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-rw-r--r--compiler/rustc_parse/src/parser/mod.rs203
1 files changed, 104 insertions, 99 deletions
diff --git a/compiler/rustc_parse/src/parser/mod.rs b/compiler/rustc_parse/src/parser/mod.rs
index ffb23b50a..da82e4724 100644
--- a/compiler/rustc_parse/src/parser/mod.rs
+++ b/compiler/rustc_parse/src/parser/mod.rs
@@ -10,7 +10,7 @@ mod path;
mod stmt;
mod ty;
-use crate::lexer::UnmatchedBrace;
+use crate::lexer::UnmatchedDelim;
pub use attr_wrapper::AttrWrapper;
pub use diagnostics::AttemptLocalParseRecovery;
pub(crate) use item::FnParseMode;
@@ -19,9 +19,8 @@ pub use path::PathStyle;
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;
@@ -37,9 +36,10 @@ use rustc_errors::{
use rustc_session::parse::ParseSess;
use rustc_span::source_map::{Span, DUMMY_SP};
use rustc_span::symbol::{kw, sym, Ident, Symbol};
-
use std::ops::Range;
use std::{cmp, mem, slice};
+use thin_vec::ThinVec;
+use tracing::debug;
use crate::errors::{
DocCommentDoesNotDocumentAnything, IncorrectVisibilityRestriction, MismatchedClosingDelimiter,
@@ -149,7 +149,7 @@ pub struct Parser<'a> {
/// A list of all unclosed delimiters found by the lexer. If an entry is used for error recovery
/// it gets removed from here. Every entry left at the end gets emitted as an independent
/// error.
- pub(super) unclosed_delims: Vec<UnmatchedBrace>,
+ pub(super) unclosed_delims: Vec<UnmatchedDelim>,
last_unexpected_token_span: Option<Span>,
/// Span pointing at the `:` for the last type ascription the parser has seen, and whether it
/// looked like it could have been a mistyped path or literal `Option:Some(42)`).
@@ -168,7 +168,7 @@ pub struct Parser<'a> {
// 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)]
@@ -221,18 +221,27 @@ impl<'a> Drop for Parser<'a> {
}
}
+/// 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
@@ -257,18 +266,6 @@ struct TokenCursor {
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)
@@ -281,38 +278,47 @@ impl TokenCursor {
// 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)
@@ -329,7 +335,7 @@ impl TokenCursor {
num_of_hashes = cmp::max(num_of_hashes, count);
}
- // `/// foo` becomes `doc = r"foo".
+ // `/// foo` becomes `doc = r"foo"`.
let delim_span = DelimSpan::from_single(span);
let body = TokenTree::Delimited(
delim_span,
@@ -346,27 +352,15 @@ impl TokenCursor {
.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]
+ }
}
}
@@ -475,7 +469,7 @@ impl<'a> Parser<'a> {
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,
@@ -739,9 +733,10 @@ impl<'a> Parser<'a> {
fn check_const_closure(&self) -> bool {
self.is_keyword_ahead(0, &[kw::Const])
&& self.look_ahead(1, |t| match &t.kind {
- token::Ident(kw::Move | kw::Static | kw::Async, _)
- | token::OrOr
- | token::BinOp(token::Or) => true,
+ // async closures do not work with const closures, so we do not parse that here.
+ token::Ident(kw::Move | kw::Static, _) | token::OrOr | token::BinOp(token::Or) => {
+ true
+ }
_ => false,
})
}
@@ -859,11 +854,11 @@ impl<'a> Parser<'a> {
sep: SeqSep,
expect: TokenExpectType,
mut f: impl FnMut(&mut Parser<'a>) -> PResult<'a, T>,
- ) -> PResult<'a, (Vec<T>, bool /* trailing */, bool /* recovered */)> {
+ ) -> PResult<'a, (ThinVec<T>, bool /* trailing */, bool /* recovered */)> {
let mut first = true;
let mut recovered = false;
let mut trailing = false;
- let mut v = vec![];
+ let mut v = ThinVec::new();
let unclosed_delims = !self.unclosed_delims.is_empty();
while !self.expect_any_with_type(kets, expect) {
@@ -987,7 +982,11 @@ impl<'a> Parser<'a> {
let initial_semicolon = self.token.span;
while self.eat(&TokenKind::Semi) {
- let _ = self.parse_stmt(ForceCollect::Yes)?;
+ let _ =
+ self.parse_stmt_without_recovery(false, ForceCollect::Yes).unwrap_or_else(|e| {
+ e.cancel();
+ None
+ });
}
expect_err.set_primary_message(
@@ -1043,7 +1042,7 @@ impl<'a> Parser<'a> {
ket: &TokenKind,
sep: SeqSep,
f: impl FnMut(&mut Parser<'a>) -> PResult<'a, T>,
- ) -> PResult<'a, (Vec<T>, bool, bool)> {
+ ) -> PResult<'a, (ThinVec<T>, bool, bool)> {
self.parse_seq_to_before_tokens(&[ket], sep, TokenExpectType::Expect, f)
}
@@ -1055,7 +1054,7 @@ impl<'a> Parser<'a> {
ket: &TokenKind,
