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Diffstat (limited to 'third_party/rust/syn/src/ty.rs')
| -rw-r--r-- | third_party/rust/syn/src/ty.rs | 1304 |
1 files changed, 1304 insertions, 0 deletions
diff --git a/third_party/rust/syn/src/ty.rs b/third_party/rust/syn/src/ty.rs new file mode 100644 index 0000000000..8c841e2f79 --- /dev/null +++ b/third_party/rust/syn/src/ty.rs @@ -0,0 +1,1304 @@ +use super::*; +use crate::punctuated::Punctuated; +use proc_macro2::TokenStream; + +ast_enum_of_structs! { + /// The possible types that a Rust value could have. + /// + /// *This type is available only if Syn is built with the `"derive"` or `"full"` + /// feature.* + /// + /// # Syntax tree enum + /// + /// This type is a [syntax tree enum]. + /// + /// [syntax tree enum]: Expr#syntax-tree-enums + #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))] + #[cfg_attr(not(syn_no_non_exhaustive), non_exhaustive)] + pub enum Type { + /// A fixed size array type: `[T; n]`. + Array(TypeArray), + + /// A bare function type: `fn(usize) -> bool`. + BareFn(TypeBareFn), + + /// A type contained within invisible delimiters. + Group(TypeGroup), + + /// An `impl Bound1 + Bound2 + Bound3` type where `Bound` is a trait or + /// a lifetime. + ImplTrait(TypeImplTrait), + + /// Indication that a type should be inferred by the compiler: `_`. + Infer(TypeInfer), + + /// A macro in the type position. + Macro(TypeMacro), + + /// The never type: `!`. + Never(TypeNever), + + /// A parenthesized type equivalent to the inner type. + Paren(TypeParen), + + /// A path like `std::slice::Iter`, optionally qualified with a + /// self-type as in `<Vec<T> as SomeTrait>::Associated`. + Path(TypePath), + + /// A raw pointer type: `*const T` or `*mut T`. + Ptr(TypePtr), + + /// A reference type: `&'a T` or `&'a mut T`. + Reference(TypeReference), + + /// A dynamically sized slice type: `[T]`. + Slice(TypeSlice), + + /// A trait object type `dyn Bound1 + Bound2 + Bound3` where `Bound` is a + /// trait or a lifetime. + TraitObject(TypeTraitObject), + + /// A tuple type: `(A, B, C, String)`. + Tuple(TypeTuple), + + /// Tokens in type position not interpreted by Syn. + Verbatim(TokenStream), + + // Not public API. + // + // For testing exhaustiveness in downstream code, use the following idiom: + // + // match ty { + // Type::Array(ty) => {...} + // Type::BareFn(ty) => {...} + // ... + // Type::Verbatim(ty) => {...} + // + // #[cfg_attr(test, deny(non_exhaustive_omitted_patterns))] + // _ => { /* some sane fallback */ } + // } + // + // This way we fail your tests but don't break your library when adding + // a variant. You will be notified by a test failure when a variant is + // added, so that you can add code to handle it, but your library will + // continue to compile and work for downstream users in the interim. + #[cfg(syn_no_non_exhaustive)] + #[doc(hidden)] + __NonExhaustive, + } +} + +ast_struct! { + /// A fixed size array type: `[T; n]`. + /// + /// *This type is available only if Syn is built with the `"derive"` or + /// `"full"` feature.* + #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))] + pub struct TypeArray { + pub bracket_token: token::Bracket, + pub elem: Box<Type>, + pub semi_token: Token![;], + pub len: Expr, + } +} + +ast_struct! { + /// A bare function type: `fn(usize) -> bool`. + /// + /// *This type is available only if Syn is built with the `"derive"` or + /// `"full"` feature.* + #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))] + pub struct TypeBareFn { + pub lifetimes: Option<BoundLifetimes>, + pub unsafety: Option<Token![unsafe]>, + pub abi: Option<Abi>, + pub fn_token: Token![fn], + pub paren_token: token::Paren, + pub inputs: Punctuated<BareFnArg, Token![,]>, + pub variadic: Option<Variadic>, + pub output: ReturnType, + } +} + +ast_struct! { + /// A type contained within invisible delimiters. + /// + /// *This type is available only if Syn is built with the `"derive"` or + /// `"full"` feature.* + #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))] + pub struct TypeGroup { + pub group_token: token::Group, + pub elem: Box<Type>, + } +} + +ast_struct! { + /// An `impl Bound1 + Bound2 + Bound3` type where `Bound` is a trait or + /// a lifetime. + /// + /// *This type is available only if Syn is built with the `"derive"` or + /// `"full"` feature.