| use crate::parse::ParseSess; |
| use crate::parse::token::{self, Token, TokenKind}; |
| use crate::symbol::{sym, Symbol}; |
| use crate::parse::unescape; |
| use crate::parse::unescape_error_reporting::{emit_unescape_error, push_escaped_char}; |
| |
| use errors::{FatalError, Diagnostic, DiagnosticBuilder}; |
| use syntax_pos::{BytePos, Pos, Span, NO_EXPANSION}; |
| use core::unicode::property::Pattern_White_Space; |
| |
| use std::borrow::Cow; |
| use std::char; |
| use std::iter; |
| use rustc_data_structures::sync::Lrc; |
| use log::debug; |
| |
| pub mod comments; |
| mod tokentrees; |
| mod unicode_chars; |
| |
| #[derive(Clone, Debug)] |
| pub struct UnmatchedBrace { |
| pub expected_delim: token::DelimToken, |
| pub found_delim: token::DelimToken, |
| pub found_span: Span, |
| pub unclosed_span: Option<Span>, |
| pub candidate_span: Option<Span>, |
| } |
| |
| pub struct StringReader<'a> { |
| crate sess: &'a ParseSess, |
| /// The absolute offset within the source_map of the next character to read |
| crate next_pos: BytePos, |
| /// The absolute offset within the source_map of the current character |
| crate pos: BytePos, |
| /// The current character (which has been read from self.pos) |
| crate ch: Option<char>, |
| crate source_file: Lrc<syntax_pos::SourceFile>, |
| /// Stop reading src at this index. |
| crate end_src_index: usize, |
| // cached: |
| peek_token: Token, |
| peek_span_src_raw: Span, |
| fatal_errs: Vec<DiagnosticBuilder<'a>>, |
| // cache a direct reference to the source text, so that we don't have to |
| // retrieve it via `self.source_file.src.as_ref().unwrap()` all the time. |
| src: Lrc<String>, |
| override_span: Option<Span>, |
| } |
| |
| impl<'a> StringReader<'a> { |
| fn mk_sp(&self, lo: BytePos, hi: BytePos) -> Span { |
| self.mk_sp_and_raw(lo, hi).0 |
| } |
| |
| fn mk_sp_and_raw(&self, lo: BytePos, hi: BytePos) -> (Span, Span) { |
| let raw = Span::new(lo, hi, NO_EXPANSION); |
| let real = self.override_span.unwrap_or(raw); |
| |
| (real, raw) |
| } |
| |
| fn unwrap_or_abort(&mut self, res: Result<Token, ()>) -> Token { |
| match res { |
| Ok(tok) => tok, |
| Err(_) => { |
| self.emit_fatal_errors(); |
| FatalError.raise(); |
| } |
| } |
| } |
| |
| fn next_token(&mut self) -> Token where Self: Sized { |
| let res = self.try_next_token(); |
| self.unwrap_or_abort(res) |
| } |
| |
| /// Returns the next token. EFFECT: advances the string_reader. |
| pub fn try_next_token(&mut self) -> Result<Token, ()> { |
| assert!(self.fatal_errs.is_empty()); |
| let ret_val = self.peek_token.take(); |
| self.advance_token()?; |
| Ok(ret_val) |
| } |
| |
| /// Immutably extract string if found at current position with given delimiters |
| fn peek_delimited(&self, from_ch: char, to_ch: char) -> Option<String> { |
| let mut pos = self.pos; |
| let mut idx = self.src_index(pos); |
| let mut ch = char_at(&self.src, idx); |
| if ch != from_ch { |
| return None; |
| } |
| pos = pos + Pos::from_usize(ch.len_utf8()); |
| let start_pos = pos; |
| idx = self.src_index(pos); |
| while idx < self.end_src_index { |
| ch = char_at(&self.src, idx); |
| if ch == to_ch { |
| return Some(self.src[self.src_index(start_pos)..self.src_index(pos)].to_string()); |
| } |
| pos = pos + Pos::from_usize(ch.len_utf8()); |
| idx = self.src_index(pos); |
| } |
| return None; |
| } |
| |
| fn try_real_token(&mut self) -> Result<Token, ()> { |
| let mut t = self.try_next_token()?; |
| loop { |
| match t.kind { |
| token::Whitespace | token::Comment | token::Shebang(_) => { |
| t = self.try_next_token()?; |
| } |
| _ => break, |
| } |
| } |
| |
| Ok(t) |
| } |
| |
| pub fn real_token(&mut self) -> Token { |
| let res = self.try_real_token(); |
| self.unwrap_or_abort(res) |
| } |
| |
| #[inline] |
| fn is_eof(&self) -> bool { |
| self.ch.is_none() |
| } |
| |
| fn fail_unterminated_raw_string(&self, pos: BytePos, hash_count: u16) -> ! { |
| let mut err = self.struct_span_fatal(pos, pos, "unterminated raw string"); |
| err.span_label(self.mk_sp(pos, pos), "unterminated raw string"); |
| |
| if hash_count > 0 { |
| err.note(&format!("this raw string should be terminated with `\"{}`", |
| "#".repeat(hash_count as usize))); |
| } |
| |
| err.emit(); |
| FatalError.raise(); |
| } |
| |
| fn fatal(&self, m: &str) -> FatalError { |
| self.fatal_span(self.peek_token.span, m) |
| } |
| |
| crate fn emit_fatal_errors(&mut self) { |
| for err in &mut self.fatal_errs { |
| err.emit(); |
| } |
| |
| self.fatal_errs.clear(); |
| } |
| |
| pub fn buffer_fatal_errors(&mut self) -> Vec<Diagnostic> { |
| let mut buffer = Vec::new(); |
| |
| for err in self.fatal_errs.drain(..) { |
| err.buffer(&mut buffer); |
| } |
| |
| buffer |
| } |
| |
| pub fn peek(&self) -> &Token { |
| &self.peek_token |
| } |
| |
| /// For comments.rs, which hackily pokes into next_pos and ch |
| fn new_raw(sess: &'a ParseSess, |
| source_file: Lrc<syntax_pos::SourceFile>, |
| override_span: Option<Span>) -> Self { |
| let mut sr = StringReader::new_raw_internal(sess, source_file, override_span); |
| sr.bump(); |
| |
| sr |
| } |
| |
| fn new_raw_internal(sess: &'a ParseSess, source_file: Lrc<syntax_pos::SourceFile>, |
| override_span: Option<Span>) -> Self |
| { |
| if source_file.src.is_none() { |
| sess.span_diagnostic.bug(&format!("Cannot lex source_file without source: {}", |
| source_file.name)); |
| } |
| |
| let src = (*source_file.src.as_ref().unwrap()).clone(); |
| |
| StringReader { |
| sess, |
| next_pos: source_file.start_pos, |
| pos: source_file.start_pos, |
| ch: Some('\n'), |
| source_file, |
| end_src_index: src.len(), |
| peek_token: Token::dummy(), |
| peek_span_src_raw: syntax_pos::DUMMY_SP, |
| src, |
| fatal_errs: Vec::new(), |
| override_span, |
| } |
| } |
| |
| pub fn new_or_buffered_errs(sess: &'a ParseSess, |
| source_file: Lrc<syntax_pos::SourceFile>, |
