Move directory `libsyntax` -> `librustc_ast`

1 files changed, 0 insertions, 486 deletions

diff --git a/src/libsyntax/tokenstream.rs b/src/libsyntax/tokenstream.rs
deleted file mode 100644
index 03e8fff247b..00000000000
--- a/src/libsyntax/tokenstream.rs
+++ /dev/null
@@ -1,486 +0,0 @@
-//! # Token Streams
-//!
-//! `TokenStream`s represent syntactic objects before they are converted into ASTs.
-//! A `TokenStream` is, roughly speaking, a sequence (eg stream) of `TokenTree`s,
-//! which are themselves a single `Token` or a `Delimited` subsequence of tokens.
-//!
-//! ## Ownership
-//!
-//! `TokenStream`s are persistent data structures constructed as ropes with reference
-//! counted-children. In general, this means that calling an operation on a `TokenStream`
-//! (such as `slice`) produces an entirely new `TokenStream` from the borrowed reference to
-//! the original. This essentially coerces `TokenStream`s into 'views' of their subparts,
-//! and a borrowed `TokenStream` is sufficient to build an owned `TokenStream` without taking
-//! ownership of the original.
-
-use crate::token::{self, DelimToken, Token, TokenKind};
-
-use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
-use rustc_data_structures::sync::Lrc;
-use rustc_macros::HashStable_Generic;
-use rustc_span::{Span, DUMMY_SP};
-use smallvec::{smallvec, SmallVec};
-
-use std::{iter, mem};
-
-/// When the main rust parser encounters a syntax-extension invocation, it
-/// parses the arguments to the invocation as a token-tree. This is a very
-/// loose structure, such that all sorts of different AST-fragments can
-/// be passed to syntax extensions using a uniform type.
-///
-/// If the syntax extension is an MBE macro, it will attempt to match its
-/// LHS token tree against the provided token tree, and if it finds a
-/// match, will transcribe the RHS token tree, splicing in any captured
-/// `macro_parser::matched_nonterminals` into the `SubstNt`s it finds.
-///
-/// The RHS of an MBE macro is the only place `SubstNt`s are substituted.
-/// Nothing special happens to misnamed or misplaced `SubstNt`s.
-#[derive(Debug, Clone, PartialEq, RustcEncodable, RustcDecodable, HashStable_Generic)]
-pub enum TokenTree {
-    /// A single token
-    Token(Token),
-    /// A delimited sequence of token trees
-    Delimited(DelimSpan, DelimToken, TokenStream),
-}
-
-// Ensure all fields of `TokenTree` is `Send` and `Sync`.
-#[cfg(parallel_compiler)]
-fn _dummy()
-where
-    Token: Send + Sync,
-    DelimSpan: Send + Sync,
-    DelimToken: Send + Sync,
-    TokenStream: Send + Sync,
-{
-}
-
-impl TokenTree {
-    /// Checks if this TokenTree is equal to the other, regardless of span information.
-    pub fn eq_unspanned(&self, other: &TokenTree) -> bool {
-        match (self, other) {
-            (TokenTree::Token(token), TokenTree::Token(token2)) => token.kind == token2.kind,
-            (TokenTree::Delimited(_, delim, tts), TokenTree::Delimited(_, delim2, tts2)) => {
-                delim == delim2 && tts.eq_unspanned(&tts2)
-            }
-            _ => false,
-        }
-    }
-
-    // See comments in `Nonterminal::to_tokenstream` for why we care about
-    // *probably* equal here rather than actual equality
-    //
-    // This is otherwise the same as `eq_unspanned`, only recursing with a
-    // different method.
-    pub fn probably_equal_for_proc_macro(&self, other: &TokenTree) -> bool {
-        match (self, other) {
-            (TokenTree::Token(token), TokenTree::Token(token2)) => {
-                token.probably_equal_for_proc_macro(token2)
-            }
-            (TokenTree::Delimited(_, delim, tts), TokenTree::Delimited(_, delim2, tts2)) => {
-                delim == delim2 && tts.probably_equal_for_proc_macro(&tts2)
-            }
-            _ => false,
-        }
-    }
-
-    /// Retrieves the TokenTree's span.
-    pub fn span(&self) -> Span {
-        match self {
-            TokenTree::Token(token) => token.span,
-            TokenTree::Delimited(sp, ..) => sp.entire(),
-        }
-    }
-
-    /// Modify the `TokenTree`'s span in-place.
-    pub fn set_span(&mut self, span: Span) {
-        match self {
-            TokenTree::Token(token) => token.span = span,
-            TokenTree::Delimited(dspan, ..) => *dspan = DelimSpan::from_single(span),
-        }
-    }
-
-    pub fn joint(self) -> TokenStream {
-        TokenStream::new(vec![(self, Joint)])
-    }
-
-    pub fn token(kind: TokenKind, span: Span) -> TokenTree {
-        TokenTree::Token(Token::new(kind, span))
-    }
-
-    /// Returns the opening delimiter as a token tree.
