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Diffstat (limited to 'third_party/rust/proc-macro2/src/lib.rs')
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diff --git a/third_party/rust/proc-macro2/src/lib.rs b/third_party/rust/proc-macro2/src/lib.rs new file mode 100644 index 0000000000..910d47b3b1 --- /dev/null +++ b/third_party/rust/proc-macro2/src/lib.rs @@ -0,0 +1,1316 @@ +//! [![github]](https://github.com/dtolnay/proc-macro2) [![crates-io]](https://crates.io/crates/proc-macro2) [![docs-rs]](crate) +//! +//! [github]: https://img.shields.io/badge/github-8da0cb?style=for-the-badge&labelColor=555555&logo=github +//! [crates-io]: https://img.shields.io/badge/crates.io-fc8d62?style=for-the-badge&labelColor=555555&logo=rust +//! [docs-rs]: https://img.shields.io/badge/docs.rs-66c2a5?style=for-the-badge&labelColor=555555&logo=docs.rs +//! +//! <br> +//! +//! A wrapper around the procedural macro API of the compiler's [`proc_macro`] +//! crate. This library serves two purposes: +//! +//! [`proc_macro`]: https://doc.rust-lang.org/proc_macro/ +//! +//! - **Bring proc-macro-like functionality to other contexts like build.rs and +//! main.rs.** Types from `proc_macro` are entirely specific to procedural +//! macros and cannot ever exist in code outside of a procedural macro. +//! Meanwhile `proc_macro2` types may exist anywhere including non-macro code. +//! By developing foundational libraries like [syn] and [quote] against +//! `proc_macro2` rather than `proc_macro`, the procedural macro ecosystem +//! becomes easily applicable to many other use cases and we avoid +//! reimplementing non-macro equivalents of those libraries. +//! +//! - **Make procedural macros unit testable.** As a consequence of being +//! specific to procedural macros, nothing that uses `proc_macro` can be +//! executed from a unit test. In order for helper libraries or components of +//! a macro to be testable in isolation, they must be implemented using +//! `proc_macro2`. +//! +//! [syn]: https://github.com/dtolnay/syn +//! [quote]: https://github.com/dtolnay/quote +//! +//! # Usage +//! +//! The skeleton of a typical procedural macro typically looks like this: +//! +//! ``` +//! extern crate proc_macro; +//! +//! # const IGNORE: &str = stringify! { +//! #[proc_macro_derive(MyDerive)] +//! # }; +//! # #[cfg(wrap_proc_macro)] +//! pub fn my_derive(input: proc_macro::TokenStream) -> proc_macro::TokenStream { +//! let input = proc_macro2::TokenStream::from(input); +//! +//! let output: proc_macro2::TokenStream = { +//! /* transform input */ +//! # input +//! }; +//! +//! proc_macro::TokenStream::from(output) +//! } +//! ``` +//! +//! If parsing with [Syn], you'll use [`parse_macro_input!`] instead to +//! propagate parse errors correctly back to the compiler when parsing fails. +//! +//! [`parse_macro_input!`]: https://docs.rs/syn/1.0/syn/macro.parse_macro_input.html +//! +//! # Unstable features +//! +//! The default feature set of proc-macro2 tracks the most recent stable +//! compiler API. Functionality in `proc_macro` that is not yet stable is not +//! exposed by proc-macro2 by default. +//! +//! To opt into the additional APIs available in the most recent nightly +//! compiler, the `procmacro2_semver_exempt` config flag must be passed to +//! rustc. We will polyfill those nightly-only APIs back to Rust 1.56.0. As +//! these are unstable APIs that track the nightly compiler, minor versions of +//! proc-macro2 may make breaking changes to them at any time. +//! +//! ```sh +//! RUSTFLAGS='--cfg procmacro2_semver_exempt' cargo build +//! ``` +//! +//! Note that this must not only be done for your crate, but for any crate that +//! depends on your crate. This infectious nature is intentional, as it serves +//! as a reminder that you are outside of the normal semver guarantees. +//! +//! Semver exempt methods are marked as such in the proc-macro2 documentation. +//! +//! # Thread-Safety +//! +//! Most types in this crate are `!Sync` because the underlying compiler +//! types make use of thread-local memory, meaning they cannot be accessed from +//! a different thread. + +// Proc-macro2 types in rustdoc of other crates get linked to here. +#![doc(html_root_url = "https://docs.rs/proc-macro2/1.0.66")] +#![cfg_attr(any(proc_macro_span, super_unstable), feature(proc_macro_span))] +#![cfg_attr(super_unstable, feature(proc_macro_def_site))] +#![cfg_attr(doc_cfg, feature(doc_cfg))] +#![allow( + clippy::cast_lossless, + clippy::cast_possible_truncation, + clippy::doc_markdown, + clippy::items_after_statements, + clippy::let_underscore_untyped, + clippy::manual_assert, + clippy::manual_range_contains, + clippy::must_use_candidate, + clippy::needless_doctest_main, + clippy::new_without_default, + clippy::return_self_not_must_use, + clippy::shadow_unrelated, + clippy::trivially_copy_pass_by_ref, + clippy::unnecessary_wraps, + clippy::unused_self, + clippy::used_underscore_binding, + clippy::vec_init_then_push +)] + +#[cfg(all(procmacro2_semver_exempt, wrap_proc_macro, not(super_unstable)))] +compile_error! {"\ + Something is not right. If you've tried to turn on \ + procmacro2_semver_exempt, you