| override_span: Option<Span>) -> Result<Self, Vec<Diagnostic>> { |
| let mut sr = StringReader::new_raw(sess, source_file, override_span); |
| if sr.advance_token().is_err() { |
| Err(sr.buffer_fatal_errors()) |
| } else { |
| Ok(sr) |
| } |
| } |
| |
| pub fn retokenize(sess: &'a ParseSess, mut span: Span) -> Self { |
| let begin = sess.source_map().lookup_byte_offset(span.lo()); |
| let end = sess.source_map().lookup_byte_offset(span.hi()); |
| |
| // Make the range zero-length if the span is invalid. |
| if span.lo() > span.hi() || begin.sf.start_pos != end.sf.start_pos { |
| span = span.shrink_to_lo(); |
| } |
| |
| let mut sr = StringReader::new_raw_internal(sess, begin.sf, None); |
| |
| // Seek the lexer to the right byte range. |
| sr.next_pos = span.lo(); |
| sr.end_src_index = sr.src_index(span.hi()); |
| |
| sr.bump(); |
| |
| if sr.advance_token().is_err() { |
| sr.emit_fatal_errors(); |
| FatalError.raise(); |
| } |
| |
| sr |
| } |
| |
| #[inline] |
| fn ch_is(&self, c: char) -> bool { |
| self.ch == Some(c) |
| } |
| |
| /// Report a fatal lexical error with a given span. |
| fn fatal_span(&self, sp: Span, m: &str) -> FatalError { |
| self.sess.span_diagnostic.span_fatal(sp, m) |
| } |
| |
| /// Report a lexical error with a given span. |
| fn err_span(&self, sp: Span, m: &str) { |
| self.sess.span_diagnostic.struct_span_err(sp, m).emit(); |
| } |
| |
| |
| /// Report a fatal error spanning [`from_pos`, `to_pos`). |
| fn fatal_span_(&self, from_pos: BytePos, to_pos: BytePos, m: &str) -> FatalError { |
| self.fatal_span(self.mk_sp(from_pos, to_pos), m) |
| } |
| |
| /// Report a lexical error spanning [`from_pos`, `to_pos`). |
| fn err_span_(&self, from_pos: BytePos, to_pos: BytePos, m: &str) { |
| self.err_span(self.mk_sp(from_pos, to_pos), m) |
| } |
| |
| /// Report a lexical error spanning [`from_pos`, `to_pos`), appending an |
| /// escaped character to the error message |
| fn fatal_span_char(&self, from_pos: BytePos, to_pos: BytePos, m: &str, c: char) -> FatalError { |
| let mut m = m.to_string(); |
| m.push_str(": "); |
| push_escaped_char(&mut m, c); |
| |
| self.fatal_span_(from_pos, to_pos, &m[..]) |
| } |
| |
| fn struct_span_fatal(&self, from_pos: BytePos, to_pos: BytePos, m: &str) |
| -> DiagnosticBuilder<'a> |
| { |
| self.sess.span_diagnostic.struct_span_fatal(self.mk_sp(from_pos, to_pos), m) |
| } |
| |
| fn struct_fatal_span_char(&self, from_pos: BytePos, to_pos: BytePos, m: &str, c: char) |
| -> DiagnosticBuilder<'a> |
| { |
| let mut m = m.to_string(); |
| m.push_str(": "); |
| push_escaped_char(&mut m, c); |
| |
| self.sess.span_diagnostic.struct_span_fatal(self.mk_sp(from_pos, to_pos), &m[..]) |
| } |
| |
| /// Advance peek_token to refer to the next token, and |
| /// possibly update the interner. |
| fn advance_token(&mut self) -> Result<(), ()> { |
| match self.scan_whitespace_or_comment() { |
| Some(comment) => { |
| self.peek_span_src_raw = comment.span; |
| self.peek_token = comment; |
| } |
| None => { |
| let (kind, start_pos, end_pos) = if self.is_eof() { |
| (token::Eof, self.source_file.end_pos, self.source_file.end_pos) |
| } else { |
| let start_pos = self.pos; |
| (self.next_token_inner()?, start_pos, self.pos) |
| }; |
| let (real, raw) = self.mk_sp_and_raw(start_pos, end_pos); |
| self.peek_token = Token::new(kind, real); |
| self.peek_span_src_raw = raw; |
| } |
| } |
| |
| Ok(()) |
| } |
| |
| #[inline] |
| fn src_index(&self, pos: BytePos) -> usize { |
| (pos - self.source_file.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) |
| } |
| |
| /// Creates a Symbol from a given offset to the current offset. |
| fn symbol_from(&self, start: BytePos) -> Symbol { |
| debug!("taking an ident from {:?} to {:?}", start, self.pos); |
| Symbol::intern(self.str_from(start)) |
| } |
| |
| /// 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)] |
| } |
| |
| /// Converts CRLF to LF in the given string, raising an error on bare CR. |
| fn translate_crlf<'b>(&self, start: BytePos, s: &'b str, errmsg: &'b str) -> Cow<'b, str> { |
| let mut chars = s.char_indices().peekable(); |
| while let Some((i, ch)) = chars.next() { |
| if ch == '\r' { |
| if let Some((lf_idx, '\n')) = chars.peek() { |
| return translate_crlf_(self, start, s, *lf_idx, chars, errmsg).into(); |
| } |
| let pos = start + BytePos(i as u32); |
| let end_pos = start + BytePos((i + ch.len_utf8()) as u32); |
| self.err_span_(pos, end_pos, errmsg); |
| } |
| } |
| return s.into(); |
| |
| fn translate_crlf_(rdr: &StringReader<'_>, |
| start: BytePos, |
| s: &str, |
| mut j: usize, |
| mut chars: iter::Peekable<impl Iterator<Item = (usize, char)>>, |
| errmsg: &str) |
| -> String { |
| let mut buf = String::with_capacity(s.len()); |
| // Skip first CR |
| buf.push_str(&s[.. j - 1]); |
| while let Some((i, ch)) = chars.next() { |
| if ch == '\r' { |
| if j < i { |
| buf.push_str(&s[j..i]); |
| } |
| let next = i + ch.len_utf8(); |
| j = next; |
| if chars.peek().map(|(_, ch)| *ch) != Some('\n') { |
| let pos = start + BytePos(i as u32); |
| let end_pos = start + BytePos(next as u32); |
| rdr.err_span_(pos, end_pos, errmsg); |
| } |
| } |
| } |
| if j < s.len() { |
| buf.push_str(&s[j..]); |
| } |
| buf |
| } |
| } |
| |
| /// Advance the StringReader by one character. |
| crate fn bump(&mut self) { |
| let next_src_index = self.src_index(self.next_pos); |
| if next_src_index < self.end_src_index { |
| let next_ch = char_at(&self.src, next_src_index); |
| let next_ch_len = next_ch.len_utf8(); |
| |
| self.ch = Some(next_ch); |
| self.pos = self.next_pos; |
| self.next_pos = self.next_pos + Pos::from_usize(next_ch_len); |
| } else { |
| self.ch = None; |
| self.pos = self.next_pos; |
| } |
| } |
| |
| fn nextch(&self) -> Option<char> { |
| let next_src_index = self.src_index(self.next_pos); |
