6	* You may obtain a copy of the License at:
064af421	7	*
a14bc59f BP	8	* http://www.apache.org/licenses/LICENSE-2.0
	9	*
	10	* Unless required by applicable law or agreed to in writing, software
	11	* distributed under the License is distributed on an "AS IS" BASIS,
	12	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	13	* See the License for the specific language governing permissions and
	14	* limitations under the License.
064af421 BP	15	*/
	16
	17	#ifndef COMPILER_H
	18	#define COMPILER_H 1
	19
2932bd05	20	#if __GNUC__ && !__CHECKER__
064af421	21	#define NO_RETURN __attribute__((__noreturn__))
67a4917b	22	#define OVS_UNUSED __attribute__((__unused__))
064af421 BP	23	#define PRINTF_FORMAT(FMT, ARG1) __attribute__((__format__(printf, FMT, ARG1)))
	24	#define STRFTIME_FORMAT(FMT) __attribute__((__format__(__strftime__, FMT, 0)))
	25	#define MALLOC_LIKE __attribute__((__malloc__))
	26	#define ALWAYS_INLINE __attribute__((always_inline))
f85f8ebb	27	#define WARN_UNUSED_RESULT __attribute__((__warn_unused_result__))
dfeb9047	28	#define SENTINEL(N) __attribute__((sentinel(N)))
4749f73d BP	29	#define OVS_LIKELY(CONDITION) __builtin_expect(!!(CONDITION), 1)
4749f73d BP	30	#define OVS_UNLIKELY(CONDITION) __builtin_expect(!!(CONDITION), 0)
4380e924 BP	31	#else
	32	#define NO_RETURN
	33	#define OVS_UNUSED
	34	#define PRINTF_FORMAT(FMT, ARG1)
	35	#define STRFTIME_FORMAT(FMT)
	36	#define MALLOC_LIKE
	37	#define ALWAYS_INLINE
02dd3123	38	#define WARN_UNUSED_RESULT
dfeb9047	39	#define SENTINEL(N)
4749f73d BP	40	#define OVS_LIKELY(CONDITION) (!!(CONDITION))
4749f73d BP	41	#define OVS_UNLIKELY(CONDITION) (!!(CONDITION))
4380e924	42	#endif
064af421	43
f25d0cf3 BP	44	/* ISO C says that a C implementation may choose any integer type for an enum
	45	* that is sufficient to hold all of its values. Common ABIs (such as the
	46	* System V ABI used on i386 GNU/Linux) always use a full-sized "int", even
	47	* when a smaller type would suffice.
	48	*
	49	* In GNU C, "enum __attribute__((packed)) name { ... }" defines 'name' as an
	50	* enum compatible with a type that is no bigger than necessary. This is the
	51	* intended use of OVS_PACKED_ENUM.
	52	*
	53	* OVS_PACKED_ENUM is intended for use only as a space optimization, since it
	54	* only works with GCC. That means that it must not be used in wire protocols
	55	* or otherwise exposed outside of a single process. */
	56	#if __GNUC__ && !__CHECKER__
	57	#define OVS_PACKED_ENUM __attribute__((__packed__))
	58	#else
	59	#define OVS_PACKED_ENUM
	60	#endif
	61
064af421	62	#endif /* compiler.h */