need to ensure that it \ + is turned on for the compilation of the proc-macro2 \ + build script as well. +"} + +extern crate alloc; + +#[cfg(feature = "proc-macro")] +extern crate proc_macro; + +mod marker; +mod parse; +mod rcvec; + +#[cfg(wrap_proc_macro)] +mod detection; + +// Public for proc_macro2::fallback::force() and unforce(), but those are quite +// a niche use case so we omit it from rustdoc. +#[doc(hidden)] +pub mod fallback; + +pub mod extra; + +#[cfg(not(wrap_proc_macro))] +use crate::fallback as imp; +#[path = "wrapper.rs"] +#[cfg(wrap_proc_macro)] +mod imp; + +#[cfg(span_locations)] +mod location; + +use crate::extra::DelimSpan; +use crate::marker::Marker; +use core::cmp::Ordering; +use core::fmt::{self, Debug, Display}; +use core::hash::{Hash, Hasher}; +use core::ops::RangeBounds; +use core::str::FromStr; +use std::error::Error; +#[cfg(procmacro2_semver_exempt)] +use std::path::PathBuf; + +#[cfg(span_locations)] +pub use crate::location::LineColumn; + +/// An abstract stream of tokens, or more concretely a sequence of token trees. +/// +/// This type provides interfaces for iterating over token trees and for +/// collecting token trees into one stream. +/// +/// Token stream is both the input and output of `#[proc_macro]`, +/// `#[proc_macro_attribute]` and `#[proc_macro_derive]` definitions. +#[derive(Clone)] +pub struct TokenStream { + inner: imp::TokenStream, + _marker: Marker, +} + +/// Error returned from `TokenStream::from_str`. +pub struct LexError { + inner: imp::LexError, + _marker: Marker, +} + +impl TokenStream { + fn _new(inner: imp::TokenStream) -> Self { + TokenStream { + inner, + _marker: Marker, + } + } + + fn _new_fallback(inner: fallback::TokenStream) -> Self { + TokenStream { + inner: inner.into(), + _marker: Marker, + } + } + + /// Returns an empty `TokenStream` containing no token trees. + pub fn new() -> Self { + TokenStream::_new(imp::TokenStream::new()) + } + + /// Checks if this `TokenStream` is empty. + pub fn is_empty(&self) -> bool { + self.inner.is_empty() + } +} + +/// `TokenStream::default()` returns an empty stream, +/// i.e. this is equivalent with `TokenStream::new()`. +impl Default for TokenStream { + fn default() -> Self { + TokenStream::new() + } +} + +/// Attempts to break the string into tokens and parse those tokens into a token +/// stream. +/// +/// May fail for a number of reasons, for example, if the string contains +/// unbalanced delimiters or characters not existing in the language. +/// +/// NOTE: Some errors may cause panics instead of returning `LexError`. We +/// reserve the right to change these errors into `LexError`s later. +impl FromStr for TokenStream { + type Err = LexError; + + fn from_str(src: &str) -> Result<TokenStream, LexError> { + let e = src.parse().map_err(|e| LexError { + inner: e, + _marker: Marker, + })?; + Ok(TokenStream::_new(e)) + } +} + +#[cfg(feature = "proc-macro")] +#[cfg_attr(doc_cfg, doc(cfg(feature = "proc-macro")))] +impl From<proc_macro::TokenStream> for TokenStream { + fn from(inner: proc_macro::TokenStream) -> Self { + TokenStream::_new(inner.into()) + } +} + +#[cfg(feature = "proc-macro")] +#[cfg_attr(doc_cfg, doc(cfg(feature = "proc-macro")))] +impl From<TokenStream> for proc_macro::TokenStream { + fn from(inner: TokenStream) -> Self { + inner.inner.into() + } +} + +impl From<TokenTree> for TokenStream { + fn from(token: TokenTree) -> Self { + TokenStream::_new(imp::TokenStream::from(token)) + } +} + +impl Extend<TokenTree> for TokenStream { + fn extend<I: IntoIterator<Item = TokenTree>>(&mut self, streams: I) { + self.inner.extend(streams); + } +} + +impl Extend<TokenStream> for TokenStream { + fn extend<I: IntoIterator<Item = TokenStream>>(&mut self, streams: I) { + self.inner + .extend(streams.into_iter().map(|stream| stream.inner)); + } +} + +/// Collects a number of token trees into a single stream. +impl FromIterator<TokenTree> for TokenStream { + fn from_iter<I: IntoIterator<Item = TokenTree>>(streams: I) -> Self { + TokenStream::_new(streams.into_iter().collect()) + } +} +impl FromIterator<TokenStream> for TokenStream { + fn from_iter<I: IntoIterator<Item = TokenStream>>(streams: I) -> Self { + TokenStream::_new(streams.into_iter().map(|i| i.inner).collect()) + } +} + +/// Prints the token stream as a string that is supposed to be losslessly +/// convertible back into the same token stream (modulo spans), except for +/// possibly `TokenTree::Group`s with `Delimiter::None` delimiters and negative +/// numeric literals. +impl Display for TokenStream { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + Display::fmt(&self.inner, f) + } +} + +/// Prints token in a form convenient for debugging. +impl Debug for TokenStream { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + Debug::fmt(&self.inner, f) + } +} + +impl LexError { + pub fn span(&self) -> Span { + Span::_new(self.inner.span()) + } +} + +impl Debug for LexError { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + Debug::fmt(&self.inner, f) + } +} + +impl Display for LexError { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + Display::fmt(&self.inner, f) + } +} + +impl Error for LexError {} + +/// The source file of a given `Span`. +/// +/// This type is semver exempt and not exposed by default. +#[cfg(all(procmacro2_semver_exempt, any(not(wrap_proc_macro), super_unstable)))] +#[cfg_attr(doc_cfg, doc(cfg(procmacro2_semver_exempt)))] +#[derive(Clone, PartialEq, Eq)] +pub struct SourceFile { + inner: imp::SourceFile, + _marker: Marker, +} + +#[cfg(all(procmacro2_semver_exempt, any(not(wrap_proc_macro), super_unstable)))] +impl SourceFile { + fn _new(inner: imp::SourceFile) -> Self { + SourceFile { + inner, + _marker: Marker, + } + } + + /// Get the path to this source file. + /// + /// ### Note + /// + /// If the code span associated with this `SourceFile` was generated by an + /// external macro, this may not be an actual path on the filesystem. Use + /// [`is_real`] to check. + /// + /// Also note that even if `is_real` returns `true`, if + /// `--remap-path-prefix` was passed on the command line, the path as given + /// may not actually be valid. + /// + /// [`is_real`]: #method.is_real + pub fn path(&self) -> PathBuf { + self.inner.path() + } + + /// Returns `true` if this source file is a real source file, and not + /// generated by an external macro's expansion. + pub fn is_real(&self) -> bool { + self.inner.is_real() + } +} + +#[cfg(all(procmacro2_semver_exempt, any(not(wrap_proc_macro), super_unstable)))] +impl Debug for SourceFile { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + Debug::fmt(&self.inner, f) + } +} + +/// A region of source code, along with macro expansion information. +#[derive(Copy, Clone)] +pub struct Span { + inner: imp::Span, + _marker: Marker, +} + +impl Span { + fn _new(inner: imp::Span) -> Self { + Span { + inner, + _marker: Marker, + } + } + + fn _new_fallback(inner: fallback::Span) -> Self { + Span { + inner: inner.into(), + _marker: Marker, + } + } + + /// The span of the invocation of the current procedural macro. + /// + /// Identifiers created with this span will be resolved as if they were + /// written directly at the macro call location (call-site hygiene) and + /// other code at the macro call site will be able to refer to them as well. + pub fn call_site() -> Self { + Span::_new(imp::Span::call_site()) + } + + /// The span located at the invocation of the procedural macro, but with + /// local variables, labels, and `$crate` resolved at the definition site + /// of the macro. This is the same hygiene behavior as `macro_rules`. + pub fn mixed_site() -> Self { + Span::_new(imp::Span::mixed_site()) + } + + /// A span that resolves at the macro definition site. + /// + /// This method is semver exempt and not exposed by default. + #[cfg(procmacro2_semver_exempt)] + #[cfg_attr(doc_cfg, doc(cfg(procmacro2_semver_exempt)))] + pub fn def_site() -> Self { + Span::_new(imp::Span::def_site()) + } + + /// Creates a new span with the same line/column information as `self` but + /// that resolves symbols as though it were at `other`. + pub fn resolved_at(&self, other: Span) -> Span { + Span::_new(self.inner.resolved_at(other.inner)) + } + + /// Creates a new span with the same name resolution behavior as `self` but + /// with the line/column information of `other`. + pub fn located_at(&self, other: Span) -> Span { + Span::_new(self.inner.located_at(other.inner)) + } + + /// Convert `proc_macro2::Span` to `proc_macro::Span`. + /// + /// This method is available when building with a nightly compiler, or when + /// building with rustc 1.29+ *without* semver exempt features. + /// + /// # Panics + /// + /// Panics if called from outside of a procedural macro. Unlike + /// `proc_macro2::Span`, the `proc_macro::Span` type can only exist within + /// the context of a procedural macro invocation. + #[cfg(wrap_proc_macro)] + pub fn unwrap(self) -> proc_macro::Span { + self.inner.unwrap() + } + + // Soft deprecated. Please use Span::unwrap. + #[cfg(wrap_proc_macro)] + #[doc(hidden)] + pub fn unstable(self) -> proc_macro::Span { + self.unwrap() + } + + /// The original source file into which this span points. + /// + /// This method is semver exempt and not exposed by default. + #[cfg(all(procmacro2_semver_exempt, any(not(wrap_proc_macro), super_unstable)))] + #[cfg_attr(doc_cfg, doc(cfg(procmacro2_semver_exempt)))] + pub fn source_file(&self) -> SourceFile { + SourceFile::_new(self.inner.source_file()) + } + + /// Get the starting line/column in the source file for this span. + /// + /// This method requires the `"span-locations"` feature to be enabled. + /// + /// When executing in a procedural macro context, the returned line/column + /// are only meaningful if compiled with a nightly toolchain. The stable + /// toolchain does not have this information available. When executing + /// outside of a procedural macro, such as main.rs or build.rs, the + /// line/column are always meaningful regardless of toolchain. + #[cfg(span_locations)] + #[cfg_attr(doc_cfg, doc(cfg(feature = "span-locations")))] + pub fn start(&self) -> LineColumn { + self.inner.start() + } + + /// Get the ending line/column in the source file for this span. + /// + /// This method requires the `"span-locations"` feature to be enabled. + /// + /// When