Re: [RFC][PATCH] rcu: Use typeof(p) instead of typeof(*p) *

From: Jan Engelhardt
Date: Tue Oct 05 2021 - 15:06:41 EST



On Tuesday 2021-10-05 20:40, Steven Rostedt wrote:
>>
>> >>>> typeof(*p) *________p1 = (typeof(*p) *__force)READ_ONCE(p);
>>
>> #define static_cast(type, expr) ((struct { type x; }){(expr)}.x)
>> typeof(p) p1 = (typeof(p) __force)static_cast(void *, READ_ONCE(p));
>>
>> Let the name not fool you; it's absolutely _not_ the same as C++'s
>> static_cast, but still: it does emit a warning when you do pass an
>> integer, which is better than no warning at all in that case.
>>
>> *flies away*
>
>Are you suggesting I should continue this exercise ;-)

“After all, why not?”

typeof(p) p1 = (typeof(p) __force)READ_ONCE(p) +
BUILD_BUG_ON_EXPR(__builtin_classify_type(p) != 5);