sep: SeqSep,
f: impl FnMut(&mut Parser<'a>) -> PResult<'a, T>,
- ) -> PResult<'a, (Vec<T>, bool /* trailing */)> {
+ ) -> PResult<'a, (ThinVec<T>, bool /* trailing */)> {
let (val, trailing, recovered) = self.parse_seq_to_before_end(ket, sep, f)?;
if !recovered {
self.eat(ket);
@@ -1072,7 +1071,7 @@ impl<'a> Parser<'a> {
ket: &TokenKind,
sep: SeqSep,
f: impl FnMut(&mut Parser<'a>) -> PResult<'a, T>,
- ) -> PResult<'a, (Vec<T>, bool)> {
+ ) -> PResult<'a, (ThinVec<T>, bool)> {
self.expect(bra)?;
self.parse_seq_to_end(ket, sep, f)
}
@@ -1081,7 +1080,7 @@ impl<'a> Parser<'a> {
&mut self,
delim: Delimiter,
f: impl FnMut(&mut Parser<'a>) -> PResult<'a, T>,
- ) -> PResult<'a, (Vec<T>, bool)> {
+ ) -> PResult<'a, (ThinVec<T>, bool)> {
self.parse_unspanned_seq(
&token::OpenDelim(delim),
&token::CloseDelim(delim),
@@ -1093,7 +1092,7 @@ impl<'a> Parser<'a> {
fn parse_paren_comma_seq<T>(
&mut self,
f: impl FnMut(&mut Parser<'a>) -> PResult<'a, T>,
- ) -> PResult<'a, (Vec<T>, bool)> {
+ ) -> PResult<'a, (ThinVec<T>, bool)> {
self.parse_delim_comma_seq(Delimiter::Parenthesis, f)
}
@@ -1142,14 +1141,16 @@ impl<'a> Parser<'a> {
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, _) => {
@@ -1203,8 +1204,18 @@ impl<'a> Parser<'a> {
/// Parses constness: `const` or nothing.
fn parse_constness(&mut self, case: Case) -> Const {
- // Avoid const blocks to be parsed as const items
- if self.look_ahead(1, |t| t != &token::OpenDelim(Delimiter::Brace))
+ self.parse_constness_(case, false)
+ }
+
+ /// Parses constness for closures
+ fn parse_closure_constness(&mut self, case: Case) -> Const {
+ self.parse_constness_(case, true)
+ }
+
+ fn parse_constness_(&mut self, case: Case, is_closure: bool) -> Const {
+ // Avoid const blocks and const closures to be parsed as const items
+ if (self.check_const_closure() == is_closure)
+ && self.look_ahead(1, |t| t != &token::OpenDelim(Delimiter::Brace))
&& self.eat_keyword_case(kw::Const, case)
{
Const::Yes(self.prev_token.uninterpolated_span())
@@ -1277,22 +1288,16 @@ impl<'a> Parser<'a> {
}
fn parse_delim_args_inner(&mut self) -> Option<DelimArgs> {
- if self.check(&token::OpenDelim(Delimiter::Parenthesis))
+ let delimited = self.check(&token::OpenDelim(Delimiter::Parenthesis))
|| self.check(&token::OpenDelim(Delimiter::Bracket))
- || self.check(&token::OpenDelim(Delimiter::Brace))
- {
- match self.parse_token_tree() {
- // We've confirmed above that there is a delimiter so unwrapping is OK.
- TokenTree::Delimited(dspan, delim, tokens) => Some(DelimArgs {
- dspan,
- delim: MacDelimiter::from_token(delim).unwrap(),
- tokens,
- }),
- _ => unreachable!(),
- }
- } else {
- None
- }
+ || self.check(&token::OpenDelim(Delimiter::Brace));
+
+ delimited.then(|| {
+ // We've confirmed above that there is a delimiter so unwrapping is OK.
+ let TokenTree::Delimited(dspan, delim, tokens) = self.parse_token_tree() else { unreachable!() };
+
+ DelimArgs { dspan, delim: MacDelimiter::from_token(delim).unwrap(), tokens }
+ })
}
fn parse_or_use_outer_attributes(
@@ -1310,10 +1315,10 @@ impl<'a> Parser<'a> {
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
@@ -1516,11 +1521,11 @@ impl<'a> Parser<'a> {
}
pub(crate) fn make_unclosed_delims_error(
- unmatched: UnmatchedBrace,
+ unmatched: UnmatchedDelim,
sess: &ParseSess,
) -> Option<DiagnosticBuilder<'_, ErrorGuaranteed>> {
// `None` here means an `Eof` was found. We already emit those errors elsewhere, we add them to
- // `unmatched_braces` only for error recovery in the `Parser`.
+ // `unmatched_delims` only for error recovery in the `Parser`.
let found_delim = unmatched.found_delim?;
let mut spans = vec![unmatched.found_span];
if let Some(sp) = unmatched.unclosed_span {
@@ -1537,7 +1542,7 @@ pub(crate) fn make_unclosed_delims_error(
Some(err)
}
-pub fn emit_unclosed_delims(unclosed_delims: &mut Vec<UnmatchedBrace>, sess: &ParseSess) {
+pub fn emit_unclosed_delims(unclosed_delims: &mut Vec<UnmatchedDelim>, sess: &ParseSess) {
*sess.reached_eof.borrow_mut() |=
unclosed_delims.iter().any(|unmatched_delim| unmatched_delim.found_delim.is_none());
for unmatched in unclosed_delims.drain(..) {
generated by cgit v1.2.3 (git 2.39.1) at 2024-05-21 18:41:47 +0000