* + #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))] + pub struct TypeImplTrait { + pub impl_token: Token![impl], + pub bounds: Punctuated<TypeParamBound, Token![+]>, + } +} + +ast_struct! { + /// Indication that a type should be inferred by the compiler: `_`. + /// + /// *This type is available only if Syn is built with the `"derive"` or + /// `"full"` feature.* + #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))] + pub struct TypeInfer { + pub underscore_token: Token![_], + } +} + +ast_struct! { + /// A macro in the type position. + /// + /// *This type is available only if Syn is built with the `"derive"` or + /// `"full"` feature.* + #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))] + pub struct TypeMacro { + pub mac: Macro, + } +} + +ast_struct! { + /// The never type: `!`. + /// + /// *This type is available only if Syn is built with the `"derive"` or + /// `"full"` feature.* + #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))] + pub struct TypeNever { + pub bang_token: Token![!], + } +} + +ast_struct! { + /// A parenthesized type equivalent to the inner type. + /// + /// *This type is available only if Syn is built with the `"derive"` or + /// `"full"` feature.* + #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))] + pub struct TypeParen { + pub paren_token: token::Paren, + pub elem: Box<Type>, + } +} + +ast_struct! { + /// A path like `std::slice::Iter`, optionally qualified with a + /// self-type as in `<Vec<T> as SomeTrait>::Associated`. + /// + /// *This type is available only if Syn is built with the `"derive"` or + /// `"full"` feature.* + #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))] + pub struct TypePath { + pub qself: Option<QSelf>, + pub path: Path, + } +} + +ast_struct! { + /// A raw pointer type: `*const T` or `*mut T`. + /// + /// *This type is available only if Syn is built with the `"derive"` or + /// `"full"` feature.* + #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))] + pub struct TypePtr { + pub star_token: Token![*], + pub const_token: Option<Token![const]>, + pub mutability: Option<Token![mut]>, + pub elem: Box<Type>, + } +} + +ast_struct! { + /// A reference type: `&'a T` or `&'a mut T`. + /// + /// *This type is available only if Syn is built with the `"derive"` or + /// `"full"` feature.* + #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))] + pub struct TypeReference { + pub and_token: Token![&], + pub lifetime: Option<Lifetime>, + pub mutability: Option<Token![mut]>, + pub elem: Box<Type>, + } +} + +ast_struct! { + /// A dynamically sized slice type: `[T]`. + /// + /// *This type is available only if Syn is built with the `"derive"` or + /// `"full"` feature.* + #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))] + pub struct TypeSlice { + pub bracket_token: token::Bracket, + pub elem: Box<Type>, + } +} + +ast_struct! { + /// A trait object type `dyn Bound1 + Bound2 + Bound3` where `Bound` is a + /// trait or a lifetime. + /// + /// *This type is available only if Syn is built with the `"derive"` or + /// `"full"` feature.* + #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))] + pub struct TypeTraitObject { + pub dyn_token: Option<Token![dyn]>, + pub bounds: Punctuated<TypeParamBound, Token![+]>, + } +} + +ast_struct! { + /// A tuple type: `(A, B, C, String)`. + /// + /// *This type is available only if Syn is built with the `"derive"` or + /// `"full"` feature.* + #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))] + pub struct TypeTuple { + pub paren_token: token::Paren, + pub elems: Punctuated<Type, Token![,]>, + } +} + +ast_struct! { + /// The binary interface of a function: `extern "C"`. + /// + /// *This type is available only if Syn is built with the `"derive"` or `"full"` + /// feature.* + #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))] + pub struct Abi { + pub extern_token: Token![extern], + pub name: Option<LitStr>, + } +} + +ast_struct! { + /// An argument in a function type: the `usize` in `fn(usize) -> bool`. + /// + /// *This type is available only if Syn is built with the `"derive"` or `"full"` + /// feature.