| use std::ops::Range; |
| |
| use crate::errors; |
| use crate::lexer::unicode_chars::UNICODE_ARRAY; |
| use crate::make_unclosed_delims_error; |
| use rustc_ast::ast::{self, AttrStyle}; |
| use rustc_ast::token::{self, CommentKind, Delimiter, Token, TokenKind}; |
| use rustc_ast::tokenstream::TokenStream; |
| use rustc_ast::util::unicode::contains_text_flow_control_chars; |
| use rustc_errors::{error_code, Applicability, Diagnostic, DiagnosticBuilder, StashKey}; |
| use rustc_lexer::unescape::{self, EscapeError, Mode}; |
| use rustc_lexer::{Base, DocStyle, RawStrError}; |
| use rustc_lexer::{Cursor, LiteralKind}; |
| use rustc_session::lint::builtin::{ |
| RUST_2021_PREFIXES_INCOMPATIBLE_SYNTAX, TEXT_DIRECTION_CODEPOINT_IN_COMMENT, |
| }; |
| use rustc_session::lint::BuiltinLintDiagnostics; |
| use rustc_session::parse::ParseSess; |
| use rustc_span::symbol::{sym, Symbol}; |
| use rustc_span::{edition::Edition, BytePos, Pos, Span}; |
| |
| mod diagnostics; |
| mod tokentrees; |
| mod unescape_error_reporting; |
| mod unicode_chars; |
| |
| use unescape_error_reporting::{emit_unescape_error, escaped_char}; |
| |
| // This type is used a lot. Make sure it doesn't unintentionally get bigger. |
| // |
| // This assertion is in this crate, rather than in `rustc_lexer`, because that |
| // crate cannot depend on `rustc_data_structures`. |
| #[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))] |
| rustc_data_structures::static_assert_size!(rustc_lexer::Token, 12); |
| |
| #[derive(Clone, Debug)] |
| pub struct UnmatchedDelim { |
| pub expected_delim: Delimiter, |
| pub found_delim: Option<Delimiter>, |
| pub found_span: Span, |
| pub unclosed_span: Option<Span>, |
| pub candidate_span: Option<Span>, |
| } |
| |
| pub(crate) fn parse_token_trees<'a>( |
| sess: &'a ParseSess, |
| mut src: &'a str, |
| mut start_pos: BytePos, |
| override_span: Option<Span>, |
| ) -> Result<TokenStream, Vec<Diagnostic>> { |
| // Skip `#!`, if present. |
| if let Some(shebang_len) = rustc_lexer::strip_shebang(src) { |
| src = &src[shebang_len..]; |
| start_pos = start_pos + BytePos::from_usize(shebang_len); |
| } |
| |
| let cursor = Cursor::new(src); |
| let string_reader = StringReader { |
| sess, |
| start_pos, |
| pos: start_pos, |
| src, |
| cursor, |
| override_span, |
| nbsp_is_whitespace: false, |
| }; |
| let (token_trees, unmatched_delims) = |
| tokentrees::TokenTreesReader::parse_all_token_trees(string_reader); |
| match token_trees { |
| Ok(stream) if unmatched_delims.is_empty() => Ok(stream), |
| _ => { |
| // Return error if there are unmatched delimiters or unclosed delimiters. |
| // We emit delimiter mismatch errors first, then emit the unclosing delimiter mismatch |
| // because the delimiter mismatch is more likely to be the root cause of error |
| |
| let mut buffer = Vec::with_capacity(1); |
| for unmatched in unmatched_delims { |
| if let Some(err) = make_unclosed_delims_error(unmatched, &sess) { |
| err.buffer(&mut buffer); |
| } |
| } |
| if let Err(err) = token_trees { |
| // Add unclosing delimiter error |
| err.buffer(&mut buffer); |
| } |
| Err(buffer) |
| } |
| } |
| } |
| |
| struct StringReader<'a> { |
| sess: &'a ParseSess, |
| /// Initial position, read-only. |
| start_pos: BytePos, |
