diff options
Diffstat (limited to 'rust')
| -rw-r--r-- | rust/macros/helpers.rs | 86 | ||||
| -rw-r--r-- | rust/macros/pin_data.rs | 70 |
2 files changed, 94 insertions, 62 deletions
diff --git a/rust/macros/helpers.rs b/rust/macros/helpers.rs index b2bdd4d8c958..afb0f2e3a36a 100644 --- a/rust/macros/helpers.rs +++ b/rust/macros/helpers.rs @@ -1,6 +1,6 @@ // SPDX-License-Identifier: GPL-2.0 -use proc_macro::{token_stream, Group, TokenTree}; +use proc_macro::{token_stream, Group, Punct, Spacing, TokenStream, TokenTree}; pub(crate) fn try_ident(it: &mut token_stream::IntoIter) -> Option<String> { if let Some(TokenTree::Ident(ident)) = it.next() { @@ -69,3 +69,87 @@ pub(crate) fn expect_end(it: &mut token_stream::IntoIter) { panic!("Expected end"); } } + +pub(crate) struct Generics { + pub(crate) impl_generics: Vec<TokenTree>, + pub(crate) ty_generics: Vec<TokenTree>, +} + +/// Parses the given `TokenStream` into `Generics` and the rest. +/// +/// The generics are not present in the rest, but a where clause might remain. +pub(crate) fn parse_generics(input: TokenStream) -> (Generics, Vec<TokenTree>) { + // `impl_generics`, the declared generics with their bounds. + let mut impl_generics = vec![]; + // Only the names of the generics, without any bounds. + let mut ty_generics = vec![]; + // Tokens not related to the generics e.g. the `where` token and definition. + let mut rest = vec![]; + // The current level of `<`. + let mut nesting = 0; + let mut toks = input.into_iter(); + // If we are at the beginning of a generic parameter. + let mut at_start = true; + for tt in &mut toks { + match tt.clone() { + TokenTree::Punct(p) if p.as_char() == '<' => { + if nesting >= 1 { + // This is inside of the generics and part of some bound. + impl_generics.push(tt); + } + nesting += 1; + } + TokenTree::Punct(p) if p.as_char() == '>' => { + // This is a parsing error, so we just end it here. + if nesting == 0 { + break; + } else { + nesting -= 1; + if nesting >= 1 { + // We are still inside of the generics and part of some bound. + impl_generics.push(tt); + } + if nesting == 0 { + break; + } + } + } + tt => { + if nesting == 1 { + // Here depending on the token, it might be a generic variable name. + match &tt { + // Ignore const. + TokenTree::Ident(i) if i.to_string() == "const" => {} + TokenTree::Ident(_) if at_start => { + ty_generics.push(tt.clone()); + // We also already push the `,` token, this makes it easier to append + // generics. + ty_generics.push(TokenTree::Punct(Punct::new(',', Spacing::Alone))); + at_start = false; + } + TokenTree::Punct(p) if p.as_char() == ',' => at_start = true, + // Lifetimes begin with `'`. + TokenTree::Punct(p) if p.as_char() == '\'' && at_start => { + ty_generics.push(tt.clone()); + } + _ => {} + } + } + if nesting >= 1 { + impl_generics.push(tt); + } else if nesting == 0 { + // If we haven't entered the generics yet, we still want to keep these tokens. + rest.push(tt); + } + } + } + } + rest.extend(toks); + ( + Generics { + impl_generics, + ty_generics, + }, + rest, + ) +} diff --git a/rust/macros/pin_data.rs b/rust/macros/pin_data.rs index 954149d77181..c593b05d9e8c 100644 --- a/rust/macros/pin_data.rs +++ b/rust/macros/pin_data.rs @@ -1,71 +1,19 @@ // SPDX-License-Identifier: Apache-2.0 OR MIT -use proc_macro::{Punct, Spacing, TokenStream, TokenTree}; +use crate::helpers::{parse_generics, Generics}; +use proc_macro::TokenStream; pub(crate) fn pin_data(args: TokenStream, input: TokenStream) -> TokenStream { // This proc-macro only does some pre-parsing and then delegates the actual parsing to // `kernel::__pin_data!`. - // - // In here we only collect the generics, since parsing them in declarative macros is very - // elaborate. We also do not need to analyse their structure, we only need to collect them. - // `impl_generics`, the declared generics with their bounds. - let mut impl_generics = vec![]; - // Only the names of the generics, without any bounds. - let mut ty_generics = vec![]; - // Tokens not related to the generics e.g. the `impl` token. - let mut rest = vec![]; - // The current level of `<`. - let mut nesting = 0; - let mut toks = input.into_iter(); - // If we are at the beginning of a generic parameter. - let mut at_start = true; - for tt in &mut toks { - match tt.clone() { - TokenTree::Punct(p) if p.as_char() == '<' => { - if nesting >= 1 { - impl_generics.push(tt); - } - nesting += 1; - } - TokenTree::Punct(p) if p.as_char() == '>' => { - if nesting == 0 { - break; - } else { - nesting -= 1; - if nesting >= 1 { - impl_generics.push(tt); - } - if nesting == 0 { - break; - } - } - } - tt => { - if nesting == 1 { - match &tt { - TokenTree::Ident(i) if i.to_string() == "const" => {} - TokenTree::Ident(_) if at_start => { - ty_generics.push(tt.clone()); - ty_generics.push(TokenTree::Punct(Punct::new(',', Spacing::Alone))); - at_start = false; - } - TokenTree::Punct(p) if p.as_char() == ',' => at_start = true, - TokenTree::Punct(p) if p.as_char() == '\'' && at_start => { - ty_generics.push(tt.clone()); - } - _ => {} - } - } - if nesting >= 1 { - impl_generics.push(tt); - } else if nesting == 0 { - rest.push(tt); - } - } - } - } - rest.extend(toks); + let ( + Generics { + impl_generics, + ty_generics, + }, + mut rest, + ) = parse_generics(input); // This should be the body of the struct `{...}`. let last = rest.pop(); quote!(::kernel::__pin_data! { |