use crate::ast::{self, Ident}; use crate::source_map::{SourceMap, FilePathMapping}; use crate::parse::{token, ParseSess}; use crate::symbol::{Symbol, keywords}; use errors::{Applicability, FatalError, Diagnostic, DiagnosticBuilder}; use syntax_pos::{BytePos, CharPos, Pos, Span, NO_EXPANSION}; use core::unicode::property::Pattern_White_Space; use std::borrow::Cow; use std::char; use std::iter; use std::mem::replace; use rustc_data_structures::sync::Lrc; use log::debug; pub mod comments; mod tokentrees; mod unicode_chars; #[derive(Clone, Debug)] pub struct TokenAndSpan { pub tok: token::Token, pub sp: Span, } impl Default for TokenAndSpan { fn default() -> Self { TokenAndSpan { tok: token::Whitespace, sp: syntax_pos::DUMMY_SP, } } } #[derive(Clone, Debug)] pub struct UnmatchedBrace { pub expected_delim: token::DelimToken, pub found_delim: token::DelimToken, pub found_span: Span, pub unclosed_span: Option, pub candidate_span: Option, } pub struct StringReader<'a> { pub sess: &'a ParseSess, /// The absolute offset within the source_map of the next character to read pub next_pos: BytePos, /// The absolute offset within the source_map of the current character pub pos: BytePos, /// The current character (which has been read from self.pos) pub ch: Option, pub source_file: Lrc, /// Stop reading src at this index. pub end_src_index: usize, // cached: peek_tok: token::Token, peek_span: Span, peek_span_src_raw: Span, fatal_errs: Vec>, // 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, token: token::Token, span: Span, /// The raw source span which *does not* take `override_span` into account span_src_raw: Span, /// Stack of open delimiters and their spans. Used for error message. open_braces: Vec<(token::DelimToken, Span)>, crate unmatched_braces: Vec, /// The type and spans for all braces /// /// Used only for error recovery when arriving to EOF with mismatched braces. matching_delim_spans: Vec<(token::DelimToken, Span, Span)>, crate override_span: Option, last_unclosed_found_span: Option, } 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 mk_ident(&self, string: &str) -> Ident { let mut ident = Ident::from_str(string); if let Some(span) = self.override_span { ident.span = span; } ident } fn unwrap_or_abort(&mut self, res: Result) -> TokenAndSpan { match res { Ok(tok) => tok, Err(_) => { self.emit_fatal_errors(); FatalError.raise(); } } } fn next_token(&mut self) -> TokenAndSpan 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 { assert!(self.fatal_errs.is_empty()); let ret_val = TokenAndSpan { tok: replace(&mut self.peek_tok, token::Whitespace), sp: self.peek_span, }; self.advance_token()?; self.span_src_raw = self.peek_span_src_raw; Ok(ret_val) } /// Immutably extract string if found at current position with given delimiters pub fn peek_delimited(&self, from_ch: char, to_ch: char) -> Option { 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 { let mut t = self.try_next_token()?; loop { match t.tok { token::Whitespace | token::Comment | token::Shebang(_) => { t = self.try_next_token()?; } _ => break, } } self.token = t.tok.clone(); self.span = t.sp; Ok(t) } pub fn real_token(&mut self) -> TokenAndSpan { 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_span, m) } pub 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 { let mut buffer = Vec::new(); for err in self.fatal_errs.drain(..) { err.buffer(&mut buffer); } buffer } pub fn peek(&self) -> TokenAndSpan { // FIXME(pcwalton): Bad copy! TokenAndSpan { tok: self.peek_tok.clone(), sp: self.peek_span, } } /// For comments.rs, which hackily pokes into next_pos and ch fn new_raw(sess: &'a ParseSess, source_file: Lrc, override_span: Option) -> 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, override_span: Option) -> 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(), // dummy values; not read peek_tok: token::Eof, peek_span: syntax_pos::DUMMY_SP, peek_span_src_raw: syntax_pos::DUMMY_SP, src, fatal_errs: Vec::new(), token: token::Eof, span: syntax_pos::DUMMY_SP, span_src_raw: syntax_pos::DUMMY_SP, open_braces: Vec::new(), unmatched_braces: Vec::new(), matching_delim_spans: Vec::new(), override_span, last_unclosed_found_span: None, } } pub fn new(sess: &'a ParseSess, source_file: Lrc, override_span: Option) -> Self { let mut sr = StringReader::new_raw(sess, source_file, override_span); if sr.advance_token().is_err() { sr.emit_fatal_errors(); FatalError.raise(); } sr } pub fn new_or_buffered_errs(sess: &'a ParseSess, source_file: Lrc, override_span: Option) -> Result> { 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) } /// Pushes a character to a message string for error reporting fn push_escaped_char_for_msg(m: &mut String, c: char) { match c { '\u{20}'..='\u{7e}' => { // Don't escape \, ' or " for user-facing messages m.push(c); } _ => { m.extend(c.escape_default()); } } } /// 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(": "); Self::push_escaped_char_for_msg(&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(": "); Self::push_escaped_char_for_msg(&mut m, c); self.sess.span_diagnostic.struct_span_fatal(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 err_span_char(&self, from_pos: BytePos, to_pos: BytePos, m: &str, c: char) { let mut m = m.to_string(); m.push_str(": "); Self::push_escaped_char_for_msg(&mut m, c); self.err_span_(from_pos, to_pos, &m[..]); } fn struct_err_span_char(&self, from_pos: BytePos, to_pos: BytePos, m: &str, c: char) -> DiagnosticBuilder<'a> { let mut m = m.to_string(); m.push_str(": "); Self::push_escaped_char_for_msg(&mut m, c); self.sess.span_diagnostic.struct_span_err(self.mk_sp(from_pos, to_pos), &m[..]) } /// Report a lexical error spanning [`from_pos`, `to_pos`), appending the /// offending string to the error message fn fatal_span_verbose(&self, from_pos: BytePos, to_pos: BytePos, mut m: String) -> FatalError { m.push_str(": "); m.push_str(&self.src[self.src_index(from_pos)..self.src_index(to_pos)]); self.fatal_span_(from_pos, to_pos, &m[..]) } /// Advance peek_tok and peek_span 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.sp; self.peek_span = comment.sp; self.peek_tok = comment.tok; } None => { if self.is_eof() { self.peek_tok = token::Eof; let (real, raw) = self.mk_sp_and_raw( self.source_file.end_pos, self.source_file.end_pos, ); self.peek_span = real; self.peek_span_src_raw = raw; } else { let start_bytepos = self.pos; self.peek_tok = self.next_token_inner()?; let (real, raw) = self.mk_sp_and_raw(start_bytepos, self.pos); self.peek_span = real; self.peek_span_src_raw = raw; }; } } Ok(()) } #[inline] fn src_index(&self, pos: BytePos) -> usize { (pos - self.source_file.start_pos).to_usize() } /// Calls `f` with a string slice of the source text spanning from `start` /// up to but excluding `self.pos`, meaning the slice does not include /// the character `self.ch`. fn with_str_from(&self, start: BytePos, f: F) -> T where F: FnOnce(&str) -> T { self.with_str_from_to(start, self.pos, f) } /// Creates a Name from a given offset to the current offset, each /// adjusted 1 towards each other (assumes that on either side there is a /// single-byte delimiter). fn name_from(&self, start: BytePos) -> ast::Name { debug!("taking an ident from {:?} to {:?}", start, self.pos); self.with_str_from(start, Symbol::intern) } /// As name_from, with an explicit endpoint. fn name_from_to(&self, start: BytePos, end: BytePos) -> ast::Name { debug!("taking an ident from {:?} to {:?}", start, end); self.with_str_from_to(start, end, Symbol::intern) } /// Calls `f` with a string slice of the source text spanning from `start` /// up to but excluding `end`. fn with_str_from_to(&self, start: BytePos, end: BytePos, f: F) -> T where F: FnOnce(&str) -> T { f(&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>, 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 { 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 { 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 *, if possible. fn scan_optional_raw_name(&mut self) -> Option { if !ident_start(self.ch) { return None; } let start = self.pos; self.bump(); while