X-Git-Url: https://git.liburcu.org/?a=blobdiff_plain;f=include%2Furcu%2Fcompiler.h;h=197656c617d786f8af88f5648a60483ac224f3c4;hb=HEAD;hp=09953f2c2b96eeb5dfd27e04b43825a717d1e38c;hpb=4b3a7ebd5597b5e241c39110eb426f7832066308;p=urcu.git

diff --git a/include/urcu/compiler.h b/include/urcu/compiler.h
index 09953f2..197656c 100644
--- a/include/urcu/compiler.h
+++ b/include/urcu/compiler.h
@@ -1,22 +1,12 @@
+// 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 */
@@ -25,10 +15,16 @@
 # 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
@@ -166,4 +162,67 @@
 	)
 #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 */