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Date:   Sun, 30 Jul 2023 19:51:03 -0700
From:   Boqun Feng <boqun.feng@gmail.com>
To:     Benno Lossin <benno.lossin@proton.me>
Cc:     Miguel Ojeda <ojeda@kernel.org>,
        Wedson Almeida Filho <wedsonaf@gmail.com>,
        Alex Gaynor <alex.gaynor@gmail.com>,
        Gary Guo <gary@garyguo.net>,
        =?iso-8859-1?Q?Bj=F6rn?= Roy Baron <bjorn3_gh@protonmail.com>,
        Alice Ryhl <aliceryhl@google.com>,
        Andreas Hindborg <nmi@metaspace.dk>,
        rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org,
        Asahi Lina <lina@asahilina.net>
Subject: Re: [PATCH v3 03/13] rust: add derive macro for `Zeroable`
Message-ID: <ZMchl359xrEdPPNn@boqun-archlinux>
References: <20230729090838.225225-1-benno.lossin@proton.me>
 <20230729090838.225225-4-benno.lossin@proton.me>
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In-Reply-To: <20230729090838.225225-4-benno.lossin@proton.me>
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On Sat, Jul 29, 2023 at 09:09:35AM +0000, Benno Lossin wrote:
[...]
> diff --git a/rust/macros/quote.rs b/rust/macros/quote.rs
> index dddbb4e6f4cb..b76c198a4ed5 100644
> --- a/rust/macros/quote.rs
> +++ b/rust/macros/quote.rs
> @@ -124,6 +124,12 @@ macro_rules! quote_spanned {
>          ));
>          quote_spanned!(@proc $v $span $($tt)*);
>      };
> +    (@proc $v:ident $span:ident ; $($tt:tt)*) => {
> +        $v.push(::proc_macro::TokenTree::Punct(
> +                ::proc_macro::Punct::new(';', ::proc_macro::Spacing::Alone)
> +        ));
> +        quote_spanned!(@proc $v $span $($tt)*);
> +    };
>      (@proc $v:ident $span:ident $id:ident $($tt:tt)*) => {
>          $v.push(::proc_macro::TokenTree::Ident(::proc_macro::Ident::new(stringify!($id), $span)));
>          quote_spanned!(@proc $v $span $($tt)*);
> diff --git a/rust/macros/zeroable.rs b/rust/macros/zeroable.rs
> new file mode 100644
> index 000000000000..0d605c46ab3b
> --- /dev/null
> +++ b/rust/macros/zeroable.rs
> @@ -0,0 +1,72 @@
[...]
> +            TokenTree::Punct(p) if nested == 0 && p.as_char() == ':' => {
> +                new_impl_generics.push(tt);
> +                if in_generic {
> +                    new_impl_generics.extend(quote! { ::kernel::init::Zeroable + });

Looks like the support of '+' in `quote!` is missing ;-)

Regards,
Boqun

> +                    inserted = true;
> +                }
> +            }
> +            TokenTree::Punct(p) if p.as_char() == '<' => {
> +                nested += 1;
> +                new_impl_generics.push(tt);
> +            }
> +            TokenTree::Punct(p) if p.as_char() == '>' => {
> +                assert!(nested > 0);
> +                nested -= 1;
> +                new_impl_generics.push(tt);
> +            }
> +            _ => new_impl_generics.push(tt),
> +        }
> +    }
> +    assert_eq!(nested, 0);
> +    if in_generic && !inserted {
> +        new_impl_generics.extend(quote! { : ::kernel::init::Zeroable });
> +    }
> +    quote! {
> +        ::kernel::__derive_zeroable!(
> +            parse_input:
> +                @sig(#(#rest)*),
> +                @impl_generics(#(#new_impl_generics)*),
> +                @ty_generics(#(#ty_generics)*),
> +                @body(#last),
> +        );
> +    }
> +}
> -- 
> 2.41.0
> 
>