use std::ops::Range;
use rustc_ast::ast::{self, AttrStyle};
use rustc_ast::token::{self, CommentKind, Delimiter, IdentIsRaw, Token, TokenKind};
use rustc_ast::tokenstream::TokenStream;
use rustc_ast::util::unicode::contains_text_flow_control_chars;
use rustc_errors::codes::*;
use rustc_errors::{Applicability, Diag, DiagCtxtHandle, StashKey};
use rustc_lexer::unescape::{self, EscapeError, Mode};
use rustc_lexer::{Base, Cursor, DocStyle, LiteralKind, RawStrError};
use rustc_session::lint::BuiltinLintDiag;
use rustc_session::lint::builtin::{
RUST_2021_PREFIXES_INCOMPATIBLE_SYNTAX, RUST_2024_GUARDED_STRING_INCOMPATIBLE_SYNTAX,
TEXT_DIRECTION_CODEPOINT_IN_COMMENT,
};
use rustc_session::parse::ParseSess;
use rustc_span::symbol::Symbol;
use rustc_span::{BytePos, Pos, Span};
use tracing::debug;
use crate::lexer::diagnostics::TokenTreeDiagInfo;
use crate::lexer::unicode_chars::UNICODE_ARRAY;
use crate::{errors, make_unclosed_delims_error};
mod diagnostics;
mod tokentrees;
mod unescape_error_reporting;
mod unicode_chars;
use unescape_error_reporting::{emit_unescape_error, escaped_char};
#[cfg(target_pointer_width = "64")]
rustc_data_structures::static_assert_size!(rustc_lexer::Token, 12);
#[derive(Clone, Debug)]
pub(crate) struct UnmatchedDelim {
pub found_delim: Option<Delimiter>,
pub found_span: Span,
pub unclosed_span: Option<Span>,
pub candidate_span: Option<Span>,
}
pub(crate) fn lex_token_trees<'psess, 'src>(
psess: &'psess ParseSess,
mut src: &'src str,
mut start_pos: BytePos,
override_span: Option<Span>,
) -> Result<TokenStream, Vec<Diag<'psess>>> {
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 mut lexer = Lexer {
psess,
start_pos,
pos: start_pos,
src,
cursor,
override_span,
nbsp_is_whitespace: false,
last_lifetime: None,
token: Token::dummy(),
diag_info: TokenTreeDiagInfo::default(),
};
let (_open_spacing, stream, res) = lexer.lex_token_trees(false);
let unmatched_delims = lexer.diag_info.unmatched_delims;
if res.is_ok() && unmatched_delims.is_empty() {
Ok(stream)
} else {
let mut buffer: Vec<_> = unmatched_delims
.into_iter()
.filter_map(|unmatched_delim| make_unclosed_delims_error(unmatched_delim, psess))
.collect();
if let Err(errs) = res {
buffer.extend(errs);
}
Err(buffer)
}
}
struct Lexer<'psess, 'src> {
psess: &'psess ParseSess,
start_pos: BytePos,
pos: BytePos,
src: &'src str,
cursor: Cursor<'src>,
override_span: Option<Span>,
nbsp_is_whitespace: bool,
last_lifetime: Option<Span>,
token: Token,
diag_info: TokenTreeDiagInfo,
}
impl<'psess, 'src> Lexer<'psess, 'src> {
fn dcx(&self) -> DiagCtxtHandle<'psess> {
self.psess.dcx()
}
fn mk_sp(&self, lo: BytePos, hi: BytePos) -> Span {
self.override_span.unwrap_or_else(|| Span::with_root_ctxt(lo, hi))
}
fn next_token_from_cursor(&mut self) -> (Token, bool) {
let mut preceded_by_whitespace = false;
let mut swallow_next_invalid = 0;
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));
if let rustc_lexer::TokenKind::Semi
| rustc_lexer::TokenKind::LineComment { .. }
| rustc_lexer::TokenKind::BlockComment { .. }
| rustc_lexer::TokenKind::CloseParen
| rustc_lexer::TokenKind::CloseBrace
| rustc_lexer::TokenKind::CloseBracket = token.kind
{
self.last_lifetime = None;
}
let kind = match token.kind {
rustc_lexer::TokenKind::LineComment { doc_style } => {
let Some(doc_style) = doc_style else {
self.lint_unicode_text_flow(start);
preceded_by_whitespace = true;
continue;
};
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);
}
let Some(doc_style) = doc_style else {
self.lint_unicode_text_flow(start);
preceded_by_whitespace = true;
continue;
};
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.psess.symbol_gallery.insert(sym, span);
if !sym.can_be_raw() {
self.dcx().emit_err(errors::CannotBeRawIdent { span, ident: sym });
}