-    pub fn open_tt(span: DelimSpan, delim: DelimToken) -> TokenTree {
-        TokenTree::token(token::OpenDelim(delim), span.open)
-    }
-
-    /// Returns the closing delimiter as a token tree.
-    pub fn close_tt(span: DelimSpan, delim: DelimToken) -> TokenTree {
-        TokenTree::token(token::CloseDelim(delim), span.close)
-    }
-}
-
-impl<CTX> HashStable<CTX> for TokenStream
-where
-    CTX: crate::HashStableContext,
-{
-    fn hash_stable(&self, hcx: &mut CTX, hasher: &mut StableHasher) {
-        for sub_tt in self.trees() {
-            sub_tt.hash_stable(hcx, hasher);
-        }
-    }
-}
-
-/// A `TokenStream` is an abstract sequence of tokens, organized into `TokenTree`s.
-///
-/// The goal is for procedural macros to work with `TokenStream`s and `TokenTree`s
-/// instead of a representation of the abstract syntax tree.
-/// Today's `TokenTree`s can still contain AST via `token::Interpolated` for back-compat.
-#[derive(Clone, Debug, Default, RustcEncodable, RustcDecodable)]
-pub struct TokenStream(pub Lrc<Vec<TreeAndJoint>>);
-
-pub type TreeAndJoint = (TokenTree, IsJoint);
-
-// `TokenStream` is used a lot. Make sure it doesn't unintentionally get bigger.
-#[cfg(target_arch = "x86_64")]
-rustc_data_structures::static_assert_size!(TokenStream, 8);
-
-#[derive(Clone, Copy, Debug, PartialEq, RustcEncodable, RustcDecodable)]
-pub enum IsJoint {
-    Joint,
-    NonJoint,
-}
-
-use IsJoint::*;
-
-impl TokenStream {
-    /// Given a `TokenStream` with a `Stream` of only two arguments, return a new `TokenStream`
-    /// separating the two arguments with a comma for diagnostic suggestions.
-    pub fn add_comma(&self) -> Option<(TokenStream, Span)> {
-        // Used to suggest if a user writes `foo!(a b);`
-        let mut suggestion = None;
-        let mut iter = self.0.iter().enumerate().peekable();
-        while let Some((pos, ts)) = iter.next() {
-            if let Some((_, next)) = iter.peek() {
-                let sp = match (&ts, &next) {
-                    (_, (TokenTree::Token(Token { kind: token::Comma, .. }), _)) => continue,
-                    (
-                        (TokenTree::Token(token_left), NonJoint),
-                        (TokenTree::Token(token_right), _),
-                    ) if ((token_left.is_ident() && !token_left.is_reserved_ident())
-                        || token_left.is_lit())
-                        && ((token_right.is_ident() && !token_right.is_reserved_ident())
-                            || token_right.is_lit()) =>
-                    {
-                        token_left.span
-                    }
-                    ((TokenTree::Delimited(sp, ..), NonJoint), _) => sp.entire(),
-                    _ => continue,
-                };
-                let sp = sp.shrink_to_hi();
-                let comma = (TokenTree::token(token::Comma, sp), NonJoint);
-                suggestion = Some((pos, comma, sp));
-            }
-        }
-        if let Some((pos, comma, sp)) = suggestion {
-            let mut new_stream = vec![];
-            let parts = self.0.split_at(pos + 1);
-            new_stream.extend_from_slice(parts.0);
-            new_stream.push(comma);
-            new_stream.extend_from_slice(parts.1);
-            return Some((TokenStream::new(new_stream), sp));
-        }
-        None
-    }
-}
-
-impl From<TokenTree> for TokenStream {
-    fn from(tree: TokenTree) -> TokenStream {
-        TokenStream::new(vec![(tree, NonJoint)])
-    }
-}
-
-impl From<TokenTree> for TreeAndJoint {
-    fn from(tree: TokenTree) -> TreeAndJoint {
-        (tree, NonJoint)
-    }
-}
-
-impl iter::FromIterator<TokenTree> for TokenStream {
-    fn from_iter<I: IntoIterator<Item = TokenTree>>(iter: I) -> Self {
-        TokenStream::new(iter.into_iter().map(Into::into).collect::<Vec<TreeAndJoint>>())
-    }
-}
-
-impl Eq for TokenStream {}
-
-impl PartialEq<TokenStream> for TokenStream {
-    fn eq(&self, other: &TokenStream) -> bool {
-        self.trees().eq(other.trees())
-    }
-}
-
-impl TokenStream {
-    pub fn new(streams: Vec<TreeAndJoint>) -> TokenStream {
-        TokenStream(Lrc::new(streams))
-    }
-
-    pub fn is_empty(&self) -> bool {
-        self.0.is_empty()
-    }
-
-    pub fn len(&self) -> usize {
-        self.0.len()
-    }
-
-    pub fn span(&self) -> Option<Span> {
-        match &**self.0 {
-            [] => None,
-            [(tt, _)] => Some(tt.span()),
-            [(tt_start, _), .., (tt_end, _)] => Some(tt_start.span().to(tt_end.span())),
-        }
-    }
-
-    pub fn from_streams(mut streams: SmallVec<[TokenStream; 2]>) -> TokenStream {
-        match streams.len() {
-            0 => TokenStream::default(),
-            1 => streams.pop().unwrap(),
-            _ => {
-                // We are going to extend the first stream in `streams` with
-                // the elements from the subsequent streams. This requires
-                // using `make_mut()` on the first stream, and in practice this
-                // doesn't cause cloning 99.9% of the time.
