715 lines
31 KiB
Rust
715 lines
31 KiB
Rust
use crate::errors;
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use crate::lexer::unicode_chars::UNICODE_ARRAY;
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use crate::make_unclosed_delims_error;
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use rustc_ast::ast::{self, AttrStyle};
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use rustc_ast::token::{self, CommentKind, Delimiter, Token, TokenKind};
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use rustc_ast::tokenstream::TokenStream;
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use rustc_ast::util::unicode::contains_text_flow_control_chars;
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use rustc_errors::{error_code, Applicability, Diagnostic, DiagnosticBuilder, StashKey};
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use rustc_lexer::unescape::{self, Mode};
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use rustc_lexer::Cursor;
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use rustc_lexer::{Base, DocStyle, RawStrError};
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use rustc_session::lint::builtin::{
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RUST_2021_PREFIXES_INCOMPATIBLE_SYNTAX, TEXT_DIRECTION_CODEPOINT_IN_COMMENT,
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};
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use rustc_session::lint::BuiltinLintDiagnostics;
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use rustc_session::parse::ParseSess;
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use rustc_span::symbol::{sym, Symbol};
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use rustc_span::{edition::Edition, BytePos, Pos, Span};
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mod diagnostics;
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mod tokentrees;
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mod unescape_error_reporting;
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mod unicode_chars;
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use unescape_error_reporting::{emit_unescape_error, escaped_char};
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// This type is used a lot. Make sure it doesn't unintentionally get bigger.
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//
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// This assertion is in this crate, rather than in `rustc_lexer`, because that
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// crate cannot depend on `rustc_data_structures`.
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#[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
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rustc_data_structures::static_assert_size!(rustc_lexer::Token, 12);
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#[derive(Clone, Debug)]
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pub struct UnmatchedDelim {
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pub expected_delim: Delimiter,
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pub found_delim: Option<Delimiter>,
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pub found_span: Span,
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pub unclosed_span: Option<Span>,
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pub candidate_span: Option<Span>,
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}
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pub(crate) fn parse_token_trees<'a>(
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sess: &'a ParseSess,
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mut src: &'a str,
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mut start_pos: BytePos,
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override_span: Option<Span>,
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) -> Result<TokenStream, Vec<Diagnostic>> {
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// Skip `#!`, if present.
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if let Some(shebang_len) = rustc_lexer::strip_shebang(src) {
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src = &src[shebang_len..];
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start_pos = start_pos + BytePos::from_usize(shebang_len);
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}
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let cursor = Cursor::new(src);
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let string_reader = StringReader {
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sess,
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start_pos,
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pos: start_pos,
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src,
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cursor,
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override_span,
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nbsp_is_whitespace: false,
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};
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let (token_trees, unmatched_delims) =
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tokentrees::TokenTreesReader::parse_all_token_trees(string_reader);
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match token_trees {
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Ok(stream) if unmatched_delims.is_empty() => Ok(stream),
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_ => {
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// Return error if there are unmatched delimiters or unclosng delimiters.
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// We emit delimiter mismatch errors first, then emit the unclosing delimiter mismatch
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// because the delimiter mismatch is more likely to be the root cause of error
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let mut buffer = Vec::with_capacity(1);
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// Not using `emit_unclosed_delims` to use `db.buffer`
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for unmatched in unmatched_delims {
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if let Some(err) = make_unclosed_delims_error(unmatched, &sess) {
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err.buffer(&mut buffer);
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}
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}
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if let Err(err) = token_trees {
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// Add unclosing delimiter error
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err.buffer(&mut buffer);
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}
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Err(buffer)
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}
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}
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}
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struct StringReader<'a> {
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sess: &'a ParseSess,
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/// Initial position, read-only.
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start_pos: BytePos,
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/// The absolute offset within the source_map of the current character.
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pos: BytePos,
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/// Source text to tokenize.
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src: &'a str,
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/// Cursor for getting lexer tokens.
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cursor: Cursor<'a>,
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override_span: Option<Span>,
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/// When a "unknown start of token: \u{a0}" has already been emitted earlier
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/// in this file, it's safe to treat further occurrences of the non-breaking
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/// space character as whitespace.
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nbsp_is_whitespace: bool,
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}
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impl<'a> StringReader<'a> {
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fn mk_sp(&self, lo: BytePos, hi: BytePos) -> Span {
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self.override_span.unwrap_or_else(|| Span::with_root_ctxt(lo, hi))
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}
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/// Returns the next token, paired with a bool indicating if the token was
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/// preceded by whitespace.
