mirror of
https://github.com/rust-lang/rust.git
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673 lines
28 KiB
Rust
673 lines
28 KiB
Rust
use crate::lexer::unicode_chars::UNICODE_ARRAY;
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use rustc_ast::ast::{self, AttrStyle};
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use rustc_ast::token::{self, CommentKind, Token, TokenKind};
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use rustc_ast::tokenstream::{Spacing, 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, DiagnosticBuilder, ErrorGuaranteed, PResult};
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use rustc_lexer::unescape::{self, Mode};
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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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use tracing::debug;
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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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#[derive(Clone, Debug)]
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pub struct UnmatchedBrace {
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pub expected_delim: token::DelimToken,
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pub found_delim: Option<token::DelimToken>,
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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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crate fn parse_token_trees<'a>(
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sess: &'a ParseSess,
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src: &'a str,
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start_pos: BytePos,
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override_span: Option<Span>,
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) -> (PResult<'a, TokenStream>, Vec<UnmatchedBrace>) {
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StringReader { sess, start_pos, pos: start_pos, end_src_index: src.len(), src, override_span }
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.into_token_trees()
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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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/// Stop reading src at this index.
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end_src_index: usize,
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/// Source text to tokenize.
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src: &'a str,
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override_span: Option<Span>,
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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, and info about preceding whitespace, if any.
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fn next_token(&mut self) -> (Spacing, Token) {
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let mut spacing = Spacing::Joint;
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// Skip `#!` at the start of the file
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let start_src_index = self.src_index(self.pos);
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let text: &str = &self.src[start_src_index..self.end_src_index];
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let is_beginning_of_file = self.pos == self.start_pos;
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if is_beginning_of_file {
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if let Some(shebang_len) = rustc_lexer::strip_shebang(text) {
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self.pos = self.pos + BytePos::from_usize(shebang_len);
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spacing = Spacing::Alone;
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}
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}
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// Skip trivial (whitespace & comments) tokens
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loop {
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let start_src_index = self.src_index(self.pos);
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let text: &str = &self.src[start_src_index..self.end_src_index];
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if text.is_empty() {
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let span = self.mk_sp(self.pos, self.pos);
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return (spacing, Token::new(token::Eof, span));
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}
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let token = rustc_lexer::first_token(text);
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let start = self.pos;
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self.pos = self.pos + BytePos::from_usize(token.len);
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debug!("next_token: {:?}({:?})", token.kind, self.str_from(start));
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match self.cook_lexer_token(token.kind, start) {
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Some(kind) => {
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let span = self.mk_sp(start, self.pos);
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return (spacing, Token::new(kind, span));
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}
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None => spacing = Spacing::Alone,
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}
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}
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}
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/// Report a fatal lexical error with a given span.
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fn fatal_span(&self, sp: Span, m: &str) -> ! {
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self.sess.span_diagnostic.span_fatal(sp, m)
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}
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/// Report a lexical error with a given span.
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fn err_span(&self, sp: Span, m: &str) {
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self.sess.span_diagnostic.struct_span_err(sp, m).emit();
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}
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/// Report a fatal error spanning [`from_pos`, `to_pos`).
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fn fatal_span_(&self, from_pos: BytePos, to_pos: BytePos, m: &str) -> ! {
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self.fatal_span(self.mk_sp(from_pos, to_pos), m)
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}
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/// Report a lexical error spanning [`from_pos`, `to_pos`).
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fn err_span_(&self, from_pos: BytePos, to_pos: BytePos, m: &str) {
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self.err_span(self.mk_sp(from_pos, to_pos), m)
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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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fn struct_err_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, ErrorGuaranteed> {
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self.sess
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.span_diagnostic
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.struct_span_err(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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/// Turns simple `rustc_lexer::TokenKind` enum into a rich
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/// `rustc_ast::TokenKind`. This turns strings into interned
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/// symbols and runs additional validation.
