| // Copyright 2016 The Rust Project Developers. See the COPYRIGHT |
| // file at the top-level directory of this distribution and at |
| // http://rust-lang.org/COPYRIGHT. |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| //! A support library for macro authors when defining new macros. |
| //! |
| //! This library, provided by the standard distribution, provides the types |
| //! consumed in the interfaces of procedurally defined macro definitions such as |
| //! function-like macros `#[proc_macro]`, macro attribures `#[proc_macro_attribute]` and |
| //! custom derive attributes`#[proc_macro_derive]`. |
| //! |
| //! Note that this crate is intentionally bare-bones currently. |
| //! This functionality is intended to be expanded over time as more surface |
| //! area for macro authors is stabilized. |
| //! |
| //! See [the book](../book/first-edition/procedural-macros.html) for more. |
| |
| #![stable(feature = "proc_macro_lib", since = "1.15.0")] |
| #![deny(missing_docs)] |
| #![doc(html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png", |
| html_favicon_url = "https://doc.rust-lang.org/favicon.ico", |
| html_root_url = "https://doc.rust-lang.org/nightly/", |
| html_playground_url = "https://play.rust-lang.org/", |
| issue_tracker_base_url = "https://github.com/rust-lang/rust/issues/", |
| test(no_crate_inject, attr(deny(warnings))), |
| test(attr(allow(dead_code, deprecated, unused_variables, unused_mut))))] |
| |
| #![cfg_attr(not(stage0), feature(nll))] |
| #![feature(rustc_private)] |
| #![feature(staged_api)] |
| #![feature(lang_items)] |
| #![feature(optin_builtin_traits)] |
| #![feature(non_exhaustive)] |
| |
| #![recursion_limit="256"] |
| |
| extern crate syntax; |
| extern crate syntax_pos; |
| extern crate rustc_errors; |
| extern crate rustc_data_structures; |
| |
| #[unstable(feature = "proc_macro_internals", issue = "27812")] |
| #[doc(hidden)] |
| pub mod rustc; |
| |
| mod diagnostic; |
| |
| #[unstable(feature = "proc_macro_diagnostic", issue = "38356")] |
| pub use diagnostic::{Diagnostic, Level}; |
| |
| use std::{ascii, fmt, iter}; |
| use std::path::PathBuf; |
| use rustc_data_structures::sync::Lrc; |
| use std::str::FromStr; |
| |
| use syntax::errors::DiagnosticBuilder; |
| use syntax::parse::{self, token}; |
| use syntax::symbol::Symbol; |
| use syntax::tokenstream; |
| use syntax_pos::{Pos, FileName}; |
| |
| /// The main type provided by this crate, representing an abstract stream of |
| /// tokens, or, more specifically, a sequence of token trees. |
| /// The type provide interfaces for iterating over those token trees and, conversely, |
| /// collecting a number of token trees into one stream. |
| /// |
| /// This is both the input and output of `#[proc_macro]`, `#[proc_macro_attribute]` |
| /// and `#[proc_macro_derive]` definitions. |
| /// |
| /// The API of this type is intentionally bare-bones, but it'll be expanded over |
| /// time! |
| #[stable(feature = "proc_macro_lib", since = "1.15.0")] |
| #[derive(Clone)] |
| pub struct TokenStream(tokenstream::TokenStream); |
| |
| #[stable(feature = "proc_macro_lib", since = "1.15.0")] |
| impl !Send for TokenStream {} |
| #[stable(feature = "proc_macro_lib", since = "1.15.0")] |
| impl !Sync for TokenStream {} |
| |
| /// Error returned from `TokenStream::from_str`. |
| #[stable(feature = "proc_macro_lib", since = "1.15.0")] |
| #[derive(Debug)] |
| pub struct LexError { |
| _inner: (), |
| } |
| |
| #[stable(feature = "proc_macro_lib", since = "1.15.0")] |
| impl !Send for LexError {} |
| #[stable(feature = "proc_macro_lib", since = "1.15.0")] |
| impl !Sync for LexError {} |
| |
| impl TokenStream { |
| /// Returns an empty `TokenStream` containing no token trees. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| pub fn new() -> TokenStream { |
| TokenStream(tokenstream::TokenStream::empty()) |
| } |
| |
| /// Checks if this `TokenStream` is empty. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| pub fn is_empty(&self) -> bool { |
| self.0.is_empty() |
| } |
| } |
| |
| /// 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. |
| /// All tokens in the parsed stream get `Span::call_site()` spans. |
| /// |
| /// NOTE: Some errors may cause panics instead of returning `LexError`. We reserve the right to |
| /// change these errors into `LexError`s later. |
| #[stable(feature = "proc_macro_lib", since = "1.15.0")] |
| impl FromStr for TokenStream { |
| type Err = LexError; |
| |
| fn from_str(src: &str) -> Result<TokenStream, LexError> { |
| __internal::with_sess(|sess, data| { |
| Ok(__internal::token_stream_wrap(parse::parse_stream_from_source_str( |