executing in a procedural macro context, the returned line/column + /// are only meaningful if compiled with a nightly toolchain. The stable + /// toolchain does not have this information available. When executing + /// outside of a procedural macro, such as main.rs or build.rs, the + /// line/column are always meaningful regardless of toolchain. + #[cfg(span_locations)] + #[cfg_attr(doc_cfg, doc(cfg(feature = "span-locations")))] + pub fn end(&self) -> LineColumn { + self.inner.end() + } + + /// Create a new span encompassing `self` and `other`. + /// + /// Returns `None` if `self` and `other` are from different files. + /// + /// Warning: the underlying [`proc_macro::Span::join`] method is + /// nightly-only. When called from within a procedural macro not using a + /// nightly compiler, this method will always return `None`. + /// + /// [`proc_macro::Span::join`]: https://doc.rust-lang.org/proc_macro/struct.Span.html#method.join + pub fn join(&self, other: Span) -> Option<Span> { + self.inner.join(other.inner).map(Span::_new) + } + + /// Compares two spans to see if they're equal. + /// + /// This method is semver exempt and not exposed by default. + #[cfg(procmacro2_semver_exempt)] + #[cfg_attr(doc_cfg, doc(cfg(procmacro2_semver_exempt)))] + pub fn eq(&self, other: &Span) -> bool { + self.inner.eq(&other.inner) + } + + /// Returns the source text behind a span. This preserves the original + /// source code, including spaces and comments. It only returns a result if + /// the span corresponds to real source code. + /// + /// Note: The observable result of a macro should only rely on the tokens + /// and not on this source text. The result of this function is a best + /// effort to be used for diagnostics only. + pub fn source_text(&self) -> Option<String> { + self.inner.source_text() + } +} + +/// Prints a span in a form convenient for debugging. +impl Debug for Span { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + Debug::fmt(&self.inner, f) + } +} + +/// A single token or a delimited sequence of token trees (e.g. `[1, (), ..]`). +#[derive(Clone)] +pub enum TokenTree { + /// A token stream surrounded by bracket delimiters. + Group(Group), + /// An identifier. + Ident(Ident), + /// A single punctuation character (`+`, `,`, `$`, etc.). + Punct(Punct), + /// A literal character (`'a'`), string (`"hello"`), number (`2.3`), etc. + Literal(Literal), +} + +impl TokenTree { + /// Returns the span of this tree, delegating to the `span` method of + /// the contained token or a delimited stream. + pub fn span(&self) -> Span { + match self { + TokenTree::Group(t) => t.span(), + TokenTree::Ident(t) => t.span(), + TokenTree::Punct(t) => t.span(), + TokenTree::Literal(t) => t.span(), + } + } + + /// Configures the span for *only this token*. + /// + /// Note that if this token is a `Group` then this method will not configure + /// the span of each of the internal tokens, this will simply delegate to + /// the `set_span` method of each variant. + pub fn set_span(&mut self, span: Span) { + match self { + TokenTree::Group(t) => t.set_span(span), + TokenTree::Ident(t) => t.set_span(span), + TokenTree::Punct(t) => t.set_span(span), + TokenTree::Literal(t) => t.set_span(span), + } + } +} + +impl From<Group> for TokenTree { + fn from(g: Group) -> Self { + TokenTree::Group(g) + } +} + +impl From<Ident> for TokenTree { + fn from(g: Ident) -> Self { + TokenTree::Ident(g) + } +} + +impl From<Punct> for TokenTree { + fn from(g: Punct) -> Self { + TokenTree::Punct(g) + } +} + +impl From<Literal> for TokenTree { + fn from(g: Literal) -> Self { + TokenTree::Literal(g) + } +} + +/// Prints the token tree as a string that is supposed to be losslessly +/// convertible back into the same token tree (modulo spans), except for +/// possibly `TokenTree::Group`s with `Delimiter::None` delimiters and negative +/// numeric literals. +impl Display for TokenTree { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + match self { + TokenTree::Group(t) => Display::fmt(t, f), + TokenTree::Ident(t) => Display::fmt(t, f), + TokenTree::Punct(t) => Display::fmt(t, f), + TokenTree::Literal(t) => Display::fmt(t, f), + } + } +} + +/// Prints token tree in a form convenient for debugging. +impl Debug for TokenTree { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + // Each of these has the name in the struct type in the derived debug, + // so don't bother with an extra layer of indirection + match self { + TokenTree::Group(t) => Debug::fmt(t, f), + TokenTree::Ident(t) => { + let mut debug = f.debug_struct("Ident"); + debug.field("sym", &format_args!