| if next_src_index < self.end_src_index { |
| Some(char_at(&self.src, next_src_index)) |
| } else { |
| None |
| } |
| } |
| |
| #[inline] |
| fn nextch_is(&self, c: char) -> bool { |
| self.nextch() == Some(c) |
| } |
| |
| fn nextnextch(&self) -> Option<char> { |
| let next_src_index = self.src_index(self.next_pos); |
| if next_src_index < self.end_src_index { |
| let next_next_src_index = |
| next_src_index + char_at(&self.src, next_src_index).len_utf8(); |
| if next_next_src_index < self.end_src_index { |
| return Some(char_at(&self.src, next_next_src_index)); |
| } |
| } |
| None |
| } |
| |
| #[inline] |
| fn nextnextch_is(&self, c: char) -> bool { |
| self.nextnextch() == Some(c) |
| } |
| |
| /// Eats <XID_start><XID_continue>*, if possible. |
| fn scan_optional_raw_name(&mut self) -> Option<Symbol> { |
| if !ident_start(self.ch) { |
| return None; |
| } |
| |
| let start = self.pos; |
| self.bump(); |
| |
| while ident_continue(self.ch) { |
| self.bump(); |
| } |
| |
| match self.str_from(start) { |
| "_" => { |
| self.sess.span_diagnostic |
| .struct_span_warn(self.mk_sp(start, self.pos), |
| "underscore literal suffix is not allowed") |
| .warn("this was previously accepted by the compiler but is \ |
| being phased out; it will become a hard error in \ |
| a future release!") |
| .note("for more information, see issue #42326 \ |
| <https://github.com/rust-lang/rust/issues/42326>") |
| .emit(); |
| None |
| } |
| name => Some(Symbol::intern(name)) |
| } |
| } |
| |
| /// PRECONDITION: self.ch is not whitespace |
| /// Eats any kind of comment. |
| fn scan_comment(&mut self) -> Option<Token> { |
| if let Some(c) = self.ch { |
| if c.is_whitespace() { |
| let msg = "called consume_any_line_comment, but there was whitespace"; |
| self.sess.span_diagnostic.span_err(self.mk_sp(self.pos, self.pos), msg); |
| } |
| } |
| |
| if self.ch_is('/') { |
| match self.nextch() { |
| Some('/') => { |
| self.bump(); |
| self.bump(); |
| |
| // line comments starting with "///" or "//!" are doc-comments |
| let doc_comment = (self.ch_is('/') && !self.nextch_is('/')) || self.ch_is('!'); |
| let start_bpos = self.pos - BytePos(2); |
| |
| while !self.is_eof() { |
| match self.ch.unwrap() { |
| '\n' => break, |
| '\r' => { |
| if self.nextch_is('\n') { |
| // CRLF |
| break; |
| } else if doc_comment { |
| self.err_span_(self.pos, |
| self.next_pos, |
| "bare CR not allowed in doc-comment"); |
| } |
| } |
| _ => (), |
| } |
| self.bump(); |
| } |
| |
| let kind = if doc_comment { |
| token::DocComment(self.symbol_from(start_bpos)) |
| } else { |
| token::Comment |
| }; |
| Some(Token::new(kind, self.mk_sp(start_bpos, self.pos))) |
| } |
| Some('*') => { |
| self.bump(); |
| self.bump(); |
| self.scan_block_comment() |
| } |
| _ => None, |
| } |
| } else if self.ch_is('#') { |
| if self.nextch_is('!') { |
| |
| // Parse an inner attribute. |
| if self.nextnextch_is('[') { |
| return None; |
| } |
| |
| let is_beginning_of_file = self.pos == self.source_file.start_pos; |
| if is_beginning_of_file { |
| debug!("Skipping a shebang"); |
| let start = self.pos; |
| while !self.ch_is('\n') && !self.is_eof() { |
| self.bump(); |
| } |
| return Some(Token::new( |
| token::Shebang(self.symbol_from(start)), |
| self.mk_sp(start, self.pos), |
| )); |
| } |
| } |
| None |
| } else { |
| None |
| } |
| } |
| |
| /// If there is whitespace, shebang, or a comment, scan it. Otherwise, |
| /// return `None`. |
| fn scan_whitespace_or_comment(&mut self) -> Option<Token> { |
| match self.ch.unwrap_or('\0') { |
| // # to handle shebang at start of file -- this is the entry point |
| // for skipping over all "junk" |
| '/' | '#' => { |
| let c = self.scan_comment(); |
| debug!("scanning a comment {:?}", c); |
| c |
| }, |
| c if is_pattern_whitespace(Some(c)) => { |
| let start_bpos = self.pos; |
| while is_pattern_whitespace(self.ch) { |
| self.bump(); |
| } |
| let c = Some(Token::new(token::Whitespace, self.mk_sp(start_bpos, self.pos))); |
| debug!("scanning whitespace: {:?}", c); |
| c |
| } |
| _ => None, |
| } |
| } |
| |
| /// Might return a sugared-doc-attr |
| fn scan_block_comment(&mut self) -> Option<Token> { |
| // block comments starting with "/**" or "/*!" are doc-comments |
| let is_doc_comment = self.ch_is('*') || self.ch_is('!'); |
| let start_bpos = self.pos - BytePos(2); |
| |
| let mut level: isize = 1; |
| let mut has_cr = false; |
| while level > 0 { |
| if self.is_eof() { |
| let msg = if is_doc_comment { |
| "unterminated block doc-comment" |
| } else { |
| "unterminated block comment" |
| }; |
| let last_bpos = self.pos; |
| self.fatal_span_(start_bpos, last_bpos, msg).raise(); |
| } |
| let n = self.ch.unwrap(); |
| match n { |
| '/' if self.nextch_is('*') => { |
| level += 1; |
| self.bump(); |
| } |
| '*' if self.nextch_is('/') => { |
| level -= 1; |
| self.bump(); |
| } |
| '\r' => { |
| has_cr = true; |
| } |
| _ => (), |
| } |
| self.bump(); |
| } |
| |
| let string = self.str_from(start_bpos); |
| // but comments with only "*"s between two "/"s are not |
| let kind = if is_block_doc_comment(string) { |
| let string = if has_cr { |
| self.translate_crlf(start_bpos, |
| string, |
| "bare CR not allowed in block doc-comment") |
| } else { |
| string.into() |
| }; |
| token::DocComment(Symbol::intern(&string[..])) |
| } else { |
| token::Comment |
| }; |
| |
| Some(Token::new(kind, self.mk_sp(start_bpos, self.pos))) |
| } |
| |
| /// Scan through any digits (base `scan_radix`) or underscores, |
| /// and return how many digits there were. |
| /// |
| /// `real_radix` represents the true radix of the number we're |
| /// interested in, and errors will be emitted for any digits |
| /// between `real_radix` and `scan_radix`. |
| fn scan_digits(&mut self, real_radix: u32, scan_radix: u32) -> usize { |
| assert!(real_radix <= scan_radix); |