| /// The absolute offset within the source_map of the current character. |
| pos: BytePos, |
| /// Source text to tokenize. |
| src: &'a str, |
| /// Cursor for getting lexer tokens. |
| cursor: Cursor<'a>, |
| override_span: Option<Span>, |
| /// When a "unknown start of token: \u{a0}" has already been emitted earlier |
| /// in this file, it's safe to treat further occurrences of the non-breaking |
| /// space character as whitespace. |
| nbsp_is_whitespace: bool, |
| } |
| |
| impl<'a> StringReader<'a> { |
| fn mk_sp(&self, lo: BytePos, hi: BytePos) -> Span { |
| self.override_span.unwrap_or_else(|| Span::with_root_ctxt(lo, hi)) |
| } |
| |
| /// Returns the next token, paired with a bool indicating if the token was |
| /// 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 str_before = self.cursor.as_str(); |
| let token = self.cursor.advance_token(); |
| let start = self.pos; |
| self.pos = self.pos + BytePos(token.len); |
| |
| debug!("next_token: {:?}({:?})", token.kind, self.str_from(start)); |
| |
| // Now "cook" the token, converting the simple `rustc_lexer::TokenKind` enum into a |
| // rich `rustc_ast::TokenKind`. This turns strings into interned symbols and runs |
| // additional validation. |
| let kind = match token.kind { |
| rustc_lexer::TokenKind::LineComment { doc_style } => { |
| // Skip non-doc comments |
| let Some(doc_style) = doc_style else { |
| self.lint_unicode_text_flow(start); |
| preceded_by_whitespace = true; |
| continue; |
| }; |
| |
| // Opening delimiter of the length 3 is not included into the symbol. |
| let content_start = start + BytePos(3); |
| let content = self.str_from(content_start); |
| self.cook_doc_comment(content_start, content, CommentKind::Line, doc_style) |
| } |
| rustc_lexer::TokenKind::BlockComment { doc_style, terminated } => { |
| if !terminated { |
| self.report_unterminated_block_comment(start, doc_style); |
| } |
| |
| // Skip non-doc comments |
| let Some(doc_style) = doc_style else { |
| self.lint_unicode_text_flow(start); |
| preceded_by_whitespace = true; |
| continue; |
| }; |
| |
| // Opening delimiter of the length 3 and closing delimiter of the length 2 |
| // are not included into the symbol. |
| let content_start = start + BytePos(3); |
| let content_end = self.pos - BytePos(if terminated { 2 } else { 0 }); |
| let content = self.str_from_to(content_start, content_end); |
| self.cook_doc_comment(content_start, content, CommentKind::Block, doc_style) |
| } |
| rustc_lexer::TokenKind::Whitespace => { |
| preceded_by_whitespace = true; |
| continue; |
| } |
| rustc_lexer::TokenKind::Ident => { |
| self.ident(start) |
| } |
| rustc_lexer::TokenKind::RawIdent => { |
| let sym = nfc_normalize(self.str_from(start + BytePos(2))); |
| let span = self.mk_sp(start, self.pos); |
| self.sess.symbol_gallery.insert(sym, span); |
| if !sym.can_be_raw() { |
| self.sess.emit_err(errors::CannotBeRawIdent { span, ident: sym }); |
| } |
| self.sess.raw_identifier_spans.push(span); |
| token::Ident(sym, true) |
| } |
| rustc_lexer::TokenKind::UnknownPrefix => { |
| self.report_unknown_prefix(start); |
| self.ident(start) |
| } |
| rustc_lexer::TokenKind::InvalidIdent |
| // Do not recover an identifier with emoji if the codepoint is a confusable |
| // with a recoverable substitution token, like `âž–`. |