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fn cook_lexer_token(&self, token: rustc_lexer::TokenKind, start: BytePos) -> Option<TokenKind> {
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Some(match token {
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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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return None;
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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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let msg = match doc_style {
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Some(_) => "unterminated block doc-comment",
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None => "unterminated block comment",
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};
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let last_bpos = self.pos;
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self.sess.span_diagnostic.span_fatal_with_code(
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self.mk_sp(start, last_bpos),
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msg,
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error_code!(E0758),
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);
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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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return None;
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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 => return None,
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rustc_lexer::TokenKind::Ident
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| rustc_lexer::TokenKind::RawIdent
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| rustc_lexer::TokenKind::UnknownPrefix => {
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let is_raw_ident = token == rustc_lexer::TokenKind::RawIdent;
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let is_unknown_prefix = token == rustc_lexer::TokenKind::UnknownPrefix;
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let mut ident_start = start;
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if is_raw_ident {
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ident_start = ident_start + BytePos(2);
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}
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if is_unknown_prefix {
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self.report_unknown_prefix(start);
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}
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let sym = nfc_normalize(self.str_from(ident_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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if is_raw_ident {
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if !sym.can_be_raw() {
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self.err_span(span, &format!("`{}` cannot be a raw identifier", sym));
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}
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self.sess.raw_identifier_spans.borrow_mut().push(span);
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}
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token::Ident(sym, is_raw_ident)
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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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.find(|&&(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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.is_none() =>
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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().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 as u32);
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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_warn(
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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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.warn(
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"this was previously accepted by the compiler but is \
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being phased out; it will become a hard error in \
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a future release!",
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)
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.note(
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"see issue #42326 \
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<https://github.com/rust-lang/rust/issues/42326> \
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for more information",
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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 } => {
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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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self.err_span_(start, self.pos, "lifetimes cannot start with a number");
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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(token::Paren),
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rustc_lexer::TokenKind::CloseParen => token::CloseDelim(token::Paren),
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rustc_lexer::TokenKind::OpenBrace => token::OpenDelim(token::Brace),
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rustc_lexer::TokenKind::CloseBrace => token::CloseDelim(token::Brace),
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rustc_lexer::TokenKind::OpenBracket => token::OpenDelim(token::Bracket),
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rustc_lexer::TokenKind::CloseBracket => token::CloseDelim(token::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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let c = self.str_from(start).chars().next().unwrap();
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let mut err =
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self.struct_err_span_char(start, self.pos, "unknown start of token", c);
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// FIXME: the lexer could be used to turn the ASCII version of unicode homoglyphs,
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// instead of keeping a table in `check_for_substitution`into the token. Ideally,
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// this should be inside `rustc_lexer`. However, we should first remove compound
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// tokens like `<<` from `rustc_lexer`, and then add fancier error recovery to it,
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// as there will be less overall work to do this way.
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let token = unicode_chars::check_for_substitution(self, start, c, &mut err);
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if c == '\x00' {
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err.help("source files must contain UTF-8 encoded text, unexpected null bytes might occur when a different encoding is used");
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}
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err.emit();
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token?
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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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self.err_span_(
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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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match comment_kind {
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CommentKind::Line => "bare CR not allowed in doc-comment",
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CommentKind::Block => "bare CR not allowed in block doc-comment",
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},
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);
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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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suffix_start: BytePos,
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kind: rustc_lexer::LiteralKind,
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) -> (token::LitKind, Symbol) {
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// prefix means `"` or `br"` or `r###"`, ...
