#ifndef UNUSED_ARG
#define UNUSED_ARG(type,arg) type arg
#endif
-#define UNUSED UNUSED_ARG /* OBSOLETE */
#ifndef UNUSED_VAR
#define UNUSED_VAR(type,name) type name
#endif
*/
#define countof(a) (sizeof(a) / sizeof(*(a)))
#endif
+#ifndef alignof
+ /**
+ * Return the alignment in memory of a generic data type.
+ *
+ * \note We need to worry about alignment when allocating memory that
+ * will be used later by unknown objects (e.g., malloc()) or, more
+ * generally, whenever creating generic container types.
+ */
+ #define alignof(type) offsetof(struct { char c; type member; }, member)
+#endif
/**
* Cast a member of a structure out to the containing structure.
*/
#if COMPILER_TYPEOF && COMPILER_STATEMENT_EXPRESSIONS
#define containerof(ptr, type, member) ({ \
- const typeof( ((type *)0)->member ) *_mptr = (ptr); /* type check */ \
- (type *)((char *)_mptr - offsetof(type, member)); \
+ typeof( ((type *)0)->member ) *_mptr = (ptr); /* type check */ \
+ (type *)(void *)((char *)_mptr - offsetof(type, member)); \
})
#else
#define containerof(ptr, type, member) \
- ( (type *)((char *)(ptr) - offsetof(type, member)) )
+ ( (type *)(void *)((char *)(ptr) - offsetof(type, member)) )
#endif
/** Issue a compilation error if the \a condition is false */