| if !UNICODE_ARRAY |
| .iter() |
| .any(|&(c, _, _)| { |
| let sym = self.str_from(start); |
| sym.chars().count() == 1 && c == sym.chars().next().unwrap() |
| }) => |
| { |
| let sym = nfc_normalize(self.str_from(start)); |
| let span = self.mk_sp(start, self.pos); |
| self.sess.bad_unicode_identifiers.borrow_mut().entry(sym).or_default() |
| .push(span); |
| token::Ident(sym, false) |
| } |
| // split up (raw) c string literals to an ident and a string literal when edition < 2021. |
| rustc_lexer::TokenKind::Literal { |
| kind: kind @ (LiteralKind::CStr { .. } | LiteralKind::RawCStr { .. }), |
| suffix_start: _, |
| } if !self.mk_sp(start, self.pos).edition().at_least_rust_2021() => { |
| let prefix_len = match kind { |
| LiteralKind::CStr { .. } => 1, |
| LiteralKind::RawCStr { .. } => 2, |
| _ => unreachable!(), |
| }; |
| |
| // reset the state so that only the prefix ("c" or "cr") |
| // was consumed. |
| let lit_start = start + BytePos(prefix_len); |
| self.pos = lit_start; |
| self.cursor = Cursor::new(&str_before[prefix_len as usize..]); |
| |
| self.report_unknown_prefix(start); |
| let prefix_span = self.mk_sp(start, lit_start); |
| return (Token::new(self.ident(start), prefix_span), preceded_by_whitespace); |
| } |
| rustc_lexer::TokenKind::Literal { kind, suffix_start } => { |
| let suffix_start = start + BytePos(suffix_start); |
| let (kind, symbol) = self.cook_lexer_literal(start, suffix_start, kind); |
| if let token::LitKind::CStr | token::LitKind::CStrRaw(_) = kind { |
| self.sess.gated_spans.gate(sym::c_str_literals, self.mk_sp(start, self.pos)); |
| } |
| let suffix = if suffix_start < self.pos { |
| let string = self.str_from(suffix_start); |
| if string == "_" { |
| self.sess |
| .span_diagnostic |
| .emit_err(errors::UnderscoreLiteralSuffix { span: self.mk_sp(suffix_start, self.pos) }); |
| None |
| } else { |
| Some(Symbol::intern(string)) |
| } |
| } else { |
| None |
| }; |
| token::Literal(token::Lit { kind, symbol, suffix }) |
| } |
| rustc_lexer::TokenKind::Lifetime { starts_with_number } => { |
| // Include the leading `'` in the real identifier, for macro |
| // expansion purposes. See #12512 for the gory details of why |
| // this is necessary. |
| let lifetime_name = self.str_from(start); |
| if starts_with_number { |
| let span = self.mk_sp(start, self.pos); |
| let mut diag = self.sess.struct_err("lifetimes cannot start with a number"); |
| diag.set_span(span); |
| diag.stash(span, StashKey::LifetimeIsChar); |
| } |
| let ident = Symbol::intern(lifetime_name); |
| token::Lifetime(ident) |
| } |
| rustc_lexer::TokenKind::Semi => token::Semi, |
| rustc_lexer::TokenKind::Comma => token::Comma, |
| rustc_lexer::TokenKind::Dot => token::Dot, |
| rustc_lexer::TokenKind::OpenParen => token::OpenDelim(Delimiter::Parenthesis), |
| rustc_lexer::TokenKind::CloseParen => token::CloseDelim(Delimiter::Parenthesis), |
| rustc_lexer::TokenKind::OpenBrace => token::OpenDelim(Delimiter::Brace), |
| rustc_lexer::TokenKind::CloseBrace => token::CloseDelim(Delimiter::Brace), |
| rustc_lexer::TokenKind::OpenBracket => token::OpenDelim(Delimiter::Bracket), |
| rustc_lexer::TokenKind::CloseBracket => token::CloseDelim(Delimiter::Bracket), |
| rustc_lexer::TokenKind::At => token::At, |