* + #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))] + pub struct BareFnArg { + pub attrs: Vec<Attribute>, + pub name: Option<(Ident, Token![:])>, + pub ty: Type, + } +} + +ast_struct! { + /// The variadic argument of a foreign function. + /// + /// ```rust + /// # struct c_char; + /// # struct c_int; + /// # + /// extern "C" { + /// fn printf(format: *const c_char, ...) -> c_int; + /// // ^^^ + /// } + /// ``` + /// + /// *This type is available only if Syn is built with the `"derive"` or `"full"` + /// feature.* + #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))] + pub struct Variadic { + pub attrs: Vec<Attribute>, + pub dots: Token![...], + } +} + +ast_enum! { + /// Return type of a function signature. + /// + /// *This type is available only if Syn is built with the `"derive"` or `"full"` + /// feature.* + #[cfg_attr(doc_cfg, doc(cfg(any(feature = "full", feature = "derive"))))] + pub enum ReturnType { + /// Return type is not specified. + /// + /// Functions default to `()` and closures default to type inference. + Default, + /// A particular type is returned. + Type(Token![->], Box<Type>), + } +} + +#[cfg(feature = "parsing")] +pub mod parsing { + use super::*; + use crate::ext::IdentExt; + use crate::parse::{Parse, ParseStream, Result}; + use crate::path; + use proc_macro2::{Punct, Spacing, Span, TokenTree}; + + #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))] + impl Parse for Type { + fn parse(input: ParseStream) -> Result<Self> { + let allow_plus = true; + let allow_group_generic = true; + ambig_ty(input, allow_plus, allow_group_generic) + } + } + + impl Type { + /// In some positions, types may not contain the `+` character, to + /// disambiguate them. For example in the expression `1 as T`, T may not + /// contain a `+` character. + /// + /// This parser does not allow a `+`, while the default parser does. + #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))] + pub fn without_plus(input: ParseStream) -> Result<Self> { + let allow_plus = false; + let allow_group_generic = true; + ambig_ty(input, allow_plus, allow_group_generic) + } + } + + pub(crate) fn ambig_ty( + input: ParseStream, + allow_plus: bool, + allow_group_generic: bool, + ) -> Result<Type> { + let begin = input.fork(); + + if input.peek(token::Group) { + let mut group: TypeGroup = input.parse()?; + if input.peek(Token![::]) && input.peek3(Ident::peek_any) { + if let Type::Path(mut ty) = *group.elem { + Path::parse_rest(input, &mut ty.path, false)?; + return Ok(Type::Path(ty)); + } else { + return Ok(Type::Path(TypePath { + qself: Some(QSelf { + lt_token: Token, + position: 0, + as_token: None, + gt_token: Token, + ty: group.elem, + }), + path: Path::parse_helper(input, false)?, + })); + } + } else if input.peek(Token![<]) && allow_group_generic + || input.peek(Token![::]) && input.peek3(Token![<]) + { + if let Type::Path(mut ty) = *group.elem { + let arguments = &mut ty.path.segments.last_mut().unwrap().arguments; + if let PathArguments::None = arguments { + *arguments = PathArguments::AngleBracketed(input.parse()?); + Path::parse_rest(input, &mut ty.path, false)?; + return Ok(Type::Path(ty)); + } else { + group.elem = Box::new(Type::Path(ty)); + } + } + } + return Ok(Type::Group(group)); + } + + let mut lifetimes = None::<BoundLifetimes>; + let mut lookahead = input.lookahead1(); + if lookahead.peek(Token![for]) { + lifetimes = input.parse()?; + lookahead = input.lookahead1(); + if !lookahead.peek(Ident) + && !lookahead.peek(Token![fn]) + && !lookahead.peek(Token![unsafe]) + && !lookahead.peek(Token![extern]) + && !lookahead.peek(Token![super]) + && !lookahead.peek(Token![self]) + && !lookahead.peek(Token![Self]) + && !lookahead.peek(Token![crate]) + || input.peek(Token![dyn]) + { + return Err(lookahead.error()); + } + } + + if lookahead.peek(token::Paren) { + let content; + let paren_token = parenthesized!