[PATCH 1/2] list.h: Fix list_for_each_entry_safe()

[Kristian Høgsberg]

On Mon, Jun 14, 2010 at 10:52 AM, Tiago Vignatti
<tiago.vignatti at nokia.com> wrote:
> On Mon, Jun 14, 2010 at 03:25:22PM +0200, ext Kristian H�gsberg wrote:
>> Can't use next as a macro argument since we're accessing the .next field
>> of struct list.
>> ---
>>  include/list.h |    6 +++---
>>  1 files changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/include/list.h b/include/list.h
>> index 89dc29d..4ce20a8 100644
>> --- a/include/list.h
>> +++ b/include/list.h
>> @@ -94,10 +94,10 @@ list_is_empty(struct list *head)
>>        &pos->member != (head);                                        \
>>        pos = __container_of(pos->member.next, pos, member))
>>
>> -#define list_for_each_entry_safe(pos, next, head, member)            \
>> +#define list_for_each_entry_safe(pos, tmp, head, member)             \
>>      for (pos = __container_of((head)->next, pos, member),            \
>> -      next = __container_of(pos->member.next, pos, member);          \
>> +      tmp = __container_of(pos->member.next, pos, member);           \
>>        &pos->member != (head);                                        \
>> -      pos = next, next = __container_of(next->member.next, next, member))
>> +      pos = tmp, tmp = __container_of(pos->member.next, tmp, member))
>>
>>  #endif
>
> Kristian, doesn't make sense then to use inline function here instead keep
> juggling with the names?

We can't do that for this macro.  If you look closer, you'll see that
it expands to a for statement without the body.  You use it like this:

    list_for_each_entry_safe(...) {
        /* do something with each entry */
    }

Kristian