("{}", t)); + imp::debug_span_field_if_nontrivial(&mut debug, t.span().inner); + debug.finish() + } + TokenTree::Punct(t) => Debug::fmt(t, f), + TokenTree::Literal(t) => Debug::fmt(t, f), + } + } +} + +/// A delimited token stream. +/// +/// A `Group` internally contains a `TokenStream` which is surrounded by +/// `Delimiter`s. +#[derive(Clone)] +pub struct Group { + inner: imp::Group, +} + +/// Describes how a sequence of token trees is delimited. +#[derive(Copy, Clone, Debug, Eq, PartialEq)] +pub enum Delimiter { + /// `( ... )` + Parenthesis, + /// `{ ... }` + Brace, + /// `[ ... ]` + Bracket, + /// `Ø ... Ø` + /// + /// An implicit delimiter, that may, for example, appear around tokens + /// coming from a "macro variable" `$var`. It is important to preserve + /// operator priorities in cases like `$var * 3` where `$var` is `1 + 2`. + /// Implicit delimiters may not survive roundtrip of a token stream through + /// a string. + None, +} + +impl Group { + fn _new(inner: imp::Group) -> Self { + Group { inner } + } + + fn _new_fallback(inner: fallback::Group) -> Self { + Group { + inner: inner.into(), + } + } + + /// Creates a new `Group` with the given delimiter and token stream. + /// + /// This constructor will set the span for this group to + /// `Span::call_site()`. To change the span you can use the `set_span` + /// method below. + pub fn new(delimiter: Delimiter, stream: TokenStream) -> Self { + Group { + inner: imp::Group::new(delimiter, stream.inner), + } + } + + /// Returns the punctuation used as the delimiter for this group: a set of + /// parentheses, square brackets, or curly braces. + pub fn delimiter(&self) -> Delimiter { + self.inner.delimiter() + } + + /// Returns the `TokenStream` of tokens that are delimited in this `Group`. + /// + /// Note that the returned token stream does not include the delimiter + /// returned above. + pub fn stream(&self) -> TokenStream { + TokenStream::_new(self.inner.stream()) + } + + /// Returns the span for the delimiters of this token stream, spanning the + /// entire `Group`. + /// + /// ```text + /// pub fn span(&self) -> Span { + /// ^^^^^^^ + /// ``` + pub fn span(&self) -> Span { + Span::_new(self.inner.span()) + } + + /// Returns the span pointing to the opening delimiter of this group. + /// + /// ```text + /// pub fn span_open(&self) -> Span { + /// ^ + /// ``` + pub fn span_open(&self) -> Span { + Span::_new(self.inner.span_open()) + } + + /// Returns the span pointing to the closing delimiter of this group. + /// + /// ```text + /// pub fn span_close(&self) -> Span { + /// ^ + /// ``` + pub fn span_close(&self) -> Span { + Span::_new(self.inner.span_close()) + } + + /// Returns an object that holds this group's `span_open()` and + /// `span_close()` together (in a more compact representation than holding + /// those 2 spans individually). + pub fn delim_span(&self) -> DelimSpan { + DelimSpan::new(&self.inner) + } + + /// Configures the span for this `Group`'s delimiters, but not its internal + /// tokens. + /// + /// This method will **not** set the span of all the internal tokens spanned + /// by this group, but rather it will only set the span of the delimiter + /// tokens at the level of the `Group`. + pub fn set_span(&mut self, span: Span) { + self.inner.set_span(span.inner); + } +} + +/// Prints the group as a string that should be losslessly convertible back +/// into the same group (modulo spans), except for possibly `TokenTree::Group`s +/// with `Delimiter::None` delimiters. +impl Display for Group { + fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + Display::fmt(&self.inner, formatter) + } +} + +impl Debug for Group { + fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + Debug::fmt(&self.inner, formatter) + } +} + +/// A `Punct` is a single punctuation character like `+`, `-` or `#`. +/// +/// Multicharacter operators like `+=` are represented as two instances of +/// `Punct` with different forms of `Spacing` returned. +#[derive(Clone)] +pub struct Punct { + ch: char, + spacing: Spacing, + span: Span, +} + +/// Whether a `Punct` is followed immediately by another `Punct` or followed by +/// another token or whitespace. +#[derive(Copy, Clone, Debug, Eq, PartialEq)] +pub enum Spacing { + /// E.g. `+` is `Alone` in `+ =`, `+ident` or `+()`. + Alone, + /// E.g. `+` is `Joint` in `+=` or `'` is `Joint` in `'#`. + /// + /// Additionally, single quote `'` can join with identifiers to form + /// lifetimes `'ident`. + Joint, +} + +impl Punct { + /// Creates a new `Punct` from the given character and spacing. + /// + /// The `ch` argument must be a valid punctuation character permitted by the + /// language, otherwise the function will panic. + /// + /// The returned `Punct` will have the default span of `Span::call_site()` + /// which can be further configured with the `set_span` method below. + pub fn new(ch: char, spacing: Spacing) -> Self { + Punct { + ch, + spacing, + span: Span::call_site(), + } + } + + /// Returns the value of this punctuation character as `char`. + pub fn as_char(&self) -> char { + self.ch + } + + /// Returns the spacing of this punctuation character, indicating whether + /// it's immediately followed by another `Punct` in the token stream, so + /// they can potentially be combined into a multicharacter operator + /// (`Joint`), or it's followed by some other token or whitespace (`Alone`) + /// so the operator has certainly ended. + pub fn spacing(&self) -> Spacing { + self.spacing + } + + /// Returns the span for this punctuation character. + pub fn span(&self) -> Span { + self.span + } + + /// Configure the span for this punctuation character. + pub fn set_span(&mut self, span: Span) { + self.span = span; + } +} + +/// Prints