| let mut len = 0; |
| |
| loop { |
| let c = self.ch; |
| if c == Some('_') { |
| debug!("skipping a _"); |
| self.bump(); |
| continue; |
| } |
| match c.and_then(|cc| cc.to_digit(scan_radix)) { |
| Some(_) => { |
| debug!("{:?} in scan_digits", c); |
| // check that the hypothetical digit is actually |
| // in range for the true radix |
| if c.unwrap().to_digit(real_radix).is_none() { |
| self.err_span_(self.pos, |
| self.next_pos, |
| &format!("invalid digit for a base {} literal", real_radix)); |
| } |
| len += 1; |
| self.bump(); |
| } |
| _ => return len, |
| } |
| } |
| } |
| |
| /// Lex a LIT_INTEGER or a LIT_FLOAT |
| fn scan_number(&mut self, c: char) -> (token::LitKind, Symbol) { |
| let mut base = 10; |
| let start_bpos = self.pos; |
| self.bump(); |
| |
| let num_digits = if c == '0' { |
| match self.ch.unwrap_or('\0') { |
| 'b' => { |
| self.bump(); |
| base = 2; |
| self.scan_digits(2, 10) |
| } |
| 'o' => { |
| self.bump(); |
| base = 8; |
| self.scan_digits(8, 10) |
| } |
| 'x' => { |
| self.bump(); |
| base = 16; |
| self.scan_digits(16, 16) |
| } |
| '0'..='9' | '_' | '.' | 'e' | 'E' => { |
| self.scan_digits(10, 10) + 1 |
| } |
| _ => { |
| // just a 0 |
| return (token::Integer, sym::integer(0)); |
| } |
| } |
| } else if c.is_digit(10) { |
| self.scan_digits(10, 10) + 1 |
| } else { |
| 0 |
| }; |
| |
| if num_digits == 0 { |
| self.err_span_(start_bpos, self.pos, "no valid digits found for number"); |
| |
| return (token::Integer, Symbol::intern("0")); |
| } |
| |
| // might be a float, but don't be greedy if this is actually an |
| // integer literal followed by field/method access or a range pattern |
| // (`0..2` and `12.foo()`) |
| if self.ch_is('.') && !self.nextch_is('.') && |
| !ident_start(self.nextch()) { |
| // might have stuff after the ., and if it does, it needs to start |
| // with a number |
| self.bump(); |
| if self.ch.unwrap_or('\0').is_digit(10) { |
| self.scan_digits(10, 10); |
| self.scan_float_exponent(); |
| } |
| let pos = self.pos; |
| self.check_float_base(start_bpos, pos, base); |
| |
| (token::Float, self.symbol_from(start_bpos)) |
| } else { |
| // it might be a float if it has an exponent |
| if self.ch_is('e') || self.ch_is('E') { |
| self.scan_float_exponent(); |
| let pos = self.pos; |
| self.check_float_base(start_bpos, pos, base); |
| return (token::Float, self.symbol_from(start_bpos)); |
| } |
| // but we certainly have an integer! |
| (token::Integer, self.symbol_from(start_bpos)) |
| } |
| } |
| |
| /// Scan over a float exponent. |
| fn scan_float_exponent(&mut self) { |
| if self.ch_is('e') || self.ch_is('E') { |
| self.bump(); |
| |
| if self.ch_is('-') || self.ch_is('+') { |
| self.bump(); |
| } |
| |
| if self.scan_digits(10, 10) == 0 { |
| let mut err = self.struct_span_fatal( |
| self.pos, self.next_pos, |
| "expected at least one digit in exponent" |
| ); |
| if let Some(ch) = self.ch { |
| // check for e.g., Unicode minus '−' (Issue #49746) |
| if unicode_chars::check_for_substitution(self, ch, &mut err) { |
| self.bump(); |
| self.scan_digits(10, 10); |
| } |
| } |
| err.emit(); |
| } |
| } |
| } |
| |
| /// Checks that a base is valid for a floating literal, emitting a nice |
| /// error if it isn't. |
| fn check_float_base(&mut self, start_bpos: BytePos, last_bpos: BytePos, base: usize) { |
| match base { |
| 16 => { |
| self.err_span_(start_bpos, |
| last_bpos, |
| "hexadecimal float literal is not supported") |
| } |
| 8 => { |
| self.err_span_(start_bpos, |
| last_bpos, |
| "octal float literal is not supported") |
| } |
| 2 => { |
| self.err_span_(start_bpos, |
| last_bpos, |
| "binary float literal is not supported") |
| } |
| _ => (), |
| } |
| } |
| |
| fn binop(&mut self, op: token::BinOpToken) -> TokenKind { |
| self.bump(); |
| if self.ch_is('=') { |
| self.bump(); |
| token::BinOpEq(op) |
| } else { |
| token::BinOp(op) |
| } |
| } |
| |
| /// Returns the next token from the string, advances the input past that |
| /// token, and updates the interner |
| fn next_token_inner(&mut self) -> Result<TokenKind, ()> { |
| let c = self.ch; |
| |
| if ident_start(c) { |
| let (is_ident_start, is_raw_ident) = |
| match (c.unwrap(), self.nextch(), self.nextnextch()) { |
| // r# followed by an identifier starter is a raw identifier. |
| // This is an exception to the r# case below. |
| ('r', Some('#'), x) if ident_start(x) => (true, true), |
| // r as in r" or r#" is part of a raw string literal. |
| // b as in b' is part of a byte literal. |
| // They are not identifiers, and are handled further down. |
| ('r', Some('"'), _) | |
| ('r', Some('#'), _) | |
| ('b', Some('"'), _) | |
| ('b', Some('\''), _) | |
| ('b', Some('r'), Some('"')) | |
| ('b', Some('r'), Some('#')) => (false, false), |
| _ => (true, false), |
| }; |
| |
| if is_ident_start { |
| let raw_start = self.pos; |
| if is_raw_ident { |
| // Consume the 'r#' characters. |
| self.bump(); |
| self.bump(); |
| } |
| |
| let start = self.pos; |
| self.bump(); |
| |
| while ident_continue(self.ch) { |
| self.bump(); |
| } |
| |
| // FIXME: perform NFKC normalization here. (Issue #2253) |
| let name = self.symbol_from(start); |
| if is_raw_ident { |
| let span = self.mk_sp(raw_start, self.pos); |
| if !name.can_be_raw() { |
| self.err_span(span, &format!("`{}` cannot be a raw identifier", name)); |
| } |
| self.sess.raw_identifier_spans.borrow_mut().push(span); |
| } |
| |
| return Ok(token::Ident(name, is_raw_ident)); |
| } |
| } |
| |
| if is_dec_digit(c) { |
| let (kind, symbol) = self.scan_number(c.unwrap()); |
| let suffix = self.scan_optional_raw_name(); |
| debug!("next_token_inner: scanned number {:?}, {:?}, {:?}", kind, symbol, suffix); |
| return Ok(TokenKind::lit(kind, symbol, suffix)); |
| } |
| |
| match c.expect("next_token_inner called at EOF") { |
| // One-byte tokens. |
