On Mon, Oct 03, 2022 at 12:02:56PM +0300, Matti Vaittinen wrote: > On 10/3/22 11:58, Matti Vaittinen wrote: > > On 10/3/22 11:43, Andy Shevchenko wrote: > > > On Mon, Oct 03, 2022 at 11:13:53AM +0300, Matti Vaittinen wrote: ... > > > > + attr[ARRAY_SIZE(iio_buffer_attrs) + i] = > > > > + (struct attribute *)&id_attr->dev_attr.attr; > > > > > > ...and explicit casting here. Isn't attr is already of a struct > > > attribute? > > > > I am glad you asked :) > > This is one of the "things" I was not really happy about. Here we hide > > the fact that our array is full of pointers to _const_ data. If we don't > > cast the compiler points this out. Old code did the same thing but it > > did this by just doing a memcpy for the pointers - which I personally > > consider even worse as it gets really easy to miss this. The cast at > > least hints there is something slightly "fishy" going on. > > > > My "gut feeling" about the correct fix is we should check if some > > attributes in the array (stored to the struct here) actually need to be > > modified later (which I doubt). If I was keen on betting I'd bet we > > could switch the struct definition to also contain pointers to const > > attributes. I am afraid this would mean quite a few more changes to the > > function signatures (changing struct attribute * to const struct > > attribute *) here and there - and possibly also require some changes to > > drivers. Thus I didn't even look at that option in the scope of this > > fix. It should probably be a separate refactoring series. But yes - this > > cast should catch attention as it did. > > > > Actually, now that you pointed it out - do you think this would warrant a > FIXME comment? Makes sense to me, but I'm not a maintainer of IIO :-) -- With Best Regards, Andy Shevchenko
