Re: [PATCH 3/5] driver core: make struct device_type.uevent() take a const *

[Jason Gunthorpe <jgg@ziepe.ca>]

On Wed, Nov 23, 2022 at 04:37:59PM +0100, Greg Kroah-Hartman wrote:
> static inline struct device *__kobj_to_dev(struct kobject *kobj)
> {
>         return container_of(kobj, struct device, kobj);
> }
> 
> static inline const struct device *__kobj_to_dev_const(const struct kobject *kobj)
> {
>         return container_of(kobj, const struct device, kobj);
> }
> 
> /*
>  * container_of() will happily take a const * and spit back a non-const * as it
>  * is just doing pointer math.  But we want to be a bit more careful in the
>  * driver code, so manually force any const * of a kobject to also be a const *
>  * to a device.
>  */
> #define kobj_to_dev(kobj)                                       \
>         _Generic((kobj),                                        \
>                  const struct kobject *: __kobj_to_dev_const,   \
>                  struct kobject *: __kobj_to_dev)(kobj)
> 
> 
> Want me to do the same thing here as well?

It would be nice to have a shared macro code gen all of the above
instead of copy and pasting it. Then maybe other cases beyond struct
device could adopt const too..

Jason