| rustc_lexer::TokenKind::Pound => token::Pound, |
| rustc_lexer::TokenKind::Tilde => token::Tilde, |
| rustc_lexer::TokenKind::Question => token::Question, |
| rustc_lexer::TokenKind::Colon => token::Colon, |
| rustc_lexer::TokenKind::Dollar => token::Dollar, |
| rustc_lexer::TokenKind::Eq => token::Eq, |
| rustc_lexer::TokenKind::Bang => token::Not, |
| rustc_lexer::TokenKind::Lt => token::Lt, |
| rustc_lexer::TokenKind::Gt => token::Gt, |
| rustc_lexer::TokenKind::Minus => token::BinOp(token::Minus), |
| rustc_lexer::TokenKind::And => token::BinOp(token::And), |
| rustc_lexer::TokenKind::Or => token::BinOp(token::Or), |
| rustc_lexer::TokenKind::Plus => token::BinOp(token::Plus), |
| rustc_lexer::TokenKind::Star => token::BinOp(token::Star), |
| rustc_lexer::TokenKind::Slash => token::BinOp(token::Slash), |
| rustc_lexer::TokenKind::Caret => token::BinOp(token::Caret), |
| rustc_lexer::TokenKind::Percent => token::BinOp(token::Percent), |
| |
| rustc_lexer::TokenKind::Unknown | rustc_lexer::TokenKind::InvalidIdent => { |
| // 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(); |
| if c == '\u{00a0}' { |
| // If an error has already been reported on non-breaking |
| // space characters earlier in the file, treat all |
| // subsequent occurrences as whitespace. |
| if self.nbsp_is_whitespace { |
| preceded_by_whitespace = true; |
| continue; |
| } |
| self.nbsp_is_whitespace = true; |
| } |
| let repeats = it.take_while(|c1| *c1 == c).count(); |
| // 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, sugg) = unicode_chars::check_for_substitution(self, start, c, repeats+1); |
| self.sess.emit_err(errors::UnknownTokenStart { |
| span: self.mk_sp(start, self.pos + Pos::from_usize(repeats * c.len_utf8())), |
| escaped: escaped_char(c), |
| sugg, |
| null: if c == '\x00' {Some(errors::UnknownTokenNull)} else {None}, |
| repeat: if repeats > 0 { |
| swallow_next_invalid = repeats; |
| Some(errors::UnknownTokenRepeat { repeats }) |
| } else {None} |
| }); |
| |
| if let Some(token) = token { |
| token |
| } else { |
| preceded_by_whitespace = true; |
| continue; |
| } |
| } |
| rustc_lexer::TokenKind::Eof => token::Eof, |
| }; |
| let span = self.mk_sp(start, self.pos); |
| return (Token::new(kind, span), preceded_by_whitespace); |
| } |
| } |
| |
| fn ident(&self, start: BytePos) -> TokenKind { |
| let sym = nfc_normalize(self.str_from(start)); |
| let span = self.mk_sp(start, self.pos); |
| self.sess.symbol_gallery.insert(sym, span); |
| token::Ident(sym, false) |
| } |
| |
| fn struct_fatal_span_char( |
| &self, |
| from_pos: BytePos, |
| to_pos: BytePos, |
| m: &str, |
| c: char, |
| ) -> DiagnosticBuilder<'a, !> { |
| self.sess |
| .span_diagnostic |
| .struct_span_fatal(self.mk_sp(from_pos, to_pos), format!("{}: {}", m, escaped_char(c))) |
| } |
| |
| /// Detect usages of Unicode codepoints changing the direction of the text on screen and loudly |
| /// complain about it. |
| fn lint_unicode_text_flow(&self, start: BytePos) { |
| // Opening delimiter of the length 2 is not included into the comment text. |
| let content_start = start + BytePos(2); |
| let content = self.str_from(content_start); |
| if contains_text_flow_control_chars(content) { |
| let span = self.mk_sp(start, self.pos); |