| ';' => { |
| self.bump(); |
| Ok(token::Semi) |
| } |
| ',' => { |
| self.bump(); |
| Ok(token::Comma) |
| } |
| '.' => { |
| self.bump(); |
| if self.ch_is('.') { |
| self.bump(); |
| if self.ch_is('.') { |
| self.bump(); |
| Ok(token::DotDotDot) |
| } else if self.ch_is('=') { |
| self.bump(); |
| Ok(token::DotDotEq) |
| } else { |
| Ok(token::DotDot) |
| } |
| } else { |
| Ok(token::Dot) |
| } |
| } |
| '(' => { |
| self.bump(); |
| Ok(token::OpenDelim(token::Paren)) |
| } |
| ')' => { |
| self.bump(); |
| Ok(token::CloseDelim(token::Paren)) |
| } |
| '{' => { |
| self.bump(); |
| Ok(token::OpenDelim(token::Brace)) |
| } |
| '}' => { |
| self.bump(); |
| Ok(token::CloseDelim(token::Brace)) |
| } |
| '[' => { |
| self.bump(); |
| Ok(token::OpenDelim(token::Bracket)) |
| } |
| ']' => { |
| self.bump(); |
| Ok(token::CloseDelim(token::Bracket)) |
| } |
| '@' => { |
| self.bump(); |
| Ok(token::At) |
| } |
| '#' => { |
| self.bump(); |
| Ok(token::Pound) |
| } |
| '~' => { |
| self.bump(); |
| Ok(token::Tilde) |
| } |
| '?' => { |
| self.bump(); |
| Ok(token::Question) |
| } |
| ':' => { |
| self.bump(); |
| if self.ch_is(':') { |
| self.bump(); |
| Ok(token::ModSep) |
| } else { |
| Ok(token::Colon) |
| } |
| } |
| |
| '$' => { |
| self.bump(); |
| Ok(token::Dollar) |
| } |
| |
| // Multi-byte tokens. |
| '=' => { |
| self.bump(); |
| if self.ch_is('=') { |
| self.bump(); |
| Ok(token::EqEq) |
| } else if self.ch_is('>') { |
| self.bump(); |
| Ok(token::FatArrow) |
| } else { |
| Ok(token::Eq) |
| } |
| } |
| '!' => { |
| self.bump(); |
| if self.ch_is('=') { |
| self.bump(); |
| Ok(token::Ne) |
| } else { |
| Ok(token::Not) |
| } |
| } |
| '<' => { |
| self.bump(); |
| match self.ch.unwrap_or('\x00') { |
| '=' => { |
| self.bump(); |
| Ok(token::Le) |
| } |
| '<' => { |
| Ok(self.binop(token::Shl)) |
| } |
| '-' => { |
| self.bump(); |
| Ok(token::LArrow) |
| } |
| _ => { |
| Ok(token::Lt) |
| } |
| } |
| } |
| '>' => { |
| self.bump(); |
| match self.ch.unwrap_or('\x00') { |
| '=' => { |
| self.bump(); |
| Ok(token::Ge) |
| } |
| '>' => { |
| Ok(self.binop(token::Shr)) |
| } |
| _ => { |
| Ok(token::Gt) |
| } |
| } |
| } |
| '\'' => { |
| // Either a character constant 'a' OR a lifetime name 'abc |
| let start_with_quote = self.pos; |
| self.bump(); |
| let start = self.pos; |
| |
| // If the character is an ident start not followed by another single |
| // quote, then this is a lifetime name: |
| let starts_with_number = self.ch.unwrap_or('\x00').is_numeric(); |
| if (ident_start(self.ch) || starts_with_number) && !self.nextch_is('\'') { |
| self.bump(); |
| while ident_continue(self.ch) { |
| self.bump(); |
| } |
| // lifetimes shouldn't end with a single quote |
| // if we find one, then this is an invalid character literal |
| if self.ch_is('\'') { |
| let symbol = self.symbol_from(start); |
| self.bump(); |
| self.validate_char_escape(start_with_quote); |
| return Ok(TokenKind::lit(token::Char, symbol, None)); |
| } |
| |
| if starts_with_number { |
| // this is a recovered lifetime written `'1`, error but accept it |
| self.err_span_( |
| start_with_quote, |
| self.pos, |
| "lifetimes cannot start with a number", |
| ); |
| } |
| |
| // Include the leading `'` in the real identifier, for macro |
| // expansion purposes. See #12512 for the gory details of why |
| // this is necessary. |
| return Ok(token::Lifetime(self.symbol_from(start_with_quote))); |
| } |
| let msg = "unterminated character literal"; |
| let symbol = self.scan_single_quoted_string(start_with_quote, msg); |
| self.validate_char_escape(start_with_quote); |
| let suffix = self.scan_optional_raw_name(); |
| Ok(TokenKind::lit(token::Char, symbol, suffix)) |
| } |
| 'b' => { |
| self.bump(); |
| let (kind, symbol) = match self.ch { |
| Some('\'') => { |
| let start_with_quote = self.pos; |
| self.bump(); |
| let msg = "unterminated byte constant"; |
| let symbol = self.scan_single_quoted_string(start_with_quote, msg); |
| self.validate_byte_escape(start_with_quote); |
| (token::Byte, symbol) |
| }, |
| Some('"') => { |
| let start_with_quote = self.pos; |
| let msg = "unterminated double quote byte string"; |
| let symbol = self.scan_double_quoted_string(msg); |
| self.validate_byte_str_escape(start_with_quote); |
| (token::ByteStr, symbol) |
| }, |
| Some('r') => { |
| let (start, end, hash_count) = self.scan_raw_string(); |
| let symbol = self.symbol_from_to(start, end); |
| self.validate_raw_byte_str_escape(start, end); |
| |
| (token::ByteStrRaw(hash_count), symbol) |
| } |
| _ => unreachable!(), // Should have been a token::Ident above. |
| }; |
| let suffix = self.scan_optional_raw_name(); |
| |
| Ok(TokenKind::lit(kind, symbol, suffix)) |
| } |
| '"' => { |
| let start_with_quote = self.pos; |
| let msg = "unterminated double quote string"; |
| let symbol = self.scan_double_quoted_string(msg); |
| self.validate_str_escape(start_with_quote); |
| let suffix = self.scan_optional_raw_name(); |
| Ok(TokenKind::lit(token::Str, symbol, suffix)) |
| } |
| 'r' => { |
| let (start, end, hash_count) = self.scan_raw_string(); |
| let symbol = self.symbol_from_to(start, end); |
| self.validate_raw_str_escape(start, end); |
| let suffix = self.scan_optional_raw_name(); |
| |
| Ok(TokenKind::lit(token::StrRaw(hash_count), symbol, suffix)) |
| } |
| '-' => { |
| if self.nextch_is('>') { |
| self.bump(); |
| self.bump(); |
| Ok(token::RArrow) |
| } else { |
| Ok(self.binop(token::Minus)) |
| } |
| } |
| '&' => { |
| if self.nextch_is('&') { |
| self.bump(); |
| self.bump(); |
| Ok(token::AndAnd) |
| } else { |
| Ok(self.binop(token::And)) |
| } |
| } |
| '|' => { |
| match self.nextch() { |
| Some('|') => { |
| self.bump(); |
| self.bump(); |
| Ok(token::OrOr) |
| } |
| _ => { |
| Ok(self.binop(token::Or)) |
| } |
| } |
| } |
| '+' => { |
| Ok(self.binop(token::Plus)) |