self.psess.raw_identifier_spans.push(span);
token::Ident(sym, IdentIsRaw::Yes)
}
rustc_lexer::TokenKind::UnknownPrefix => {
self.report_unknown_prefix(start);
self.ident(start)
}
rustc_lexer::TokenKind::UnknownPrefixLifetime => {
self.report_unknown_prefix(start);
let lifetime_name = self.str_from(start);
self.last_lifetime = Some(self.mk_sp(start, start + BytePos(1)));
let ident = Symbol::intern(lifetime_name);
token::Lifetime(ident, IdentIsRaw::No)
}
rustc_lexer::TokenKind::InvalidIdent
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.psess
.bad_unicode_identifiers
.borrow_mut()
.entry(sym)
.or_default()
.push(span);
token::Ident(sym, IdentIsRaw::No)
}
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!(),
};
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::GuardedStrPrefix => {
self.maybe_report_guarded_str(start, str_before)
}
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);
let suffix = if suffix_start < self.pos {
let string = self.str_from(suffix_start);
if string == "_" {
self.dcx().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 } => {
let lifetime_name = self.str_from(start);
self.last_lifetime = Some(self.mk_sp(start, start + BytePos(1)));
if starts_with_number {
let span = self.mk_sp(start, self.pos);
self.dcx()
.struct_err("lifetimes cannot start with a number")
.with_span(span)
.stash(span, StashKey::LifetimeIsChar);
}
let ident = Symbol::intern(lifetime_name);
token::Lifetime(ident, IdentIsRaw::No)
}
rustc_lexer::TokenKind::RawLifetime => {
self.last_lifetime = Some(self.mk_sp(start, start + BytePos(1)));
let ident_start = start + BytePos(3);
let prefix_span = self.mk_sp(start, ident_start);
if prefix_span.at_least_rust_2021() {
if self.cursor.as_str().starts_with('\'') {
let lit_span = self.mk_sp(start, self.pos + BytePos(1));
let contents = self.str_from_to(start + BytePos(1), self.pos);
emit_unescape_error(
self.dcx(),
contents,
lit_span,
lit_span,
Mode::Char,
0..contents.len(),
EscapeError::MoreThanOneChar,
)
.expect("expected error");
}
let span = self.mk_sp(start, self.pos);
let lifetime_name_without_tick =
Symbol::intern(&self.str_from(ident_start));
if !lifetime_name_without_tick.can_be_raw() {
self.dcx().emit_err(
errors::CannotBeRawLifetime {
span,
ident: lifetime_name_without_tick
}
);
}
let mut lifetime_name =
String::with_capacity(lifetime_name_without_tick.as_str().len() + 1);
lifetime_name.push('\'');
lifetime_name += lifetime_name_without_tick.as_str();
let sym = Symbol::intern(&lifetime_name);
self.psess.raw_identifier_spans.push(span);
token::Lifetime(sym, IdentIsRaw::Yes)
} else {
self.psess.buffer_lint(
RUST_2021_PREFIXES_INCOMPATIBLE_SYNTAX,
prefix_span,
ast::CRATE_NODE_ID,
BuiltinLintDiag::RawPrefix(prefix_span),
);
let lt_start = start + BytePos(2);
self.pos = lt_start;
self.cursor = Cursor::new(&str_before[2 as usize..]);
let lifetime_name = self.str_from(start);
let ident = Symbol::intern(lifetime_name);
token::Lifetime(ident, IdentIsRaw::No)
}
}
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 => {
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 self.nbsp_is_whitespace {
preceded_by_whitespace = true;
continue;
}
self.nbsp_is_whitespace = true;
}
let repeats = it.take_while(|c1| *c1 == c).count();
let (token, sugg) =
unicode_chars::check_for_substitution(self, start, c, repeats + 1);
self.dcx().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.psess.symbol_gallery.insert(sym, span);
token::Ident(sym, IdentIsRaw::No)
}
fn lint_unicode_text_flow(&self, start: BytePos) {
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.psess.buffer_lint(
TEXT_DIRECTION_CODEPOINT_IN_COMMENT,
span,
ast::CRATE_NODE_ID,
BuiltinLintDiag::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.dcx().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 {
