use rustc_ast::ptr::P;
use rustc_ast::token::{self, Delimiter, Nonterminal, Token, TokenKind};
-use rustc_ast::tokenstream::AttributesData;
-use rustc_ast::tokenstream::{self, DelimSpan, Spacing};
-use rustc_ast::tokenstream::{TokenStream, TokenTree};
+use rustc_ast::tokenstream::{AttributesData, DelimSpan, Spacing};
+use rustc_ast::tokenstream::{TokenStream, TokenTree, TokenTreeCursor};
use rustc_ast::util::case::Case;
use rustc_ast::AttrId;
use rustc_ast::DUMMY_NODE_ID;
// This type is used a lot, e.g. it's cloned when matching many declarative macro rules with nonterminals. Make sure
// it doesn't unintentionally get bigger.
#[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
-rustc_data_structures::static_assert_size!(Parser<'_>, 336);
+rustc_data_structures::static_assert_size!(Parser<'_>, 312);
/// Stores span information about a closure.
#[derive(Clone)]
}
}
+/// Iterator over a `TokenStream` that produces `Token`s. It's a bit odd that
+/// we (a) lex tokens into a nice tree structure (`TokenStream`), and then (b)
+/// use this type to emit them as a linear sequence. But a linear sequence is
+/// what the parser expects, for the most part.
#[derive(Clone)]
struct TokenCursor {
- // The current (innermost) frame. `frame` and `stack` could be combined,
- // but it's faster to have them separately to access `frame` directly
- // rather than via something like `stack.last().unwrap()` or
- // `stack[stack.len() - 1]`.
- frame: TokenCursorFrame,
- // Additional frames that enclose `frame`.
- stack: Vec<TokenCursorFrame>,
+ // Cursor for the current (innermost) token stream. The delimiters for this
+ // token stream are found in `self.stack.last()`; when that is `None` then
+ // we are in the outermost token stream which never has delimiters.
+ tree_cursor: TokenTreeCursor,
+
+ // Token streams surrounding the current one. The delimiters for stack[n]'s
+ // tokens are in `stack[n-1]`. `stack[0]` (when present) has no delimiters
+ // because it's the outermost token stream which never has delimiters.
+ stack: Vec<(TokenTreeCursor, Delimiter, DelimSpan)>,
+
desugar_doc_comments: bool,
+
// Counts the number of calls to `{,inlined_}next`.
num_next_calls: usize,
+
// During parsing, we may sometimes need to 'unglue' a
// glued token into two component tokens
// (e.g. '>>' into '>' and '>), so that the parser
break_last_token: bool,
}
-#[derive(Clone)]
-struct TokenCursorFrame {
- delim_sp: Option<(Delimiter, DelimSpan)>,
- tree_cursor: tokenstream::Cursor,
-}
-
-impl TokenCursorFrame {
- fn new(delim_sp: Option<(Delimiter, DelimSpan)>, tts: TokenStream) -> Self {
- TokenCursorFrame { delim_sp, tree_cursor: tts.into_trees() }
- }
-}
-
impl TokenCursor {
fn next(&mut self, desugar_doc_comments: bool) -> (Token, Spacing) {
self.inlined_next(desugar_doc_comments)
// FIXME: we currently don't return `Delimiter` open/close delims. To fix #67062 we will
// need to, whereupon the `delim != Delimiter::Invisible` conditions below can be
// removed.
- if let Some(tree) = self.frame.tree_cursor.next_ref() {
+ if let Some(tree) = self.tree_cursor.next_ref() {
match tree {
&TokenTree::Token(ref token, spacing) => match (desugar_doc_comments, token) {
(true, &Token { kind: token::DocComment(_, attr_style, data), span }) => {
- return self.desugar(attr_style, data, span);
+ let desugared = self.desugar(attr_style, data, span);
+ self.tree_cursor.replace_prev_and_rewind(desugared);
+ // Continue to get the first token of the desugared doc comment.
+ }
+ _ => {
+ debug_assert!(!matches!(
+ token.kind,
+ token::OpenDelim(_) | token::CloseDelim(_)
+ ));
+ return (token.clone(), spacing);
}
- _ => return (token.clone(), spacing),
},
&TokenTree::Delimited(sp, delim, ref tts) => {
- // Set `open_delim` to true here because we deal with it immediately.
