Re: [PATCH v10 01/13] rust: hrtimer: introduce hrtimer support

[Andreas Hindborg <a.hindborg@kernel.org>]

"Benno Lossin" <benno.lossin@proton.me> writes:

> On Fri Mar 7, 2025 at 2:10 PM CET, Andreas Hindborg wrote:
>> "Benno Lossin" <benno.lossin@proton.me> writes:
>>> On Fri Mar 7, 2025 at 11:11 AM CET, Andreas Hindborg wrote:
>>>> +/// Use to implement the [`HasHrTimer<T>`] trait.
>>>> +///
>>>> +/// See [`module`] documentation for an example.
>>>> +///
>>>> +/// [`module`]: crate::time::hrtimer
>>>> +#[macro_export]
>>>> +macro_rules! impl_has_hr_timer {
>>>> +    (
>>>> +        impl$({$($generics:tt)*})?
>>>> +            HasHrTimer<$timer_type:ty>
>>>> +            for $self:ty
>>>> +        { self.$field:ident }
>>>> +        $($rest:tt)*
>>>> +    ) => {
>>>> +        // SAFETY: This implementation of `raw_get_timer` only compiles if the
>>>> +        // field has the right type.
>>>> +        unsafe impl$(<$($generics)*>)? $crate::time::hrtimer::HasHrTimer<$timer_type> for $self {
>>>> +
>>>> +            #[inline]
>>>> +            unsafe fn raw_get_timer(this: *const Self) ->
>>>> +                *const $crate::time::hrtimer::HrTimer<$timer_type>
>>>> +            {
>>>> +                // SAFETY: The caller promises that the pointer is not dangling.
>>>> +                unsafe {
>>>> +                    ::core::ptr::addr_of!((*this).$field)
>>>> +                }
>>>> +            }
>>>> +
>>>> +            #[inline]
>>>> +            unsafe fn timer_container_of(ptr: *mut $crate::time::hrtimer::HrTimer<$timer_type>) ->
>>>> +                *mut Self
>>>
>>> This formatting looks a bit weird, (macro formatting is annoying, I
>>> know).
>>
>> How would you change it?
>
> Just use `rustfmt` (copy the macro arm, replace all `$` with `_` in
> names and remove repetitions, `rustfmt` and then revert. You're lucky,
> since you only have one repetition that doesn't cause the line to go
> over the 100 column threshold):
>
>         // SAFETY: This implementation of `raw_get_timer` only compiles if the
>         // field has the right type.
>         unsafe impl$(<$($generics)*>)? $crate::time::hrtimer::HasHrTimer<$timer_type> for $self {
>
>             #[inline]
>             unsafe fn raw_get_timer(
>                 this: *const Self,
>             ) -> *const $crate::time::hrtimer::HrTimer<$timer_type> {
>                 // SAFETY: The caller promises that the pointer is not dangling.
>                 unsafe { ::core::ptr::addr_of!((*this).$field) }
>             }
>
>             #[inline]
>             unsafe fn timer_container_of(
>                 ptr: *mut $crate::time::hrtimer::HrTimer<$timer_type>,
>             ) -> *mut Self {
>                 // SAFETY: As per the safety requirement of this function, `ptr`
>                 // is pointing inside a `$timer_type`.
>                 unsafe { ::kernel::container_of!(ptr, $timer_type, $field).cast_mut() }
>             }
>         }

That is better.


Best regards,
Andreas Hindborg