(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))
+ __GNUC_PATCHLEVEL__)
#endif
-#ifdef __cplusplus
-#define caa_unqual_scalar_typeof(x) \
- std::remove_cv<std::remove_reference<decltype(x)>::type>::type
-#else
-#define caa_scalar_type_to_expr(type) \
- unsigned type: (unsigned type)0, \
- signed type: (signed type)0
-
-/*
- * Use C11 _Generic to express unqualified type from expression. This removes
- * volatile qualifier from expression type.
- */
-#define caa_unqual_scalar_typeof(x) \
- __typeof__( \
- _Generic((x), \
- char: (char)0, \
- caa_scalar_type_to_expr(char), \
- caa_scalar_type_to_expr(short), \
- caa_scalar_type_to_expr(int), \
- caa_scalar_type_to_expr(long), \
- caa_scalar_type_to_expr(long long), \
- default: (x) \
- ) \
- )
-#endif
-
#endif /* _URCU_COMPILER_H */