| self.sess.buffer_lint_with_diagnostic( |
| &TEXT_DIRECTION_CODEPOINT_IN_COMMENT, |
| span, |
| ast::CRATE_NODE_ID, |
| "unicode codepoint changing visible direction of text present in comment", |
| BuiltinLintDiagnostics::UnicodeTextFlow(span, content.to_string()), |
| ); |
| } |
| } |
| |
| fn cook_doc_comment( |
| &self, |
| content_start: BytePos, |
| content: &str, |
| comment_kind: CommentKind, |
| doc_style: DocStyle, |
| ) -> TokenKind { |
| if content.contains('\r') { |
| for (idx, _) in content.char_indices().filter(|&(_, c)| c == '\r') { |
| let span = self.mk_sp( |
| content_start + BytePos(idx as u32), |
| content_start + BytePos(idx as u32 + 1), |
| ); |
| let block = matches!(comment_kind, CommentKind::Block); |
| self.sess.emit_err(errors::CrDocComment { span, block }); |
| } |
| } |
| |
| let attr_style = match doc_style { |
| DocStyle::Outer => AttrStyle::Outer, |
| DocStyle::Inner => AttrStyle::Inner, |
| }; |
| |
| token::DocComment(comment_kind, attr_style, Symbol::intern(content)) |
| } |
| |
| fn cook_lexer_literal( |
| &self, |
| start: BytePos, |
| end: BytePos, |
| kind: rustc_lexer::LiteralKind, |
| ) -> (token::LitKind, Symbol) { |
| match kind { |
| rustc_lexer::LiteralKind::Char { terminated } => { |
| if !terminated { |
| self.sess.span_diagnostic.span_fatal_with_code( |
| self.mk_sp(start, end), |
| "unterminated character literal", |
| error_code!(E0762), |
| ) |
| } |
| self.cook_quoted(token::Char, Mode::Char, start, end, 1, 1) // ' ' |
| } |
| rustc_lexer::LiteralKind::Byte { terminated } => { |
| if !terminated { |
| self.sess.span_diagnostic.span_fatal_with_code( |
| self.mk_sp(start + BytePos(1), end), |
| "unterminated byte constant", |
| error_code!(E0763), |
| ) |
| } |
| self.cook_quoted(token::Byte, Mode::Byte, start, end, 2, 1) // b' ' |
| } |
| rustc_lexer::LiteralKind::Str { terminated } => { |
| if !terminated { |
| self.sess.span_diagnostic.span_fatal_with_code( |
| self.mk_sp(start, end), |
| "unterminated double quote string", |
| error_code!(E0765), |
| ) |
| } |
| self.cook_quoted(token::Str, Mode::Str, start, end, 1, 1) // " " |
| } |
| rustc_lexer::LiteralKind::ByteStr { terminated } => { |
| if !terminated { |
| self.sess.span_diagnostic.span_fatal_with_code( |
| self.mk_sp(start + BytePos(1), end), |
| "unterminated double quote byte string", |
| error_code!(E0766), |
| ) |
| } |
| self.cook_quoted(token::ByteStr, Mode::ByteStr, start, end, 2, 1) // b" " |
| } |
| rustc_lexer::LiteralKind::CStr { terminated } => { |
| if !terminated { |
| self.sess.span_diagnostic.span_fatal_with_code( |
| self.mk_sp(start + BytePos(1), end), |
| "unterminated C string", |
| error_code!(E0767), |
| ) |
| } |
| self.cook_c_string(token::CStr, Mode::CStr, start, end, 2, 1) // c" " |
| } |
| rustc_lexer::LiteralKind::RawStr { n_hashes } => { |
| if let Some(n_hashes) = n_hashes { |
| let n = u32::from(n_hashes); |
| let kind = token::StrRaw(n_hashes); |
| self.cook_quoted(kind, Mode::RawStr, start, end, 2 + n, 1 + n) // r##" "## |
| } else { |
| self.report_raw_str_error(start, 1); |
| } |
| } |
| rustc_lexer::LiteralKind::RawByteStr { n_hashes } => { |
| if let Some(n_hashes) = n_hashes { |
| let n = u32::from(n_hashes); |
| let kind = token::ByteStrRaw(n_hashes); |
