From d1073fab35280ed4fac22f619beda75ca132f386 Mon Sep 17 00:00:00 2001 From: yukang Date: Fri, 3 Mar 2023 22:48:21 +0000 Subject: [PATCH] Remove unclosed_delims from parser --- .../rustc_parse/src/parser/diagnostics.rs | 116 +----------------- compiler/rustc_parse/src/parser/expr.rs | 13 -- compiler/rustc_parse/src/parser/item.rs | 24 +--- compiler/rustc_parse/src/parser/mod.rs | 17 +-- 4 files changed, 12 insertions(+), 158 deletions(-) diff --git a/compiler/rustc_parse/src/parser/diagnostics.rs b/compiler/rustc_parse/src/parser/diagnostics.rs index a051dbe9ff5b9..0a65c37ea7b79 100644 --- a/compiler/rustc_parse/src/parser/diagnostics.rs +++ b/compiler/rustc_parse/src/parser/diagnostics.rs @@ -19,7 +19,6 @@ use crate::errors::{ }; use crate::fluent_generated as fluent; -use crate::lexer::UnmatchedDelim; use crate::parser; use rustc_ast as ast; use rustc_ast::ptr::P; @@ -220,7 +219,6 @@ impl MultiSugg { /// is dropped. pub struct SnapshotParser<'a> { parser: Parser<'a>, - unclosed_delims: Vec, } impl<'a> Deref for SnapshotParser<'a> { @@ -255,27 +253,15 @@ impl<'a> Parser<'a> { &self.sess.span_diagnostic } - /// Replace `self` with `snapshot.parser` and extend `unclosed_delims` with `snapshot.unclosed_delims`. - /// This is to avoid losing unclosed delims errors `create_snapshot_for_diagnostic` clears. + /// Replace `self` with `snapshot.parser`. pub(super) fn restore_snapshot(&mut self, snapshot: SnapshotParser<'a>) { *self = snapshot.parser; - self.unclosed_delims.extend(snapshot.unclosed_delims); - } - - pub fn unclosed_delims(&self) -> &[UnmatchedDelim] { - &self.unclosed_delims } /// Create a snapshot of the `Parser`. pub fn create_snapshot_for_diagnostic(&self) -> SnapshotParser<'a> { - let mut snapshot = self.clone(); - let unclosed_delims = self.unclosed_delims.clone(); - // Clear `unclosed_delims` in snapshot to avoid - // duplicate errors being emitted when the `Parser` - // is dropped (which may or may not happen, depending - // if the parsing the snapshot is created for is successful) - snapshot.unclosed_delims.clear(); - SnapshotParser { parser: snapshot, unclosed_delims } + let snapshot = self.clone(); + SnapshotParser { parser: snapshot } } pub(super) fn span_to_snippet(&self, span: Span) -> Result { @@ -579,21 +565,6 @@ impl<'a> Parser<'a> { } else { label_sp }; - match self.recover_closing_delimiter( - &expected - .iter() - .filter_map(|tt| match tt { - TokenType::Token(t) => Some(t.clone()), - _ => None, - }) - .collect::>(), - err, - ) { - Err(e) => err = e, - Ok(recovered) => { - return Ok(recovered); - } - } if self.check_too_many_raw_str_terminators(&mut err) { if expected.contains(&TokenType::Token(token::Semi)) && self.eat(&token::Semi) { @@ -1573,12 +1544,6 @@ impl<'a> Parser<'a> { ); let mut err = self.struct_span_err(sp, &msg); let label_exp = format!("expected `{token_str}`"); - match self.recover_closing_delimiter(&[t.clone()], err) { - Err(e) => err = e, - Ok(recovered) => { - return Ok(recovered); - } - } let sm = self.sess.source_map(); if !sm.is_multiline(prev_sp.until(sp)) { // When the spans are in the same line, it means that the only content @@ -1795,81 +1760,6 @@ impl<'a> Parser<'a> { } } - pub(super) fn recover_closing_delimiter( - &mut self, - tokens: &[TokenKind], - mut err: DiagnosticBuilder<'a, ErrorGuaranteed>, - ) -> PResult<'a, bool> { - let mut pos = None; - // We want to use the last closing delim that would apply. - for (i, unmatched) in self.unclosed_delims.iter().enumerate().rev() { - if tokens.contains(&token::CloseDelim(unmatched.expected_delim)) - && Some(self.token.span) > unmatched.unclosed_span - { - pos = Some(i); - } - } - match pos { - Some(pos) => { - // Recover and assume that the detected unclosed delimiter was meant for - // this location. Emit the diagnostic and act as if the delimiter was - // present for the parser's sake. - - // Don't attempt to recover from this unclosed delimiter more than once. - let unmatched = self.unclosed_delims.remove(pos); - let delim = TokenType::Token(token::CloseDelim(unmatched.expected_delim)); - if unmatched.found_delim.is_none() { - // We encountered `Eof`, set this fact here to avoid complaining about missing - // `fn main()` when we found place to suggest the closing brace. - *self.sess.reached_eof.borrow_mut() = true; - } - - // We want to suggest the inclusion of the closing delimiter where it makes - // the most sense, which is immediately after the last token: - // - // {foo(bar {}} - // ^ ^ - // | | - // | help: `)` may belong here - // | - // unclosed delimiter - if let Some(sp) = unmatched.unclosed_span { - let mut primary_span: Vec = - err.span.primary_spans().iter().cloned().collect(); - primary_span.push(sp); - let mut primary_span: MultiSpan = primary_span.into(); - for span_label in err.span.span_labels() { - if let Some(label) = span_label.label { - primary_span.push_span_label(span_label.span, label); - } - } - err.set_span(primary_span); - err.span_label(sp, "unclosed delimiter"); - } - // Backticks should be removed to apply suggestions. - let mut delim = delim.to_string(); - delim.retain(|c| c != '`'); - err.span_suggestion_short( - self.prev_token.span.shrink_to_hi(), - &format!("`{delim}` may belong here"), - delim, - Applicability::MaybeIncorrect, - ); - if unmatched.found_delim.is_none() { - // Encountered `Eof` when lexing blocks. Do not recover here to avoid knockdown - // errors which would be emitted elsewhere in the parser and let other error - // recovery consume the rest of the file. - Err(err) - } else { - err.emit(); - self.expected_tokens.clear(); // Reduce the number of errors. - Ok(true) - } - } - _ => Err(err), - } - } - /// Eats tokens until we can be relatively sure we reached the end of the /// statement. This is something of a best-effort heuristic. /// diff --git a/compiler/rustc_parse/src/parser/expr.rs b/compiler/rustc_parse/src/parser/expr.rs index b2951e7a1847d..90d8674ab94a6 100644 --- a/compiler/rustc_parse/src/parser/expr.rs +++ b/compiler/rustc_parse/src/parser/expr.rs @@ -1389,19 +1389,6 @@ impl<'a> Parser<'a> { self.parse_expr_let() } else if self.eat_keyword(kw::Underscore) { Ok(self.mk_expr(self.prev_token.span, ExprKind::Underscore)) - } else if !self.unclosed_delims.is_empty() && self.check(&token::Semi) { - // Don't complain about bare semicolons after unclosed braces - // recovery in order to keep the error count down. Fixing the - // delimiters will possibly also fix the bare semicolon found in - // expression context. For example, silence the following error: - // - // error: expected expression, found `;` - // --> file.rs:2:13 - // | - // 2 | foo(bar(; - // | ^ expected expression - self.bump(); - Ok(self.mk_expr_err(self.token.span)) } else if self.token.uninterpolated_span().rust_2018() { // `Span::rust_2018()` is somewhat expensive; don't get it repeatedly. if