From e90e2593ea9c29ff6be20ec38b314fb2d6d927a4 Mon Sep 17 00:00:00 2001 From: Pavel Grigorenko Date: Sat, 21 Sep 2024 20:07:52 +0300 Subject: Parser: recover from `:::` to `::` --- compiler/rustc_parse/src/parser/mod.rs | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-) (limited to 'compiler/rustc_parse/src/parser/mod.rs') diff --git a/compiler/rustc_parse/src/parser/mod.rs b/compiler/rustc_parse/src/parser/mod.rs index 9d9265d5318..3b58b2337f3 100644 --- a/compiler/rustc_parse/src/parser/mod.rs +++ b/compiler/rustc_parse/src/parser/mod.rs @@ -1562,12 +1562,25 @@ impl<'a> Parser<'a> { }) } + /// Checks for `::` or, potentially, `:::` and then look ahead after it. + fn check_path_sep_and_look_ahead(&mut self, looker: impl Fn(&Token) -> bool) -> bool { + if self.check(&token::PathSep) { + if self.may_recover() && self.look_ahead(1, |t| t.kind == token::Colon) { + debug_assert!(!self.look_ahead(1, &looker), "Looker must not match on colon"); + self.look_ahead(2, looker) + } else { + self.look_ahead(1, looker) + } + } else { + false + } + } + /// `::{` or `::*` fn is_import_coupler(&mut self) -> bool { - self.check(&token::PathSep) - && self.look_ahead(1, |t| { - *t == token::OpenDelim(Delimiter::Brace) || *t == token::BinOp(token::Star) - }) + self.check_path_sep_and_look_ahead(|t| { + matches!(t.kind, token::OpenDelim(Delimiter::Brace) | token::BinOp(token::Star)) + }) } // Debug view of the parser's token stream, up to `{lookahead}` tokens. -- cgit 1.4.1-3-g733a5