(content in input); + if content.is_empty() { + return Ok(Type::Tuple(TypeTuple { + paren_token, + elems: Punctuated::new(), + })); + } + if content.peek(Lifetime) { + return Ok(Type::Paren(TypeParen { + paren_token, + elem: Box::new(Type::TraitObject(content.parse()?)), + })); + } + if content.peek(Token![?]) { + return Ok(Type::TraitObject(TypeTraitObject { + dyn_token: None, + bounds: { + let mut bounds = Punctuated::new(); + bounds.push_value(TypeParamBound::Trait(TraitBound { + paren_token: Some(paren_token), + ..content.parse()? + })); + while let Some(plus) = input.parse()? { + bounds.push_punct(plus); + bounds.push_value(input.parse()?); + } + bounds + }, + })); + } + let mut first: Type = content.parse()?; + if content.peek(Token![,]) { + return Ok(Type::Tuple(TypeTuple { + paren_token, + elems: { + let mut elems = Punctuated::new(); + elems.push_value(first); + elems.push_punct(content.parse()?); + while !content.is_empty() { + elems.push_value(content.parse()?); + if content.is_empty() { + break; + } + elems.push_punct(content.parse()?); + } + elems + }, + })); + } + if allow_plus && input.peek(Token![+]) { + loop { + let first = match first { + Type::Path(TypePath { qself: None, path }) => { + TypeParamBound::Trait(TraitBound { + paren_token: Some(paren_token), + modifier: TraitBoundModifier::None, + lifetimes: None, + path, + }) + } + Type::TraitObject(TypeTraitObject { + dyn_token: None, + bounds, + }) => { + if bounds.len() > 1 || bounds.trailing_punct() { + first = Type::TraitObject(TypeTraitObject { + dyn_token: None, + bounds, + }); + break; + } + match bounds.into_iter().next().unwrap() { + TypeParamBound::Trait(trait_bound) => { + TypeParamBound::Trait(TraitBound { + paren_token: Some(paren_token), + ..trait_bound + }) + } + other @ TypeParamBound::Lifetime(_) => other, + } + } + _ => break, + }; + return Ok(Type::TraitObject(TypeTraitObject { + dyn_token: None, + bounds: { + let mut bounds = Punctuated::new(); + bounds.push_value(first); + while let Some(plus) = input.parse()? { + bounds.push_punct(plus); + bounds.push_value(input.parse()?); + } + bounds + }, + })); + } + } + Ok(Type::Paren(TypeParen { + paren_token, + elem: Box::new(first), + })) + } else if lookahead.peek(Token![fn]) + || lookahead.peek(Token![unsafe]) + || lookahead.peek(Token![extern]) + { + let allow_mut_self = true; + if let Some(mut bare_fn) = parse_bare_fn(input, allow_mut_self)? { + bare_fn.lifetimes = lifetimes; + Ok(Type::BareFn(bare_fn)) + } else { + Ok(Type::Verbatim(verbatim::between(begin, input))) + } + } else if lookahead.peek(Ident) + || input.peek(Token![super]) + || input.peek(Token![self]) + || input.peek(Token![Self]) + || input.peek(Token![crate]) + || lookahead.peek(Token![::]) + || lookahead.peek(Token![<]) + { + let dyn_token: Option<Token![dyn]> = input.parse()?; + if let Some(dyn_token) = dyn_token { + let dyn_span = dyn_token.span; + let star_token: Option<Token![*]> = input.parse()?; + let bounds = TypeTraitObject::parse_bounds(dyn_span, input, allow_plus)?; + return Ok(if star_token.is_some() { + Type::Verbatim(verbatim::between(begin, input)) + } else { + Type::TraitObject(TypeTraitObject { + dyn_token: Some(dyn_token), + bounds, + }) + }); + } + + let ty: TypePath = input.parse()?; + if ty.qself.is_some() { + return Ok(Type::Path(ty)); + } + + if input.peek(Token![!]) && !input.peek(Token![!=]) { + let mut contains_arguments = false; + for segment in &ty.path.segments { + match segment.arguments { + PathArguments::None => {} + PathArguments::AngleBracketed(_) | PathArguments::Parenthesized(_) => { + contains_arguments = true; + } + } + } + + if !contains_arguments { + let bang_token: Token![!] = input.parse()?; + let (delimiter, tokens) = mac::parse_delimiter(input)?; + return Ok(Type::Macro(TypeMacro { + mac: Macro { + path: ty.path, + bang_token, + delimiter, + tokens, + }, + })); + } + } + + if lifetimes.is_some() || allow_plus && input.peek(Token![+]) { + let mut bounds = Punctuated::new(); + bounds.push_value(TypeParamBound::Trait(TraitBound { + paren_token: None, + modifier: TraitBoundModifier::None, + lifetimes, + path: ty.path, + })); + if allow_plus { + while input.peek(Token![+]) { + bounds.push_punct(input.parse()?); + if !(input.peek(Ident::peek_any) + || input.peek(Token![::]) + || input.peek(Token![?]) + || input.peek(Lifetime) + || input.peek(token::Paren)) + { + break; + } + bounds.push_value(input.parse()?); + } + } + return Ok(Type::TraitObject(TypeTraitObject { + dyn_token: None, + bounds, + })); + } + + Ok(Type::Path(ty)) + } else if lookahead.peek(token::Bracket) { + let content; + let bracket_token = bracketed!