diff options
Diffstat (limited to 'compiler/rustc_parse/src/lexer/mod.rs')
| -rw-r--r-- | compiler/rustc_parse/src/lexer/mod.rs | 28 |
1 files changed, 24 insertions, 4 deletions
diff --git a/compiler/rustc_parse/src/lexer/mod.rs b/compiler/rustc_parse/src/lexer/mod.rs index f027843e6b4..8761c23625b 100644 --- a/compiler/rustc_parse/src/lexer/mod.rs +++ b/compiler/rustc_parse/src/lexer/mod.rs @@ -79,7 +79,7 @@ impl<'a> StringReader<'a> { /// preceded by whitespace. fn next_token(&mut self) -> (Token, bool) { let mut preceded_by_whitespace = false; - + let mut swallow_next_invalid = 0; // Skip trivial (whitespace & comments) tokens loop { let token = self.cursor.advance_token(); @@ -232,19 +232,34 @@ impl<'a> StringReader<'a> { rustc_lexer::TokenKind::Percent => token::BinOp(token::Percent), rustc_lexer::TokenKind::Unknown | rustc_lexer::TokenKind::InvalidIdent => { - let c = self.str_from(start).chars().next().unwrap(); + // Don't emit diagnostics for sequences of the same invalid token + if swallow_next_invalid > 0 { + swallow_next_invalid -= 1; + continue; + } + let mut it = self.str_from_to_end(start).chars(); + let c = it.next().unwrap(); + let repeats = it.take_while(|c1| *c1 == c).count(); let mut err = - self.struct_err_span_char(start, self.pos, "unknown start of token", c); + self.struct_err_span_char(start, self.pos + Pos::from_usize(repeats * c.len_utf8()), "unknown start of token", c); // FIXME: the lexer could be used to turn the ASCII version of unicode // homoglyphs, instead of keeping a table in `check_for_substitution`into the // token. Ideally, this should be inside `rustc_lexer`. However, we should // first remove compound tokens like `<<` from `rustc_lexer`, and then add // fancier error recovery to it, as there will be less overall work to do this // way. - let token = unicode_chars::check_for_substitution(self, start, c, &mut err); + let token = unicode_chars::check_for_substitution(self, start, c, &mut err, repeats+1); if c == '\x00' { err.help("source files must contain UTF-8 encoded text, unexpected null bytes might occur when a different encoding is used"); } + if repeats > 0 { + if repeats == 1 { + err.note(format!("character appears once more")); + } else { + err.note(format!("character appears {repeats} more times")); + } + swallow_next_invalid = repeats; + } err.emit(); if let Some(token) = token { token @@ -486,6 +501,11 @@ impl<'a> StringReader<'a> { &self.src[self.src_index(start)..self.src_index(end)] } + /// Slice of the source text spanning from `start` until the end + fn str_from_to_end(&self, start: BytePos) -> &str { + &self.src[self.src_index(start)..] + } + fn report_raw_str_error(&self, start: BytePos, prefix_len: u32) -> ! { match rustc_lexer::validate_raw_str(self.str_from(start), prefix_len) { Err(RawStrError::InvalidStarter { bad_char }) => { |