Re: [PATCH v2 09/10] gpiolib: use gpiochip_dup_line_label() in for_each helpers

From: Andy Shevchenko
Date: Thu Nov 30 2023 - 12:54:23 EST


On Thu, Nov 30, 2023 at 06:42:37PM +0100, Bartosz Golaszewski wrote:
> On Thu, Nov 30, 2023 at 5:40 PM Andy Shevchenko
> <andriy.shevchenko@xxxxxxxxxxxxxxx> wrote:
> > On Thu, Nov 30, 2023 at 02:46:29PM +0100, Bartosz Golaszewski wrote:

...

> > > const char *gpiochip_is_requested(struct gpio_chip *gc, unsigned int offset);
> > > char *gpiochip_dup_line_label(struct gpio_chip *gc, unsigned int offset);
> > >
> > > +
> >
> > One blank line is enough.
> >
> > > +struct _gpiochip_for_each_data {
> > > + const char **label;
> > > + int *i;
> >
> > Why is this a signed?
>
> Some users use signed, others use unsigned. It doesn't matter as we
> can't overflow it with the limit on the lines we have.

What's the problem to make it unsigned and be done with that for good?

> > > +};

...

> > > +DEFINE_CLASS(_gpiochip_for_each_data,
> > > + struct _gpiochip_for_each_data,
> > > + if (*_T.label) kfree(*_T.label),
> > > + ({ struct _gpiochip_for_each_data _data = { label, i };
> > > + *_data.i = 0;
> > > + _data; }),
> >
> > To me indentation of ({}) is quite weird. Where is this style being used
> > instead of more readable
>
> There are no guidelines for this type of C abuse AFAIK. The macro may
> be ugly but at least it hides the details from users which look nice
> instead.

If we can make it more readable for free, why not doing that way?

> > ({
> > ...
> > })
> >
> > ?

--
With Best Regards,
Andy Shevchenko