diff options
Diffstat (limited to 'rust/macros')
| -rw-r--r-- | rust/macros/helpers.rs | 86 | ||||
| -rw-r--r-- | rust/macros/lib.rs | 117 | ||||
| -rw-r--r-- | rust/macros/module.rs | 2 | ||||
| -rw-r--r-- | rust/macros/paste.rs | 96 | ||||
| -rw-r--r-- | rust/macros/pin_data.rs | 168 | ||||
| -rw-r--r-- | rust/macros/quote.rs | 26 | ||||
| -rw-r--r-- | rust/macros/vtable.rs | 1 | ||||
| -rw-r--r-- | rust/macros/zeroable.rs | 72 |
8 files changed, 500 insertions, 68 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/lib.rs b/rust/macros/lib.rs index 3fc74cb4ea19..c42105c2ff96 100644 --- a/rust/macros/lib.rs +++ b/rust/macros/lib.rs @@ -7,9 +7,11 @@ mod quote; mod concat_idents; mod helpers; mod module; +mod paste; mod pin_data; mod pinned_drop; mod vtable; +mod zeroable; use proc_macro::TokenStream; @@ -246,3 +248,118 @@ pub fn pin_data(inner: TokenStream, item: TokenStream) -> TokenStream { pub fn pinned_drop(args: TokenStream, input: TokenStream) -> TokenStream { pinned_drop::pinned_drop(args, input) } + +/// Paste identifiers together. +/// +/// Within the `paste!` macro, identifiers inside `[<` and `>]` are concatenated together to form a +/// single identifier. +/// +/// This is similar to the [`paste`] crate, but with pasting feature limited to identifiers +/// (literals, lifetimes and documentation strings are not supported). There is a difference in +/// supported modifiers as well. +/// +/// # Example +/// +/// ```ignore +/// use kernel::macro::paste; +/// +/// macro_rules! pub_no_prefix { +/// ($prefix:ident, $($newname:ident),+) => { +/// paste! { +/// $(pub(crate) const $newname: u32 = [<$prefix $newname>];)+ +/// } +/// }; +/// } +/// +/// pub_no_prefix!( +/// binder_driver_return_protocol_, +/// BR_OK, +/// BR_ERROR, +/// BR_TRANSACTION, +/// BR_REPLY, +/// BR_DEAD_REPLY, +/// BR_TRANSACTION_COMPLETE, +/// BR_INCREFS, +/// BR_ACQUIRE, +/// BR_RELEASE, +/// BR_DECREFS, +/// BR_NOOP, +/// BR_SPAWN_LOOPER, +/// BR_DEAD_BINDER, +/// BR_CLEAR_DEATH_NOTIFICATION_DONE, +/// BR_FAILED_REPLY +/// ); +/// +/// assert_eq!(BR_OK, binder_driver_return_protocol_BR_OK); +/// ``` +/// +/// # Modifiers +/// +/// For each identifier, it is possible to attach one or multiple modifiers to +/// it. +/// +/// Currently supported modifiers are: +/// * `span`: change the span of concatenated identifier to the span of the specified token. By +/// default the span of the `[< >]` group is used. +/// * `lower`: change the identifier to lower case. +/// * `upper`: change the identifier to upper case. +/// +/// ```ignore +/// use kernel::macro::paste; +/// +/// macro_rules! pub_no_prefix { +/// ($prefix:ident, $($newname:ident),+) => { +/// kernel::macros::paste! { +/// $(pub(crate) const fn [<$newname:lower:span>]: u32 = [<$prefix $newname:span>];)+ +/// } +/// }; +/// } +/// +/// pub_no_prefix!( +/// binder_driver_return_protocol_, +/// BR_OK, +/// BR_ERROR, +/// BR_TRANSACTION, +/// BR_REPLY, +/// BR_DEAD_REPLY, +/// BR_TRANSACTION_COMPLETE, +/// BR_INCREFS, +/// BR_ACQUIRE, +/// BR_RELEASE, +/// BR_DECREFS, +/// BR_NOOP, +/// BR_SPAWN_LOOPER, +/// BR_DEAD_BINDER, +/// BR_CLEAR_DEATH_NOTIFICATION_DONE, +/// BR_FAILED_REPLY +/// ); +/// +/// assert_eq!(br_ok(), binder_driver_return_protocol_BR_OK); +/// ``` +/// +/// [`paste`]: https://docs.rs/paste/ +#[proc_macro] +pub fn paste(input: TokenStream) -> TokenStream { + let mut tokens = input.into_iter().collect(); + 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/module.rs b/rust/macros/module.rs index fb1244f8c2e6..d62d8710d77a 100644 --- a/rust/macros/module.rs +++ b/rust/macros/module.rs @@ -199,7 +199,7 @@ pub(crate) fn module(ts: TokenStream) -> TokenStream { /// Used by the printing macros, e.g. [`info!