/*
- * Copyright (c) 2008, 2009 Nicira Networks.
- *
- * Permission to use, copy, modify, and/or distribute this software for any
- * purpose with or without fee is hereby granted, provided that the above
- * copyright notice and this permission notice appear in all copies.
- *
- * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
- * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
- * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
- * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
- * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
- * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013 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 UNUSED __attribute__((__unused__))
-#define PACKED __attribute__((__packed__))
+#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 likely(x) __builtin_expect((x),1)
-#define unlikely(x) __builtin_expect((x),0)
+#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
+
+#ifdef __CHECKER__
+/* "sparse" annotations for mutexes and mutex-like constructs.
+ *
+ * In a function prototype, OVS_ACQUIRES(MUTEX) indicates that the function
+ * must be called without MUTEX acquired and that it returns with MUTEX
+ * acquired. OVS_RELEASES(MUTEX) indicates the reverse. OVS_MUST_HOLD
+ * indicates that the function must be called with MUTEX acquired by the
+ * caller and that the function does not release MUTEX.
+ *
+ * In practice, sparse ignores the MUTEX argument. It need not even be a
+ * valid expression. It is meant to indicate to human readers what mutex is
+ * being acquired.
+ *
+ * Since sparse ignores MUTEX, it need not be an actual mutex. It can be
+ * any construct on which paired acquire and release semantics make sense:
+ * read/write locks, temporary memory allocations, whatever.
+ *
+ * OVS_ACQUIRE, OVS_RELEASE, and OVS_HOLDS are suitable for use within macros,
+ * where there is no function prototype to annotate. */
+#define OVS_ACQUIRES(MUTEX) __attribute__((context(MUTEX, 0, 1)))
+#define OVS_RELEASES(MUTEX) __attribute__((context(MUTEX, 1, 0)))
+#define OVS_MUST_HOLD(MUTEX) __attribute__((context(MUTEX, 1, 1)))
+#define OVS_ACQUIRE(MUTEX) __context__(MUTEX, 0, 1)
+#define OVS_RELEASE(MUTEX) __context__(MUTEX, 1, 0)
+#define OVS_HOLDS(MUTEX) __context__(MUTEX, 1, 1)
+#else
+#define OVS_ACQUIRES(MUTEX)
+#define OVS_RELEASES(MUTEX)
+#define OVS_MUST_HOLD(MUTEX)
+#define OVS_ACQUIRE(MUTEX)
+#define OVS_RELEASE(MUTEX)
+#define OVS_HOLDS(MUTEX)
+#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 */
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