diff options
Diffstat (limited to 'compiler/rustc_parse/src/parser/diagnostics.rs')
| -rw-r--r-- | compiler/rustc_parse/src/parser/diagnostics.rs | 247 |
1 files changed, 102 insertions, 145 deletions
diff --git a/compiler/rustc_parse/src/parser/diagnostics.rs b/compiler/rustc_parse/src/parser/diagnostics.rs index a051dbe9f..e03ce5d71 100644 --- a/compiler/rustc_parse/src/parser/diagnostics.rs +++ b/compiler/rustc_parse/src/parser/diagnostics.rs @@ -6,20 +6,19 @@ use super::{ use crate::errors::{ AmbiguousPlus, AttributeOnParamType, BadQPathStage2, BadTypePlus, BadTypePlusSub, ComparisonOperatorsCannotBeChained, ComparisonOperatorsCannotBeChainedSugg, - ConstGenericWithoutBraces, ConstGenericWithoutBracesSugg, DocCommentOnParamType, - DoubleColonInBound, ExpectedIdentifier, ExpectedSemi, ExpectedSemiSugg, - GenericParamsWithoutAngleBrackets, GenericParamsWithoutAngleBracketsSugg, InInTypo, - IncorrectAwait, IncorrectSemicolon, IncorrectUseOfAwait, ParenthesesInForHead, - ParenthesesInForHeadSugg, PatternMethodParamWithoutBody, QuestionMarkInType, - QuestionMarkInTypeSugg, SelfParamNotFirst, StructLiteralBodyWithoutPath, - StructLiteralBodyWithoutPathSugg, StructLiteralNeedingParens, StructLiteralNeedingParensSugg, - SuggEscapeToUseAsIdentifier, SuggRemoveComma, UnexpectedConstInGenericParam, - UnexpectedConstParamDeclaration, UnexpectedConstParamDeclarationSugg, UnmatchedAngleBrackets, - UseEqInstead, + ConstGenericWithoutBraces, ConstGenericWithoutBracesSugg, DocCommentDoesNotDocumentAnything, + DocCommentOnParamType, DoubleColonInBound, ExpectedIdentifier, ExpectedSemi, ExpectedSemiSugg, + GenericParamsWithoutAngleBrackets, GenericParamsWithoutAngleBracketsSugg, + HelpIdentifierStartsWithNumber, InInTypo, IncorrectAwait, IncorrectSemicolon, + IncorrectUseOfAwait, ParenthesesInForHead, ParenthesesInForHeadSugg, + PatternMethodParamWithoutBody, QuestionMarkInType, QuestionMarkInTypeSugg, SelfParamNotFirst, + StructLiteralBodyWithoutPath, StructLiteralBodyWithoutPathSugg, StructLiteralNeedingParens, + StructLiteralNeedingParensSugg, SuggEscapeIdentifier, SuggRemoveComma, + UnexpectedConstInGenericParam, UnexpectedConstParamDeclaration, + UnexpectedConstParamDeclarationSugg, UnmatchedAngleBrackets, UseEqInstead, }; use crate::fluent_generated as fluent; -use crate::lexer::UnmatchedDelim; use crate::parser; use rustc_ast as ast; use rustc_ast::ptr::P; @@ -39,7 +38,7 @@ use rustc_errors::{ use rustc_session::errors::ExprParenthesesNeeded; use rustc_span::source_map::Spanned; use rustc_span::symbol::{kw, sym, Ident}; -use rustc_span::{Span, SpanSnippetError, DUMMY_SP}; +use rustc_span::{Span, SpanSnippetError, Symbol, DUMMY_SP}; use std::mem::take; use std::ops::{Deref, DerefMut}; use thin_vec::{thin_vec, ThinVec}; @@ -220,7 +219,6 @@ impl MultiSugg { /// is dropped. pub struct SnapshotParser<'a> { parser: Parser<'a>, - unclosed_delims: Vec<UnmatchedDelim>, } impl<'a> Deref for SnapshotParser<'a> { @@ -255,34 +253,36 @@ 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<String, SpanSnippetError> { self.sess.source_map().span_to_snippet(span) } - pub(super) fn expected_ident_found(&mut self) -> DiagnosticBuilder<'a, ErrorGuaranteed> { + /// Emits an error with suggestions if an identifier was expected but not found. + /// + /// Returns a possibly recovered identifier. + pub(super) fn expected_ident_found( + &mut self, + recover: bool, + ) -> PResult<'a, (Ident, /* is_raw */ bool)> { + if let TokenKind::DocComment(..) = self.prev_token.kind { + return Err(DocCommentDoesNotDocumentAnything { + span: self.prev_token.span, + missing_comma: None, + } + .into_diagnostic(&self.sess.span_diagnostic)); + } + let valid_follow = &[ TokenKind::Eq, TokenKind::Colon, @@ -294,38 +294,61 @@ impl<'a> Parser<'a> { TokenKind::CloseDelim(Delimiter::Brace), TokenKind::CloseDelim(Delimiter::Parenthesis), ]; - let suggest_raw = match self.token.ident() { - Some((ident, false)) - if ident.is_raw_guess() - && self.look_ahead(1, |t| valid_follow.contains(&t.kind)) => - { - Some(SuggEscapeToUseAsIdentifier { - span: ident.span.shrink_to_lo(), - // `Symbol::to_string()` is different from `Symbol::into_diagnostic_arg()`, - // which uses `Symbol::to_ident_string()` and "helpfully" adds an implicit `r#` - ident_name: ident.name.to_string(), - }) - } - _ => None, - }; + + let mut recovered_ident = None; + // we take this here so that the correct original token is retained in + // the diagnostic, regardless of eager recovery. + let bad_token = self.token.clone(); + + // suggest prepending a keyword in identifier position with `r#` + let suggest_raw = if let Some((ident, false)) = self.token.ident() + && ident.is_raw_guess() + && self.look_ahead(1, |t| valid_follow.contains(&t.kind)) + { + recovered_ident = Some((ident, true)); + + // `Symbol::to_string()` is different from `Symbol::into_diagnostic_arg()`, + // which uses `Symbol::to_ident_string()` and "helpfully" adds an implicit `r#` + let ident_name = ident.name.to_string(); + + Some(SuggEscapeIdentifier { + span: ident.span.shrink_to_lo(), + ident_name + }) + } else { None }; let suggest_remove_comma = if self.token == token::Comma && self.look_ahead(1, |t| t.is_ident()) { - Some(SuggRemoveComma { span: self.token.span }) + if recover { + self.bump(); + recovered_ident = self.ident_or_err(false).ok(); + }; + + Some(SuggRemoveComma { span: bad_token.span }) } else { None }; + let help_cannot_start_number = self.is_lit_bad_ident().map(|(len, valid_portion)| { + let (invalid, valid) = self.token.span.split_at(len as u32); + + recovered_ident = Some((Ident::new(valid_portion, valid), false)); + + HelpIdentifierStartsWithNumber { num_span: invalid } + }); + let err = ExpectedIdentifier { - span: self.token.span, - token: self.token.clone(), + span: bad_token.span, + token: bad_token, suggest_raw, suggest_remove_comma, + help_cannot_start_number, }; let mut err = err.into_diagnostic(&self.sess.span_diagnostic); // if the token we have is a `<` // it *might* be a misplaced generic + // FIXME: could we recover with this? if self.token == token::Lt { // all keywords that could have generic applied let valid_prev_keywords = @@ -376,7 +399,38 @@ impl<'a> Parser<'a> { } } - err + if let Some(recovered_ident) = recovered_ident && recover { + err.emit(); + Ok(recovered_ident) + } else { + Err(err) + } + } + + pub(super) fn expected_ident_found_err(&mut self) -> DiagnosticBuilder<'a, ErrorGuaranteed> { + self.expected_ident_found(false).unwrap_err() + } + + /// Checks if the current token is a integer or float literal and looks like + /// it could be a invalid identifier with digits at the start. + /// + /// Returns the number of characters (bytes) composing the invalid portion + /// of the identifier and the valid portion of the identifier. + pub(super) fn is_lit_bad_ident(&mut self) -> Option<(usize, Symbol)> { + // ensure that the integer literal is followed by a *invalid* + // suffix: this is how we know that it is a identifier with an + // invalid beginning. + if let token::Literal(Lit { + kind: token::LitKind::Integer | token::LitKind::Float, + symbol, + suffix: Some(suffix), // no suffix makes it a valid literal + }) = self.token.kind + && rustc_ast::MetaItemLit::from_token(&self.token).is_none() + { + Some((symbol.as_str().len(), suffix)) + } else { + None + } } pub(super) fn expected_one_of_not_found( @@ -579,21 +633,6 @@ 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::<Vec<_>>(), - 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) { @@ -950,8 +989,7 @@ impl<'a> Parser<'a> { } if self.token.kind == token::OpenDelim(Delimiter::Parenthesis) { // Recover from bad turbofish: `foo.collect::Vec<_>()`. - let args = AngleBracketedArgs { args, span }.into(); - segment.args = args; + segment.args = Some(AngleBracketedArgs { args, span }.into()); self.sess.emit_err(GenericParamsWithoutAngleBrackets { span, @@ -1573,12 +1611,6 @@ 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 +1827,6 @@ 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<Span> = - 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. /// |