From f88cf0206faa5fb169deebbbd1024d9a0381ecd3 Mon Sep 17 00:00:00 2001 From: sjwang05 <63834813+sjwang05@users.noreply.github.com> Date: Sat, 11 Nov 2023 13:39:08 -0800 Subject: [PATCH] Move unclosed delim errors to separate function --- compiler/rustc_parse/src/lexer/tokentrees.rs | 111 ++++++++++--------- tests/ui/parser/brace-in-let-chain.stderr | 14 +-- 2 files changed, 62 insertions(+), 63 deletions(-) diff --git a/compiler/rustc_parse/src/lexer/tokentrees.rs b/compiler/rustc_parse/src/lexer/tokentrees.rs index 41f4d0055aa..db795ce9f72 100644 --- a/compiler/rustc_parse/src/lexer/tokentrees.rs +++ b/compiler/rustc_parse/src/lexer/tokentrees.rs @@ -117,59 +117,8 @@ fn parse_token_tree_open_delim( // We stop at any delimiter so we can try to recover if the user // uses an incorrect delimiter. let (tts, res) = self.parse_token_trees(/* is_delimited */ true); - if let Err(mut errs) = res { - // If there are unclosed delims, see if there are diff markers and if so, point them - // out instead of complaining about the unclosed delims. - let mut parser = crate::stream_to_parser(self.string_reader.sess, tts, None); - let mut diff_errs = vec![]; - // Suggest removing a `{` we think appears in an `if`/`while` condition - // We want to suggest removing a `{` only if we think we're in an `if`/`while` condition, but - // we have no way of tracking this in the lexer itself, so we piggyback on the parser - let mut in_cond = false; - while parser.token != token::Eof { - if let Err(diff_err) = parser.err_diff_marker() { - diff_errs.push(diff_err); - } else if parser.is_keyword_ahead(0, &[kw::If, kw::While]) { - in_cond = true; - } else if matches!( - parser.token.kind, - token::CloseDelim(Delimiter::Brace) | token::FatArrow - ) { - // end of the `if`/`while` body, or the end of a `match` guard - in_cond = false; - } else if in_cond && parser.token == token::OpenDelim(Delimiter::Brace) { - // Store the `&&` and `let` to use their spans later when creating the diagnostic - let maybe_andand = parser.look_ahead(1, |t| t.clone()); - let maybe_let = parser.look_ahead(2, |t| t.clone()); - if maybe_andand == token::OpenDelim(Delimiter::Brace) { - // This might be the beginning of the `if`/`while` body (i.e., the end of the condition) - in_cond = false; - } else if maybe_andand == token::AndAnd && maybe_let.is_keyword(kw::Let) { - let mut err = parser.struct_span_err( - parser.token.span, - "found a `{` in the middle of a let-chain", - ); - err.span_suggestion( - parser.token.span, - "consider removing this brace to parse the `let` as part of the same chain", - "", Applicability::MachineApplicable - ); - err.span_note( - maybe_andand.span.to(maybe_let.span), - "you might have meant to continue the let-chain here", - ); - errs.push(err); - } - } - parser.bump(); - } - if !diff_errs.is_empty() { - errs.iter_mut().for_each(|err| { - err.delay_as_bug(); - }); - return Err(diff_errs); - } - return Err(errs); + if let Err(errs) = res { + return Err(self.unclosed_delim_err(tts, errs)); } // Expand to cover the entire delimited token tree @@ -256,6 +205,62 @@ fn parse_token_tree_open_delim( Ok(TokenTree::Delimited(delim_span, open_delim, tts)) } + fn unclosed_delim_err(&mut self, tts: TokenStream, mut errs: Vec>) -> Vec> { + // If there are unclosed delims, see if there are diff markers and if so, point them + // out instead of complaining about the unclosed delims. + let mut parser = crate::stream_to_parser(self.string_reader.sess, tts, None); + let mut diff_errs = vec![]; + // Suggest removing a `{` we think appears in an `if`/`while` condition + // We want to suggest removing a `{` only if we think we're in an `if`/`while` condition, but + // we have no way of tracking this in the lexer itself, so we piggyback on the parser + let mut in_cond = false; + while parser.token != token::Eof { + if let Err(diff_err) = parser.err_diff_marker() { + diff_errs.push(diff_err); + } else if parser.is_keyword_ahead(0, &[kw::If, kw::While]) { + in_cond = true; + } else if matches!( + parser.token.kind, + token::CloseDelim(Delimiter::Brace) | token::FatArrow + ) { + // end of the `if`/`while` body, or the end of a `match` guard + in_cond = false; + } else if in_cond && parser.token == token::OpenDelim(Delimiter::Brace) { + // Store the `&&` and `let` to use their spans later when creating the diagnostic + let maybe_andand = parser.look_ahead(1, |t| t.clone()); + let maybe_let = parser.look_ahead(2, |t| t.clone()); + if maybe_andand == token::OpenDelim(Delimiter::Brace) { + // This might be the beginning of the `if`/`while` body (i.e., the end of the condition) + in_cond = false; + } else if maybe_andand == token::AndAnd && maybe_let.is_keyword(kw::Let) { + let mut err = parser.struct_span_err( + parser.token.span, + "found a `{` in the middle of a let-chain", + ); + err.span_suggestion( + parser.token.span, + "consider removing this brace to parse the `let` as part of the same chain", + "", + Applicability::MachineApplicable, + ); + err.span_label( + maybe_andand.span.to(maybe_let.span), + "you might have meant to continue the let-chain here", + ); + errs.push(err); + } + } + parser.bump(); + } + if !diff_errs.is_empty() { + errs.iter_mut().for_each(|err| { + err.delay_as_bug(); + }); + return diff_errs; + } + return errs; + } + fn close_delim_err(&mut self, delim: Delimiter) -> PErr<'a> { // An unexpected closing delimiter (i.e., there is no // matching opening delimiter). diff --git a/tests/ui/parser/brace-in-let-chain.stderr b/tests/ui/parser/brace-in-let-chain.stderr index c43310f4736..7182d86d001 100644 --- a/tests/ui/parser/brace-in-let-chain.stderr +++ b/tests/ui/parser/brace-in-let-chain.stderr @@ -38,12 +38,9 @@ error: found a `{` in the middle of a let-chain | LL | && let () = () { | ^ - | -note: you might have meant to continue the let-chain here - --> $DIR/brace-in-let-chain.rs:15:9 - | LL | && let () = () - | ^^^^^^ + | ------ you might have meant to continue the let-chain here + | help: consider removing this brace to parse the `let` as part of the same chain | LL - && let () = () { @@ -55,12 +52,9 @@ error: found a `{` in the middle of a let-chain | LL | && let () = () { | ^ - | -note: you might have meant to continue the let-chain here - --> $DIR/brace-in-let-chain.rs:7:9 - | LL | && let () = () - | ^^^^^^ + | ------ you might have meant to continue the let-chain here + | help: consider removing this brace to parse the `let` as part of the same chain | LL - && let () = () {