-                //
-                // One very common use case is when `streams` has two elements,
-                // where the first stream has any number of elements within
-                // (often 1, but sometimes many more) and the second stream has
-                // a single element within.
-
-                // Determine how much the first stream will be extended.
-                // Needed to avoid quadratic blow up from on-the-fly
-                // reallocations (#57735).
-                let num_appends = streams.iter().skip(1).map(|ts| ts.len()).sum();
-
-                // Get the first stream. If it's `None`, create an empty
-                // stream.
-                let mut iter = streams.drain(..);
-                let mut first_stream_lrc = iter.next().unwrap().0;
-
-                // Append the elements to the first stream, after reserving
-                // space for them.
-                let first_vec_mut = Lrc::make_mut(&mut first_stream_lrc);
-                first_vec_mut.reserve(num_appends);
-                for stream in iter {
-                    first_vec_mut.extend(stream.0.iter().cloned());
-                }
-
-                // Create the final `TokenStream`.
-                TokenStream(first_stream_lrc)
-            }
-        }
-    }
-
-    pub fn trees(&self) -> Cursor {
-        self.clone().into_trees()
-    }
-
-    pub fn into_trees(self) -> Cursor {
-        Cursor::new(self)
-    }
-
-    /// Compares two `TokenStream`s, checking equality without regarding span information.
-    pub fn eq_unspanned(&self, other: &TokenStream) -> bool {
-        let mut t1 = self.trees();
-        let mut t2 = other.trees();
-        for (t1, t2) in t1.by_ref().zip(t2.by_ref()) {
-            if !t1.eq_unspanned(&t2) {
-                return false;
-            }
-        }
-        t1.next().is_none() && t2.next().is_none()
-    }
-
-    // See comments in `Nonterminal::to_tokenstream` for why we care about
-    // *probably* equal here rather than actual equality
-    //
-    // This is otherwise the same as `eq_unspanned`, only recursing with a
-    // different method.
-    pub fn probably_equal_for_proc_macro(&self, other: &TokenStream) -> bool {
-        // When checking for `probably_eq`, we ignore certain tokens that aren't
-        // preserved in the AST. Because they are not preserved, the pretty
-        // printer arbitrarily adds or removes them when printing as token
-        // streams, making a comparison between a token stream generated from an
-        // AST and a token stream which was parsed into an AST more reliable.
-        fn semantic_tree(tree: &TokenTree) -> bool {
-            if let TokenTree::Token(token) = tree {
-                if let
-                    // The pretty printer tends to add trailing commas to
-                    // everything, and in particular, after struct fields.
-                    | token::Comma
-                    // The pretty printer emits `NoDelim` as whitespace.
-                    | token::OpenDelim(DelimToken::NoDelim)
-                    | token::CloseDelim(DelimToken::NoDelim)
-                    // The pretty printer collapses many semicolons into one.
-                    | token::Semi
-                    // The pretty printer collapses whitespace arbitrarily and can
-                    // introduce whitespace from `NoDelim`.
-                    | token::Whitespace
-                    // The pretty printer can turn `$crate` into `::crate_name`
-                    | token::ModSep = token.kind {
-                    return false;
-                }
-            }
-            true
-        }
-
-        let mut t1 = self.trees().filter(semantic_tree);
-        let mut t2 = other.trees().filter(semantic_tree);
-        for (t1, t2) in t1.by_ref().zip(t2.by_ref()) {
-            if !t1.probably_equal_for_proc_macro(&t2) {
-                return false;
-            }
-        }
-        t1.next().is_none() && t2.next().is_none()
-    }
-
-    pub fn map_enumerated<F: FnMut(usize, TokenTree) -> TokenTree>(self, mut f: F) -> TokenStream {
-        TokenStream(Lrc::new(
-            self.0
-                .iter()
-                .enumerate()
-                .map(|(i, (tree, is_joint))| (f(i, tree.clone()), *is_joint))
-                .collect(),
-        ))
-    }
-
-    pub fn map<F: FnMut(TokenTree) -> TokenTree>(self, mut f: F) -> TokenStream {
-        TokenStream(Lrc::new(
-            self.0.iter().map(|(tree, is_joint)| (f(tree.clone()), *is_joint)).collect(),
-        ))
-    }
-}
-
-// 99.5%+ of the time we have 1 or 2 elements in this vector.
