rust: add `impl_flags!` macro for defining common bitflag operations

2026-02-02T07:09:11Z

We have seen a proliferation of `mod_whatever::foo::Flags` being defined with essentially the same implementation for `BitAnd`, `BitOr`, `.contains()` etc. This macro aims to bring a solution for this, allowing to generate these methods for user-defined structs. With some use cases in KMS and upcoming GPU drivers. Link: https://rust-for-linux.zulipchat.com/#narrow/channel/288089-General/topic/We.20really.20need.20a.20common.20.60Flags.60.20type Suggested-by: Daniel Almeida Suggested-by: Lyude Paul Reviewed-by: Daniel Almeida Reviewed-by: Lyude Paul Tested-by: Andreas Hindborg Reviewed-by: Andreas Hindborg Signed-off-by: Filipe Xavier Link: https://patch.msgid.link/20260117-feat-add-bitmask-macro-v9-1-45ea1f00f846@gmail.com [ Implemented missing `BitXorAssign<$flag> for $flags`. Sorted `impl`s. Removed prelude addition for now -- I asked the team and they also felt it wasn't needed. We can always add it later on if needed. Fixed intra-doc link (by removing the sentence since it was superfluous anyway). Simplified `empty()` title. Reworded commit slightly. Added docs to enum variants in example to avoid 'missing_docs' lint when used in actual code. - Miguel ] Signed-off-by: Miguel Ojeda

wireguard-linux/rust/kernel/impl_flags.rs, branch devel

rust: add `impl_flags!` macro for defining common bitflag operations