| } |
| '*' => { |
| Ok(self.binop(token::Star)) |
| } |
| '/' => { |
| Ok(self.binop(token::Slash)) |
| } |
| '^' => { |
| Ok(self.binop(token::Caret)) |
| } |
| '%' => { |
| Ok(self.binop(token::Percent)) |
| } |
| c => { |
| let last_bpos = self.pos; |
| let bpos = self.next_pos; |
| let mut err = self.struct_fatal_span_char(last_bpos, |
| bpos, |
| "unknown start of token", |
| c); |
| unicode_chars::check_for_substitution(self, c, &mut err); |
| self.fatal_errs.push(err); |
| |
| Err(()) |
| } |
| } |
| } |
| |
| fn read_to_eol(&mut self) -> String { |
| let mut val = String::new(); |
| while !self.ch_is('\n') && !self.is_eof() { |
| val.push(self.ch.unwrap()); |
| self.bump(); |
| } |
| |
| if self.ch_is('\n') { |
| self.bump(); |
| } |
| |
| val |
| } |
| |
| fn read_one_line_comment(&mut self) -> String { |
| let val = self.read_to_eol(); |
| assert!((val.as_bytes()[0] == b'/' && val.as_bytes()[1] == b'/') || |
| (val.as_bytes()[0] == b'#' && val.as_bytes()[1] == b'!')); |
| val |
| } |
| |
| fn consume_non_eol_whitespace(&mut self) { |
| while is_pattern_whitespace(self.ch) && !self.ch_is('\n') && !self.is_eof() { |
| self.bump(); |
| } |
| } |
| |
| fn peeking_at_comment(&self) -> bool { |
| (self.ch_is('/') && self.nextch_is('/')) || (self.ch_is('/') && self.nextch_is('*')) || |
| // consider shebangs comments, but not inner attributes |
| (self.ch_is('#') && self.nextch_is('!') && !self.nextnextch_is('[')) |
| } |
| |
| fn scan_single_quoted_string(&mut self, |
| start_with_quote: BytePos, |
| unterminated_msg: &str) -> Symbol { |
| // assumes that first `'` is consumed |
| let start = self.pos; |
| // lex `'''` as a single char, for recovery |
| if self.ch_is('\'') && self.nextch_is('\'') { |
| self.bump(); |
| } else { |
| let mut first = true; |
| loop { |
| if self.ch_is('\'') { |
| break; |
| } |
| if self.ch_is('\\') && (self.nextch_is('\'') || self.nextch_is('\\')) { |
| self.bump(); |
| self.bump(); |
| } else { |
| // Only attempt to infer single line string literals. If we encounter |
| // a slash, bail out in order to avoid nonsensical suggestion when |
| // involving comments. |
| if self.is_eof() |
| || (self.ch_is('/') && !first) |
| || (self.ch_is('\n') && !self.nextch_is('\'')) { |
| |
| self.fatal_span_(start_with_quote, self.pos, unterminated_msg.into()) |
| .raise() |
| } |
| self.bump(); |
| } |
| first = false; |
| } |
| } |
| |
| let id = self.symbol_from(start); |
| self.bump(); |
| id |
| } |
| |
| fn scan_double_quoted_string(&mut self, unterminated_msg: &str) -> Symbol { |
| debug_assert!(self.ch_is('\"')); |
| let start_with_quote = self.pos; |
| self.bump(); |
| let start = self.pos; |
| while !self.ch_is('"') { |
| if self.is_eof() { |
| let pos = self.pos; |
| self.fatal_span_(start_with_quote, pos, unterminated_msg).raise(); |
| } |
| if self.ch_is('\\') && (self.nextch_is('\\') || self.nextch_is('"')) { |
| self.bump(); |
| } |
| self.bump(); |
| } |
| let id = self.symbol_from(start); |
| self.bump(); |
| id |
| } |
| |
| /// Scans a raw (byte) string, returning byte position range for `"<literal>"` |
| /// (including quotes) along with `#` character count in `(b)r##..."<literal>"##...`; |
| fn scan_raw_string(&mut self) -> (BytePos, BytePos, u16) { |
| let start_bpos = self.pos; |
| self.bump(); |
| let mut hash_count: u16 = 0; |
| while self.ch_is('#') { |
| if hash_count == 65535 { |
| let bpos = self.next_pos; |
| self.fatal_span_(start_bpos, |
| bpos, |
| "too many `#` symbols: raw strings may be \ |
| delimited by up to 65535 `#` symbols").raise(); |
| } |
| self.bump(); |
| hash_count += 1; |
| } |
| |
| if self.is_eof() { |
| self.fail_unterminated_raw_string(start_bpos, hash_count); |
| } else if !self.ch_is('"') { |
| let last_bpos = self.pos; |
| let curr_char = self.ch.unwrap(); |
| self.fatal_span_char(start_bpos, |
| last_bpos, |
| "found invalid character; only `#` is allowed \ |
| in raw string delimitation", |
| curr_char).raise(); |
| } |
| self.bump(); |
| let content_start_bpos = self.pos; |
| let mut content_end_bpos; |
| 'outer: loop { |
| match self.ch { |
| None => { |
| self.fail_unterminated_raw_string(start_bpos, hash_count); |
| } |
| Some('"') => { |
| content_end_bpos = self.pos; |
| for _ in 0..hash_count { |
| self.bump(); |
| if !self.ch_is('#') { |
| continue 'outer; |
| } |
| } |
| break; |
| } |
| _ => (), |
| } |
| self.bump(); |
| } |
| |
| self.bump(); |
| |
| (content_start_bpos, content_end_bpos, hash_count) |
| } |
| |
| fn validate_char_escape(&self, start_with_quote: BytePos) { |
| let lit = self.str_from_to(start_with_quote + BytePos(1), self.pos - BytePos(1)); |
| if let Err((off, err)) = unescape::unescape_char(lit) { |
| emit_unescape_error( |
| &self.sess.span_diagnostic, |
| lit, |
| self.mk_sp(start_with_quote, self.pos), |
| unescape::Mode::Char, |
| 0..off, |
| err, |
| ) |
| } |
| } |
| |
| fn validate_byte_escape(&self, start_with_quote: BytePos) { |
| let lit = self.str_from_to(start_with_quote + BytePos(1), self.pos - BytePos(1)); |
| if let Err((off, err)) = unescape::unescape_byte(lit) { |
| emit_unescape_error( |
| &self.sess.span_diagnostic, |
| lit, |
| self.mk_sp(start_with_quote, self.pos), |
| unescape::Mode::Byte, |
| 0..off, |
| err, |
| ) |
| } |
| } |
| |
| fn validate_str_escape(&self, start_with_quote: BytePos) { |
| let lit = self.str_from_to(start_with_quote + BytePos(1), self.pos - BytePos(1)); |
| unescape::unescape_str(lit, &mut |range, c| { |
| if let Err(err) = c { |
| emit_unescape_error( |
| &self.sess.span_diagnostic, |
| lit, |
| self.mk_sp(start_with_quote, self.pos), |
| unescape::Mode::Str, |
| range, |
| err, |
| ) |
| } |
| }) |
| } |
| |
| fn validate_raw_str_escape(&self, content_start: BytePos, content_end: BytePos) { |
| let lit = self.str_from_to(content_start, content_end); |