the punctuation character as a string that should be losslessly +/// convertible back into the same character. +impl Display for Punct { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + Display::fmt(&self.ch, f) + } +} + +impl Debug for Punct { + fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result { + let mut debug = fmt.debug_struct("Punct"); + debug.field("char", &self.ch); + debug.field("spacing", &self.spacing); + imp::debug_span_field_if_nontrivial(&mut debug, self.span.inner); + debug.finish() + } +} + +/// A word of Rust code, which may be a keyword or legal variable name. +/// +/// An identifier consists of at least one Unicode code point, the first of +/// which has the XID_Start property and the rest of which have the XID_Continue +/// property. +/// +/// - The empty string is not an identifier. Use `Option<Ident>`. +/// - A lifetime is not an identifier. Use `syn::Lifetime` instead. +/// +/// An identifier constructed with `Ident::new` is permitted to be a Rust +/// keyword, though parsing one through its [`Parse`] implementation rejects +/// Rust keywords. Use `input.call(Ident::parse_any)` when parsing to match the +/// behaviour of `Ident::new`. +/// +/// [`Parse`]: https://docs.rs/syn/1.0/syn/parse/trait.Parse.html +/// +/// # Examples +/// +/// A new ident can be created from a string using the `Ident::new` function. +/// A span must be provided explicitly which governs the name resolution +/// behavior of the resulting identifier. +/// +/// ``` +/// use proc_macro2::{Ident, Span}; +/// +/// fn main() { +/// let call_ident = Ident::new("calligraphy", Span::call_site()); +/// +/// println!("{}", call_ident); +/// } +/// ``` +/// +/// An ident can be interpolated into a token stream using the `quote!` macro. +/// +/// ``` +/// use proc_macro2::{Ident, Span}; +/// use quote::quote; +/// +/// fn main() { +/// let ident = Ident::new("demo", Span::call_site()); +/// +/// // Create a variable binding whose name is this ident. +/// let expanded = quote! { let #ident = 10; }; +/// +/// // Create a variable binding with a slightly different name. +/// let temp_ident = Ident::new(&format!("new_{}", ident), Span::call_site()); +/// let expanded = quote! { let #temp_ident = 10; }; +/// } +/// ``` +/// +/// A string representation of the ident is available through the `to_string()` +/// method. +/// +/// ``` +/// # use proc_macro2::{Ident, Span}; +/// # +/// # let ident = Ident::new("another_identifier", Span::call_site()); +/// # +/// // Examine the ident as a string. +/// let ident_string = ident.to_string(); +/// if ident_string.len() > 60 { +/// println!("Very long identifier: {}", ident_string) +/// } +/// ``` +#[derive(Clone)] +pub struct Ident { + inner: imp::Ident, + _marker: Marker, +} + +impl Ident { + fn _new(inner: imp::Ident) -> Self { + Ident { + inner, + _marker: Marker, + } + } + + /// Creates a new `Ident` with the given `string` as well as the specified + /// `span`. + /// + /// The `string` argument must be a valid identifier permitted by the + /// language, otherwise the function will panic. + /// + /// Note that `span`, currently in rustc, configures the hygiene information + /// for this identifier. + /// + /// As of this time `Span::call_site()` explicitly opts-in to "call-site" + /// hygiene meaning that identifiers created with this span will be resolved + /// as if they were written directly at the location of the macro call, and + /// other code at the macro call site will be able to refer to them as well. + /// + /// Later spans like `Span::def_site()` will allow to opt-in to + /// "definition-site" hygiene meaning that identifiers created with this + /// span will be resolved at the location of the macro definition and other + /// code at the macro call site will not be able to refer to them. + /// + /// Due to the current importance of hygiene this constructor, unlike other + /// tokens, requires a `Span` to be specified at construction. + /// + /// # Panics + /// + /// Panics if the input string is neither a keyword nor a legal variable + /// name. If you are not sure whether the string contains an identifier and + /// need to handle an error case, use + /// <a href="https://docs.rs/syn/1.0/syn/fn.parse_str.html"><code + /// style="padding-right:0;">syn::parse_str</code></a><code + /// style="padding-left:0;">::<Ident></code> + /// rather than `Ident::new`. + pub fn new(string: &str, span: Span) -> Self { + Ident::_new(imp::Ident::new(string, span.inner)) + } + + /// Same as `Ident::new`, but creates a raw identifier (`r#ident`). The + /// `string` argument must be a valid identifier permitted by the language + /// (including keywords, e.g. `fn`). Keywords which are usable in path + /// segments (e.g. `self`, `super`) are not supported, and will cause a + /// panic. + pub fn new_raw(string: &str, span: Span) -> Self { + Ident::_new_raw(string, span) + } + + fn _new_raw(string: &str, span: Span) -> Self { + Ident::_new(imp::Ident::new_raw(string, span.inner)) + } + + /// Returns the span of this `Ident`. + pub fn span(&self) -> Span { + Span::_new(self.inner.span()) + } + + /// Configures the span of this `Ident`, possibly changing its hygiene + /// context. + pub fn set_span(&mut self, span: Span) { + self.inner.set_span(span.inner); + } +} + +impl PartialEq for Ident { + fn eq(&self, other: &Ident) -> bool { + self.inner == other.inner + } +} + +impl<T> PartialEq<T> for Ident +where + T: ?Sized + AsRef<str>, +{ + fn eq(&self, other: &T) -> bool { + self.inner == other + } +} + +impl Eq for Ident {} + +impl PartialOrd for Ident { + fn partial_cmp(&self, other: &Ident) -> Option<Ordering> { + Some(self.cmp(other)) + } +} + +impl Ord for Ident { + fn cmp(&self, other: &Ident) -> Ordering { + self.to_string().cmp(&other.to_string()) + } +} + +impl Hash for Ident { + fn hash<H: Hasher>(&self, hasher: &mut H) { + self.to_string().hash(hasher); + } +} + +/// Prints the identifier as a string that should be losslessly convertible back +/// into the same identifier. +impl Display for Ident { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + Display::fmt(&self.inner, f) + } +} + +impl Debug for Ident { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + Debug::fmt(&self.inner, f) + } +} + +/// A literal string (`"hello"`), byte string (`b"hello"`), character (`'a'`), +/// byte character (`b'a'`), an integer or floating point number with or without +/// a suffix (`1`, `1u8`, `2.3`, `2.3f32`). +/// +/// Boolean literals like `true` and `false` do not belong here, they are +/// `Ident`s. +#[derive(Clone)] +pub struct Literal { + inner: imp::Literal, + _marker: Marker, +} + +macro_rules! suffixed_int_literals { + ($($name:ident => $kind:ident,)*) => ($( + /// Creates a new suffixed integer literal with the specified value. + /// + /// This function will create an integer like `1u32` where the integer + /// value specified is the first part of the token and the integral is + /// also suffixed at the end. Literals created from negative numbers may + /// not survive roundtrips through `TokenStream` or strings and may be + /// broken into two tokens (`-` and positive literal). + /// + /// Literals created through this method have the `Span::call_site()` + /// span by default, which can be configured with the `set_span` method + /// below. + pub fn $name(n: $kind) -> Literal { + Literal::_new(imp::Literal::$name(n)) + } + )*) +} + +macro_rules! unsuffixed_int_literals { + ($($name:ident => $kind:ident,)*) => ($( + /// Creates a new unsuffixed integer literal with the specified value. + /// + /// This function will create an integer like `1` where the integer + /// value specified is the first part of the token. No suffix is + /// specified on this token, meaning that invocations like + /// `Literal::i8_unsuffixed(1)` are equivalent to + /// `Literal::u32_unsuffixed(1)`. Literals created from negative numbers + /// may not survive roundtrips through `TokenStream` or strings and may + /// be broken into two tokens (`-` and positive literal). + /// + /// Literals created through this method have the `Span::call_site()` + /// span by default, which can be configured with the `set_span` method + /// below. + pub fn $name(n: $kind) -> Literal { + Literal::_new(imp::Literal::$name(n)) + } + )*) +} + +impl Literal { + fn _new(inner: imp::Literal) -> Self { + Literal { + inner, + _marker: Marker, + } + } + + fn _new_fallback(inner: fallback::Literal) -> Self { + Literal { + inner: inner.into(), + _marker: Marker, + } + } + + suffixed_int_literals! { + u8_suffixed => u8, + u16_suffixed => u16, + u32_suffixed => u32, + u64_suffixed => u64, + u128_suffixed => u128, + usize_suffixed => usize, + i8_suffixed => i8, + i16_suffixed => i16, + i32_suffixed => i32, + i64_suffixed => i64, + i128_suffixed => i128, + isize_suffixed => isize, + } + + unsuffixed_int_literals! { + u8_unsuffixed => u8, + u16_unsuffixed => u16, + u32_unsuffixed => u32, + u64_unsuffixed => u64, + u128_unsuffixed => u128, + usize_unsuffixed => usize, + i8_unsuffixed => i8, + i16_unsuffixed => i16, + i32_unsuffixed => i32, + i64_unsuffixed => i64, + i128_unsuffixed => i128, + isize_unsuffixed => isize, + } + + /// Creates a new unsuffixed floating-point literal. + /// + /// This constructor is similar to those like `Literal::i8_unsuffixed` where + /// the float's value is emitted directly into the token but no suffix is + /// used, so it may be inferred to be a `f64` later in the compiler. + /// Literals created from negative numbers may not survive round-trips + /// through `TokenStream` or strings and may be broken into two tokens (`-` + /// and positive literal). + /// + /// # Panics + /// + /// This function requires that the specified float is finite, for example + /// if it is infinity or NaN this function will panic. + pub fn f64_unsuffixed(f: f64) -> Literal { + assert!(f.is_finite()); + Literal::_new(imp::Literal::f64_unsuffixed(f)) + } + + /// Creates a new suffixed floating-point literal. + /// + /// This constructor will create a literal like `1.0f64` where the value + /// specified is the preceding part of the token and `f64` is the suffix of + /// the token. This token will always be inferred to be an `f64` in the + /// compiler. Literals created from negative numbers may not survive + /// round-trips through `TokenStream` or strings and may be broken into two + /// tokens (`-` and positive literal). + /// + /// # Panics + /// + /// This function requires that the specified float is finite, for example + /// if it is infinity or NaN this function will panic. + pub fn f64_suffixed(f: f64) -> Literal { + assert!