linux/.clippy.toml

# SPDX-License-Identifier: GPL-2.0

msrv = "1.78.0"

check-private-items = true

disallowed-macros = [
    # The `clippy::dbg_macro` lint only works with `std::dbg!`, thus we simulate
    # it here, see: https://github.com/rust-lang/rust-clippy/issues/11303.
    { path = "kernel::dbg", reason = "the `dbg!` macro is intended as a debugging tool", allow-invalid = true },
]
rust: introduce `.clippy.toml` Some Clippy lints can be configured/tweaked. We will use these knobs to our advantage in later commits. This is done via a configuration file, `.clippy.toml` [1]. The file is currently unstable. This may be a problem in the future, but we can adapt as needed. In addition, we proposed adding Clippy to the Rust CI's RFL job [2], so we should be able to catch issues pre-merge. Thus introduce the file. Link: https://doc.rust-lang.org/clippy/configuration.html [1] Link: https://github.com/rust-lang/rust/pull/128928 [2] Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Trevor Gross <tmgross@umich.edu> Tested-by: Gary Guo <gary@garyguo.net> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://lore.kernel.org/r/20240904204347.168520-12-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org> 2024-09-04 22:43:39 +02:00			`# SPDX-License-Identifier: GPL-2.0`
rust: replace `clippy::dbg_macro` with `disallowed_macros` Back when we used Rust 1.60.0 (before Rust was merged in the kernel), we added `-Wclippy::dbg_macro` to the compilation flags. This worked great with our custom `dbg!` macro (vendored from `std`, but slightly modified to use the kernel printing facilities). However, in the very next version, 1.61.0, it stopped working [1] since the lint started to use a Rust diagnostic item rather than a path to find the `dbg!` macro [1]. This behavior remains until the current nightly (1.83.0). Therefore, currently, the `dbg_macro` is not doing anything, which explains why we can invoke `dbg!` in samples/rust/rust_print.rs`, as well as why changing the `#[allow()]`s to `#[expect()]`s in `std_vendor.rs` doctests does not work since they are not fulfilled. One possible workaround is using `rustc_attrs` like the standard library does. However, this is intended to be internal, and we just started supporting several Rust compiler versions, so it is best to avoid it. Therefore, instead, use `disallowed_macros`. It is a stable lint and is more flexible (in that we can provide different macros), although its diagnostic message(s) are not as nice as the specialized one (yet), and does not allow to set different lint levels per macro/path [2]. In turn, this requires allowing the (intentional) `dbg!` use in the sample, as one would have expected. Finally, in a single case, the `allow` is fixed to be an inner attribute, since otherwise it was not being applied. Link: https://github.com/rust-lang/rust-clippy/issues/11303 [1] Link: https://github.com/rust-lang/rust-clippy/issues/11307 [2] Tested-by: Gary Guo <gary@garyguo.net> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://lore.kernel.org/r/20240904204347.168520-13-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org> 2024-09-04 22:43:40 +02:00
rust: give Clippy the minimum supported Rust version Clippy's lints may avoid emitting a suggestion to use a language or library feature that is not supported by the minimum supported version, if given by the `msrv` field in the configuration file. For instance, Clippy should not suggest using `let ... else` in a lint if the MSRV did not implement that syntax. If the MSRV is not provided, Clippy will assume all features are available. Thus enable it with the minimum Rust version the kernel supports. Note that there is currently a small disadvantage in doing so: since we still use unstable features that nevertheless work in the range of versions we support (e.g. `#[expect(...)]`), we lose suggestions for those. However, over time we will stop using unstable features (especially language and library ones) as it is our goal, thus, in the end, we will want to have the `msrv` set. Rust is also considering adding a similar feature in `rustc` too, which we should probably enable if it becomes available [2]. Link: https://github.com/rust-lang/rust-clippy/blob/8298da72e7b81fa30c515631b40fc4c0845948cb/clippy_utils/src/msrvs.rs#L20 [1] Link: https://github.com/rust-lang/compiler-team/issues/772 [2] Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20241123222345.346976-1-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org> 2024-11-23 23:23:45 +01:00			`msrv = "1.78.0"`

rust: enable Clippy's `check-private-items` In Rust 1.76.0, Clippy added the `check-private-items` lint configuration option. When turned on (the default is off), it makes several lints check private items as well. In our case, it affects two lints we have enabled [1]: `missing_safety_doc` and `unnecessary_safety_doc`. It also seems to affect the new `too_long_first_doc_paragraph` lint [2], even though the documentation does not mention it. Thus allow the few instances remaining we currently hit and enable the lint. Link: https://doc.rust-lang.org/nightly/clippy/lint_configuration.html#check-private-items [1] Link: https://rust-lang.github.io/rust-clippy/master/index.html#/too_long_first_doc_paragraph [2] Reviewed-by: Trevor Gross <tmgross@umich.edu> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Tested-by: Gary Guo <gary@garyguo.net> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://lore.kernel.org/r/20240904204347.168520-16-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org> 2024-09-04 22:43:43 +02:00			`check-private-items = true`

