Re: Doubt in linux/list.h

[Thomas Petazzoni <thomas.petazzoni@xxxxxxxx>]

Hi,

Libin Varghese wrote:

>>> #define INIT_LIST_HEAD(ptr) do { \
>>>       (ptr)->next = (ptr); (ptr)->prev = (ptr); \
>>> } while (0)

> I understand that it is neccessary for a block of statments, but we are
> they using it for a single statement

(ptr)->next = (ptr); <= First statement.
(ptr)->prev = (ptr); <= Second one.

So, here, there are two statements.

Of course, if there's a single statement, no need to use the do {}
while(0) trick:

#define foo(a) bar(42,a+42)

Sincerly,

Thomas
-- 
Thomas Petazzoni
thomas.petazzoni@xxxxxxxx

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