let mut err = self
.dcx()
.struct_span_fatal(self.mk_sp(start, end), "unterminated character literal")
.with_code(E0762);
if let Some(lt_sp) = self.last_lifetime {
err.multipart_suggestion(
"if you meant to write a string literal, use double quotes",
vec![
(lt_sp, "\"".to_string()),
(self.mk_sp(start, start + BytePos(1)), "\"".to_string()),
],
Applicability::MaybeIncorrect,
);
}
err.emit()
}
self.cook_unicode(token::Char, Mode::Char, start, end, 1, 1) }
rustc_lexer::LiteralKind::Byte { terminated } => {
if !terminated {
self.dcx()
.struct_span_fatal(
self.mk_sp(start + BytePos(1), end),
"unterminated byte constant",
)
.with_code(E0763)
.emit()
}
self.cook_unicode(token::Byte, Mode::Byte, start, end, 2, 1) }
rustc_lexer::LiteralKind::Str { terminated } => {
if !terminated {
self.dcx()
.struct_span_fatal(
self.mk_sp(start, end),
"unterminated double quote string",
)
.with_code(E0765)
.emit()
}
self.cook_unicode(token::Str, Mode::Str, start, end, 1, 1) }
rustc_lexer::LiteralKind::ByteStr { terminated } => {
if !terminated {
self.dcx()
.struct_span_fatal(
self.mk_sp(start + BytePos(1), end),
"unterminated double quote byte string",
)
.with_code(E0766)
.emit()
}
self.cook_unicode(token::ByteStr, Mode::ByteStr, start, end, 2, 1) }
rustc_lexer::LiteralKind::CStr { terminated } => {
if !terminated {
self.dcx()
.struct_span_fatal(
self.mk_sp(start + BytePos(1), end),
"unterminated C string",
)
.with_code(E0767)
.emit()
}
self.cook_mixed(token::CStr, Mode::CStr, start, end, 2, 1) }
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_unicode(kind, Mode::RawStr, start, end, 2 + n, 1 + n) } 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_unicode(kind, Mode::RawByteStr, start, end, 3 + n, 1 + n) } 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_unicode(kind, Mode::RawCStr, start, end, 3 + n, 1 + n) } else {
self.report_raw_str_error(start, 2);
}
}
rustc_lexer::LiteralKind::Int { base, empty_int } => {
let mut kind = token::Integer;
if empty_int {
let span = self.mk_sp(start, end);
let guar = self.dcx().emit_err(errors::NoDigitsLiteral { span });
kind = token::Err(guar);
} 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() {
let guar =
self.dcx().emit_err(errors::InvalidDigitLiteral { span, base });
kind = token::Err(guar);
}
}
}
(kind, self.symbol_from_to(start, end))
}
rustc_lexer::LiteralKind::Float { base, empty_exponent } => {
let mut kind = token::Float;
if empty_exponent {
let span = self.mk_sp(start, self.pos);
let guar = self.dcx().emit_err(errors::EmptyExponentFloat { span });
kind = token::Err(guar);
}
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);
let guar =
self.dcx().emit_err(errors::FloatLiteralUnsupportedBase { span, base });
kind = token::Err(guar)
}
(kind, self.symbol_from_to(start, end))
}
}
}
#[inline]
fn src_index(&self, pos: BytePos) -> usize {
(pos - self.start_pos).to_usize()
}
fn str_from(&self, start: BytePos) -> &'src str {
self.str_from_to(start, self.pos)
}
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))
}
fn str_from_to(&self, start: BytePos, end: BytePos) -> &'src str {
&self.src[self.src_index(start)..self.src_index(end)]
}
fn str_from_to_end(&self, start: BytePos) -> &'src 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.dcx()
.struct_span_fatal(
self.mk_sp(start, self.pos),
format!(
"found invalid character; only `#` is allowed in raw string delimitation: {}",
escaped_char(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.dcx().struct_span_fatal(self.mk_sp(start, start), "unterminated raw string");
err.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.dcx().struct_span_fatal(self.mk_sp(start, last_bpos), msg);
err.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();
}
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.at_least_rust_2021() {
