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| author | Xiangfei Ding <dingxiangfei2009@gmail.com> | 2024-12-04 04:47:49 +0800 |
|---|---|---|
| committer | Miguel Ojeda <ojeda@kernel.org> | 2025-01-13 23:45:30 +0100 |
| commit | 47cb6bf7860ce33bdd000198f8b65cf9fb3324b4 (patch) | |
| tree | 5c6e52fa3e22467e8c876eb79d16f3e62c45a22f /rust/kernel/lib.rs | |
| parent | 91da5a24144e5a82bf88c5f72068cf1628198668 (diff) | |
| download | linux-47cb6bf7860ce33bdd000198f8b65cf9fb3324b4.tar.gz linux-47cb6bf7860ce33bdd000198f8b65cf9fb3324b4.tar.bz2 linux-47cb6bf7860ce33bdd000198f8b65cf9fb3324b4.zip | |
rust: use derive(CoercePointee) on rustc >= 1.84.0
The `kernel` crate relies on both `coerce_unsized` and `dispatch_from_dyn`
unstable features.
Alice Ryhl has proposed [1] the introduction of the unstable macro
`SmartPointer` to reduce such dependence, along with a RFC patch [2].
Since Rust 1.81.0 this macro, later renamed to `CoercePointee` in
Rust 1.84.0 [3], has been fully implemented with the naming discussion
resolved.
This feature is now on track to stabilization in the language.
In order to do so, we shall start using this macro in the `kernel` crate
to prove the functionality and utility of the macro as the justification
of its stabilization.
This patch makes this switch in such a way that the crate remains
backward compatible with older Rust compiler versions,
via the new Kconfig option `RUSTC_HAS_COERCE_POINTEE`.
A minimal demonstration example is added to the
`samples/rust/rust_print_main.rs` module.
Link: https://rust-lang.github.io/rfcs/3621-derive-smart-pointer.html [1]
Link: https://lore.kernel.org/all/20240823-derive-smart-pointer-v1-1-53769cd37239@google.com/ [2]
Link: https://github.com/rust-lang/rust/pull/131284 [3]
Signed-off-by: Xiangfei Ding <dingxiangfei2009@gmail.com>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20241203205050.679106-2-dingxiangfei2009@gmail.com
[ Fixed version to 1.84. Renamed option to `RUSTC_HAS_COERCE_POINTEE`
to match `CC_HAS_*` ones. Moved up new config option, closer to the
`CC_HAS_*` ones. Simplified Kconfig line. Fixed typos and slightly
reworded example and commit. Added Link to PR. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Diffstat (limited to 'rust/kernel/lib.rs')
| -rw-r--r-- | rust/kernel/lib.rs | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs index 6063f4a3d9c0..545d1170ee63 100644 --- a/rust/kernel/lib.rs +++ b/rust/kernel/lib.rs @@ -13,11 +13,12 @@ #![no_std] #![feature(arbitrary_self_types)] -#![feature(coerce_unsized)] -#![feature(dispatch_from_dyn)] +#![cfg_attr(CONFIG_RUSTC_HAS_COERCE_POINTEE, feature(derive_coerce_pointee))] +#![cfg_attr(not(CONFIG_RUSTC_HAS_COERCE_POINTEE), feature(coerce_unsized))] +#![cfg_attr(not(CONFIG_RUSTC_HAS_COERCE_POINTEE), feature(dispatch_from_dyn))] +#![cfg_attr(not(CONFIG_RUSTC_HAS_COERCE_POINTEE), feature(unsize))] #![feature(inline_const)] #![feature(lint_reasons)] -#![feature(unsize)] // Ensure conditional compilation based on the kernel configuration works; // otherwise we may silently break things like initcall handling. |