| FileName::ProcMacroSourceCode, src.to_string(), sess, Some(data.call_site.0) |
| ))) |
| }) |
| } |
| } |
| |
| /// 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. |
| #[stable(feature = "proc_macro_lib", since = "1.15.0")] |
| impl fmt::Display for TokenStream { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| self.0.fmt(f) |
| } |
| } |
| |
| /// Prints token in a form convenient for debugging. |
| #[stable(feature = "proc_macro_lib", since = "1.15.0")] |
| impl fmt::Debug for TokenStream { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| f.write_str("TokenStream ")?; |
| f.debug_list().entries(self.clone()).finish() |
| } |
| } |
| |
| #[unstable(feature = "proc_macro_quote", issue = "38356")] |
| pub use quote::{quote, quote_span}; |
| |
| /// Creates a token stream containing a single token tree. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| impl From<TokenTree> for TokenStream { |
| fn from(tree: TokenTree) -> TokenStream { |
| TokenStream(tree.to_internal()) |
| } |
| } |
| |
| /// Collects a number of token trees into a single stream. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| impl iter::FromIterator<TokenTree> for TokenStream { |
| fn from_iter<I: IntoIterator<Item = TokenTree>>(trees: I) -> Self { |
| trees.into_iter().map(TokenStream::from).collect() |
| } |
| } |
| |
| /// A "flattening" operation on token streams, collects token trees |
| /// from multiple token streams into a single stream. |
| #[stable(feature = "proc_macro_lib", since = "1.15.0")] |
| impl iter::FromIterator<TokenStream> for TokenStream { |
| fn from_iter<I: IntoIterator<Item = TokenStream>>(streams: I) -> Self { |
| let mut builder = tokenstream::TokenStreamBuilder::new(); |
| for stream in streams { |
| builder.push(stream.0); |
| } |
| TokenStream(builder.build()) |
| } |
| } |
| |
| #[stable(feature = "token_stream_extend", since = "1.30.0")] |
| impl Extend<TokenTree> for TokenStream { |
| fn extend<I: IntoIterator<Item = TokenTree>>(&mut self, trees: I) { |
| self.extend(trees.into_iter().map(TokenStream::from)); |
| } |
| } |
| |
| #[stable(feature = "token_stream_extend", since = "1.30.0")] |
| impl Extend<TokenStream> for TokenStream { |
| fn extend<I: IntoIterator<Item = TokenStream>>(&mut self, streams: I) { |
| self.0.extend(streams.into_iter().map(|stream| stream.0)); |
| } |
| } |
| |
| /// Public implementation details for the `TokenStream` type, such as iterators. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| pub mod token_stream { |
| use syntax::tokenstream; |
| use {TokenTree, TokenStream, Delimiter}; |
| |
| /// 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)] |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| pub struct IntoIter { |
| cursor: tokenstream::Cursor, |
| stack: Vec<TokenTree>, |
| } |
| |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| impl Iterator for IntoIter { |
| type Item = TokenTree; |
| |
| fn next(&mut self) -> Option<TokenTree> { |
| loop { |
| let tree = self.stack.pop().or_else(|| { |
| let next = self.cursor.next_as_stream()?; |
| Some(TokenTree::from_internal(next, &mut self.stack)) |
| })?; |
| // HACK: The condition "dummy span + group with empty delimiter" represents an AST |
| // fragment approximately converted into a token stream. This may happen, for |
| // example, with inputs to proc macro attributes, including derives. Such "groups" |
| // need to flattened during iteration over stream's token trees. |
| // Eventually this needs to be removed in favor of keeping original token trees |
| // and not doing the roundtrip through AST. |
| if tree.span().0.is_dummy() { |
| if let TokenTree::Group(ref group) = tree { |
| if group.delimiter() == Delimiter::None { |
| self.cursor.insert(group.stream.clone().0); |
| continue |
| } |
| } |
| } |
| return Some(tree); |
| } |
| } |
| } |
| |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| impl IntoIterator for TokenStream { |
| type Item = TokenTree; |
| type IntoIter = IntoIter; |
| |
| fn into_iter(self) -> IntoIter { |
| IntoIter { cursor: self.0.trees(), stack: Vec::new() } |
| } |
| } |
| } |
| |
| /// `quote!(..)` accepts arbitrary tokens and expands into a `TokenStream` describing the input. |
| /// For example, `quote!(a + b)` will produce a expression, that, when evaluated, constructs |
| /// the `TokenStream` `[Ident("a"), Punct('+', Alone), Ident("b")]`. |
| /// |
| /// Unquoting is done with `$`, and works by taking the single next ident as the unquoted term. |
| /// To quote `$` itself, use `$$`. |
| /// |
| /// This is a dummy macro, the actual implementation is in `quote::quote`.` |