| unescape::unescape_raw_str(lit, &mut |range, c| { |
| if let Err(err) = c { |
| emit_unescape_error( |
| &self.sess.span_diagnostic, |
| lit, |
| self.mk_sp(content_start - BytePos(1), content_end + BytePos(1)), |
| unescape::Mode::Str, |
| range, |
| err, |
| ) |
| } |
| }) |
| } |
| |
| fn validate_raw_byte_str_escape(&self, content_start: BytePos, content_end: BytePos) { |
| let lit = self.str_from_to(content_start, content_end); |
| unescape::unescape_raw_byte_str(lit, &mut |range, c| { |
| if let Err(err) = c { |
| emit_unescape_error( |
| &self.sess.span_diagnostic, |
| lit, |
| self.mk_sp(content_start - BytePos(1), content_end + BytePos(1)), |
| unescape::Mode::ByteStr, |
| range, |
| err, |
| ) |
| } |
| }) |
| } |
| |
| fn validate_byte_str_escape(&self, start_with_quote: BytePos) { |
| let lit = self.str_from_to(start_with_quote + BytePos(1), self.pos - BytePos(1)); |
| unescape::unescape_byte_str(lit, &mut |range, c| { |
| if let Err(err) = c { |
| emit_unescape_error( |
| &self.sess.span_diagnostic, |
| lit, |
| self.mk_sp(start_with_quote, self.pos), |
| unescape::Mode::ByteStr, |
| range, |
| err, |
| ) |
| } |
| }) |
| } |
| } |
| |
| // This tests the character for the unicode property 'PATTERN_WHITE_SPACE' which |
| // is guaranteed to be forward compatible. http://unicode.org/reports/tr31/#R3 |
| #[inline] |
| crate fn is_pattern_whitespace(c: Option<char>) -> bool { |
| c.map_or(false, Pattern_White_Space) |
| } |
| |
| #[inline] |
| fn in_range(c: Option<char>, lo: char, hi: char) -> bool { |
| c.map_or(false, |c| lo <= c && c <= hi) |
| } |
| |
| #[inline] |
| fn is_dec_digit(c: Option<char>) -> bool { |
| in_range(c, '0', '9') |
| } |
| |
| fn is_doc_comment(s: &str) -> bool { |
| let res = (s.starts_with("///") && *s.as_bytes().get(3).unwrap_or(&b' ') != b'/') || |
| s.starts_with("//!"); |
| debug!("is {:?} a doc comment? {}", s, res); |
| res |
| } |
| |
| fn is_block_doc_comment(s: &str) -> bool { |
| // Prevent `/**/` from being parsed as a doc comment |
| let res = ((s.starts_with("/**") && *s.as_bytes().get(3).unwrap_or(&b' ') != b'*') || |
| s.starts_with("/*!")) && s.len() >= 5; |
| debug!("is {:?} a doc comment? {}", s, res); |
| res |
| } |
| |
| /// Determine whether `c` is a valid start for an ident. |
| fn ident_start(c: Option<char>) -> bool { |
| let c = match c { |
| Some(c) => c, |
| None => return false, |
| }; |
| |
| (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || c == '_' || (c > '\x7f' && c.is_xid_start()) |
| } |
| |
| fn ident_continue(c: Option<char>) -> bool { |
| let c = match c { |
| Some(c) => c, |
| None => return false, |
| }; |
| |
| (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || (c >= '0' && c <= '9') || c == '_' || |
| (c > '\x7f' && c.is_xid_continue()) |
| } |
| |
| #[inline] |
| fn char_at(s: &str, byte: usize) -> char { |
| s[byte..].chars().next().unwrap() |
| } |
| |
| #[cfg(test)] |
| mod tests { |
| use super::*; |
| |
| use crate::ast::CrateConfig; |
| use crate::symbol::Symbol; |
| use crate::source_map::{SourceMap, FilePathMapping}; |
| use crate::feature_gate::UnstableFeatures; |
| use crate::parse::token; |
| use crate::diagnostics::plugin::ErrorMap; |
| use crate::with_default_globals; |
| use std::io; |
| use std::path::PathBuf; |
| use syntax_pos::{BytePos, Span, NO_EXPANSION, edition::Edition}; |
| use rustc_data_structures::fx::{FxHashSet, FxHashMap}; |
| use rustc_data_structures::sync::Lock; |
| |
| fn mk_sess(sm: Lrc<SourceMap>) -> ParseSess { |
| let emitter = errors::emitter::EmitterWriter::new(Box::new(io::sink()), |
| Some(sm.clone()), |
| false, |
| false, |
| false); |
| ParseSess { |
| span_diagnostic: errors::Handler::with_emitter(true, None, Box::new(emitter)), |
| unstable_features: UnstableFeatures::from_environment(), |
| config: CrateConfig::default(), |
| included_mod_stack: Lock::new(Vec::new()), |
| source_map: sm, |
| missing_fragment_specifiers: Lock::new(FxHashSet::default()), |
| raw_identifier_spans: Lock::new(Vec::new()), |
| registered_diagnostics: Lock::new(ErrorMap::new()), |
| buffered_lints: Lock::new(vec![]), |
| edition: Edition::from_session(), |
| ambiguous_block_expr_parse: Lock::new(FxHashMap::default()), |
| param_attr_spans: Lock::new(Vec::new()), |
| let_chains_spans: Lock::new(Vec::new()), |
| } |
| } |
| |
| // open a string reader for the given string |
| fn setup<'a>(sm: &SourceMap, |
| sess: &'a ParseSess, |
| teststr: String) |
| -> StringReader<'a> { |
| let sf = sm.new_source_file(PathBuf::from(teststr.clone()).into(), teststr); |
| let mut sr = StringReader::new_raw(sess, sf, None); |
| if sr.advance_token().is_err() { |
| sr.emit_fatal_errors(); |
| FatalError.raise(); |
| } |
| sr |
| } |
| |
| #[test] |
| fn t1() { |
| with_default_globals(|| { |
| let sm = Lrc::new(SourceMap::new(FilePathMapping::empty())); |
| let sh = mk_sess(sm.clone()); |
| let mut string_reader = setup(&sm, |
| &sh, |
| "/* my source file */ fn main() { println!(\"zebra\"); }\n" |
| .to_string()); |
| assert_eq!(string_reader.next_token(), token::Comment); |
| assert_eq!(string_reader.next_token(), token::Whitespace); |
| let tok1 = string_reader.next_token(); |
| let tok2 = Token::new( |
| mk_ident("fn"), |
| Span::new(BytePos(21), BytePos(23), NO_EXPANSION), |
| ); |
| assert_eq!(tok1.kind, tok2.kind); |
| assert_eq!(tok1.span, tok2.span); |
| assert_eq!(string_reader.next_token(), token::Whitespace); |
| // the 'main' id is already read: |
| assert_eq!(string_reader.pos.clone(), BytePos(28)); |
| // read another token: |
| let tok3 = string_reader.next_token(); |
| let tok4 = Token::new( |
| mk_ident("main"), |
| Span::new(BytePos(24), BytePos(28), NO_EXPANSION), |
| ); |
| assert_eq!(tok3.kind, tok4.kind); |
| assert_eq!(tok3.span, tok4.span); |
| // the lparen is already read: |