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let (lit_kind, mode, prefix_len, postfix_len) = 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, suffix_start),
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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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(token::Char, Mode::Char, 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), suffix_start),
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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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(token::Byte, Mode::Byte, 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, suffix_start),
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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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(token::Str, Mode::Str, 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), suffix_start),
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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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(token::ByteStr, Mode::ByteStr, 2, 1) // b" "
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}
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rustc_lexer::LiteralKind::RawStr { n_hashes, err } => {
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self.report_raw_str_error(start, err);
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let n = u32::from(n_hashes);
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(token::StrRaw(n_hashes), Mode::RawStr, 2 + n, 1 + n) // r##" "##
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}
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rustc_lexer::LiteralKind::RawByteStr { n_hashes, err } => {
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self.report_raw_str_error(start, err);
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let n = u32::from(n_hashes);
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(token::ByteStrRaw(n_hashes), Mode::RawByteStr, 3 + n, 1 + n) // br##" "##
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}
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rustc_lexer::LiteralKind::Int { base, empty_int } => {
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return if empty_int {
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self.sess
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.span_diagnostic
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.struct_span_err_with_code(
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self.mk_sp(start, suffix_start),
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"no valid digits found for number",
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error_code!(E0768),
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)
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.emit();
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(token::Integer, sym::integer(0))
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} else {
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self.validate_int_literal(base, start, suffix_start);
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(token::Integer, self.symbol_from_to(start, suffix_start))
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};
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}
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rustc_lexer::LiteralKind::Float { base, empty_exponent } => {
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if empty_exponent {
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self.err_span_(start, self.pos, "expected at least one digit in exponent");
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}
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|
||
match base {
|
||
Base::Hexadecimal => self.err_span_(
|
||
start,
|
||
suffix_start,
|
||
"hexadecimal float literal is not supported",
|
||
),
|
||
Base::Octal => {
|
||
self.err_span_(start, suffix_start, "octal float literal is not supported")
|
||
}
|
||
Base::Binary => {
|
||
self.err_span_(start, suffix_start, "binary float literal is not supported")
|
||
}
|
||
_ => (),
|
||
}
|
||
|
||
let id = self.symbol_from_to(start, suffix_start);
|
||
return (token::Float, id);
|
||
}
|
||
};
|
||
let content_start = start + BytePos(prefix_len);
|
||
let content_end = suffix_start - BytePos(postfix_len);
|
||
let id = self.symbol_from_to(content_start, content_end);
|
||
self.validate_literal_escape(mode, content_start, content_end, prefix_len, postfix_len);
|
||
(lit_kind, id)
|
||
}
|
||
|
||
#[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) -> &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) -> &str {
|
||
&self.src[self.src_index(start)..self.src_index(end)]
|
||
}
|
||
|
||
fn report_raw_str_error(&self, start: BytePos, opt_err: Option<RawStrError>) {
|
||
match opt_err {
|
||
Some(RawStrError::InvalidStarter { bad_char }) => {
|
||
self.report_non_started_raw_string(start, bad_char)
|
||
}
|
||
Some(RawStrError::NoTerminator { expected, found, possible_terminator_offset }) => self
|
||
.report_unterminated_raw_string(start, expected, possible_terminator_offset, found),
|
||
Some(RawStrError::TooManyDelimiters { found }) => {
|
||
self.report_too_many_hashes(start, found)
|
||
}
|
||
None => (),
|
||
}
|
||
}
|
||
|
||
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: usize,
|
||
possible_offset: Option<usize>,
|
||
found_terminators: usize,
|
||
) -> ! {
|
||
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)
|
||
));
|
||
}
|
||
|
||
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),
|
||
Applicability::MaybeIncorrect,
|
||
);
|
||
}
|
||
|
||
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_str = self.str_from_to(start, self.pos);
|
||
let msg = format!("prefix `{}` is unknown", prefix_str);
|
||
|
||
let expn_data = prefix_span.ctxt().outer_expn_data();
|
||
|
||
if expn_data.edition >= Edition::Edition2021 {
|
||
// In Rust 2021, this is a hard error.
|
||
let mut err = self.sess.span_diagnostic.struct_span_err(prefix_span, &msg);
|
||
err.span_label(prefix_span, "unknown prefix");
|
||
if prefix_str == "rb" {
|
||
err.span_suggestion_verbose(
|
||
prefix_span,
|
||
"use `br` for a raw byte string",
|
||
"br".to_string(),
|
||
Applicability::MaybeIncorrect,
|
||
);
|
||
} else if expn_data.is_root() {
|
||
err.span_suggestion_verbose(
|
||
prefix_span.shrink_to_hi(),
|
||
"consider inserting whitespace here",
|
||
" ".into(),
|
||
Applicability::MaybeIncorrect,
|
||
);
|
||
}
|
||
err.note("prefixed identifiers and literals are reserved since Rust 2021");
|
||
err.emit();
|
||
} 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,
|
||
&msg,
|
||
BuiltinLintDiagnostics::ReservedPrefix(prefix_span),
|
||
);
|
||
}
|
||
}
|
||
|
||
/// Note: It was decided to not add a test case, because it would be too big.
|
||
/// <https://github.com/rust-lang/rust/pull/50296#issuecomment-392135180>
|
||
fn report_too_many_hashes(&self, start: BytePos, found: usize) -> ! {
|
||
self.fatal_span_(
|
||
start,
|
||
self.pos,
|
||
&format!(
|
||
"too many `#` symbols: raw strings may be delimited \
|
||
by up to 65535 `#` symbols, but found {}",
|
||
found
|
||
),
|
||
)
|
||
}
|
||
|
||
fn validate_literal_escape(
|
||
&self,
|
||
mode: Mode,
|
||
content_start: BytePos,
|
||
content_end: BytePos,
|
||
prefix_len: u32,
|
||
postfix_len: u32,
|
||
) {
|
||
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(content_start - BytePos(prefix_len), content_end + BytePos(postfix_len));
|
||
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);
|
||
emit_unescape_error(
|
||
&self.sess.span_diagnostic,
|
||
lit_content,
|
||
span_with_quotes,
|
||
span,
|
||
mode,
|
||
range,
|
||
err,
|
||
);
|
||
}
|
||
});
|
||
}
|
||
|
||
fn validate_int_literal(&self, base: Base, content_start: BytePos, content_end: BytePos) {
|
||
let base = match base {
|
||
Base::Binary => 2,
|
||
Base::Octal => 8,
|
||
_ => return,
|
||
};
|
||
let s = self.str_from_to(content_start + BytePos(2), content_end);
|
||
for (idx, c) in s.char_indices() {
|
||
let idx = idx as u32;
|
||
if c != '_' && c.to_digit(base).is_none() {
|
||
let lo = content_start + BytePos(2 + idx);
|
||
let hi = content_start + BytePos(2 + idx + c.len_utf8() as u32);
|
||
self.err_span_(lo, hi, &format!("invalid digit for a base {} literal", base));
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
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)
|
||
}
|
||
}
|
||
}
|