(content in input); + let elem: Type = content.parse()?; + if content.peek(Token![;]) { + Ok(Type::Array(TypeArray { + bracket_token, + elem: Box::new(elem), + semi_token: content.parse()?, + len: content.parse()?, + })) + } else { + Ok(Type::Slice(TypeSlice { + bracket_token, + elem: Box::new(elem), + })) + } + } else if lookahead.peek(Token![*]) { + input.parse().map(Type::Ptr) + } else if lookahead.peek(Token![&]) { + input.parse().map(Type::Reference) + } else if lookahead.peek(Token![!]) && !input.peek(Token![=]) { + input.parse().map(Type::Never) + } else if lookahead.peek(Token![impl]) { + TypeImplTrait::parse(input, allow_plus).map(Type::ImplTrait) + } else if lookahead.peek(Token![_]) { + input.parse().map(Type::Infer) + } else if lookahead.peek(Lifetime) { + input.parse().map(Type::TraitObject) + } else { + Err(lookahead.error()) + } + } + + #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))] + impl Parse for TypeSlice { + fn parse(input: ParseStream) -> Result<Self> { + let content; + Ok(TypeSlice { + bracket_token: bracketed!(content in input), + elem: content.parse()?, + }) + } + } + + #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))] + impl Parse for TypeArray { + fn parse(input: ParseStream) -> Result<Self> { + let content; + Ok(TypeArray { + bracket_token: bracketed!(content in input), + elem: content.parse()?, + semi_token: content.parse()?, + len: content.parse()?, + }) + } + } + + #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))] + impl Parse for TypePtr { + fn parse(input: ParseStream) -> Result<Self> { + let star_token: Token![*] = input.parse()?; + + let lookahead = input.lookahead1(); + let (const_token, mutability) = if lookahead.peek(Token![const]) { + (Some(input.parse()?), None) + } else if lookahead.peek(Token![mut]) { + (None, Some(input.parse()?)) + } else { + return Err(lookahead.error()); + }; + + Ok(TypePtr { + star_token, + const_token, + mutability, + elem: Box::new(input.call(Type::without_plus)?), + }) + } + } + + #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))] + impl Parse for TypeReference { + fn parse(input: ParseStream) -> Result<Self> { + Ok(TypeReference { + and_token: input.parse()?, + lifetime: input.parse()?, + mutability: input.parse()?, + // & binds tighter than +, so we don't allow + here. + elem: Box::new(input.call(Type::without_plus)?), + }) + } + } + + #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))] + impl Parse for TypeBareFn { + fn parse(input: ParseStream) -> Result<Self> { + let allow_mut_self = false; + parse_bare_fn(input, allow_mut_self).map(Option::unwrap) + } + } + + fn parse_bare_fn(input: ParseStream, allow_mut_self: bool) -> Result<Option<TypeBareFn>> { + let args; + let mut variadic = None; + let mut has_mut_self = false; + + let bare_fn = TypeBareFn { + lifetimes: input.parse()?, + unsafety: input.parse()?, + abi: input.parse()?, + fn_token: input.parse()?, + paren_token: parenthesized!(args in input), + inputs: { + let mut inputs = Punctuated::new(); + + while !args.is_empty() { + let attrs = args.call(Attribute::parse_outer)?; + + if inputs.empty_or_trailing() && args.peek(Token![...]) { + variadic = Some(Variadic { + attrs, + dots: args.parse()?, + }); + break; + } + + if let Some(arg) = parse_bare_fn_arg(&args, allow_mut_self)? { + inputs.push_value(BareFnArg { attrs, ..arg }); + } else { + has_mut_self = true; + } + if args.is_empty() { + break; + } + + let comma = args.parse()?; + if !has_mut_self { + inputs.push_punct(comma); + } + } + + inputs + }, + variadic, + output: input.call(ReturnType::without_plus)?, + }; + + if has_mut_self { + Ok(None) + } else { + Ok(Some(bare_fn)) + } + } + + #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))] + impl Parse for TypeNever { + fn parse(input: ParseStream) -> Result<Self> { + Ok(TypeNever { + bang_token: input.parse()?, + }) + } + } + + #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))] + impl Parse for TypeInfer { + fn parse(input: ParseStream) -> Result<Self> { + Ok(TypeInfer { + underscore_token: input.parse()?, + }) + } + } + + #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))] + impl Parse for TypeTuple { + fn parse(input: ParseStream) -> Result<Self> { + let content; + let paren_token = parenthesized!