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fn next_token(&mut self) -> (Token, bool) {
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let mut preceded_by_whitespace = false;
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let mut swallow_next_invalid = 0;
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// Skip trivial (whitespace & comments) tokens
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loop {
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let token = self.cursor.advance_token();
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let start = self.pos;
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self.pos = self.pos + BytePos(token.len);
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debug!("next_token: {:?}({:?})", token.kind, self.str_from(start));
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// Now "cook" the token, converting the simple `rustc_lexer::TokenKind` enum into a
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// rich `rustc_ast::TokenKind`. This turns strings into interned symbols and runs
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// additional validation.
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let kind = match token.kind {
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rustc_lexer::TokenKind::LineComment { doc_style } => {
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// Skip non-doc comments
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let Some(doc_style) = doc_style else {
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self.lint_unicode_text_flow(start);
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preceded_by_whitespace = true;
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continue;
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};
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// Opening delimiter of the length 3 is not included into the symbol.
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let content_start = start + BytePos(3);
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let content = self.str_from(content_start);
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self.cook_doc_comment(content_start, content, CommentKind::Line, doc_style)
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}
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rustc_lexer::TokenKind::BlockComment { doc_style, terminated } => {
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if !terminated {
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self.report_unterminated_block_comment(start, doc_style);
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}
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// Skip non-doc comments
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let Some(doc_style) = doc_style else {
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self.lint_unicode_text_flow(start);
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preceded_by_whitespace = true;
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continue;
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};
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// Opening delimiter of the length 3 and closing delimiter of the length 2
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// are not included into the symbol.
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let content_start = start + BytePos(3);
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let content_end = self.pos - BytePos(if terminated { 2 } else { 0 });
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let content = self.str_from_to(content_start, content_end);
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self.cook_doc_comment(content_start, content, CommentKind::Block, doc_style)
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}
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rustc_lexer::TokenKind::Whitespace => {
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preceded_by_whitespace = true;
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continue;
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}
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rustc_lexer::TokenKind::Ident => {
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let sym = nfc_normalize(self.str_from(start));
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let span = self.mk_sp(start, self.pos);
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self.sess.symbol_gallery.insert(sym, span);
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token::Ident(sym, false)
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}
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rustc_lexer::TokenKind::RawIdent => {
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let sym = nfc_normalize(self.str_from(start + BytePos(2)));
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let span = self.mk_sp(start, self.pos);
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self.sess.symbol_gallery.insert(sym, span);
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if !sym.can_be_raw() {
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self.sess.emit_err(errors::CannotBeRawIdent { span, ident: sym });
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}
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self.sess.raw_identifier_spans.borrow_mut().push(span);
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token::Ident(sym, true)
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}
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rustc_lexer::TokenKind::UnknownPrefix => {
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self.report_unknown_prefix(start);
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let sym = nfc_normalize(self.str_from(start));
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let span = self.mk_sp(start, self.pos);
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self.sess.symbol_gallery.insert(sym, span);
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token::Ident(sym, false)
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}
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rustc_lexer::TokenKind::InvalidIdent
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// Do not recover an identifier with emoji if the codepoint is a confusable
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// with a recoverable substitution token, like `➖`.
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if !UNICODE_ARRAY
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.iter()
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.any(|&(c, _, _)| {
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let sym = self.str_from(start);
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sym.chars().count() == 1 && c == sym.chars().next().unwrap()
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}) =>
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{
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let sym = nfc_normalize(self.str_from(start));
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let span = self.mk_sp(start, self.pos);
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self.sess.bad_unicode_identifiers.borrow_mut().entry(sym).or_default()
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.push(span);
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token::Ident(sym, false)
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}
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rustc_lexer::TokenKind::Literal { kind, suffix_start } => {
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let suffix_start = start + BytePos(suffix_start);
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let (kind, symbol) = self.cook_lexer_literal(start, suffix_start, kind);
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let suffix = if suffix_start < self.pos {
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let string = self.str_from(suffix_start);
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if string == "_" {
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self.sess
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.span_diagnostic
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.struct_span_err(
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self.mk_sp(suffix_start, self.pos),
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"underscore literal suffix is not allowed",
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)
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.emit();
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None
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} else {
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Some(Symbol::intern(string))
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}
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} else {
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None
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};
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token::Literal(token::Lit { kind, symbol, suffix })
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}
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rustc_lexer::TokenKind::Lifetime { starts_with_number, contains_emoji } => {
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// Include the leading `'` in the real identifier, for macro
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// expansion purposes. See #12512 for the gory details of why
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// this is necessary.