`]. const __LOG_PREFIX: &[u8] = b\"{name}\\0\"; - /// The \"Rust loadable module\" mark, for `scripts/is_rust_module.sh`. + /// The \"Rust loadable module\" mark. // // This may be best done another way later on, e.g. as a new modinfo // key or a new section. For the moment, keep it simple. diff --git a/rust/macros/paste.rs b/rust/macros/paste.rs new file mode 100644 index 000000000000..385a78434224 --- /dev/null +++ b/rust/macros/paste.rs @@ -0,0 +1,96 @@ +// SPDX-License-Identifier: GPL-2.0 + +use proc_macro::{Delimiter, Group, Ident, Spacing, Span, TokenTree}; + +fn concat(tokens: &[TokenTree], group_span: Span) -> TokenTree { + let mut tokens = tokens.iter(); + let mut segments = Vec::new(); + let mut span = None; + loop { + match tokens.next() { + None => break, + Some(TokenTree::Literal(lit)) => segments.push((lit.to_string(), lit.span())), + Some(TokenTree::Ident(ident)) => { + let mut value = ident.to_string(); + if value.starts_with("r#") { + value.replace_range(0..2, ""); + } + segments.push((value, ident.span())); + } + Some(TokenTree::Punct(p)) if p.as_char() == ':' => { + let Some(TokenTree::Ident(ident)) = tokens.next() else { + panic!("expected identifier as modifier"); + }; + + let (mut value, sp) = segments.pop().expect("expected identifier before modifier"); + match ident.to_string().as_str() { + // Set the overall span of concatenated token as current span + "span" => { + assert!( + span.is_none(), + "span modifier should only appear at most once" + ); + span = Some(sp); + } + "lower" => value = value.to_lowercase(), + "upper" => value = value.to_uppercase(), + v => panic!("unknown modifier `{v}`"), + }; + segments.push((value, sp)); + } + _ => panic!("unexpected token in paste segments"), + }; + } + + let pasted: String = segments.into_iter().map(|x| x.0).collect(); + TokenTree::Ident(Ident::new(&pasted, span.unwrap_or(group_span))) +} + +pub(crate) fn expand(tokens: &mut Vec<TokenTree>) { + for token in tokens.iter_mut() { + if let TokenTree::Group(group) = token { + let delimiter = group.delimiter(); + let span = group.span(); + let mut stream: Vec<_> = group.stream().into_iter().collect(); + // Find groups that looks like `[< A B C D >]` + if delimiter == Delimiter::Bracket + && stream.len() >= 3 + && matches!(&stream[0], TokenTree::Punct(p) if p.as_char() == '<') + && matches!(&stream[stream.len() - 1], TokenTree::Punct(p) if p.as_char() == '>') + { + // Replace the group with concatenated token + *token = concat(&stream[1..stream.len() - 1], span); + } else { + // Recursively expand tokens inside the group + expand(&mut stream); + let mut group = Group::new(delimiter, stream.into_iter().collect()); + group.set_span(span); + *token = TokenTree::Group(group); + } + } + } + + // Path segments cannot contain invisible delimiter group, so remove them if any. + for i in (0..tokens.len().saturating_sub(3)).rev() { + // Looking for a double colon + if matches!( + (&tokens[i + 1], &tokens[i + 2]), + (TokenTree::Punct(a), TokenTree::Punct(b)) + if a.as_char() == ':' && a.spacing() == Spacing::Joint && b.as_char() == ':' + ) { + match &tokens[i + 3] { + TokenTree::Group(group) if group.delimiter() == Delimiter::None => { + tokens.splice(i + 3..i + 4, group.stream()); + } + _ => (), + } + + match &tokens[i] { + TokenTree::Group(group) if group.delimiter() == Delimiter::None => { + tokens.splice(i..i + 1, group.stream()); + } + _ => (), + } + } + } +} diff --git a/rust/macros/pin_data.rs b/rust/macros/pin_data.rs index 954149d77181..6d58cfda9872 100644 --- a/rust/macros/pin_data.rs +++ b/rust/macros/pin_data.rs @@ -1,79 +1,127 @@ // SPDX-License-Identifier: Apache-2.0 OR MIT -use proc_macro::{Punct, Spacing, TokenStream, TokenTree}; +use crate::helpers::{parse_generics, Generics}; +use proc_macro::{Group, Punct, Spacing, TokenStream, TokenTree}; 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; - } + let ( + Generics { + impl_generics, + ty_generics, + }, + rest, + ) = parse_generics(input); + // The struct definition might contain the `Self` type. Since `__pin_data!` will define a new + // type with the same generics and bounds, this poses a problem, since `Self` will refer to the + // new type as opposed to this struct definition. Therefore we have to replace `Self` with the + // concrete name. + + // Errors that occur when replacing `Self` with `struct_name`. + let mut errs = TokenStream::new(); + // The name of the struct with ty_generics. + let struct_name = rest + .iter() + .skip_while(|tt| !matches!