(content in input); + + if content.is_empty() { + return Ok(TypeTuple { + paren_token, + elems: Punctuated::new(), + }); + } + + let first: Type = content.parse()?; + Ok(TypeTuple { + paren_token, + elems: { + let mut elems = Punctuated::new(); + elems.push_value(first); + elems.push_punct(content.parse()?); + while !content.is_empty() { + elems.push_value(content.parse()?); + if content.is_empty() { + break; + } + elems.push_punct(content.parse()?); + } + elems + }, + }) + } + } + + #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))] + impl Parse for TypeMacro { + fn parse(input: ParseStream) -> Result<Self> { + Ok(TypeMacro { + mac: input.parse()?, + }) + } + } + + #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))] + impl Parse for TypePath { + fn parse(input: ParseStream) -> Result<Self> { + let expr_style = false; + let (qself, mut path) = path::parsing::qpath(input, expr_style)?; + + while path.segments.last().unwrap().arguments.is_empty() + && (input.peek(token::Paren) || input.peek(Token![::]) && input.peek3(token::Paren)) + { + input.parse::<Option<Token![::]>>()?; + let args: ParenthesizedGenericArguments = input.parse()?; + let allow_associated_type = cfg!(feature = "full") + && match &args.output { + ReturnType::Default => true, + ReturnType::Type(_, ty) => match **ty { + // TODO: probably some of the other kinds allow this too. + Type::Paren(_) => true, + _ => false, + }, + }; + let parenthesized = PathArguments::Parenthesized(args); + path.segments.last_mut().unwrap().arguments = parenthesized; + if allow_associated_type { + Path::parse_rest(input, &mut path, expr_style)?; + } + } + + Ok(TypePath { qself, path }) + } + } + + impl ReturnType { + #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))] + pub fn without_plus(input: ParseStream) -> Result<Self> { + let allow_plus = false; + Self::parse(input, allow_plus) + } + + pub(crate) fn parse(input: ParseStream, allow_plus: bool) -> Result<Self> { + if input.peek(Token![->]) { + let arrow = input.parse()?; + let allow_group_generic = true; + let ty = ambig_ty(input, allow_plus, allow_group_generic)?; + Ok(ReturnType::Type(arrow, Box::new(ty))) + } else { + Ok(ReturnType::Default) + } + } + } + + #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))] + impl Parse for ReturnType { + fn parse(input: ParseStream) -> Result<Self> { + let allow_plus = true; + Self::parse(input, allow_plus) + } + } + + #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))] + impl Parse for TypeTraitObject { + fn parse(input: ParseStream) -> Result<Self> { + let allow_plus = true; + Self::parse(input, allow_plus) + } + } + + impl TypeTraitObject { + #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))] + pub fn without_plus(input: ParseStream) -> Result<Self> { + let allow_plus = false; + Self::parse(input, allow_plus) + } + + // Only allow multiple trait references if allow_plus is true. + pub(crate) fn parse(input: ParseStream, allow_plus: bool) -> Result<Self> { + let dyn_token: Option<Token![dyn]> = input.parse()?; + let dyn_span = match &dyn_token { + Some(token) => token.span, + None => input.span(), + }; + let bounds = Self::parse_bounds(dyn_span, input, allow_plus)?; + Ok(TypeTraitObject { dyn_token, bounds }) + } + + fn parse_bounds( + dyn_span: Span, + input: ParseStream, + allow_plus: bool, + ) -> Result<Punctuated<TypeParamBound, Token![+]>> { + let bounds = TypeParamBound::parse_multiple(input, allow_plus)?; + let mut last_lifetime_span = None; + let mut at_least_one_trait = false; + for bound in &bounds { + match bound { + TypeParamBound::Trait(_) => { + at_least_one_trait = true; + break; + } + TypeParamBound::Lifetime(lifetime) => { + last_lifetime_span = Some(lifetime.ident.span()); + } + } + } + // Just lifetimes like `'a + 'b` is not a TraitObject. + if !at_least_one_trait { + let msg = "at least one trait is required for an object type"; + return Err(error::new2(dyn_span, last_lifetime_span.unwrap(), msg)); + } + Ok(bounds) + } + } + + #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))] + impl Parse for TypeImplTrait { + fn parse(input: ParseStream) -> Result<Self> { + let allow_plus = true; + Self::parse(input, allow_plus) + } + } + + impl TypeImplTrait { + #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))] + pub fn without_plus(input: ParseStream) -> Result<Self> { + let allow_plus = false; + Self::parse(input, allow_plus) + } + + pub(crate) fn parse(input: ParseStream, allow_plus: bool) -> Result<Self> { + let impl_token: Token![impl] = input.parse()?; + let bounds = TypeParamBound::parse_multiple(input, allow_plus)?; + let mut last_lifetime_span = None; + let mut at_least_one_trait = false; + for bound in &bounds { + match bound { + TypeParamBound::Trait(_) => { + at_least_one_trait = true; + break; + } + TypeParamBound::Lifetime(lifetime) => { + last_lifetime_span = Some(lifetime.ident.span()); + } + } + } + if !at_least_one_trait { + let msg = "at least one trait must be specified"; + return Err(error::new2( + impl_token.span, + last_lifetime_span.unwrap(), + msg, + )); + } + Ok(TypeImplTrait { impl_token, bounds }) + } + } + + #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))] + impl Parse for TypeGroup { + fn parse(input: ParseStream) -> Result<Self> { + let group = crate::group::parse_group(input)?; + Ok(TypeGroup { + group_token: group.token, + elem: group.content.parse()?, + }) + } + } + + #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))] + impl Parse for TypeParen { + fn parse(input: ParseStream) -> Result<Self> { + let allow_plus = false; + Self::parse(input, allow_plus) + } + } + + impl TypeParen { + fn parse(input: ParseStream, allow_plus: bool) -> Result<Self> { + let content; + Ok(TypeParen { + paren_token: parenthesized!(content in input), + elem: Box::new({ + let allow_group_generic = true; + ambig_ty(&content, allow_plus, allow_group_generic)? + }), + }) + } + } + + #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))] + impl Parse for BareFnArg { + fn parse(input: ParseStream) -> Result<Self> { + let allow_mut_self = false; + parse_bare_fn_arg(input, allow_mut_self).map(Option::unwrap) + } + } + + fn parse_bare_fn_arg( + input: ParseStream, + mut allow_mut_self: bool, + ) -> Result<Option<BareFnArg>> { + let mut has_mut_self = false; + let arg = BareFnArg { + attrs: input.call(Attribute::parse_outer)?, + name: { + if (input.peek(Ident) || input.peek(Token![_]) || input.peek(Token![self])) + && input.peek2(Token![:]) + && !input.peek2(Token![::]) + { + let name = input.call(Ident::parse_any)?; + let colon: Token![:] = input.parse()?; + Some((name, colon)) + } else if allow_mut_self + && input.peek(Token![mut]) + && input.peek2(Token![self]) + && input.peek3(Token![:]) + && !input.peek3(Token![::]) + { + has_mut_self = true; + allow_mut_self = false; + input.parse::<Token![mut]>()?; + input.parse::<Token![self]>()?; + input.parse::<Token![:]>()?; + None + } else { + None + } + }, + ty: if !has_mut_self && input.peek(Token![...]) { + let dot3 = input.parse::<Token![...]>()?; + let args = vec![ + TokenTree::Punct(Punct::new('.', Spacing::Joint)), + TokenTree::Punct(Punct::new('.', Spacing::Joint)), + TokenTree::Punct(Punct::new('.', Spacing::Alone)), + ]; + let tokens: TokenStream = args + .into_iter() + .zip(&dot3.spans) + .map(|(mut arg, span)| { + arg.set_span(*span); + arg + }) + .collect(); + Type::Verbatim(tokens) + } else if allow_mut_self && input.peek(Token![mut]) && input.peek2(Token![self]) { + has_mut_self = true; + input.parse::<Token![mut]>()?; + Type::Path(TypePath { + qself: None, + path: input.parse::<Token![self]>()?.into(), + }) + } else { + input.parse()? + }, + }; + + if has_mut_self { + Ok(None) + } else { + Ok(Some(arg)) + } + } + + #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))] + impl Parse for Abi { + fn parse(input: ParseStream) -> Result<Self> { + Ok(Abi { + extern_token: input.parse()?, + name: input.parse()?, + }) + } + } + + #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))] + impl Parse for Option<Abi> { + fn parse(input: ParseStream) -> Result<Self> { + if input.peek(Token![extern]) { + input.parse().map(Some) + } else { + Ok(None) + } + } + } +} + +#[cfg(feature = "printing")] +mod printing { + use super::*; + use crate::attr::FilterAttrs; + use crate::print::TokensOrDefault; + use proc_macro2::TokenStream; + use quote::{ToTokens, TokenStreamExt}; + + #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))] + impl ToTokens for TypeSlice { + fn to_tokens(&self, tokens: &mut TokenStream) { + self.bracket_token.surround(tokens, |tokens| { + self.elem.to_tokens(tokens); + }); + } + } + + #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))] + impl ToTokens for TypeArray { + fn to_tokens(&self, tokens: &mut