2 Commits

Author	SHA1	Message	Date
Qingsong Chen	3fa7187ece	rust: macros: vtable: fix HAS_* redefinition (gen_const_name) ... 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: b44becc5ee ("rust: macros: add `#[vtable]` proc macro") Signed-off-by: Qingsong Chen <changxian.cqs@antgroup.com> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Sergio González Collado <sergio.collado@gmail.com> Link: https://lore.kernel.org/r/20230808025404.2053471-1-changxian.cqs@antgroup.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>	2023-08-09 21:15:07 +02:00
Gary Guo	b44becc5ee	rust: macros: add #[vtable] proc macro ... 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<usize> { Err(EINVAL) } fn write(...) -> Result<usize> { Err(EINVAL) } } #[vtable] impl Operations for S { fn read(...) -> Result<usize> { ... } } assert_eq!(<S as Operations>::HAS_READ, true); assert_eq!(<S as Operations>::HAS_WRITE, false); Signed-off-by: Gary Guo <gary@garyguo.net> Reviewed-by: Sergio González Collado <sergio.collado@gmail.com> [Reworded, adapted for upstream and applied latest changes] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>	2022-12-04 01:59:15 +01:00