+// SPDX-FileCopyrightText: 2009 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+//
+// SPDX-License-Identifier: LGPL-2.1-or-later
+
#ifndef _URCU_COMPILER_H
#define _URCU_COMPILER_H
/*
- * compiler.h
- *
* Compiler definitions.
- *
- * Copyright (c) 2009 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
*/
#include <stddef.h> /* for offsetof */
# include <type_traits> /* for std::remove_cv */
#endif
+#include <urcu/config.h>
+
#define caa_likely(x) __builtin_expect(!!(x), 1)
#define caa_unlikely(x) __builtin_expect(!!(x), 0)
-#define cmm_barrier() __asm__ __volatile__ ("" : : : "memory")
+#ifdef CONFIG_RCU_USE_ATOMIC_BUILTINS
+# define cmm_barrier() __atomic_signal_fence(__ATOMIC_SEQ_CST)
+#else
+# define cmm_barrier() __asm__ __volatile__ ("" : : : "memory")
+#endif
/*
* Instruct the compiler to perform only a single access to a variable
(type *)((char *)__ptr - offsetof(type, member)); \
})
+/*
+ * caa_container_of_check_null - Get the address of an object containing a field.
+ *
+ * @ptr: pointer to the field.
+ * @type: type of the object.
+ * @member: name of the field within the object.
+ *
+ * Return the address of the object containing the field. Return NULL if
+ * @ptr is NULL.
+ */
+#define caa_container_of_check_null(ptr, type, member) \
+ __extension__ \
+ ({ \
+ const __typeof__(((type *) NULL)->member) * __ptr = (ptr); \
+ (__ptr) ? (type *)((char *)__ptr - offsetof(type, member)) : NULL; \
+ })
+
#define CAA_BUILD_BUG_ON_ZERO(cond) (sizeof(struct { int:-!!(cond); }))
#define CAA_BUILD_BUG_ON(cond) ((void)CAA_BUILD_BUG_ON_ZERO(cond))
)
#endif
+/*
+ * Allow user to manually define CMM_SANITIZE_THREAD if their toolchain is not
+ * supported by this check.
+ */
+#ifndef CMM_SANITIZE_THREAD
+# if defined(__GNUC__) && defined(__SANITIZE_THREAD__)
+# define CMM_SANITIZE_THREAD
+# elif defined(__clang__) && defined(__has_feature)
+# if __has_feature(thread_sanitizer)
+# define CMM_SANITIZE_THREAD
+# endif
+# endif
+#endif /* !CMM_SANITIZE_THREAD */
+
+/*
+ * Helper to add the volatile qualifier to a pointer.
+ */
+#if defined __cplusplus
+template <typename T>
+volatile T cmm_cast_volatile(T t)
+{
+ return static_cast<volatile T>(t);
+}
+#else
+# define cmm_cast_volatile(ptr) \
+ __extension__ \
+ ({ \
+ (volatile __typeof__(ptr))(ptr); \
+ })
+#endif
+
+/*
+ * Compile time assertion.
+ * - predicate: boolean expression to evaluate,
+ * - msg: string to print to the user on failure when `static_assert()` is
+ * supported,
+ * - c_identifier_msg: message to be included in the typedef to emulate a
+ * static assertion. This parameter must be a valid C identifier as it will
+ * be used as a typedef name.
+ */
+#ifdef __cplusplus
+#define urcu_static_assert(predicate, msg, c_identifier_msg) \
+ static_assert(predicate, msg)
+#elif defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 201112L)
+#define urcu_static_assert(predicate, msg, c_identifier_msg) \
+ _Static_assert(predicate, msg)
+#else
+/*
+ * Evaluates the predicate and emit a compilation error on failure.
+ *
+ * If the predicate evaluates to true, this macro emits a function
+ * prototype with an argument type which is an array of size 0.
+ *
+ * If the predicate evaluates to false, this macro emits a function
+ * prototype with an argument type which is an array of negative size
+ * which is invalid in C and forces a compiler error. The
+ * c_identifier_msg parameter is used as the argument identifier so it
+ * is printed to the user when the error is reported.
+ */
+#define urcu_static_assert(predicate, msg, c_identifier_msg) \
+ void urcu_static_assert_proto(char c_identifier_msg[2*!!(predicate)-1])
+#endif
+
#endif /* _URCU_COMPILER_H */