| #[unstable(feature = "proc_macro_quote", issue = "38356")] |
| #[macro_export] |
| macro_rules! quote { () => {} } |
| |
| #[unstable(feature = "proc_macro_internals", issue = "27812")] |
| #[doc(hidden)] |
| mod quote; |
| |
| /// A region of source code, along with macro expansion information. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| #[derive(Copy, Clone)] |
| pub struct Span(syntax_pos::Span); |
| |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| impl !Send for Span {} |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| impl !Sync for Span {} |
| |
| macro_rules! diagnostic_method { |
| ($name:ident, $level:expr) => ( |
| /// Create a new `Diagnostic` with the given `message` at the span |
| /// `self`. |
| #[unstable(feature = "proc_macro_diagnostic", issue = "38356")] |
| pub fn $name<T: Into<String>>(self, message: T) -> Diagnostic { |
| Diagnostic::spanned(self, $level, message) |
| } |
| ) |
| } |
| |
| impl Span { |
| /// A span that resolves at the macro definition site. |
| #[unstable(feature = "proc_macro_span", issue = "38356")] |
| pub fn def_site() -> Span { |
| ::__internal::with_sess(|_, data| data.def_site) |
| } |
| |
| /// 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. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| pub fn call_site() -> Span { |
| ::__internal::with_sess(|_, data| data.call_site) |
| } |
| |
| /// The original source file into which this span points. |
| #[unstable(feature = "proc_macro_span", issue = "38356")] |
| pub fn source_file(&self) -> SourceFile { |
| SourceFile { |
| source_file: __internal::lookup_char_pos(self.0.lo()).file, |
| } |
| } |
| |
| /// The `Span` for the tokens in the previous macro expansion from which |
| /// `self` was generated from, if any. |
| #[unstable(feature = "proc_macro_span", issue = "38356")] |
| pub fn parent(&self) -> Option<Span> { |
| self.0.parent().map(Span) |
| } |
| |
| /// The span for the origin source code that `self` was generated from. If |
| /// this `Span` wasn't generated from other macro expansions then the return |
| /// value is the same as `*self`. |
| #[unstable(feature = "proc_macro_span", issue = "38356")] |
| pub fn source(&self) -> Span { |
| Span(self.0.source_callsite()) |
| } |
| |
| /// Get the starting line/column in the source file for this span. |
| #[unstable(feature = "proc_macro_span", issue = "38356")] |
| pub fn start(&self) -> LineColumn { |
| let loc = __internal::lookup_char_pos(self.0.lo()); |
| LineColumn { |
| line: loc.line, |
| column: loc.col.to_usize() |
| } |
| } |
| |
| /// Get the ending line/column in the source file for this span. |
| #[unstable(feature = "proc_macro_span", issue = "38356")] |
| pub fn end(&self) -> LineColumn { |
| let loc = __internal::lookup_char_pos(self.0.hi()); |
| LineColumn { |
| line: loc.line, |
| column: loc.col.to_usize() |
| } |
| } |
| |
| /// Create a new span encompassing `self` and `other`. |
| /// |
| /// Returns `None` if `self` and `other` are from different files. |
| #[unstable(feature = "proc_macro_span", issue = "38356")] |
| pub fn join(&self, other: Span) -> Option<Span> { |
| let self_loc = __internal::lookup_char_pos(self.0.lo()); |
| let other_loc = __internal::lookup_char_pos(other.0.lo()); |
| |
| if self_loc.file.name != other_loc.file.name { return None } |
| |
| Some(Span(self.0.to(other.0))) |
| } |
| |
| /// Creates a new span with the same line/column information as `self` but |
| /// that resolves symbols as though it were at `other`. |
| #[unstable(feature = "proc_macro_span", issue = "38356")] |
| pub fn resolved_at(&self, other: Span) -> Span { |
| Span(self.0.with_ctxt(other.0.ctxt())) |
| } |
| |
| /// Creates a new span with the same name resolution behavior as `self` but |
| /// with the line/column information of `other`. |
| #[unstable(feature = "proc_macro_span", issue = "38356")] |
| pub fn located_at(&self, other: Span) -> Span { |
| other.resolved_at(*self) |
| } |
| |
| /// Compares to spans to see if they're equal. |
| #[unstable(feature = "proc_macro_span", issue = "38356")] |
| pub fn eq(&self, other: &Span) -> bool { |
| self.0 == other.0 |
| } |
| |
| diagnostic_method!(error, Level::Error); |
| diagnostic_method!(warning, Level::Warning); |
| diagnostic_method!(note, Level::Note); |
| diagnostic_method!(help, Level::Help); |
| } |
| |
| /// Prints a span in a form convenient for debugging. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| impl fmt::Debug for Span { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| write!(f, "{:?} bytes({}..{})", |
| self.0.ctxt(), |
