Re: [PATCH v3 0/7] Prepare mutable list iterators to cache cursor state

在 2026/6/22 16:37, Jani Nikula 写道:
> On Mon, 22 Jun 2026, Kaitao Cheng <[email protected]> wrote:
>> Add *_mutable() iterator variants for list, hlist and llist.  The new
>> helpers are variadic and support both forms.  In the common case, the
>> caller omits the temporary cursor and the macro creates a unique internal
>> cursor with typeof(pos) and __UNIQUE_ID().  If a loop really needs an
>> explicit temporary cursor, the caller can still pass it and the helper
>> keeps the existing *_safe() behaviour.
>>
>> For example, a call site may use the shorter form:
>>
>>   list_for_each_entry_mutable(pos, head, member)
>>
>> or keep the explicit temporary cursor form:
>>
>>   list_for_each_entry_mutable(pos, tmp, head, member)
> 
> I'm unconvinced it's a good idea to allow two forms with macro trickery,
> *especially* when it's not the last argument you can omit. I think it's
> a footgun.
> 
> IMO stick with the first form only, and there'll always be the _safe
> variant that can be used when the temp pointer is needed.

Could we go back to the v1 version? What do you think of that
implementation approach?

https://lore.kernel.org/all/[email protected]/

-- 
Thanks
Kaitao Cheng