rust: replace `clippy::dbg_macro` with `disallowed_macros` Back when we used Rust 1.60.0 (before Rust was merged in the kernel), we added `-Wclippy::dbg_macro` to the compilation flags. This worked great with our custom `dbg!` macro (vendored from `std`, but slightly modified to use the kernel printing facilities). However, in the very next version, 1.61.0, it stopped working [1] since the lint started to use a Rust diagnostic item rather than a path to find the `dbg!` macro [1]. This behavior remains until the current nightly (1.83.0). Therefore, currently, the `dbg_macro` is not doing anything, which explains why we can invoke `dbg!` in samples/rust/rust_print.rs`, as well as why changing the `#[allow()]`s to `#[expect()]`s in `std_vendor.rs` doctests does not work since they are not fulfilled. One possible workaround is using `rustc_attrs` like the standard library does. However, this is intended to be internal, and we just started supporting several Rust compiler versions, so it is best to avoid it. Therefore, instead, use `disallowed_macros`. It is a stable lint and is more flexible (in that we can provide different macros), although its diagnostic message(s) are not as nice as the specialized one (yet), and does not allow to set different lint levels per macro/path [2]. In turn, this requires allowing the (intentional) `dbg!` use in the sample, as one would have expected. Finally, in a single case, the `allow` is fixed to be an inner attribute, since otherwise it was not being applied. Link: https://github.com/rust-lang/rust-clippy/issues/11303 [1] Link: https://github.com/rust-lang/rust-clippy/issues/11307 [2] Tested-by: Gary Guo <gary@garyguo.net> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://lore.kernel.org/r/20240904204347.168520-13-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org> 2024-09-04 22:43:40 +02:00			`disallowed-macros = [`
			# The `clippy::dbg_macro` lint only works with `std::dbg!`, thus we simulate
			`# it here, see: https://github.com/rust-lang/rust-clippy/issues/11303.`
rust: clean Rust 1.88.0's warning about `clippy::disallowed_macros` configuration Starting with Rust 1.88.0 (expected 2025-06-26) [1], Clippy may start warning about paths that do not resolve in the `disallowed_macros` configuration: warning: `kernel::dbg` does not refer to an existing macro --> .clippy.toml:10:5 \| 10 \| { path = "kernel::dbg", reason = "the `dbg!` macro is intended as a debugging tool" }, \| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ This is a lint we requested at [2], due to the trouble debugging the lint due to false negatives (e.g. [3]), which we use to emulate `clippy::dbg_macro` [4]. See commit 8577c9dca799 ("rust: replace `clippy::dbg_macro` with `disallowed_macros`") for more details. Given the false negatives are not resolved yet, it is expected that Clippy complains about not finding this macro. Thus, until the false negatives are fixed (and, even then, probably we will need to wait for the MSRV to raise enough), use the escape hatch to allow an invalid path. Cc: stable@vger.kernel.org # Needed in 6.12.y and later (Rust is pinned in older LTSs). Link: https://github.com/rust-lang/rust-clippy/pull/14397 [1] Link: https://github.com/rust-lang/rust-clippy/issues/11432 [2] Link: https://github.com/rust-lang/rust-clippy/issues/11431 [3] Link: https://github.com/rust-lang/rust-clippy/issues/11303 [4] Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20250502140237.1659624-5-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org> 2025-05-02 16:02:36 +02:00			{ path = "kernel::dbg", reason = "the `dbg!` macro is intended as a debugging tool", allow-invalid = true },
rust: replace `clippy::dbg_macro` with `disallowed_macros` Back when we used Rust 1.60.0 (before Rust was merged in the kernel), we added `-Wclippy::dbg_macro` to the compilation flags. This worked great with our custom `dbg!` macro (vendored from `std`, but slightly modified to use the kernel printing facilities). However, in the very next version, 1.61.0, it stopped working [1] since the lint started to use a Rust diagnostic item rather than a path to find the `dbg!` macro [1]. This behavior remains until the current nightly (1.83.0). Therefore, currently, the `dbg_macro` is not doing anything, which explains why we can invoke `dbg!` in samples/rust/rust_print.rs`, as well as why changing the `#[allow()]`s to `#[expect()]`s in `std_vendor.rs` doctests does not work since they are not fulfilled. One possible workaround is using `rustc_attrs` like the standard library does. However, this is intended to be internal, and we just started supporting several Rust compiler versions, so it is best to avoid it. Therefore, instead, use `disallowed_macros`. It is a stable lint and is more flexible (in that we can provide different macros), although its diagnostic message(s) are not as nice as the specialized one (yet), and does not allow to set different lint levels per macro/path [2]. In turn, this requires allowing the (intentional) `dbg!` use in the sample, as one would have expected. Finally, in a single case, the `allow` is fixed to be an inner attribute, since otherwise it was not being applied. Link: https://github.com/rust-lang/rust-clippy/issues/11303 [1] Link: https://github.com/rust-lang/rust-clippy/issues/11307 [2] Tested-by: Gary Guo <gary@garyguo.net> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://lore.kernel.org/r/20240904204347.168520-13-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org> 2024-09-04 22:43:40 +02:00			`]`