| self.0.lo().0, |
| self.0.hi().0) |
| } |
| } |
| |
| /// A line-column pair representing the start or end of a `Span`. |
| #[unstable(feature = "proc_macro_span", issue = "38356")] |
| #[derive(Copy, Clone, Debug, PartialEq, Eq)] |
| pub struct LineColumn { |
| /// The 1-indexed line in the source file on which the span starts or ends (inclusive). |
| #[unstable(feature = "proc_macro_span", issue = "38356")] |
| pub line: usize, |
| /// The 0-indexed column (in UTF-8 characters) in the source file on which |
| /// the span starts or ends (inclusive). |
| #[unstable(feature = "proc_macro_span", issue = "38356")] |
| pub column: usize |
| } |
| |
| #[unstable(feature = "proc_macro_span", issue = "38356")] |
| impl !Send for LineColumn {} |
| #[unstable(feature = "proc_macro_span", issue = "38356")] |
| impl !Sync for LineColumn {} |
| |
| /// The source file of a given `Span`. |
| #[unstable(feature = "proc_macro_span", issue = "38356")] |
| #[derive(Clone)] |
| pub struct SourceFile { |
| source_file: Lrc<syntax_pos::SourceFile>, |
| } |
| |
| #[unstable(feature = "proc_macro_span", issue = "38356")] |
| impl !Send for SourceFile {} |
| #[unstable(feature = "proc_macro_span", issue = "38356")] |
| impl !Sync for SourceFile {} |
| |
| impl SourceFile { |
| /// Get the path to this source file. |
| /// |
| /// ### Note |
| /// If the code span associated with this `SourceFile` was generated by an external macro, this |
| /// 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 |
| #[unstable(feature = "proc_macro_span", issue = "38356")] |
| pub fn path(&self) -> PathBuf { |
| match self.source_file.name { |
| FileName::Real(ref path) => path.clone(), |
| _ => PathBuf::from(self.source_file.name.to_string()) |
| } |
| } |
| |
| /// Returns `true` if this source file is a real source file, and not generated by an external |
| /// macro's expansion. |
| #[unstable(feature = "proc_macro_span", issue = "38356")] |
| pub fn is_real(&self) -> bool { |
| // This is a hack until intercrate spans are implemented and we can have real source files |
| // for spans generated in external macros. |
| // https://github.com/rust-lang/rust/pull/43604#issuecomment-333334368 |
| self.source_file.is_real_file() |
| } |
| } |
| |
| |
| #[unstable(feature = "proc_macro_span", issue = "38356")] |
| impl fmt::Debug for SourceFile { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| f.debug_struct("SourceFile") |
| .field("path", &self.path()) |
| .field("is_real", &self.is_real()) |
| .finish() |
| } |
| } |
| |
| #[unstable(feature = "proc_macro_span", issue = "38356")] |
| impl PartialEq for SourceFile { |
| fn eq(&self, other: &Self) -> bool { |
| Lrc::ptr_eq(&self.source_file, &other.source_file) |
| } |
| } |
| |
| #[unstable(feature = "proc_macro_span", issue = "38356")] |
| impl Eq for SourceFile {} |
| |
| /// A single token or a delimited sequence of token trees (e.g. `[1, (), ..]`). |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| #[derive(Clone)] |
| pub enum TokenTree { |
| /// A token stream surrounded by bracket delimiters. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| Group( |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| Group |
| ), |
| /// An identifier. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| Ident( |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| Ident |
| ), |
| /// A single punctuation character (`+`, `,`, `$`, etc.). |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| Punct( |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| Punct |
| ), |
| /// A literal character (`'a'`), string (`"hello"`), number (`2.3`), etc. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| Literal( |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| Literal |
| ), |
| } |
| |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| impl !Send for TokenTree {} |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| impl !Sync for TokenTree {} |
| |
| impl TokenTree { |
| /// Returns the span of this tree, delegating to the `span` method of |
| /// the contained token or a delimited stream. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| pub fn span(&self) -> Span { |
| match *self { |
| TokenTree::Group(ref t) => t.span(), |
| TokenTree::Ident(ref t) => t.span(), |
| TokenTree::Punct(ref t) => t.span(), |
| TokenTree::Literal(ref 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. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| pub fn set_span(&mut self, span: Span) { |
| match *self { |
| TokenTree::Group(ref mut t) => t.set_span(span), |
| TokenTree::Ident(ref mut t) => t.set_span(span), |
