/*
- * Copyright (c) 2008, 2009 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2014 Nicira, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
#ifndef COMPILER_H
#define COMPILER_H 1
+#ifndef __has_feature
+ #define __has_feature(x) 0
+#endif
+#ifndef __has_extension
+ #define __has_extension(x) 0
+#endif
+
+#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 SCANF_FORMAT(FMT, ARG1) __attribute__((__format__(scanf, 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 SCANF_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
+
+#if __has_feature(c_thread_safety_attributes)
+/* "clang" annotations for thread safety check.
+ *
+ * OVS_LOCKABLE indicates that the struct contains mutex element
+ * which can be locked by functions like ovs_mutex_lock().
+ *
+ * Below, the word MUTEX stands for the name of an object with an OVS_LOCKABLE
+ * struct type. It can also be a comma-separated list of multiple structs,
+ * e.g. to require a function to hold multiple locks while invoked.
+ *
+ *
+ * On a variable:
+ *
+ * - OVS_GUARDED indicates that the variable may only be accessed some mutex
+ * is held.
+ *
+ * - OVS_GUARDED_BY(MUTEX) indicates that the variable may only be accessed
+ * while the specific MUTEX is held.
+ *
+ *
+ * On a variable A of mutex type:
+ *
+ * - OVS_ACQ_BEFORE(B), where B is a mutex or a comma-separated list of
+ * mutexes, declare that if both A and B are acquired at the same time,
+ * then A must be acquired before B. That is, B nests inside A.
+ *
+ * - OVS_ACQ_AFTER(B) is the opposite of OVS_ACQ_BEFORE(B), that is, it
+ * declares that A nests inside B.
+ *
+ *
+ * On a function, the following attributes apply to mutexes:
+ *
+ * - OVS_ACQUIRES(MUTEX) indicate that the function must be called without
+ * holding MUTEX and that it returns holding MUTEX.
+ *
+ * - OVS_RELEASES(MUTEX) indicates that the function may only be called with
+ * MUTEX held and that it returns with MUTEX released. It can be used for
+ * all types of MUTEX.
+ *
+ * - OVS_TRY_LOCK(RETVAL, MUTEX) indicate that the function will try to
+ * acquire MUTEX. RETVAL is an integer or boolean value specifying the
+ * return value of a successful lock acquisition.
+ *
+ * - OVS_REQUIRES(MUTEX) indicate that the function may only be called with
+ * MUTEX held and that the function does not release MUTEX.
+ *
+ * - OVS_EXCLUDED(MUTEX) indicates that the function may only be called when
+ * MUTEX is not held.
+ *
+ *
+ * The following variants, with the same syntax, apply to reader-writer locks:
+ *
+ * mutex rwlock, for reading rwlock, for writing
+ * ------------------- ------------------- -------------------
+ * OVS_ACQUIRES OVS_ACQ_RDLOCK OVS_ACQ_WRLOCK
+ * OVS_RELEASES OVS_RELEASES OVS_RELEASES
+ * OVS_TRY_LOCK OVS_TRY_RDLOCK OVS_TRY_WRLOCK
+ * OVS_REQUIRES OVS_REQ_RDLOCK OVS_REQ_WRLOCK
+ * OVS_EXCLUDED OVS_EXCLUDED OVS_EXCLUDED
+ */
+#define OVS_LOCKABLE __attribute__((lockable))
+#define OVS_REQ_RDLOCK(...) __attribute__((shared_locks_required(__VA_ARGS__)))
+#define OVS_ACQ_RDLOCK(...) __attribute__((shared_lock_function(__VA_ARGS__)))
+#define OVS_REQ_WRLOCK(...) \
+ __attribute__((exclusive_locks_required(__VA_ARGS__)))
+#define OVS_ACQ_WRLOCK(...) \