- let frame = TokenCursorFrame::new(Some((delim, sp)), tts.clone());
- self.stack.push(mem::replace(&mut self.frame, frame));
+ let trees = tts.clone().into_trees();
+ self.stack.push((mem::replace(&mut self.tree_cursor, trees), delim, sp));
if delim != Delimiter::Invisible {
return (Token::new(token::OpenDelim(delim), sp.open), Spacing::Alone);
}
// No open delimiter to return; continue on to the next iteration.
}
};
- } else if let Some(frame) = self.stack.pop() {
- if let Some((delim, span)) = self.frame.delim_sp && delim != Delimiter::Invisible {
- self.frame = frame;
+ } else if let Some((tree_cursor, delim, span)) = self.stack.pop() {
+ // We have exhausted this token stream. Move back to its parent token stream.
+ self.tree_cursor = tree_cursor;
+ if delim != Delimiter::Invisible {
return (Token::new(token::CloseDelim(delim), span.close), Spacing::Alone);
}
- self.frame = frame;
// No close delimiter to return; continue on to the next iteration.
} else {
+ // We have exhausted the outermost token stream.
return (Token::new(token::Eof, DUMMY_SP), Spacing::Alone);
}
}
}
- fn desugar(&mut self, attr_style: AttrStyle, data: Symbol, span: Span) -> (Token, Spacing) {
+ // Desugar a doc comment into something like `#[doc = r"foo"]`.
+ fn desugar(&mut self, attr_style: AttrStyle, data: Symbol, span: Span) -> Vec<TokenTree> {
// Searches for the occurrences of `"#*` and returns the minimum number of `#`s
// required to wrap the text. E.g.
// - `abc d` is wrapped as `r"abc d"` (num_of_hashes = 0)
.collect::<TokenStream>(),
);
- self.stack.push(mem::replace(
- &mut self.frame,
- TokenCursorFrame::new(
- None,
- if attr_style == AttrStyle::Inner {
- [
- TokenTree::token_alone(token::Pound, span),
- TokenTree::token_alone(token::Not, span),
- body,
- ]
- .into_iter()
- .collect::<TokenStream>()
- } else {
- [TokenTree::token_alone(token::Pound, span), body]
- .into_iter()
- .collect::<TokenStream>()
- },
- ),
- ));
-
- self.next(/* desugar_doc_comments */ false)
+ if attr_style == AttrStyle::Inner {
+ vec![
+ TokenTree::token_alone(token::Pound, span),
+ TokenTree::token_alone(token::Not, span),
+ body,
+ ]
+ } else {
+ vec![TokenTree::token_alone(token::Pound, span), body]
+ }
}
}
restrictions: Restrictions::empty(),
expected_tokens: Vec::new(),
token_cursor: TokenCursor {
- frame: TokenCursorFrame::new(None, tokens),
+ tree_cursor: tokens.into_trees(),
stack: Vec::new(),
num_next_calls: 0,
desugar_doc_comments,
return looker(&self.token);
}
- let frame = &self.token_cursor.frame;
- if let Some((delim, span)) = frame.delim_sp && delim != Delimiter::Invisible {
+ let tree_cursor = &self.token_cursor.tree_cursor;
+ if let Some(&(_, delim, span)) = self.token_cursor.stack.last()
+ && delim != Delimiter::Invisible
+ {
let all_normal = (0..dist).all(|i| {
- let token = frame.tree_cursor.look_ahead(i);
+ let token = tree_cursor.look_ahead(i);
!matches!(token, Some(TokenTree::Delimited(_, Delimiter::Invisible, _)))
});
if all_normal {
- return match frame.tree_cursor.look_ahead(dist - 1) {
+ return match tree_cursor.look_ahead(dist - 1) {
Some(tree) => match tree {
TokenTree::Token(token, _) => looker(token),
TokenTree::Delimited(dspan, delim, _) => {
pub(crate) fn parse_token_tree(&mut self) -> TokenTree {
match self.token.kind {
token::OpenDelim(..) => {
- // Grab the tokens from this frame.
- let frame = &self.token_cursor.frame;
- let stream = frame.tree_cursor.stream.clone();
- let (delim, span) = frame.delim_sp.unwrap();
+ // Grab the tokens within the delimiters.
+ let tree_cursor = &self.token_cursor.tree_cursor;
+ let stream = tree_cursor.stream.clone();
+ let (_, delim, span) = *self.token_cursor.stack.last().unwrap();
// Advance the token cursor through the entire delimited
// sequence. After getting the `OpenDelim` we are *within* the
projects / rust.git / blobdiff