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let lifetime_name = self.str_from(start);
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if starts_with_number {
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let span = self.mk_sp(start, self.pos);
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let mut diag = self.sess.struct_err("lifetimes or labels cannot start with a number");
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diag.set_span(span);
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diag.stash(span, StashKey::LifetimeIsChar);
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} else if contains_emoji {
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let span = self.mk_sp(start, self.pos);
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let mut diag = self.sess.struct_err("lifetimes or labels cannot contain emojis");
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diag.set_span(span);
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diag.stash(span, StashKey::LifetimeContainsEmoji);
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}
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let ident = Symbol::intern(lifetime_name);
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token::Lifetime(ident)
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}
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rustc_lexer::TokenKind::Semi => token::Semi,
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rustc_lexer::TokenKind::Comma => token::Comma,
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rustc_lexer::TokenKind::Dot => token::Dot,
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rustc_lexer::TokenKind::OpenParen => token::OpenDelim(Delimiter::Parenthesis),
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rustc_lexer::TokenKind::CloseParen => token::CloseDelim(Delimiter::Parenthesis),
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rustc_lexer::TokenKind::OpenBrace => token::OpenDelim(Delimiter::Brace),
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rustc_lexer::TokenKind::CloseBrace => token::CloseDelim(Delimiter::Brace),
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rustc_lexer::TokenKind::OpenBracket => token::OpenDelim(Delimiter::Bracket),
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rustc_lexer::TokenKind::CloseBracket => token::CloseDelim(Delimiter::Bracket),
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rustc_lexer::TokenKind::At => token::At,
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rustc_lexer::TokenKind::Pound => token::Pound,
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rustc_lexer::TokenKind::Tilde => token::Tilde,
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rustc_lexer::TokenKind::Question => token::Question,
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rustc_lexer::TokenKind::Colon => token::Colon,
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rustc_lexer::TokenKind::Dollar => token::Dollar,
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rustc_lexer::TokenKind::Eq => token::Eq,
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rustc_lexer::TokenKind::Bang => token::Not,
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rustc_lexer::TokenKind::Lt => token::Lt,
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rustc_lexer::TokenKind::Gt => token::Gt,
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rustc_lexer::TokenKind::Minus => token::BinOp(token::Minus),
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rustc_lexer::TokenKind::And => token::BinOp(token::And),
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rustc_lexer::TokenKind::Or => token::BinOp(token::Or),
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rustc_lexer::TokenKind::Plus => token::BinOp(token::Plus),
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rustc_lexer::TokenKind::Star => token::BinOp(token::Star),
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rustc_lexer::TokenKind::Slash => token::BinOp(token::Slash),
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rustc_lexer::TokenKind::Caret => token::BinOp(token::Caret),
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rustc_lexer::TokenKind::Percent => token::BinOp(token::Percent),
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rustc_lexer::TokenKind::Unknown | rustc_lexer::TokenKind::InvalidIdent => {
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// Don't emit diagnostics for sequences of the same invalid token
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if swallow_next_invalid > 0 {
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swallow_next_invalid -= 1;
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continue;
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}
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let mut it = self.str_from_to_end(start).chars();
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let c = it.next().unwrap();
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if c == '\u{00a0}' {
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// If an error has already been reported on non-breaking
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// space characters earlier in the file, treat all
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// subsequent occurrences as whitespace.
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if self.nbsp_is_whitespace {
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preceded_by_whitespace = true;
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continue;
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}
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self.nbsp_is_whitespace = true;
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}
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let repeats = it.take_while(|c1| *c1 == c).count();
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// FIXME: the lexer could be used to turn the ASCII version of unicode
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// homoglyphs, instead of keeping a table in `check_for_substitution`into the
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// token. Ideally, this should be inside `rustc_lexer`. However, we should
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// first remove compound tokens like `<<` from `rustc_lexer`, and then add
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// fancier error recovery to it, as there will be less overall work to do this
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// way.
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let (token, sugg) = unicode_chars::check_for_substitution(self, start, c, repeats+1);
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self.sess.emit_err(errors::UnknownTokenStart {
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span: self.mk_sp(start, self.pos + Pos::from_usize(repeats * c.len_utf8())),
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escaped: escaped_char(c),
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sugg,
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null: if c == '\x00' {Some(errors::UnknownTokenNull)} else {None},
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repeat: if repeats > 0 {
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swallow_next_invalid = repeats;
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Some(errors::UnknownTokenRepeat { repeats })
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} else {None}
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});
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if let Some(token) = token {
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token
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} else {
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preceded_by_whitespace = true;
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continue;
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}
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}
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rustc_lexer::TokenKind::Eof => token::Eof,
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};
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let span = self.mk_sp(start, self.pos);
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return (Token::new(kind, span), preceded_by_whitespace);
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}
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}
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fn struct_fatal_span_char(
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&self,
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from_pos: BytePos,
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to_pos: BytePos,
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m: &str,
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c: char,
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) -> DiagnosticBuilder<'a, !> {
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self.sess
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.span_diagnostic
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.struct_span_fatal(self.mk_sp(from_pos, to_pos), &format!("{}: {}", m, escaped_char(c)))
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}
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/// Detect usages of Unicode codepoints changing the direction of the text on screen and loudly
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/// complain about it.