ident_continue(self.ch) { self.bump(); } self.with_str_from(start, |string| { if string == "_" { 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 \ ") .emit(); None } else { Some(Symbol::intern(string)) } }) } /// PRECONDITION: self.ch is not whitespace /// Eats any kind of comment. fn scan_comment(&mut self) -> Option { 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(); } if doc_comment { self.with_str_from(start_bpos, |string| { // comments with only more "/"s are not doc comments let tok = if is_doc_comment(string) { token::DocComment(Symbol::intern(string)) } else { token::Comment }; Some(TokenAndSpan { tok, sp: self.mk_sp(start_bpos, self.pos), }) }) } else { Some(TokenAndSpan { tok: token::Comment, sp: 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; } // I guess this is the only way to figure out if // we're at the beginning of the file... let smap = SourceMap::new(FilePathMapping::empty()); smap.files.borrow_mut().source_files.push(self.source_file.clone()); let loc = smap.lookup_char_pos_adj(self.pos); debug!("Skipping a shebang"); if loc.line == 1 && loc.col == CharPos(0) { // FIXME: Add shebang "token", return it let start = self.pos; while !self.ch_is('\n') && !self.is_eof() { self.bump(); } return Some(TokenAndSpan { tok: token::Shebang(self.name_from(start)), sp: 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 { 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(TokenAndSpan { tok: token::Whitespace, sp: 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 { // 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(); } self.with_str_from(start_bpos, |string| { // but comments with only "*"s between two "/"s are not let tok = 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(TokenAndSpan { tok, sp: 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::Lit { 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(self.name_from(start_bpos)); } } } 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.name_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.name_from(start_bpos)); } // but we certainly have an integer! token::Integer(self.name_from(start_bpos)) } } /// Scan over `n_digits` hex digits, stopping at `delim`, reporting an /// error if too many or too few digits are encountered. fn scan_hex_digits(&mut self, n_digits: usize, delim: char, below_0x7f_only: bool) -> bool { debug!("scanning {} digits until {:?}", n_digits, delim); let start_bpos = self.pos; let mut accum_int = 0; let mut valid = true; for _ in 0..n_digits { if self.is_eof() { let last_bpos = self.pos; self.fatal_span_(start_bpos, last_bpos, "unterminated numeric character escape").raise(); } if self.ch_is(delim) { let last_bpos = self.pos; self.err_span_(start_bpos, last_bpos, "numeric character escape is too short"); valid = false; break; } let c = self.ch.unwrap_or('\x00'); accum_int *= 16; accum_int += c.to_digit(16).unwrap_or_else(|| { self.err_span_char(self.pos, self.next_pos, "invalid character in numeric character escape", c); valid = false; 0 }); self.bump(); } if below_0x7f_only && accum_int >= 0x80 { self.err_span_(start_bpos, self.pos, "this form of character escape may only be used with characters in \ the range [\\x00-\\x7f]"); valid = false; } match char::from_u32(accum_int) { Some(_) => valid, None => { let last_bpos = self.pos; self.err_span_(start_bpos, last_bpos, "invalid numeric character escape"); false } } } /// Scan for a single (possibly escaped) byte or char /// in a byte, (non-raw) byte string, char, or (non-raw) string literal. /// `start` is the position of `first_source_char`, which is already consumed. /// /// Returns `true` if there was a valid char/byte. fn scan_char_or_byte(&mut self, start: BytePos, first_source_char: char, ascii_only: bool, delim: char) -> bool { match first_source_char { '\\' => { // '\X' for some X must be a character constant: let escaped = self.ch; let escaped_pos = self.pos; self.bump(); match escaped { None => {} // EOF here is an error that will be checked later. Some(e) => { return match e { 'n' | 'r' | 