| TokenTree::Punct(ref mut t) => t.set_span(span), |
| TokenTree::Literal(ref mut t) => t.set_span(span), |
| } |
| } |
| } |
| |
| /// Prints token treee in a form convenient for debugging. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| impl fmt::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(ref tt) => tt.fmt(f), |
| TokenTree::Ident(ref tt) => tt.fmt(f), |
| TokenTree::Punct(ref tt) => tt.fmt(f), |
| TokenTree::Literal(ref tt) => tt.fmt(f), |
| } |
| } |
| } |
| |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| impl From<Group> for TokenTree { |
| fn from(g: Group) -> TokenTree { |
| TokenTree::Group(g) |
| } |
| } |
| |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| impl From<Ident> for TokenTree { |
| fn from(g: Ident) -> TokenTree { |
| TokenTree::Ident(g) |
| } |
| } |
| |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| impl From<Punct> for TokenTree { |
| fn from(g: Punct) -> TokenTree { |
| TokenTree::Punct(g) |
| } |
| } |
| |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| impl From<Literal> for TokenTree { |
| fn from(g: Literal) -> TokenTree { |
| 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. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| impl fmt::Display for TokenTree { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| match *self { |
| TokenTree::Group(ref t) => t.fmt(f), |
| TokenTree::Ident(ref t) => t.fmt(f), |
| TokenTree::Punct(ref t) => t.fmt(f), |
| TokenTree::Literal(ref t) => t.fmt(f), |
| } |
| } |
| } |
| |
| /// A delimited token stream. |
| /// |
| /// A `Group` internally contains a `TokenStream` which is surrounded by `Delimiter`s. |
| #[derive(Clone)] |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| pub struct Group { |
| delimiter: Delimiter, |
| stream: TokenStream, |
| span: Span, |
| } |
| |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| impl !Send for Group {} |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| impl !Sync for Group {} |
| |
| /// Describes how a sequence of token trees is delimited. |
| #[derive(Copy, Clone, Debug, PartialEq, Eq)] |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| pub enum Delimiter { |
| /// `( ... )` |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| Parenthesis, |
| /// `{ ... }` |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| Brace, |
| /// `[ ... ]` |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| 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. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| None, |
| } |
| |
| impl Group { |
| /// 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. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| pub fn new(delimiter: Delimiter, stream: TokenStream) -> Group { |
| Group { |
| delimiter: delimiter, |
| stream: stream, |
| span: Span::call_site(), |
| } |
| } |
| |
| /// Returns the delimiter of this `Group` |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| pub fn delimiter(&self) -> Delimiter { |
| self.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. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| pub fn stream(&self) -> TokenStream { |
| self.stream.clone() |
| } |
| |
| /// Returns the span for the delimiters of this token stream, spanning the |
| /// entire `Group`. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| pub fn span(&self) -> Span { |
| self.span |
| } |
| |
| /// 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`. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| pub fn set_span(&mut self, span: Span) { |
| self.span = span; |
| } |
| } |
| |
| /// 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. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| impl fmt::Display for Group { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| TokenStream::from(TokenTree::from(self.clone())).fmt(f) |
| } |
| } |
| |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| impl fmt::Debug for Group { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| f.debug_struct("Group") |
| .field("delimiter", &self.delimiter()) |
| .field("stream", &self.stream()) |
| .field("span", &self.span()) |
| .finish() |
| } |
| } |
| |
| /// An `Punct` is an single punctuation character like `+`, `-` or `#`. |
| /// |
| /// Multicharacter operators like `+=` are represented as two instances of `Punct` with different |
| /// forms of `Spacing` returned. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| #[derive(Clone)] |
| pub struct Punct { |
| ch: char, |
| spacing: Spacing, |
| span: Span, |
| } |