(tt, TokenTree::Ident(i) if i.to_string() == "struct")) + .nth(1) + .and_then(|tt| match tt { + TokenTree::Ident(_) => { + let tt = tt.clone(); + let mut res = vec![tt]; + if !ty_generics.is_empty() { + // We add this, so it is maximally compatible with e.g. `Self::CONST` which + // will be replaced by `StructName::<$generics>::CONST`. + res.push(TokenTree::Punct(Punct::new(':', Spacing::Joint))); + res.push(TokenTree::Punct(Punct::new(':', Spacing::Alone))); + res.push(TokenTree::Punct(Punct::new('<', Spacing::Alone))); + res.extend(ty_generics.iter().cloned()); + res.push(TokenTree::Punct(Punct::new('>', Spacing::Alone))); } + Some(res) } - 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); - } + _ => None, + }) + .unwrap_or_else(|| { + // If we did not find the name of the struct then we will use `Self` as the replacement + // and add a compile error to ensure it does not compile. + errs.extend( + "::core::compile_error!(\"Could not locate type name.\");" + .parse::<TokenStream>() + .unwrap(), + ); + "Self".parse::<TokenStream>().unwrap().into_iter().collect() + }); + let impl_generics = impl_generics + .into_iter() + .flat_map(|tt| replace_self_and_deny_type_defs(&struct_name, tt, &mut errs)) + .collect::<Vec<_>>(); + let mut rest = rest + .into_iter() + .flat_map(|tt| { + // We ignore top level `struct` tokens, since they would emit a compile error. + if matches!(&tt, TokenTree::Ident(i) if i.to_string() == "struct") { + vec![tt] + } else { + replace_self_and_deny_type_defs(&struct_name, tt, &mut errs) } - } - } - rest.extend(toks); + }) + .collect::<Vec<_>>(); // This should be the body of the struct `{...}`. let last = rest.pop(); - quote!(::kernel::__pin_data! { + let mut quoted = quote!(::kernel::__pin_data! { parse_input: @args(#args), @sig(#(#rest)*), @impl_generics(#(#impl_generics)*), @ty_generics(#(#ty_generics)*), @body(#last), - }) + }); + quoted.extend(errs); + quoted +} + +/// Replaces `Self` with `struct_name` and errors on `enum`, `trait`, `struct` `union` and `impl` +/// keywords. +/// +/// The error is appended to `errs` to allow normal parsing to continue. +fn replace_self_and_deny_type_defs( + struct_name: &Vec<TokenTree>, + tt: TokenTree, + errs: &mut TokenStream, +) -> Vec<TokenTree> { + match tt { + TokenTree::Ident(ref i) + if i.to_string() == "enum" + || i.to_string() == "trait" + || i.to_string() == "struct" + || i.to_string() == "union" + || i.to_string() == "impl" => + { + errs.extend( + format!( + "::core::compile_error!(\"Cannot use `{i}` inside of struct definition with \ + `#[pin_data]`.\");" + ) + .parse::<TokenStream>() + .unwrap() + .into_iter() + .map(|mut tok| { + tok.set_span(tt.span()); + tok + }), + ); + vec![tt] + } + TokenTree::Ident(i) if i.to_string() == "Self" => struct_name.clone(), + TokenTree::Literal(_) | TokenTree::Punct(_) | TokenTree::Ident(_) => vec![tt], + TokenTree::Group(g) => vec![TokenTree::Group(Group::new( + g.delimiter(), + g.stream() + .into_iter() + .flat_map(|tt| replace_self_and_deny_type_defs(struct_name, tt, errs)) + .collect(), + ))], + } } diff --git a/rust/macros/quote.rs b/rust/macros/quote.rs index c8e08b3c1e4c..33a199e4f176 100644 --- a/rust/macros/quote.rs +++ b/rust/macros/quote.rs @@ -39,12 +39,14 @@ impl ToTokens for TokenStream { /// [`quote_spanned!`](https://docs.rs/quote/latest/quote/macro.quote_spanned.html) macro from the /// `quote` crate but provides only just enough functionality needed by the current `macros` crate. macro_rules! quote_spanned { - ($span:expr => $($tt:tt)*) => { - #[allow(clippy::vec_init_then_push)] - { - let mut tokens = ::std::vec::Vec::new(); - let span = $span; - quote_spanned!(@proc tokens span $($tt)*); + ($span:expr => $($tt:tt)*) => {{ + let mut tokens; + #[allow(clippy::vec_init_then_push)] + { + tokens = ::std::vec::Vec::new(); + let span = $span; + quote_spanned!(@proc tokens span $($tt)*); + } ::proc_macro::TokenStream::from_iter(tokens) }}; (@proc $v:ident $span:ident) => {}; @@ -122,6 +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/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(); 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), + ); + } +} |