Re: [PATCH 3/3] rust: upgrade to Rust 1.73.0

["Vincenzo Palazzo" <vincenzopalazzodev@gmail.com>]

> The vast majority of changes are due to our `alloc` fork being upgraded
> at once.

Ah this is annoying sometimes :/

>
> 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.
>
> 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@kernel.org>
> ---
>  Documentation/process/changes.rst |  2 +-
>  rust/alloc/alloc.rs               | 22 --------------
>  rust/alloc/boxed.rs               | 48 ++++++++++++++++++++-----------
>  rust/alloc/lib.rs                 |  5 ++--
>  rust/alloc/raw_vec.rs             | 30 ++++++++++++-------
>  rust/alloc/vec/mod.rs             |  4 +--
>  rust/alloc/vec/spec_extend.rs     |  8 +++---
>  rust/compiler_builtins.rs         |  1 +
>  scripts/min-tool-version.sh       |  2 +-
>  9 files changed, 63 insertions(+), 59 deletions(-)
>
> diff --git a/Documentation/process/changes.rst b/Documentation/process/changes.rst
> index 731cc104c56f..bb96ca0f774b 100644
> --- a/Documentation/process/changes.rst

Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>