| |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| impl !Send for Punct {} |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| impl !Sync for Punct {} |
| |
| /// Whether an `Punct` is followed immediately by another `Punct` or |
| /// followed by another token or whitespace. |
| #[derive(Copy, Clone, Debug, PartialEq, Eq)] |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| pub enum Spacing { |
| /// E.g. `+` is `Alone` in `+ =`, `+ident` or `+()`. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| Alone, |
| /// E.g. `+` is `Joint` in `+=` or `'#`. |
| /// Additionally, single quote `'` can join with identifiers to form lifetimes `'ident`. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| 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. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| pub fn new(ch: char, spacing: Spacing) -> Punct { |
| const LEGAL_CHARS: &[char] = &['=', '<', '>', '!', '~', '+', '-', '*', '/', '%', '^', |
| '&', '|', '@', '.', ',', ';', ':', '#', '$', '?', '\'']; |
| if !LEGAL_CHARS.contains(&ch) { |
| panic!("unsupported character `{:?}`", ch) |
| } |
| Punct { |
| ch: ch, |
| spacing: spacing, |
| span: Span::call_site(), |
| } |
| } |
| |
| /// Returns the value of this punctuation character as `char`. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| 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. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| pub fn spacing(&self) -> Spacing { |
| self.spacing |
| } |
| |
| /// Returns the span for this punctuation character. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| pub fn span(&self) -> Span { |
| self.span |
| } |
| |
| /// Configure the span for this punctuation character. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| 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. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| impl fmt::Display for Punct { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| TokenStream::from(TokenTree::from(self.clone())).fmt(f) |
| } |
| } |
| |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| impl fmt::Debug for Punct { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| f.debug_struct("Punct") |
| .field("ch", &self.as_char()) |
| .field("spacing", &self.spacing()) |
| .field("span", &self.span()) |
| .finish() |
| } |
| } |
| |
| /// An identifier (`ident`). |
| #[derive(Clone)] |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| pub struct Ident { |
| sym: Symbol, |
| span: Span, |
| is_raw: bool, |
| } |
| |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| impl !Send for Ident {} |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| impl !Sync for Ident {} |
| |
| impl Ident { |
| fn is_valid(string: &str) -> bool { |
| let mut chars = string.chars(); |
| if let Some(start) = chars.next() { |
| (start == '_' || start.is_xid_start()) |
| && chars.all(|cont| cont == '_' || cont.is_xid_continue()) |
| } else { |
| false |
| } |
| } |
| |
| /// 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. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| pub fn new(string: &str, span: Span) -> Ident { |
| if !Ident::is_valid(string) { |
| panic!("`{:?}` is not a valid identifier", string) |
| } |
| Ident::new_maybe_raw(string, span, false) |
| } |
| |
| /// Same as `Ident::new`, but creates a raw identifier (`r#ident`). |
| #[unstable(feature = "proc_macro_raw_ident", issue = "38356")] |
| pub fn new_raw(string: &str, span: Span) -> Ident { |
| if !Ident::is_valid(string) { |
| panic!("`{:?}` is not a valid identifier", string) |
| } |
| Ident::new_maybe_raw(string, span, true) |
| } |
| |
| /// Returns the span of this `Ident`, encompassing the entire string returned |
| /// by `as_str`. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| pub fn span(&self) -> Span { |
| self.span |
| } |
| |
| /// Configures the span of this `Ident`, possibly changing its hygiene context. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| pub fn set_span(&mut self, span: Span) { |
| self.span = span; |
| } |
| } |
| |
| /// Prints the identifier as a string that should be losslessly convertible |
| /// back into the same identifier. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| impl fmt::Display for Ident { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| TokenStream::from(TokenTree::from(self.clone())).fmt(f) |
| } |
| } |
| |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| impl fmt::Debug for Ident { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| f.debug_struct("Ident") |
| .field("ident", &self.to_string()) |
| .field("span", &self.span()) |
| .finish() |
| } |
| } |
| |
| /// 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. |