| assert_eq!(string_reader.pos.clone(), BytePos(29)) |
| }) |
| } |
| |
| // check that the given reader produces the desired stream |
| // of tokens (stop checking after exhausting the expected vec) |
| fn check_tokenization(mut string_reader: StringReader<'_>, expected: Vec<TokenKind>) { |
| for expected_tok in &expected { |
| assert_eq!(&string_reader.next_token(), expected_tok); |
| } |
| } |
| |
| // make the identifier by looking up the string in the interner |
| fn mk_ident(id: &str) -> TokenKind { |
| token::Ident(Symbol::intern(id), false) |
| } |
| |
| fn mk_lit(kind: token::LitKind, symbol: &str, suffix: Option<&str>) -> TokenKind { |
| TokenKind::lit(kind, Symbol::intern(symbol), suffix.map(Symbol::intern)) |
| } |
| |
| #[test] |
| fn doublecolonparsing() { |
| with_default_globals(|| { |
| let sm = Lrc::new(SourceMap::new(FilePathMapping::empty())); |
| let sh = mk_sess(sm.clone()); |
| check_tokenization(setup(&sm, &sh, "a b".to_string()), |
| vec![mk_ident("a"), token::Whitespace, mk_ident("b")]); |
| }) |
| } |
| |
| #[test] |
| fn dcparsing_2() { |
| with_default_globals(|| { |
| let sm = Lrc::new(SourceMap::new(FilePathMapping::empty())); |
| let sh = mk_sess(sm.clone()); |
| check_tokenization(setup(&sm, &sh, "a::b".to_string()), |
| vec![mk_ident("a"), token::ModSep, mk_ident("b")]); |
| }) |
| } |
| |
| #[test] |
| fn dcparsing_3() { |
| with_default_globals(|| { |
| let sm = Lrc::new(SourceMap::new(FilePathMapping::empty())); |
| let sh = mk_sess(sm.clone()); |
| check_tokenization(setup(&sm, &sh, "a ::b".to_string()), |
| vec![mk_ident("a"), token::Whitespace, token::ModSep, mk_ident("b")]); |
| }) |
| } |
| |
| #[test] |
| fn dcparsing_4() { |
| with_default_globals(|| { |
| let sm = Lrc::new(SourceMap::new(FilePathMapping::empty())); |
| let sh = mk_sess(sm.clone()); |
| check_tokenization(setup(&sm, &sh, "a:: b".to_string()), |
| vec![mk_ident("a"), token::ModSep, token::Whitespace, mk_ident("b")]); |
| }) |
| } |
| |
| #[test] |
| fn character_a() { |
| with_default_globals(|| { |
| let sm = Lrc::new(SourceMap::new(FilePathMapping::empty())); |
| let sh = mk_sess(sm.clone()); |
| assert_eq!(setup(&sm, &sh, "'a'".to_string()).next_token(), |
| mk_lit(token::Char, "a", None)); |
| }) |
| } |
| |
| #[test] |
| fn character_space() { |
| with_default_globals(|| { |
| let sm = Lrc::new(SourceMap::new(FilePathMapping::empty())); |
| let sh = mk_sess(sm.clone()); |
| assert_eq!(setup(&sm, &sh, "' '".to_string()).next_token(), |
| mk_lit(token::Char, " ", None)); |
| }) |
| } |
| |
| #[test] |
| fn character_escaped() { |
| with_default_globals(|| { |
| let sm = Lrc::new(SourceMap::new(FilePathMapping::empty())); |
| let sh = mk_sess(sm.clone()); |
| assert_eq!(setup(&sm, &sh, "'\\n'".to_string()).next_token(), |
| mk_lit(token::Char, "\\n", None)); |
| }) |
| } |
| |
| #[test] |
| fn lifetime_name() { |
| with_default_globals(|| { |
| let sm = Lrc::new(SourceMap::new(FilePathMapping::empty())); |
| let sh = mk_sess(sm.clone()); |
| assert_eq!(setup(&sm, &sh, "'abc".to_string()).next_token(), |
| token::Lifetime(Symbol::intern("'abc"))); |
| }) |
| } |
| |
| #[test] |
| fn raw_string() { |
| with_default_globals(|| { |
| let sm = Lrc::new(SourceMap::new(FilePathMapping::empty())); |
| let sh = mk_sess(sm.clone()); |
| assert_eq!(setup(&sm, &sh, "r###\"\"#a\\b\x00c\"\"###".to_string()).next_token(), |
| mk_lit(token::StrRaw(3), "\"#a\\b\x00c\"", None)); |
| }) |
| } |
| |
| #[test] |
| fn literal_suffixes() { |
| with_default_globals(|| { |
| let sm = Lrc::new(SourceMap::new(FilePathMapping::empty())); |
| let sh = mk_sess(sm.clone()); |
| macro_rules! test { |
| ($input: expr, $tok_type: ident, $tok_contents: expr) => {{ |
| assert_eq!(setup(&sm, &sh, format!("{}suffix", $input)).next_token(), |
| mk_lit(token::$tok_type, $tok_contents, Some("suffix"))); |
| // with a whitespace separator: |
| assert_eq!(setup(&sm, &sh, format!("{} suffix", $input)).next_token(), |
| mk_lit(token::$tok_type, $tok_contents, None)); |
| }} |
| } |
| |
| test!("'a'", Char, "a"); |
| test!("b'a'", Byte, "a"); |
| test!("\"a\"", Str, "a"); |
| test!("b\"a\"", ByteStr, "a"); |
| test!("1234", Integer, "1234"); |
| test!("0b101", Integer, "0b101"); |
| test!("0xABC", Integer, "0xABC"); |
| test!("1.0", Float, "1.0"); |
| test!("1.0e10", Float, "1.0e10"); |
| |
| assert_eq!(setup(&sm, &sh, "2us".to_string()).next_token(), |
| mk_lit(token::Integer, "2", Some("us"))); |
| assert_eq!(setup(&sm, &sh, "r###\"raw\"###suffix".to_string()).next_token(), |
| mk_lit(token::StrRaw(3), "raw", Some("suffix"))); |
| assert_eq!(setup(&sm, &sh, "br###\"raw\"###suffix".to_string()).next_token(), |
| mk_lit(token::ByteStrRaw(3), "raw", Some("suffix"))); |
| }) |
| } |
| |
| #[test] |
| fn line_doc_comments() { |
| assert!(is_doc_comment("///")); |
| assert!(is_doc_comment("/// blah")); |
| assert!(!is_doc_comment("////")); |
| } |
| |
| #[test] |
| fn nested_block_comments() { |
| with_default_globals(|| { |
| let sm = Lrc::new(SourceMap::new(FilePathMapping::empty())); |
| let sh = mk_sess(sm.clone()); |
| let mut lexer = setup(&sm, &sh, "/* /* */ */'a'".to_string()); |
| assert_eq!(lexer.next_token(), token::Comment); |
| assert_eq!(lexer.next_token(), mk_lit(token::Char, "a", None)); |
| }) |
| } |
| |
| #[test] |
| fn crlf_comments() { |
| with_default_globals(|| { |
| let sm = Lrc::new(SourceMap::new(FilePathMapping::empty())); |
| let sh = mk_sess(sm.clone()); |
| let mut lexer = setup(&sm, &sh, "// test\r\n/// test\r\n".to_string()); |
| let comment = lexer.next_token(); |
| assert_eq!(comment.kind, token::Comment); |
| assert_eq!((comment.span.lo(), comment.span.hi()), (BytePos(0), BytePos(7))); |
| assert_eq!(lexer.next_token(), token::Whitespace); |
| assert_eq!(lexer.next_token(), token::DocComment(Symbol::intern("/// test"))); |
| }) |
| } |
| } |
