Re: [PATCH v3] rust: macros: vtable: fix `HAS_*` redefinition (`gen_const_name`)

Sergio González Collado
2023-08-09T19:06:10Z

On Tue, 8 Aug 2023 at 04:54, Qingsong Chen <changxian.cqs@antgroup.com> wrote:
>
> 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 <changxian.cqs@antgroup.com>

Reviewed-by: Sergio González Collado<sergio.collado@gmail.com>

> ---
> v1 -> v2:
> - Use `BTreeSet` and existing `consts` as suggested by Alice and Gary.
> - Reword commit messages as suggested by Miguel.
> v2 -> v3:
> - No need to replace `HashSet` with `BTreeSet`, since `consts` is never
> iterated on.
>
> rust/macros/vtable.rs | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/rust/macros/vtable.rs b/rust/macros/vtable.rs
> index 34d5e7fb5768..ee06044fcd4f 100644
> --- a/rust/macros/vtable.rs
> +++ b/rust/macros/vtable.rs
> @@ -74,6 +74,7 @@ pub(crate) fn vtable(_attr: TokenStream, ts: TokenStream) -> TokenStream {
> const {gen_const_name}: bool = false;",
> )
> .unwrap();
> + consts.insert(gen_const_name);
> }
> } else {
> const_items = "const USE_VTABLE_ATTR: () = ();".to_owned();
> --
> 2.40.1
>
>