| self.cook_quoted(kind, Mode::RawByteStr, start, end, 3 + n, 1 + n) // br##" "## |
| } else { |
| self.report_raw_str_error(start, 2); |
| } |
| } |
| rustc_lexer::LiteralKind::RawCStr { n_hashes } => { |
| if let Some(n_hashes) = n_hashes { |
| let n = u32::from(n_hashes); |
| let kind = token::CStrRaw(n_hashes); |
| self.cook_c_string(kind, Mode::RawCStr, start, end, 3 + n, 1 + n) // cr##" "## |
| } else { |
| self.report_raw_str_error(start, 2); |
| } |
| } |
| rustc_lexer::LiteralKind::Int { base, empty_int } => { |
| if empty_int { |
| let span = self.mk_sp(start, end); |
| self.sess.emit_err(errors::NoDigitsLiteral { span }); |
| (token::Integer, sym::integer(0)) |
| } else { |
| if matches!(base, Base::Binary | Base::Octal) { |
| let base = base as u32; |
| let s = self.str_from_to(start + BytePos(2), end); |
| for (idx, c) in s.char_indices() { |
| let span = self.mk_sp( |
| start + BytePos::from_usize(2 + idx), |
| start + BytePos::from_usize(2 + idx + c.len_utf8()), |
| ); |
| if c != '_' && c.to_digit(base).is_none() { |
| self.sess.emit_err(errors::InvalidDigitLiteral { span, base }); |
| } |
| } |
| } |
| (token::Integer, self.symbol_from_to(start, end)) |
| } |
| } |
| rustc_lexer::LiteralKind::Float { base, empty_exponent } => { |
| if empty_exponent { |
| let span = self.mk_sp(start, self.pos); |
| self.sess.emit_err(errors::EmptyExponentFloat { span }); |
| } |
| let base = match base { |
| Base::Hexadecimal => Some("hexadecimal"), |
| Base::Octal => Some("octal"), |
| Base::Binary => Some("binary"), |
| _ => None, |
| }; |
| if let Some(base) = base { |
| let span = self.mk_sp(start, end); |
| self.sess.emit_err(errors::FloatLiteralUnsupportedBase { span, base }); |
| } |
| (token::Float, self.symbol_from_to(start, end)) |
| } |
| } |
| } |
| |
| #[inline] |
| fn src_index(&self, pos: BytePos) -> usize { |
| (pos - self.start_pos).to_usize() |
| } |
| |
| /// Slice of the source text from `start` up to but excluding `self.pos`, |
| /// meaning the slice does not include the character `self.ch`. |
| fn str_from(&self, start: BytePos) -> &'a str { |
| self.str_from_to(start, self.pos) |
| } |
| |
| /// As symbol_from, with an explicit endpoint. |
| fn symbol_from_to(&self, start: BytePos, end: BytePos) -> Symbol { |
| debug!("taking an ident from {:?} to {:?}", start, end); |
| Symbol::intern(self.str_from_to(start, end)) |
| } |
| |
| /// Slice of the source text spanning from `start` up to but excluding `end`. |
| fn str_from_to(&self, start: BytePos, end: BytePos) -> &'a str { |
| &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) -> &'a 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 }) => { |
| self.report_non_started_raw_string(start, bad_char) |
| } |
| Err(RawStrError::NoTerminator { expected, found, possible_terminator_offset }) => self |
| .report_unterminated_raw_string(start, expected, possible_terminator_offset, found), |
| Err(RawStrError::TooManyDelimiters { found }) => { |
| self.report_too_many_hashes(start, found) |
| } |
| Ok(()) => panic!("no error found for supposedly invalid raw string literal"), |
| } |
| } |
| |
| fn report_non_started_raw_string(&self, start: BytePos, bad_char: char) -> ! { |
| self.struct_fatal_span_char( |
| start, |
| self.pos, |
