Re: [PATCH 1/1] rust: macros: fix redefine const_name in `vtable`

[Gary Guo <gary@garyguo.net>]

On Mon, 26 Jun 2023 15:42:42 +0800
"Qingsong Chen" <changxian.cqs@antgroup.com> wrote:

> If the trait has same function name, the `vtable` macro
> will redefine its `gen_const_name`, e.g.:
> ```rust
>     #[vtable]
>     pub trait Foo {
>         #[cfg(CONFIG_X)]
>         fn bar();
> 
>         #[cfg(not(CONFIG_X))]
>         fn bar(x: usize);
>     }
> ```
> Use `HashSet` to avoid this.
> 
> Signed-off-by: Qingsong Chen <changxian.cqs@antgroup.com>

Reviewed-by: Gary Guo <gary@garyguo.net>

> ---
>  rust/macros/vtable.rs | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/rust/macros/vtable.rs b/rust/macros/vtable.rs
> index 34d5e7fb5768..08eb0355f99b 100644
> --- a/rust/macros/vtable.rs
> +++ b/rust/macros/vtable.rs
> @@ -27,7 +27,7 @@ pub(crate) fn vtable(_attr: TokenStream, ts: TokenStream) -> TokenStream {
>      };
>  
>      let mut body_it = body.stream().into_iter();
> -    let mut functions = Vec::new();
> +    let mut functions = HashSet::new();
>      let mut consts = HashSet::new();
>      while let Some(token) = body_it.next() {
>          match token {
> @@ -37,7 +37,7 @@ pub(crate) fn vtable(_attr: TokenStream, ts: TokenStream) -> TokenStream {
>                      // Possibly we've encountered a fn pointer type instead.
>                      _ => continue,
>                  };
> -                functions.push(fn_name);
> +                functions.insert(fn_name);
>              }
>              TokenTree::Ident(ident) if ident.to_string() == "const" => {
>                  let const_name = match body_it.next() {