TokenStream) { + self.bracket_token.surround(tokens, |tokens| { + self.elem.to_tokens(tokens); + self.semi_token.to_tokens(tokens); + self.len.to_tokens(tokens); + }); + } + } + + #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))] + impl ToTokens for TypePtr { + fn to_tokens(&self, tokens: &mut TokenStream) { + self.star_token.to_tokens(tokens); + match &self.mutability { + Some(tok) => tok.to_tokens(tokens), + None => { + TokensOrDefault(&self.const_token).to_tokens(tokens); + } + } + self.elem.to_tokens(tokens); + } + } + + #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))] + impl ToTokens for TypeReference { + fn to_tokens(&self, tokens: &mut TokenStream) { + self.and_token.to_tokens(tokens); + self.lifetime.to_tokens(tokens); + self.mutability.to_tokens(tokens); + self.elem.to_tokens(tokens); + } + } + + #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))] + impl ToTokens for TypeBareFn { + fn to_tokens(&self, tokens: &mut TokenStream) { + self.lifetimes.to_tokens(tokens); + self.unsafety.to_tokens(tokens); + self.abi.to_tokens(tokens); + self.fn_token.to_tokens(tokens); + self.paren_token.surround(tokens, |tokens| { + self.inputs.to_tokens(tokens); + if let Some(variadic) = &self.variadic { + if !self.inputs.empty_or_trailing() { + let span = variadic.dots.spans[0]; + Token.to_tokens(tokens); + } + variadic.to_tokens(tokens); + } + }); + self.output.to_tokens(tokens); + } + } + + #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))] + impl ToTokens for TypeNever { + fn to_tokens(&self, tokens: &mut TokenStream) { + self.bang_token.to_tokens(tokens); + } + } + + #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))] + impl ToTokens for TypeTuple { + fn to_tokens(&self, tokens: &mut TokenStream) { + self.paren_token.surround(tokens, |tokens| { + self.elems.to_tokens(tokens); + }); + } + } + + #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))] + impl ToTokens for TypePath { + fn to_tokens(&self, tokens: &mut TokenStream) { + path::printing::print_path(tokens, &self.qself, &self.path); + } + } + + #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))] + impl ToTokens for TypeTraitObject { + fn to_tokens(&self, tokens: &mut TokenStream) { + self.dyn_token.to_tokens(tokens); + self.bounds.to_tokens(tokens); + } + } + + #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))] + impl ToTokens for TypeImplTrait { + fn to_tokens(&self, tokens: &mut TokenStream) { + self.impl_token.to_tokens(tokens); + self.bounds.to_tokens(tokens); + } + } + + #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))] + impl ToTokens for TypeGroup { + fn to_tokens(&self, tokens: &mut TokenStream) { + self.group_token.surround(tokens, |tokens| { + self.elem.to_tokens(tokens); + }); + } + } + + #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))] + impl ToTokens for TypeParen { + fn to_tokens(&self, tokens: &mut TokenStream) { + self.paren_token.surround(tokens, |tokens| { + self.elem.to_tokens(tokens); + }); + } + } + + #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))] + impl ToTokens for TypeInfer { + fn to_tokens(&self, tokens: &mut TokenStream) { + self.underscore_token.to_tokens(tokens); + } + } + + #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))] + impl ToTokens for TypeMacro { + fn to_tokens(&self, tokens: &mut TokenStream) { + self.mac.to_tokens(tokens); + } + } + + #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))] + impl ToTokens for ReturnType { + fn to_tokens(&self, tokens: &mut TokenStream) { + match self { + ReturnType::Default => {} + ReturnType::Type(arrow, ty) => { + arrow.to_tokens(tokens); + ty.to_tokens(tokens); + } + } + } + } + + #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))] + impl ToTokens for BareFnArg { + fn to_tokens(&self, tokens: &mut TokenStream) { + tokens.append_all(self.attrs.outer()); + if let Some((name, colon)) = &self.name { + name.to_tokens(tokens); + colon.to_tokens(tokens); + } + self.ty.to_tokens(tokens); + } + } + + #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))] + impl ToTokens for Variadic { + fn to_tokens(&self, tokens: &mut TokenStream) { + tokens.append_all(self.attrs.outer()); + self.dots.to_tokens(tokens); + } + } + + #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))] + impl ToTokens for Abi { + fn to_tokens(&self, tokens: &mut TokenStream) { + self.extern_token.to_tokens(tokens); + self.name.to_tokens(tokens); + } + } +} |