-#[derive(Clone)]
-pub struct TokenStreamBuilder(SmallVec<[TokenStream; 2]>);
-
-impl TokenStreamBuilder {
-    pub fn new() -> TokenStreamBuilder {
-        TokenStreamBuilder(SmallVec::new())
-    }
-
-    pub fn push<T: Into<TokenStream>>(&mut self, stream: T) {
-        let mut stream = stream.into();
-
-        // If `self` is not empty and the last tree within the last stream is a
-        // token tree marked with `Joint`...
-        if let Some(TokenStream(ref mut last_stream_lrc)) = self.0.last_mut() {
-            if let Some((TokenTree::Token(last_token), Joint)) = last_stream_lrc.last() {
-                // ...and `stream` is not empty and the first tree within it is
-                // a token tree...
-                let TokenStream(ref mut stream_lrc) = stream;
-                if let Some((TokenTree::Token(token), is_joint)) = stream_lrc.first() {
-                    // ...and the two tokens can be glued together...
-                    if let Some(glued_tok) = last_token.glue(&token) {
-                        // ...then do so, by overwriting the last token
-                        // tree in `self` and removing the first token tree
-                        // from `stream`. This requires using `make_mut()`
-                        // on the last stream in `self` and on `stream`,
-                        // and in practice this doesn't cause cloning 99.9%
-                        // of the time.
-
-                        // Overwrite the last token tree with the merged
-                        // token.
-                        let last_vec_mut = Lrc::make_mut(last_stream_lrc);
-                        *last_vec_mut.last_mut().unwrap() =
-                            (TokenTree::Token(glued_tok), *is_joint);
-
-                        // Remove the first token tree from `stream`. (This
-                        // is almost always the only tree in `stream`.)
-                        let stream_vec_mut = Lrc::make_mut(stream_lrc);
-                        stream_vec_mut.remove(0);
-
-                        // Don't push `stream` if it's empty -- that could
-                        // block subsequent token gluing, by getting
-                        // between two token trees that should be glued
-                        // together.
-                        if !stream.is_empty() {
-                            self.0.push(stream);
-                        }
-                        return;
-                    }
-                }
-            }
-        }
-        self.0.push(stream);
-    }
-
-    pub fn build(self) -> TokenStream {
-        TokenStream::from_streams(self.0)
-    }
-}
-
-#[derive(Clone)]
-pub struct Cursor {
-    pub stream: TokenStream,
-    index: usize,
-}
-
-impl Iterator for Cursor {
-    type Item = TokenTree;
-
-    fn next(&mut self) -> Option<TokenTree> {
-        self.next_with_joint().map(|(tree, _)| tree)
-    }
-}
-
-impl Cursor {
-    fn new(stream: TokenStream) -> Self {
-        Cursor { stream, index: 0 }
-    }
-
-    pub fn next_with_joint(&mut self) -> Option<TreeAndJoint> {
-        if self.index < self.stream.len() {
-            self.index += 1;
-            Some(self.stream.0[self.index - 1].clone())
-        } else {
-            None
-        }
-    }
-
-    pub fn append(&mut self, new_stream: TokenStream) {
-        if new_stream.is_empty() {
-            return;
-        }
-        let index = self.index;
-        let stream = mem::take(&mut self.stream);
-        *self = TokenStream::from_streams(smallvec![stream, new_stream]).into_trees();
-        self.index = index;
-    }
-
-    pub fn look_ahead(&self, n: usize) -> Option<TokenTree> {
-        self.stream.0[self.index..].get(n).map(|(tree, _)| tree.clone())
-    }
-}
-
-#[derive(Debug, Copy, Clone, PartialEq, RustcEncodable, RustcDecodable, HashStable_Generic)]
-pub struct DelimSpan {
-    pub open: Span,
-    pub close: Span,
-}
-
-impl DelimSpan {
-    pub fn from_single(sp: Span) -> Self {
-        DelimSpan { open: sp, close: sp }
-    }
-
-    pub fn from_pair(open: Span, close: Span) -> Self {
-        DelimSpan { open, close }
-    }
-
-    pub fn dummy() -> Self {
-        Self::from_single(DUMMY_SP)
-    }
-
-    pub fn entire(self) -> Span {
-        self.open.with_hi(self.close.hi())
-    }
-}