+ __attribute__((exclusive_lock_function(__VA_ARGS__)))
+#define OVS_REQUIRES(...) \
+ __attribute__((exclusive_locks_required(__VA_ARGS__)))
+#define OVS_ACQUIRES(...) \
+ __attribute__((exclusive_lock_function(__VA_ARGS__)))
+#define OVS_TRY_WRLOCK(RETVAL, ...) \
+ __attribute__((exclusive_trylock_function(RETVAL, __VA_ARGS__)))
+#define OVS_TRY_RDLOCK(RETVAL, ...) \
+ __attribute__((shared_trylock_function(RETVAL, __VA_ARGS__)))
+#define OVS_TRY_LOCK(RETVAL, ...) \
+ __attribute__((exclusive_trylock_function(RETVAL, __VA_ARGS__)))
+#define OVS_GUARDED __attribute__((guarded_var))
+#define OVS_GUARDED_BY(...) __attribute__((guarded_by(__VA_ARGS__)))
+#define OVS_RELEASES(...) __attribute__((unlock_function(__VA_ARGS__)))
+#define OVS_EXCLUDED(...) __attribute__((locks_excluded(__VA_ARGS__)))
+#define OVS_ACQ_BEFORE(...) __attribute__((acquired_before(__VA_ARGS__)))
+#define OVS_ACQ_AFTER(...) __attribute__((acquired_after(__VA_ARGS__)))
+#define OVS_NO_THREAD_SAFETY_ANALYSIS \
+ __attribute__((no_thread_safety_analysis))
+#else /* not Clang */
+#define OVS_LOCKABLE
+#define OVS_REQ_RDLOCK(...)
+#define OVS_ACQ_RDLOCK(...)
+#define OVS_REQ_WRLOCK(...)
+#define OVS_ACQ_WRLOCK(...)
+#define OVS_REQUIRES(...)
+#define OVS_ACQUIRES(...)
+#define OVS_TRY_WRLOCK(...)
+#define OVS_TRY_RDLOCK(...)
+#define OVS_TRY_LOCK(...)
+#define OVS_GUARDED
+#define OVS_GUARDED_BY(...)
+#define OVS_EXCLUDED(...)
+#define OVS_RELEASES(...)
+#define OVS_ACQ_BEFORE(...)
+#define OVS_ACQ_AFTER(...)
+#define OVS_NO_THREAD_SAFETY_ANALYSIS
+#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
+
+#ifndef _MSC_VER
+#define OVS_PACKED(DECL) DECL __attribute__((__packed__))
+#else
+#define OVS_PACKED(DECL) __pragma(pack(push, 1)) DECL __pragma(pack(pop))
+#endif
+
+/* For defining a structure whose instances should aligned on an N-byte
+ * boundary.
+ *
+ * e.g. The following:
+ * OVS_ALIGNED_STRUCT(64, mystruct) { ... };
+ * is equivalent to the following except that it specifies 64-byte alignment:
+ * struct mystruct { ... };
+ */
+#ifndef _MSC_VER
+#define OVS_ALIGNED_STRUCT(N, TAG) struct __attribute__((aligned(N))) TAG
+#else
+#define OVS_ALIGNED_STRUCT(N, TAG) __declspec(align(N)) struct TAG
+#endif
+
+#ifdef _MSC_VER
+#define CCALL __cdecl
+#pragma section(".CRT$XCU",read)
+#define OVS_CONSTRUCTOR(f) \
+ static void __cdecl f(void); \
+ __declspec(allocate(".CRT$XCU")) void (__cdecl*f##_)(void) = f; \
+ static void __cdecl f(void)
+#else
+#define OVS_CONSTRUCTOR(f) \
+ static void f(void) __attribute__((constructor)); \
+ static void f(void)
+#endif
+
+/* OVS_PREFETCH() can be used to instruct the CPU to fetch the cache
+ * line containing the given address to a CPU cache.
+ * OVS_PREFETCH_WRITE() should be used when the memory is going to be
+ * written to. Depending on the target CPU, this can generate the same
+ * instruction as OVS_PREFETCH(), or bring the data into the cache in an
+ * exclusive state. */
+#if __GNUC__
+#define OVS_PREFETCH(addr) __builtin_prefetch((addr))
+#define OVS_PREFETCH_WRITE(addr) __builtin_prefetch((addr), 1)
+#else
+#define OVS_PREFETCH(addr)
+#define OVS_PREFETCH_WRITE(addr)
+#endif
#endif /* compiler.h */
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