#ifndef _URCU_COMPILER_H #define _URCU_COMPILER_H /* * compiler.h * * Compiler definitions. * * Copyright (c) 2009 Mathieu Desnoyers * * 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 /* for offsetof */ #define caa_likely(x) __builtin_expect(!!(x), 1) #define caa_unlikely(x) __builtin_expect(!!(x), 0) #define cmm_barrier() __asm__ __volatile__ ("" : : : "memory") /* * Instruct the compiler to perform only a single access to a variable * (prohibits merging and refetching). The compiler is also forbidden to reorder * successive instances of CMM_ACCESS_ONCE(), but only when the compiler is aware of * particular ordering. Compiler ordering can be ensured, for example, by * putting two CMM_ACCESS_ONCE() in separate C statements. * * This macro does absolutely -nothing- to prevent the CPU from reordering, * merging, or refetching absolutely anything at any time. Its main intended * use is to mediate communication between process-level code and irq/NMI * handlers, all running on the same CPU. */ #define CMM_ACCESS_ONCE(x) (*(__volatile__ __typeof__(x) *)&(x)) #ifndef caa_max #define caa_max(a,b) ((a)>(b)?(a):(b)) #endif #ifndef caa_min #define caa_min(a,b) ((a)<(b)?(a):(b)) #endif #if defined(__SIZEOF_LONG__) #define CAA_BITS_PER_LONG (__SIZEOF_LONG__ * 8) #elif defined(_LP64) #define CAA_BITS_PER_LONG 64 #else #define CAA_BITS_PER_LONG 32 #endif /* * caa_container_of - 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. */ #define caa_container_of(ptr, type, member) \ __extension__ \ ({ \ const __typeof__(((type *) NULL)->member) * __ptr = (ptr); \ (type *)((char *)__ptr - offsetof(type, member)); \ }) #define CAA_BUILD_BUG_ON_ZERO(cond) (sizeof(struct { int:-!!(cond); })) #define CAA_BUILD_BUG_ON(cond) ((void)CAA_BUILD_BUG_ON_ZERO(cond)) /* * __rcu is an annotation that documents RCU pointer accesses that need * to be protected by a read-side critical section. Eventually, a static * checker will be able to use this annotation to detect incorrect RCU * usage. */ #define __rcu #ifdef __cplusplus #define URCU_FORCE_CAST(type, arg) (reinterpret_cast(arg)) #else #define URCU_FORCE_CAST(type, arg) ((type) (arg)) #endif #define caa_is_signed_type(type) ((type) -1 < (type) 0) /* * Cast to unsigned long, sign-extending if @v is signed. * Note: casting to a larger type or to same type size keeps the sign of * the expression being cast (see C99 6.3.1.3). */ #define caa_cast_long_keep_sign(v) ((unsigned long) (v)) #if defined (__GNUC__) \ && ((__GNUC__ == 4) && (__GNUC_MINOR__ >= 5) \ || __GNUC__ >= 5) #define CDS_DEPRECATED(msg) \ __attribute__((deprecated(msg))) #else #define CDS_DEPRECATED(msg) \ __attribute__((deprecated)) #endif #define CAA_ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0])) /* * Don't allow compiling with buggy compiler. */ #ifdef __GNUC__ # define URCU_GCC_VERSION (__GNUC__ * 10000 \ + __GNUC_MINOR__ * 100 \ + __GNUC_PATCHLEVEL__) /* * http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58854 */ # ifdef __ARMEL__ # if URCU_GCC_VERSION >= 40800 && URCU_GCC_VERSION <= 40802 # error Your gcc version produces clobbered frame accesses # endif # endif #endif #endif /* _URCU_COMPILER_H */