let sugg = if prefix == "rb" {
Some(errors::UnknownPrefixSugg::UseBr(prefix_span))
} else if expn_data.is_root() {
if self.cursor.first() == '\''
&& let Some(start) = self.last_lifetime
&& self.cursor.third() != '\''
&& let end = self.mk_sp(self.pos, self.pos + BytePos(1))
&& !self.psess.source_map().is_multiline(start.until(end))
{
Some(errors::UnknownPrefixSugg::MeantStr { start, end })
} else {
Some(errors::UnknownPrefixSugg::Whitespace(prefix_span.shrink_to_hi()))
}
} else {
None
};
self.dcx().emit_err(errors::UnknownPrefix { span: prefix_span, prefix, sugg });
} else {
self.psess.buffer_lint(
RUST_2021_PREFIXES_INCOMPATIBLE_SYNTAX,
prefix_span,
ast::CRATE_NODE_ID,
BuiltinLintDiag::ReservedPrefix(prefix_span, prefix.to_string()),
);
}
}
fn maybe_report_guarded_str(&mut self, start: BytePos, str_before: &'src str) -> TokenKind {
let span = self.mk_sp(start, self.pos);
let edition2024 = span.edition().at_least_rust_2024();
let space_pos = start + BytePos(1);
let space_span = self.mk_sp(space_pos, space_pos);
let mut cursor = Cursor::new(str_before);
let (is_string, span, unterminated) = match cursor.guarded_double_quoted_string() {
Some(rustc_lexer::GuardedStr { n_hashes, terminated, token_len }) => {
let end = start + BytePos(token_len);
let span = self.mk_sp(start, end);
let str_start = start + BytePos(n_hashes);
if edition2024 {
self.cursor = cursor;
self.pos = end;
}
let unterminated = if terminated { None } else { Some(str_start) };
(true, span, unterminated)
}
None => {
debug_assert_eq!(self.str_from_to(start, start + BytePos(2)), "##");
(false, span, None)
}
};
if edition2024 {
if let Some(str_start) = unterminated {
self.dcx()
.struct_span_fatal(
self.mk_sp(str_start, self.pos),
"unterminated double quote string",
)
.with_code(E0765)
.emit()
}
let sugg = if span.from_expansion() {
None
} else {
Some(errors::GuardedStringSugg(space_span))
};
let err = if is_string {
self.dcx().emit_err(errors::ReservedString { span, sugg })
} else {
self.dcx().emit_err(errors::ReservedMultihash { span, sugg })
};
token::Literal(token::Lit {
kind: token::Err(err),
symbol: self.symbol_from_to(start, self.pos),
suffix: None,
})
} else {
self.psess.buffer_lint(
RUST_2024_GUARDED_STRING_INCOMPATIBLE_SYNTAX,
span,
ast::CRATE_NODE_ID,
BuiltinLintDiag::ReservedString { is_string, suggestion: space_span },
);
self.pos = start + BytePos(1);
self.cursor = Cursor::new(&str_before[1..]);
token::Pound
}
}
fn report_too_many_hashes(&self, start: BytePos, num: u32) -> ! {
self.dcx().emit_fatal(errors::TooManyHashes { span: self.mk_sp(start, self.pos), num });
}
fn cook_common(
&self,
mut 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 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| {
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);
let is_fatal = err.is_fatal();
if let Some(guar) = emit_unescape_error(
self.dcx(),
lit_content,
span_with_quotes,
span,
mode,
range,
err,
) {
assert!(is_fatal);
kind = token::Err(guar);
}
}
});
let sym = if !matches!(kind, token::Err(_)) {
Symbol::intern(lit_content)
} else {
self.symbol_from_to(start, end)
};
(kind, sym)
}
fn cook_unicode(
&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_unicode(src, mode, &mut |span, result| {
callback(span, result.map(drop))
})
})
}
fn cook_mixed(
&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_mixed(src, mode, &mut |span, result| {
callback(span, result.map(drop))
})
})
}
}
pub fn nfc_normalize(string: &str) -> Symbol {
use unicode_normalization::{IsNormalized, UnicodeNormalization, is_nfc_quick};
match is_nfc_quick(string.chars()) {
IsNormalized::Yes => Symbol::intern(string),
_ => {
let normalized_str: String = string.chars().nfc().collect();
Symbol::intern(&normalized_str)
}
}
}