| // FIXME(eddyb) `Literal` should not expose internal `Debug` impls. |
| #[derive(Clone, Debug)] |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| pub struct Literal { |
| lit: token::Lit, |
| suffix: Option<Symbol>, |
| span: Span, |
| } |
| |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| impl !Send for Literal {} |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| impl !Sync for Literal {} |
| |
| 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 rountrips 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. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| pub fn $name(n: $kind) -> Literal { |
| Literal { |
| lit: token::Lit::Integer(Symbol::intern(&n.to_string())), |
| suffix: Some(Symbol::intern(stringify!($kind))), |
| span: Span::call_site(), |
| } |
| } |
| )*) |
| } |
| |
| 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 rountrips 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. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| pub fn $name(n: $kind) -> Literal { |
| Literal { |
| lit: token::Lit::Integer(Symbol::intern(&n.to_string())), |
| suffix: None, |
| span: Span::call_site(), |
| } |
| } |
| )*) |
| } |
| |
| impl Literal { |
| 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 rountrips 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. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| pub fn f32_unsuffixed(n: f32) -> Literal { |
| if !n.is_finite() { |
| panic!("Invalid float literal {}", n); |
| } |
| Literal { |
| lit: token::Lit::Float(Symbol::intern(&n.to_string())), |
| suffix: None, |
| span: Span::call_site(), |
| } |
| } |
| |
| /// Creates a new suffixed floating-point literal. |
| /// |
| /// This consturctor 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 rountrips 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. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| pub fn f32_suffixed(n: f32) -> Literal { |
| if !n.is_finite() { |
| panic!("Invalid float literal {}", n); |
| } |
| Literal { |
| lit: token::Lit::Float(Symbol::intern(&n.to_string())), |
| suffix: Some(Symbol::intern("f32")), |
| span: Span::call_site(), |
| } |
| } |
| |
| /// 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 rountrips 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. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| pub fn f64_unsuffixed(n: f64) -> Literal { |
| if !n.is_finite() { |
| panic!("Invalid float literal {}", n); |
| } |
| Literal { |
| lit: token::Lit::Float(Symbol::intern(&n.to_string())), |
| suffix: None, |
| span: Span::call_site(), |
| } |
| } |
| |
| /// Creates a new suffixed floating-point literal. |
| /// |
| /// This consturctor 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 rountrips 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. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| pub fn f64_suffixed(n: f64) -> Literal { |
| if !n.is_finite() { |
| panic!("Invalid float literal {}", n); |
| } |
| Literal { |
| lit: token::Lit::Float(Symbol::intern(&n.to_string())), |
| suffix: Some(Symbol::intern("f64")), |
| span: Span::call_site(), |
| } |
| } |
| |
| /// String literal. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| pub fn string(string: &str) -> Literal { |
| let mut escaped = String::new(); |
| for ch in string.chars() { |
| escaped.extend(ch.escape_debug()); |
| } |
| Literal { |
| lit: token::Lit::Str_(Symbol::intern(&escaped)), |
| suffix: None, |
| span: Span::call_site(), |
| } |
| } |
| |
| /// Character literal. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| pub fn character(ch: char) -> Literal { |
| let mut escaped = String::new(); |
| escaped.extend(ch.escape_unicode()); |
| Literal { |
| lit: token::Lit::Char(Symbol::intern(&escaped)), |
| suffix: None, |
| span: Span::call_site(), |
| } |
| } |
| |
| /// Byte string literal. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| pub fn byte_string(bytes: &[u8]) -> Literal { |
| let string = bytes.iter().cloned().flat_map(ascii::escape_default) |
| .map(Into::<char>::into).collect::<String>(); |
| Literal { |
| lit: token::Lit::ByteStr(Symbol::intern(&string)), |
| suffix: None, |
| span: Span::call_site(), |
| } |
| } |
| |
| /// Returns the span encompassing this literal. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| pub fn span(&self) -> Span { |
| self.span |
| } |
| |
| /// Configures the span associated for this literal. |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| pub fn set_span(&mut self, span: Span) { |
| self.span = span; |
| } |
| } |
| |
| /// Prints the literal as a string that should be losslessly convertible |
