Miguel Ojeda <ojeda@xxxxxxxxxx> writes:
> This is the next upgrade to the Rust toolchain, from 1.72.1 to 1.73.0
> (i.e. the latest) [1].
>
> See the upgrade policy [2] and the comments on the first upgrade in
> commit 3ed03f4da06e ("rust: upgrade to Rust 1.68.2").
>
> # Unstable features
>
> No unstable features (that we use) were stabilized.
>
> Therefore, the only unstable feature allowed to be used outside
> the `kernel` crate is still `new_uninit`, though other code to be
> upstreamed may increase the list.
>
> Please see [3] for details.
>
> # Required changes
>
> For the upgrade, the following changes are required:
>
> - Allow `internal_features` for `feature(compiler_builtins)` since
> now Rust warns about using internal compiler and standard library
> features (similar to how it also warns about incomplete ones) [4].
>
> - A cleanup for a documentation link thanks to a new `rustdoc` lint.
> See previous commits for details.
>
> - A need to make an intra-doc link to a macro explicit, due to a
> change in behavior in `rustdoc`. See previous commits for details.
>
> # `alloc` upgrade and reviewing
>
> The vast majority of changes are due to our `alloc` fork being upgraded
> at once.
>
> There are two kinds of changes to be aware of: the ones coming from
> upstream, which we should follow as closely as possible, and the updates
> needed in our added fallible APIs to keep them matching the newer
> infallible APIs coming from upstream.
>
> Instead of taking a look at the diff of this patch, an alternative
> approach is reviewing a diff of the changes between upstream `alloc` and
> the kernel's. This allows to easily inspect the kernel additions only,
> especially to check if the fallible methods we already have still match
> the infallible ones in the new version coming from upstream.
>
> Another approach is reviewing the changes introduced in the additions in
> the kernel fork between the two versions. This is useful to spot
> potentially unintended changes to our additions.
>
> To apply these approaches, one may follow steps similar to the following
> to generate a pair of patches that show the differences between upstream
> Rust and the kernel (for the subset of `alloc` we use) before and after
> applying this patch:
>
> # Get the difference with respect to the old version.
> git -C rust checkout $(linux/scripts/min-tool-version.sh rustc)
> git -C linux ls-tree -r --name-only HEAD -- rust/alloc |
> cut -d/ -f3- |
> grep -Fv README.md |
> xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH
> git -C linux diff --patch-with-stat --summary -R > old.patch
> git -C linux restore rust/alloc
>
> # Apply this patch.
> git -C linux am rust-upgrade.patch
>
> # Get the difference with respect to the new version.
> git -C rust checkout $(linux/scripts/min-tool-version.sh rustc)
> git -C linux ls-tree -r --name-only HEAD -- rust/alloc |
> cut -d/ -f3- |
> grep -Fv README.md |
> xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH
> git -C linux diff --patch-with-stat --summary -R > new.patch
> git -C linux restore rust/alloc
>
> Now one may check the `new.patch` to take a look at the additions (first
> approach) or at the difference between those two patches (second
> approach). For the latter, a side-by-side tool is recommended.
I followed these instructions, and it looks good to me:
$ diff old.patch new.patch
18c18
< index e24a0fe51bda..51821feb20b1 100644
---
> index 5205ed9fb50a..8cb4a31cf6e5 100644
28c28
< index 8ef2bac9282c..bdab710f7737 100644
---
> index 96b93830f960..9620eba17268 100644
60c60
< index 967ad3a0e690..115fcb053e73 100644
---
> index ffe6d6373875..73b9ffd845d9 100644
69c69
< @@ -107,7 +109,7 @@
---
> @@ -109,7 +111,7 @@
78c78
< @@ -217,6 +219,7 @@
---
> @@ -218,6 +220,7 @@
86c86
< @@ -237,15 +240,19 @@
---
> @@ -238,15 +241,19 @@
107c107
< index dfd30d99cf04..65d5ce15828e 100644
---
> index 01b03de6acb5..a7425582a323 100644
238c238
< index 598ecf05e824..a4e9a5002a6d 100644
---
> index e45ddc7896be..209a88cfe598 100644
679c679
< index 56065ce565bf..a6a735201e59 100644
---
> index e2f865d0f716..ada919537446 100644
756c756
< impl<'a, T: 'a, I, A: Allocator + 'a> SpecExtend<&'a T, I> for Vec<T, A>
---
> impl<'a, T: 'a, I, A: Allocator> SpecExtend<&'a T, I> for Vec<T, A>
759c759
< @@ -46,6 +87,17 @@ impl<'a, T: 'a, I, A: Allocator + 'a> SpecExtend<&'a T, I> for Vec<T, A>
---
> @@ -46,6 +87,17 @@ impl<'a, T: 'a, I, A: Allocator> SpecExtend<&'a T, I> for Vec<T, A>
763c763
< +impl<'a, T: 'a, I, A: Allocator + 'a> TrySpecExtend<&'a T, I> for Vec<T, A>
---
> +impl<'a, T: 'a, I, A: Allocator> TrySpecExtend<&'a T, I> for Vec<T, A>
774c774
< impl<'a, T: 'a, A: Allocator + 'a> SpecExtend<&'a T, slice::Iter<'a, T>> for Vec<T, A>
---
> impl<'a, T: 'a, A: Allocator> SpecExtend<&'a T, slice::Iter<'a, T>> for Vec<T, A>
782c782
< +impl<'a, T: 'a, A: Allocator + 'a> TrySpecExtend<&'a T, slice::Iter<'a, T>> for Vec<T, A>
---
> +impl<'a, T: 'a, A: Allocator> TrySpecExtend<&'a T, slice::Iter<'a, T>> for Vec<T, A>
> Link: https://github.com/rust-lang/rust/blob/stable/RELEASES.md#version-1730-2023-10-05 [1]
> Link: https://rust-for-linux.com/rust-version-policy [2]
> Link: https://github.com/Rust-for-Linux/linux/issues/2 [3]
> Link: https://github.com/rust-lang/compiler-team/issues/596 [4]
> Signed-off-by: Miguel Ojeda <ojeda@xxxxxxxxxx>
Reviewed-by: Alice Ryhl <aliceryhl@xxxxxxxxxx>
