diff --git a/compiler/rustc_parse/src/lexer/mod.rs b/compiler/rustc_parse/src/lexer/mod.rs index bcd078a8967..88540e13ef2 100644 --- a/compiler/rustc_parse/src/lexer/mod.rs +++ b/compiler/rustc_parse/src/lexer/mod.rs @@ -52,7 +52,7 @@ pub(crate) fn parse_token_trees<'a>( let cursor = Cursor::new(src); let string_reader = StringReader { sess, start_pos, pos: start_pos, src, cursor, override_span }; - tokentrees::TokenTreesReader::parse_token_trees(string_reader) + tokentrees::TokenTreesReader::parse_all_token_trees(string_reader) } struct StringReader<'a> { diff --git a/compiler/rustc_parse/src/lexer/tokentrees.rs b/compiler/rustc_parse/src/lexer/tokentrees.rs index 364753154db..b06f23d7c7b 100644 --- a/compiler/rustc_parse/src/lexer/tokentrees.rs +++ b/compiler/rustc_parse/src/lexer/tokentrees.rs @@ -27,7 +27,7 @@ pub(super) struct TokenTreesReader<'a> { } impl<'a> TokenTreesReader<'a> { - pub(super) fn parse_token_trees( + pub(super) fn parse_all_token_trees( string_reader: StringReader<'a>, ) -> (PResult<'a, TokenStream>, Vec) { let mut tt_reader = TokenTreesReader { @@ -40,34 +40,29 @@ impl<'a> TokenTreesReader<'a> { last_delim_empty_block_spans: FxHashMap::default(), matching_block_spans: Vec::new(), }; - let res = tt_reader.parse_all_token_trees(); + let res = tt_reader.parse_token_trees(/* is_top_level */ true); (res, tt_reader.unmatched_braces) } - // Parse a stream of tokens into a list of `TokenTree`s, up to an `Eof`. - fn parse_all_token_trees(&mut self) -> PResult<'a, TokenStream> { + // Parse a stream of tokens into a list of `TokenTree`s. + fn parse_token_trees(&mut self, is_top_level: bool) -> PResult<'a, TokenStream> { self.token = self.string_reader.next_token().0; let mut buf = TokenStreamBuilder::default(); loop { match self.token.kind { token::OpenDelim(delim) => buf.push(self.parse_token_tree_open_delim(delim)), - token::CloseDelim(delim) => return Err(self.close_delim_err(delim)), - token::Eof => return Ok(buf.into_token_stream()), - _ => buf.push(self.parse_token_tree_non_delim_non_eof()), - } - } - } - - // Parse a stream of tokens into a list of `TokenTree`s, up to a `CloseDelim`. - fn parse_token_trees_until_close_delim(&mut self) -> TokenStream { - let mut buf = TokenStreamBuilder::default(); - loop { - match self.token.kind { - token::OpenDelim(delim) => buf.push(self.parse_token_tree_open_delim(delim)), - token::CloseDelim(..) => return buf.into_token_stream(), + token::CloseDelim(delim) => { + return if !is_top_level { + Ok(buf.into_token_stream()) + } else { + Err(self.close_delim_err(delim)) + }; + } token::Eof => { - self.eof_err().emit(); - return buf.into_token_stream(); + if !is_top_level { + self.eof_err().emit(); + } + return Ok(buf.into_token_stream()); } _ => buf.push(self.parse_token_tree_non_delim_non_eof()), } @@ -113,14 +108,12 @@ impl<'a> TokenTreesReader<'a> { // The span for beginning of the delimited section let pre_span = self.token.span; - // Move past the open delimiter. self.open_braces.push((open_delim, self.token.span)); - self.token = self.string_reader.next_token().0; // Parse the token trees within the delimiters. // We stop at any delimiter so we can try to recover if the user // uses an incorrect delimiter. - let tts = self.parse_token_trees_until_close_delim(); + let tts = self.parse_token_trees(/* is_top_level */ false).unwrap(); // Expand to cover the entire delimited token tree let delim_span = DelimSpan::from_pair(pre_span, self.token.span);