| "found invalid character; only `#` is allowed in raw string delimitation", |
| bad_char, |
| ) |
| .emit() |
| } |
| |
| fn report_unterminated_raw_string( |
| &self, |
| start: BytePos, |
| n_hashes: u32, |
| possible_offset: Option<u32>, |
| found_terminators: u32, |
| ) -> ! { |
| let mut err = self.sess.span_diagnostic.struct_span_fatal_with_code( |
| self.mk_sp(start, start), |
| "unterminated raw string", |
| error_code!(E0748), |
| ); |
| |
| err.span_label(self.mk_sp(start, start), "unterminated raw string"); |
| |
| if n_hashes > 0 { |
| err.note(format!( |
| "this raw string should be terminated with `\"{}`", |
| "#".repeat(n_hashes as usize) |
| )); |
| } |
| |
| if let Some(possible_offset) = possible_offset { |
| let lo = start + BytePos(possible_offset); |
| let hi = lo + BytePos(found_terminators); |
| let span = self.mk_sp(lo, hi); |
| err.span_suggestion( |
| span, |
| "consider terminating the string here", |
| "#".repeat(n_hashes as usize), |
| Applicability::MaybeIncorrect, |
| ); |
| } |
| |
| err.emit() |
| } |
| |
| fn report_unterminated_block_comment(&self, start: BytePos, doc_style: Option<DocStyle>) { |
| let msg = match doc_style { |
| Some(_) => "unterminated block doc-comment", |
| None => "unterminated block comment", |
| }; |
| let last_bpos = self.pos; |
| let mut err = self.sess.span_diagnostic.struct_span_fatal_with_code( |
| self.mk_sp(start, last_bpos), |
| msg, |
| error_code!(E0758), |
| ); |
| let mut nested_block_comment_open_idxs = vec![]; |
| let mut last_nested_block_comment_idxs = None; |
| let mut content_chars = self.str_from(start).char_indices().peekable(); |
| |
| while let Some((idx, current_char)) = content_chars.next() { |
| match content_chars.peek() { |
| Some((_, '*')) if current_char == '/' => { |
| nested_block_comment_open_idxs.push(idx); |
| } |
| Some((_, '/')) if current_char == '*' => { |
| last_nested_block_comment_idxs = |
| nested_block_comment_open_idxs.pop().map(|open_idx| (open_idx, idx)); |
| } |
| _ => {} |
| }; |
| } |
| |
| if let Some((nested_open_idx, nested_close_idx)) = last_nested_block_comment_idxs { |
| err.span_label(self.mk_sp(start, start + BytePos(2)), msg) |
| .span_label( |
| self.mk_sp( |
| start + BytePos(nested_open_idx as u32), |
| start + BytePos(nested_open_idx as u32 + 2), |
| ), |
| "...as last nested comment starts here, maybe you want to close this instead?", |
| ) |
| .span_label( |
| self.mk_sp( |
| start + BytePos(nested_close_idx as u32), |
| start + BytePos(nested_close_idx as u32 + 2), |
| ), |
| "...and last nested comment terminates here.", |
| ); |
| } |
| |
| err.emit(); |
| } |
| |
| // RFC 3101 introduced the idea of (reserved) prefixes. As of Rust 2021, |
| // using a (unknown) prefix is an error. In earlier editions, however, they |
| // only result in a (allowed by default) lint, and are treated as regular |
| // identifier tokens. |
| fn report_unknown_prefix(&self, start: BytePos) { |
| let prefix_span = self.mk_sp(start, self.pos); |
| let prefix = self.str_from_to(start, self.pos); |
| |
| let expn_data = prefix_span.ctxt().outer_expn_data(); |
| |
| if expn_data.edition >= Edition::Edition2021 { |
| // In Rust 2021, this is a hard error. |
| let sugg = if prefix == "rb" { |
| Some(errors::UnknownPrefixSugg::UseBr(prefix_span)) |