self.check_keyword(kw::Async) { diff --git a/compiler/rustc_parse/src/parser/item.rs b/compiler/rustc_parse/src/parser/item.rs index 9d9ae154ad42e..85cc8ca02a977 100644 --- a/compiler/rustc_parse/src/parser/item.rs +++ b/compiler/rustc_parse/src/parser/item.rs @@ -125,16 +125,13 @@ impl<'a> Parser<'a> { return Ok(Some(item.into_inner())); }; - let mut unclosed_delims = vec![]; let item = self.collect_tokens_trailing_token(attrs, force_collect, |this: &mut Self, attrs| { let item = this.parse_item_common_(attrs, mac_allowed, attrs_allowed, fn_parse_mode); - unclosed_delims.append(&mut this.unclosed_delims); Ok((item?, TrailingToken::None)) })?; - self.unclosed_delims.append(&mut unclosed_delims); Ok(item) } @@ -1960,21 +1957,12 @@ impl<'a> Parser<'a> { // FIXME: This will make us not emit the help even for declarative // macros within the same crate (that we can fix), which is sad. if !span.from_expansion() { - if self.unclosed_delims.is_empty() { - let DelimSpan { open, close } = args.dspan; - err.multipart_suggestion( - "change the delimiters to curly braces", - vec![(open, "{".to_string()), (close, '}'.to_string())], - Applicability::MaybeIncorrect, - ); - } else { - err.span_suggestion( - span, - "change the delimiters to curly braces", - " { /* items */ }", - Applicability::HasPlaceholders, - ); - } + let DelimSpan { open, close } = args.dspan; + err.multipart_suggestion( + "change the delimiters to curly braces", + vec![(open, "{".to_string()), (close, '}'.to_string())], + Applicability::MaybeIncorrect, + ); err.span_suggestion( span.shrink_to_hi(), "add a semicolon", diff --git a/compiler/rustc_parse/src/parser/mod.rs b/compiler/rustc_parse/src/parser/mod.rs index b1b79fe4e054b..d027fc1150189 100644 --- a/compiler/rustc_parse/src/parser/mod.rs +++ b/compiler/rustc_parse/src/parser/mod.rs @@ -146,10 +146,7 @@ pub struct Parser<'a> { /// See the comments in the `parse_path_segment` function for more details. unmatched_angle_bracket_count: u32, max_angle_bracket_count: u32, - /// 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, + last_unexpected_token_span: Option, /// 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 +165,7 @@ 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<'_>, 312); +rustc_data_structures::static_assert_size!(Parser<'_>, 288); /// Stores span information about a closure. #[derive(Clone)] @@ -215,12 +212,6 @@ struct CaptureState { inner_attr_ranges: FxHashMap, } -impl<'a> Drop for Parser<'a> { - fn drop(&mut self) { - emit_unclosed_delims(&mut self.unclosed_delims, &self.sess); - } -} - /// 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 @@ -478,7 +469,6 @@ impl<'a> Parser<'a> { desugar_doc_comments, unmatched_angle_bracket_count: 0, max_angle_bracket_count: 0, - unclosed_delims: Vec::new(), last_unexpected_token_span: None, last_type_ascription: None, subparser_name, @@ -859,7 +849,6 @@ impl<'a> Parser<'a> { let mut recovered = false; let mut trailing = false; let mut v = ThinVec::new(); - let unclosed_delims = !self.unclosed_delims.is_empty(); while !self.expect_any_with_type(kets, expect) { if let token::CloseDelim(..) | token::Eof = self.token.kind { @@ -901,7 +890,7 @@ impl<'a> Parser<'a> { _ => { // Attempt to keep parsing if it was a similar separator. if let Some(tokens) = t.similar_tokens() { - if tokens.contains(&self.token.kind) && !unclosed_delims { + if tokens.contains(&self.token.kind) { self.bump(); } }