| /// back into the same literal (except for possible rounding for floating point literals). |
| #[stable(feature = "proc_macro_lib2", since = "1.29.0")] |
| impl fmt::Display for Literal { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| TokenStream::from(TokenTree::from(self.clone())).fmt(f) |
| } |
| } |
| |
| /// Permanently unstable internal implementation details of this crate. This |
| /// should not be used. |
| /// |
| /// These methods are used by the rest of the compiler to generate instances of |
| /// `TokenStream` to hand to macro definitions, as well as consume the output. |
| /// |
| /// Note that this module is also intentionally separate from the rest of the |
| /// crate. This allows the `#[unstable]` directive below to naturally apply to |
| /// all of the contents. |
| #[unstable(feature = "proc_macro_internals", issue = "27812")] |
| #[doc(hidden)] |
| pub mod __internal { |
| use std::cell::Cell; |
| use std::ptr; |
| |
| use syntax::ast; |
| use syntax::ext::base::ExtCtxt; |
| use syntax::ptr::P; |
| use syntax::parse::{self, ParseSess}; |
| use syntax::parse::token::{self, Token}; |
| use syntax::tokenstream; |
| use syntax_pos::{BytePos, Loc, DUMMY_SP}; |
| use syntax_pos::hygiene::{SyntaxContext, Transparency}; |
| |
| use super::{TokenStream, LexError, Span}; |
| |
| pub fn lookup_char_pos(pos: BytePos) -> Loc { |
| with_sess(|sess, _| sess.source_map().lookup_char_pos(pos)) |
| } |
| |
| pub fn new_token_stream(item: P<ast::Item>) -> TokenStream { |
| let token = Token::interpolated(token::NtItem(item)); |
| TokenStream(tokenstream::TokenTree::Token(DUMMY_SP, token).into()) |
| } |
| |
| pub fn token_stream_wrap(inner: tokenstream::TokenStream) -> TokenStream { |
| TokenStream(inner) |
| } |
| |
| pub fn token_stream_parse_items(stream: TokenStream) -> Result<Vec<P<ast::Item>>, LexError> { |
| with_sess(move |sess, _| { |
| let mut parser = parse::stream_to_parser(sess, stream.0); |
| let mut items = Vec::new(); |
| |
| while let Some(item) = try!(parser.parse_item().map_err(super::parse_to_lex_err)) { |
| items.push(item) |
| } |
| |
| Ok(items) |
| }) |
| } |
| |
| pub fn token_stream_inner(stream: TokenStream) -> tokenstream::TokenStream { |
| stream.0 |
| } |
| |
| pub trait Registry { |
| fn register_custom_derive(&mut self, |
| trait_name: &str, |
| expand: fn(TokenStream) -> TokenStream, |
| attributes: &[&'static str]); |
| |
| fn register_attr_proc_macro(&mut self, |
| name: &str, |
| expand: fn(TokenStream, TokenStream) -> TokenStream); |
| |
| fn register_bang_proc_macro(&mut self, |
| name: &str, |
| expand: fn(TokenStream) -> TokenStream); |
| } |
| |
| #[derive(Clone, Copy)] |
| pub struct ProcMacroData { |
| pub def_site: Span, |
| pub call_site: Span, |
| } |
| |
| #[derive(Clone, Copy)] |
| struct ProcMacroSess { |
| parse_sess: *const ParseSess, |
| data: ProcMacroData, |
| } |
| |
| // Emulate scoped_thread_local!() here essentially |
| thread_local! { |
| static CURRENT_SESS: Cell<ProcMacroSess> = Cell::new(ProcMacroSess { |
| parse_sess: ptr::null(), |
| data: ProcMacroData { def_site: Span(DUMMY_SP), call_site: Span(DUMMY_SP) }, |
| }); |
| } |
| |
| pub fn set_sess<F, R>(cx: &ExtCtxt, f: F) -> R |
| where F: FnOnce() -> R |
| { |
| struct Reset { prev: ProcMacroSess } |
| |
| impl Drop for Reset { |
| fn drop(&mut self) { |
| CURRENT_SESS.with(|p| p.set(self.prev)); |
| } |
| } |
| |
| CURRENT_SESS.with(|p| { |
| let _reset = Reset { prev: p.get() }; |
| |
| // No way to determine def location for a proc macro right now, so use call location. |
| let location = cx.current_expansion.mark.expn_info().unwrap().call_site; |
| let to_span = |transparency| Span(location.with_ctxt( |
| SyntaxContext::empty().apply_mark_with_transparency(cx.current_expansion.mark, |
| transparency)) |
| ); |
| p.set(ProcMacroSess { |
| parse_sess: cx.parse_sess, |
| data: ProcMacroData { |
| def_site: to_span(Transparency::Opaque), |
| call_site: to_span(Transparency::Transparent), |
| }, |
| }); |
| f() |
| }) |
| } |
| |
| pub fn in_sess() -> bool |
| { |
| !CURRENT_SESS.with(|sess| sess.get()).parse_sess.is_null() |
| } |
| |
| pub fn with_sess<F, R>(f: F) -> R |
| where F: FnOnce(&ParseSess, &ProcMacroData) -> R |
| { |
| let sess = CURRENT_SESS.with(|sess| sess.get()); |
| if sess.parse_sess.is_null() { |
| panic!("procedural macro API is used outside of a procedural macro"); |
| } |
| f(unsafe { &*sess.parse_sess }, &sess.data) |
| } |
| } |
| |
| fn parse_to_lex_err(mut err: DiagnosticBuilder) -> LexError { |
| err.cancel(); |
| LexError { _inner: () } |
| } |
