diff options
Diffstat (limited to 'rust/macros')
| -rw-r--r-- | rust/macros/lib.rs | 20 | ||||
| -rw-r--r-- | rust/macros/quote.rs | 12 | ||||
| -rw-r--r-- | rust/macros/zeroable.rs | 72 |
3 files changed, 104 insertions, 0 deletions
diff --git a/rust/macros/lib.rs b/rust/macros/lib.rs index b4bc44c27bd4..c42105c2ff96 100644 --- a/rust/macros/lib.rs +++ b/rust/macros/lib.rs @@ -11,6 +11,7 @@ mod paste; mod pin_data; mod pinned_drop; mod vtable; +mod zeroable; use proc_macro::TokenStream; @@ -343,3 +344,22 @@ pub fn paste(input: TokenStream) -> TokenStream { paste::expand(&mut tokens); tokens.into_iter().collect() } + +/// Derives the [`Zeroable`] trait for the given struct. +/// +/// This can only be used for structs where every field implements the [`Zeroable`] trait. +/// +/// # Examples +/// +/// ```rust,ignore +/// #[derive(Zeroable)] +/// pub struct DriverData { +/// id: i64, +/// buf_ptr: *mut u8, +/// len: usize, +/// } +/// ``` +#[proc_macro_derive(Zeroable)] +pub fn derive_zeroable(input: TokenStream) -> TokenStream { + zeroable::derive(input) +} diff --git a/rust/macros/quote.rs b/rust/macros/quote.rs index dddbb4e6f4cb..33a199e4f176 100644 --- a/rust/macros/quote.rs +++ b/rust/macros/quote.rs @@ -124,6 +124,18 @@ 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 + $($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 @@ +// SPDX-License-Identifier: GPL-2.0 + +use crate::helpers::{parse_generics, Generics}; +use proc_macro::{TokenStream, TokenTree}; + +pub(crate) fn derive(input: TokenStream) -> TokenStream { + let ( + Generics { + impl_generics, + ty_generics, + }, + mut rest, + ) = parse_generics(input); + // This should be the body of the struct `{...}`. + let last = rest.pop(); + // Now we insert `Zeroable` as a bound for every generic parameter in `impl_generics`. + let mut new_impl_generics = Vec::with_capacity(impl_generics.len()); + // Are we inside of a generic where we want to add `Zeroable`? + let mut in_generic = !impl_generics.is_empty(); + // Have we already inserted `Zeroable`? + let mut inserted = false; + // Level of `<>` nestings. + let mut nested = 0; + for tt in impl_generics { + match &tt { + // If we find a `,`, then we have finished a generic/constant/lifetime parameter. + TokenTree::Punct(p) if nested == 0 && p.as_char() == ',' => { + if in_generic && !inserted { + new_impl_generics.extend(quote! { : ::kernel::init::Zeroable }); + } + in_generic = true; + inserted = false; + new_impl_generics.push(tt); + } + // If we find `'`, then we are entering a lifetime. + TokenTree::Punct(p) if nested == 0 && p.as_char() == '\'' => { + in_generic = false; + new_impl_generics.push(tt); + } + 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 + }); + 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), + ); + } +} |