(f.is_finite()); + Literal::_new(imp::Literal::f64_suffixed(f)) + } + + /// Creates a new unsuffixed floating-point literal. + /// + /// This constructor is similar to those like `Literal::i8_unsuffixed` where + /// the float's value is emitted directly into the token but no suffix is + /// used, so it may be inferred to be a `f64` later in the compiler. + /// Literals created from negative numbers may not survive round-trips + /// through `TokenStream` or strings and may be broken into two tokens (`-` + /// and positive literal). + /// + /// # Panics + /// + /// This function requires that the specified float is finite, for example + /// if it is infinity or NaN this function will panic. + pub fn f32_unsuffixed(f: f32) -> Literal { + assert!(f.is_finite()); + Literal::_new(imp::Literal::f32_unsuffixed(f)) + } + + /// Creates a new suffixed floating-point literal. + /// + /// This constructor will create a literal like `1.0f32` where the value + /// specified is the preceding part of the token and `f32` is the suffix of + /// the token. This token will always be inferred to be an `f32` in the + /// compiler. Literals created from negative numbers may not survive + /// round-trips through `TokenStream` or strings and may be broken into two + /// tokens (`-` and positive literal). + /// + /// # Panics + /// + /// This function requires that the specified float is finite, for example + /// if it is infinity or NaN this function will panic. + pub fn f32_suffixed(f: f32) -> Literal { + assert!(f.is_finite()); + Literal::_new(imp::Literal::f32_suffixed(f)) + } + + /// String literal. + pub fn string(string: &str) -> Literal { + Literal::_new(imp::Literal::string(string)) + } + + /// Character literal. + pub fn character(ch: char) -> Literal { + Literal::_new(imp::Literal::character(ch)) + } + + /// Byte string literal. + pub fn byte_string(s: &[u8]) -> Literal { + Literal::_new(imp::Literal::byte_string(s)) + } + + /// Returns the span encompassing this literal. + pub fn span(&self) -> Span { + Span::_new(self.inner.span()) + } + + /// Configures the span associated for this literal. + pub fn set_span(&mut self, span: Span) { + self.inner.set_span(span.inner); + } + + /// Returns a `Span` that is a subset of `self.span()` containing only + /// the source bytes in range `range`. Returns `None` if the would-be + /// trimmed span is outside the bounds of `self`. + /// + /// Warning: the underlying [`proc_macro::Literal::subspan`] method is + /// nightly-only. When called from within a procedural macro not using a + /// nightly compiler, this method will always return `None`. + /// + /// [`proc_macro::Literal::subspan`]: https://doc.rust-lang.org/proc_macro/struct.Literal.html#method.subspan + pub fn subspan<R: RangeBounds<usize>>(&self, range: R) -> Option<Span> { + self.inner.subspan(range).map(Span::_new) + } + + // Intended for the `quote!` macro to use when constructing a proc-macro2 + // token out of a macro_rules $:literal token, which is already known to be + // a valid literal. This avoids reparsing/validating the literal's string + // representation. This is not public API other than for quote. + #[doc(hidden)] + pub unsafe fn from_str_unchecked(repr: &str) -> Self { + Literal::_new(imp::Literal::from_str_unchecked(repr)) + } +} + +impl FromStr for Literal { + type Err = LexError; + + fn from_str(repr: &str) -> Result<Self, LexError> { + repr.parse().map(Literal::_new).map_err(|inner| LexError { + inner, + _marker: Marker, + }) + } +} + +impl Debug for Literal { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + Debug::fmt(&self.inner, f) + } +} + +impl Display for Literal { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + Display::fmt(&self.inner, f) + } +} + +/// Public implementation details for the `TokenStream` type, such as iterators. +pub mod token_stream { + use crate::marker::Marker; + use crate::{imp, TokenTree}; + use core::fmt::{self, Debug}; + + pub use crate::TokenStream; + + /// An iterator over `TokenStream`'s `TokenTree`s. + /// + /// The iteration is "shallow", e.g. the iterator doesn't recurse into + /// delimited groups, and returns whole groups as token trees. + #[derive(Clone)] + pub struct IntoIter { + inner: imp::TokenTreeIter, + _marker: Marker, + } + + impl Iterator for IntoIter { + type Item = TokenTree; + + fn next(&mut self) -> Option<TokenTree> { + self.inner.next() + } + + fn size_hint(&self) -> (usize, Option<usize>) { + self.inner.size_hint() + } + } + + impl Debug for IntoIter { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + f.write_str("TokenStream ")?; + f.debug_list().entries(self.clone()).finish() + } + } + + impl IntoIterator for TokenStream { + type Item = TokenTree; + type IntoIter = IntoIter; + + fn into_iter(self) -> IntoIter { + IntoIter { + inner: self.inner.into_iter(), + _marker: Marker, + } + } + } +} |