Re: [PATCH 3/5] rust: list: use consistent type parameter names

[Tamir Duberstein]

On Mon, Mar 24, 2025 at 5:51 PM Tamir Duberstein <tamird@xxxxxxxxx> wrote:
>
> On Mon, Mar 24, 2025 at 5:42 PM Boqun Feng <boqun.feng@xxxxxxxxx> wrote:
> >
> > On Mon, Mar 24, 2025 at 05:33:45PM -0400, Tamir Duberstein wrote:
> > > Refer to the type parameters of `impl_has_list_links{,_self_ptr}!` by
> > > the same name used in `impl_list_item!`.
> > >
> > > Signed-off-by: Tamir Duberstein <tamird@xxxxxxxxx>
> > > ---
> > >  rust/kernel/list/impl_list_item_mod.rs | 10 +++++-----
> > >  1 file changed, 5 insertions(+), 5 deletions(-)
> > >
> > > diff --git a/rust/kernel/list/impl_list_item_mod.rs b/rust/kernel/list/impl_list_item_mod.rs
> > > index 5ed66fdce953..9d2102138c48 100644
> > > --- a/rust/kernel/list/impl_list_item_mod.rs
> > > +++ b/rust/kernel/list/impl_list_item_mod.rs
> > > @@ -41,7 +41,7 @@ unsafe fn raw_get_list_links(ptr: *mut Self) -> *mut ListLinks<ID> {
> > >  /// Implements the [`HasListLinks`] trait for the given type.
> > >  #[macro_export]
> > >  macro_rules! impl_has_list_links {
> > > -    ($(impl$(<$($implarg:ident),*>)?
> > > +    ($(impl$(<$($generics:ident),*>)?
> > >         HasListLinks$(<$id:tt>)?
> > >         for $self:ty
> > >         { self$(.$field:ident)* }
> > > @@ -51,7 +51,7 @@ macro_rules! impl_has_list_links {
> > >          //
> > >          // The behavior of `raw_get_list_links` is not changed since the `addr_of_mut!` macro is
> > >          // equivalent to the pointer offset operation in the trait definition.
> > > -        unsafe impl$(<$($implarg),*>)? $crate::list::HasListLinks$(<$id>)? for $self {
> > > +        unsafe impl$(<$($generics),*>)? $crate::list::HasListLinks$(<$id>)? for $self {
> > >              const OFFSET: usize = ::core::mem::offset_of!(Self, $($field).*) as usize;
> > >
> > >              #[inline]
> > > @@ -81,16 +81,16 @@ pub unsafe trait HasSelfPtr<T: ?Sized, const ID: u64 = 0>
> > >  /// Implements the [`HasListLinks`] and [`HasSelfPtr`] traits for the given type.
> > >  #[macro_export]
> > >  macro_rules! impl_has_list_links_self_ptr {
> > > -    ($(impl$({$($implarg:tt)*})?
> > > +    ($(impl$({$($generics:tt)*})?
> >
> > While you're at it, can you also change this to be
> >
> >         ($(impl$(<$($generics:tt)*>)?
> >
> > ?
> >
> > I don't know why we chose <> for impl_has_list_links, but {} for
> > impl_has_list_links_self_ptr ;-)
>
> This doesn't work in all cases:
>
> error: local ambiguity when calling macro `impl_has_work`: multiple
> parsing options: built-in NTs tt ('generics') or 1 other option.
>    --> ../rust/kernel/workqueue.rs:522:11
>     |
> 522 |     impl<T> HasWork<Self> for ClosureWork<T> { self.work }
>
> The reason that `impl_has_list_links` uses <> and all others use {} is
> that `impl_has_list_links` is the only one that captures the generic
> parameter as an `ident`, the rest use `tt`. So we could change
> `impl_has_list_links` to use {}, but not the other way around.

I've changed it to `{}` so it's consistent everywhere.