kernel/linux.git/rust/macros/vtable.rs, branch v7.0-rc7

rust: macros: support `#[cfg]` properly in `#[vtable]` macro.

2026-01-28T12:44:17+00:00

Currently, we generate `HAS_` constants as long as the definition exists in the source, regardless if it is cfg-ed out or not. Currently, uses of `#[cfg]` present in both trait and impl, so it is not a problem; however if only the impl side uses `#[cfg]` then `HAS_` constants will incorrectly be true while it shouldnt't. With `syn` support, we can now implement `#[cfg]` handling properly by propagating the `#[cfg]` attributes to the constants. Signed-off-by: Gary Guo Reviewed-by: Benno Lossin Link: https://patch.msgid.link/20260113170529.2240744-1-gary@kernel.org Signed-off-by: Miguel Ojeda

rust: macros: convert `#[vtable]` macro to use `syn`

2026-01-27T23:55:24+00:00

`#[vtable]` is converted to use syn. This is more robust than the previous heuristic-based searching of defined methods and functions. When doing so, the trait and impl are split into two code paths as the types are distinct when parsed by `syn`. Reviewed-by: Tamir Duberstein Signed-off-by: Gary Guo Reviewed-by: Benno Lossin Link: https://patch.msgid.link/20260112170919.1888584-4-gary@kernel.org Signed-off-by: Miguel Ojeda

rust: macros: use `quote!` from vendored crate

2026-01-27T23:55:24+00:00

With `quote` crate now vendored in the kernel, we can remove our custom `quote!` macro implementation and just rely on that crate instead. The `quote` crate uses types from the `proc-macro2` library so we also update to use that, and perform conversion in the top-level lib.rs. Clippy complains about unnecessary `.to_string()` as `proc-macro2` provides additional `PartialEq` impl, so they are removed. Reviewed-by: Tamir Duberstein Reviewed-by: Benno Lossin Signed-off-by: Gary Guo Acked-by: David Gow # for kunit Link: https://patch.msgid.link/20260112170919.1888584-3-gary@kernel.org Signed-off-by: Miguel Ojeda

rust: macros: vtable: fix `HAS_*` redefinition (`gen_const_name`)

2023-08-09T19:15:07+00:00

If we define the same function name twice in a trait (using `#[cfg]`), the `vtable` macro will redefine its `gen_const_name`, e.g. this will define `HAS_BAR` twice: #[vtable] pub trait Foo { #[cfg(CONFIG_X)] fn bar(); #[cfg(not(CONFIG_X))] fn bar(x: usize); } Fixes: b44becc5ee80 ("rust: macros: add `#[vtable]` proc macro") Signed-off-by: Qingsong Chen Reviewed-by: Andreas Hindborg Reviewed-by: Gary Guo Reviewed-by: Sergio González Collado Link: https://lore.kernel.org/r/20230808025404.2053471-1-changxian.cqs@antgroup.com Signed-off-by: Miguel Ojeda

rust: macros: add `#[vtable]` proc macro

2022-12-04T00:59:15+00:00

This procedural macro attribute provides a simple way to declare a trait with a set of operations that later users can partially implement, providing compile-time `HAS_*` boolean associated constants that indicate whether a particular operation was overridden. This is useful as the Rust counterpart to structs like `file_operations` where some pointers may be `NULL`, indicating an operation is not provided. For instance: #[vtable] trait Operations { fn read(...) -> Result { Err(EINVAL) } fn write(...) -> Result { Err(EINVAL) } } #[vtable] impl Operations for S { fn read(...) -> Result { ... } } assert_eq!(::HAS_READ, true); assert_eq!(~~::HAS_WRITE, false); Signed-off-by: Gary Guo Reviewed-by: Sergio González Collado [Reworded, adapted for upstream and applied latest changes] Signed-off-by: Miguel Ojeda~~