| } else if expn_data.is_root() { |
| Some(errors::UnknownPrefixSugg::Whitespace(prefix_span.shrink_to_hi())) |
| } else { |
| None |
| }; |
| self.sess.emit_err(errors::UnknownPrefix { span: prefix_span, prefix, sugg }); |
| } else { |
| // Before Rust 2021, only emit a lint for migration. |
| self.sess.buffer_lint_with_diagnostic( |
| &RUST_2021_PREFIXES_INCOMPATIBLE_SYNTAX, |
| prefix_span, |
| ast::CRATE_NODE_ID, |
| format!("prefix `{prefix}` is unknown"), |
| BuiltinLintDiagnostics::ReservedPrefix(prefix_span), |
| ); |
| } |
| } |
| |
| fn report_too_many_hashes(&self, start: BytePos, num: u32) -> ! { |
| self.sess.emit_fatal(errors::TooManyHashes { span: self.mk_sp(start, self.pos), num }); |
| } |
| |
| fn cook_common( |
| &self, |
| kind: token::LitKind, |
| mode: Mode, |
| start: BytePos, |
| end: BytePos, |
| prefix_len: u32, |
| postfix_len: u32, |
| unescape: fn(&str, Mode, &mut dyn FnMut(Range<usize>, Result<(), EscapeError>)), |
| ) -> (token::LitKind, Symbol) { |
| let mut has_fatal_err = false; |
| let content_start = start + BytePos(prefix_len); |
| let content_end = end - BytePos(postfix_len); |
| let lit_content = self.str_from_to(content_start, content_end); |
| unescape(lit_content, mode, &mut |range, result| { |
| // Here we only check for errors. The actual unescaping is done later. |
| if let Err(err) = result { |
| let span_with_quotes = self.mk_sp(start, end); |
| let (start, end) = (range.start as u32, range.end as u32); |
| let lo = content_start + BytePos(start); |
| let hi = lo + BytePos(end - start); |
| let span = self.mk_sp(lo, hi); |
| if err.is_fatal() { |
| has_fatal_err = true; |
| } |
| emit_unescape_error( |
| &self.sess.span_diagnostic, |
| lit_content, |
| span_with_quotes, |
| span, |
| mode, |
| range, |
| err, |
| ); |
| } |
| }); |
| |
| // We normally exclude the quotes for the symbol, but for errors we |
| // include it because it results in clearer error messages. |
| if !has_fatal_err { |
| (kind, Symbol::intern(lit_content)) |
| } else { |
| (token::Err, self.symbol_from_to(start, end)) |
| } |
| } |
| |
| fn cook_quoted( |
| &self, |
| kind: token::LitKind, |
| mode: Mode, |
| start: BytePos, |
| end: BytePos, |
| prefix_len: u32, |
| postfix_len: u32, |
| ) -> (token::LitKind, Symbol) { |
| self.cook_common(kind, mode, start, end, prefix_len, postfix_len, |src, mode, callback| { |
| unescape::unescape_literal(src, mode, &mut |span, result| { |
| callback(span, result.map(drop)) |
| }) |
| }) |
| } |
| |
| fn cook_c_string( |
| &self, |
| kind: token::LitKind, |
| mode: Mode, |
| start: BytePos, |
| end: BytePos, |
| prefix_len: u32, |
| postfix_len: u32, |
| ) -> (token::LitKind, Symbol) { |
| self.cook_common(kind, mode, start, end, prefix_len, postfix_len, |src, mode, callback| { |
| unescape::unescape_c_string(src, mode, &mut |span, result| { |
| callback(span, result.map(drop)) |
| }) |
| }) |
| } |
| } |
| |
| pub fn nfc_normalize(string: &str) -> Symbol { |
| use unicode_normalization::{is_nfc_quick, IsNormalized, UnicodeNormalization}; |
| match is_nfc_quick(string.chars()) { |
| IsNormalized::Yes => Symbol::intern(string), |
| _ => { |
| let normalized_str: String = string.chars().nfc().collect(); |
| Symbol::intern(&normalized_str) |
| } |
| } |
| } |