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fn lint_unicode_text_flow(&self, start: BytePos) {
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// Opening delimiter of the length 2 is not included into the comment text.
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let content_start = start + BytePos(2);
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let content = self.str_from(content_start);
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if contains_text_flow_control_chars(content) {
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let span = self.mk_sp(start, self.pos);
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self.sess.buffer_lint_with_diagnostic(
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&TEXT_DIRECTION_CODEPOINT_IN_COMMENT,
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span,
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ast::CRATE_NODE_ID,
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"unicode codepoint changing visible direction of text present in comment",
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BuiltinLintDiagnostics::UnicodeTextFlow(span, content.to_string()),
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);
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}
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}
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fn cook_doc_comment(
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&self,
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content_start: BytePos,
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content: &str,
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comment_kind: CommentKind,
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doc_style: DocStyle,
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) -> TokenKind {
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if content.contains('\r') {
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for (idx, _) in content.char_indices().filter(|&(_, c)| c == '\r') {
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let span = self.mk_sp(
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content_start + BytePos(idx as u32),
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content_start + BytePos(idx as u32 + 1),
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);
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let block = matches!(comment_kind, CommentKind::Block);
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self.sess.emit_err(errors::CrDocComment { span, block });
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}
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}
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let attr_style = match doc_style {
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DocStyle::Outer => AttrStyle::Outer,
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DocStyle::Inner => AttrStyle::Inner,
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};
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token::DocComment(comment_kind, attr_style, Symbol::intern(content))
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}
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fn cook_lexer_literal(
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&self,
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start: BytePos,
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end: BytePos,
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kind: rustc_lexer::LiteralKind,
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) -> (token::LitKind, Symbol) {
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match kind {
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rustc_lexer::LiteralKind::Char { terminated } => {
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if !terminated {
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self.sess.span_diagnostic.span_fatal_with_code(
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self.mk_sp(start, end),
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"unterminated character literal",
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error_code!(E0762),
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)
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}
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self.cook_quoted(token::Char, Mode::Char, start, end, 1, 1) // ' '
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}
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rustc_lexer::LiteralKind::Byte { terminated } => {
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if !terminated {
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self.sess.span_diagnostic.span_fatal_with_code(
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self.mk_sp(start + BytePos(1), end),
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"unterminated byte constant",
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error_code!(E0763),
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)
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}
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self.cook_quoted(token::Byte, Mode::Byte, start, end, 2, 1) // b' '
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}
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rustc_lexer::LiteralKind::Str { terminated } => {
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if !terminated {
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self.sess.span_diagnostic.span_fatal_with_code(
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self.mk_sp(start, end),
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"unterminated double quote string",
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error_code!(E0765),
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)
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}
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self.cook_quoted(token::Str, Mode::Str, start, end, 1, 1) // " "
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}
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rustc_lexer::LiteralKind::ByteStr { terminated } => {
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if !terminated {
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self.sess.span_diagnostic.span_fatal_with_code(
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self.mk_sp(start + BytePos(1), end),
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"unterminated double quote byte string",
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error_code!(E0766),
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)
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}
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self.cook_quoted(token::ByteStr, Mode::ByteStr, start, end, 2, 1) // b" "
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}
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rustc_lexer::LiteralKind::RawStr { n_hashes } => {
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if let Some(n_hashes) = n_hashes {
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let n = u32::from(n_hashes);
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let kind = token::StrRaw(n_hashes);
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self.cook_quoted(kind, Mode::RawStr, start, end, 2 + n, 1 + n) // r##" "##
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} else {
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self.report_raw_str_error(start, 1);
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}
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}
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rustc_lexer::LiteralKind::RawByteStr { n_hashes } => {
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if let Some(n_hashes) = n_hashes {
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let n = u32::from(n_hashes);
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let kind = token::ByteStrRaw(n_hashes);
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self.cook_quoted(kind, Mode::RawByteStr, start, end, 3 + n, 1 + n) // br##" "##
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} else {
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self.report_raw_str_error(start, 2);
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}
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}
|
||
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 as u32);
|
||
let hi = lo + BytePos(found_terminators as u32);
|
||
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_quoted(
|
||
&self,
|
||
kind: token::LitKind,
|
||
mode: Mode,
|
||
start: BytePos,
|
||
end: BytePos,
|
||
prefix_len: u32,
|
||
postfix_len: u32,
|
||
) -> (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::unescape_literal(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))
|
||
}
|
||
}
|
||
}
|
||
|
||
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)
|
||
}
|
||
}
|
||
}
|