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=?utf-8?B?ZytWdzJNcTh0cnV2SjNuYjl1ZzZFYVFoQVVSRHFKNkdnemdZTnlSdz09?= X-OriginatorOrg: garyguo.net X-MS-Exchange-CrossTenant-Network-Message-Id: 0eead55c-25d0-4165-64c2-08de802d4b0a X-MS-Exchange-CrossTenant-AuthSource: LOVP265MB8871.GBRP265.PROD.OUTLOOK.COM X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 12 Mar 2026 11:48:35.5251 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: bbc898ad-b10f-4e10-8552-d9377b823d45 X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: wbMPJwC4M8zjrOJ0rrErN4DS6KK/73Gw0mfvzxK3vSlP2Zre1xMgjCujpIbDTq272LoENaQppKmCKAHsbWfrZA== X-MS-Exchange-Transport-CrossTenantHeadersStamped: CWLP265MB6974 On Thu Mar 12, 2026 at 11:10 AM GMT, Miguel Ojeda wrote: > Starting with the upcoming Rust 1.96.0 (to be released 2026-05-28), > `rustc` introduces the new lint `unused_features` [1], which warns [2]: >=20 > warning: feature `used_with_arg` is declared but not used > --> :1:93 > | > 1 | #![feature(asm_const,asm_goto,arbitrary_self_types,lint_reasons,o= ffset_of_nested,raw_ref_op,used_with_arg)] > | = ^^^^^^^^^^^^^ > | > =3D note: `#[warn(unused_features)]` (part of `#[warn(unused)]`) on= by default >=20 > The original goal of using `-Zcrate-attr` automatically was that there > is a consistent set of features enabled and managed globally for all > Rust kernel code (modulo exceptions like the `rust/` crated). >=20 > While we could require crates to enable features manually (even if we > still keep the `-Zallow-features=3D` list, i.e. removing the `-Zcrate-att= r` > list), it is not really worth making all developers worry about it just > for a new lint. >=20 > The features are expected to eventually become stable anyway (most alread= y > did), and thus having to remove features in every file that may use them > is not worth it either. >=20 > Thus just allow the new lint globally. >=20 > The lint actually existed for a long time, which is why `rustc` does > not complain about an unknown lint in the stable versions we support, > but it was "disabled" years ago [3], and now it was made to work again. >=20 > For extra context, the new implementation of the lint has already been > improved to avoid linting about features that became stable thanks to > Benno's report and the ensuing discussion [4] [5], but while that helps, > it is still the case that we may have features enabled that are not used > for one reason or another in a particular crate. >=20 > Cc: stable@vger.kernel.org # Needed in 6.12.y and later (Rust is pinned i= n older LTSs). > Link: https://github.com/rust-lang/rust/pull/152164 [1] > Link: https://github.com/Rust-for-Linux/pin-init/pull/114 [2] > Link: https://github.com/rust-lang/rust/issues/44232 [3] > Link: https://github.com/rust-lang/rust/issues/153523 [4] > Link: https://github.com/rust-lang/rust/pull/153610 [5] > Signed-off-by: Miguel Ojeda Reviewed-by: Gary Guo > --- > Makefile | 1 + > 1 file changed, 1 insertion(+)