't' | '\\' | '\'' | '"' | '0' => true, 'x' => self.scan_byte_escape(delim, !ascii_only), 'u' => { let valid = if self.ch_is('{') { self.scan_unicode_escape(delim) && !ascii_only } else { let span = self.mk_sp(start, self.pos); let mut suggestion = "\\u{".to_owned(); let mut err = self.sess.span_diagnostic.struct_span_err( span, "incorrect unicode escape sequence", ); let mut i = 0; while let (Some(ch), true) = (self.ch, i < 6) { if ch.is_digit(16) { suggestion.push(ch); self.bump(); i += 1; } else { break; } } if i != 0 { suggestion.push('}'); err.span_suggestion( self.mk_sp(start, self.pos), "format of unicode escape sequences uses braces", suggestion, Applicability::MaybeIncorrect, ); } else { err.span_help( span, "format of unicode escape sequences is `\\u{...}`", ); } err.emit(); false }; if ascii_only { self.err_span_(start, self.pos, "unicode escape sequences cannot be used as a \ byte or in a byte string"); } valid } '\n' if delim == '"' => { self.consume_whitespace(); true } '\r' if delim == '"' && self.ch_is('\n') => { self.consume_whitespace(); true } c => { let pos = self.pos; let mut err = self.struct_err_span_char(escaped_pos, pos, if ascii_only { "unknown byte escape" } else { "unknown character \ escape" }, c); if e == '\r' { err.span_help(self.mk_sp(escaped_pos, pos), "this is an isolated carriage return; consider \ checking your editor and version control \ settings"); } if (e == '{' || e == '}') && !ascii_only { err.span_help(self.mk_sp(escaped_pos, pos), "if used in a formatting string, curly braces \ are escaped with `{{` and `}}`"); } err.emit(); false } } } } } '\t' | '\n' | '\r' | '\'' if delim == '\'' => { let pos = self.pos; self.err_span_char(start, pos, if ascii_only { "byte constant must be escaped" } else { "character constant must be escaped" }, first_source_char); return false; } '\r' => { if self.ch_is('\n') { self.bump(); return true; } else { self.err_span_(start, self.pos, "bare CR not allowed in string, use \\r instead"); return false; } } _ => { if ascii_only && first_source_char > '\x7F' { let pos = self.pos; self.err_span_(start, pos, "byte constant must be ASCII. Use a \\xHH escape for a \ non-ASCII byte"); return false; } } } true } /// Scan over a `\u{...}` escape /// /// At this point, we have already seen the `\` and the `u`, the `{` is the current character. /// We will read a hex number (with `_` separators), with 1 to 6 actual digits, /// and pass over the `}`. fn scan_unicode_escape(&mut self, delim: char) -> bool { self.bump(); // past the { let start_bpos = self.pos; let mut valid = true; if let Some('_') = self.ch { // disallow leading `_` self.err_span_(self.pos, self.next_pos, "invalid start of unicode escape"); valid = false; } let count = self.scan_digits(16, 16); if count > 6 { self.err_span_(start_bpos, self.pos, "overlong unicode escape (must have at most 6 hex digits)"); valid = false; } loop { match self.ch { Some('}') => { if valid && count == 0 { self.err_span_(start_bpos, self.pos, "empty unicode escape (must have at least 1 hex digit)"); valid = false; } self.bump(); // past the ending `}` break; }, Some(c) => { if c == delim { self.err_span_(self.pos, self.pos, "unterminated unicode escape (needed a `}`)"); valid = false; break; } else if valid { self.err_span_char(start_bpos, self.pos, "invalid character in unicode escape", c); valid = false; } }, None => { self.fatal_span_(start_bpos, self.pos, "unterminated unicode escape (found EOF)").raise(); } } self.bump(); } valid } /// 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) -> token::Token { 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 { 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(); } return Ok(self.with_str_from(start, |string| { // FIXME: perform NFKC normalization here. (Issue #2253) let ident = self.mk_ident(string); if is_raw_ident && (ident.is_path_segment_keyword() || ident.name == keywords::Underscore.name()) { self.fatal_span_(raw_start, self.pos, &format!("`r#{}` is not currently supported.", ident.name) ).raise(); } if is_raw_ident { let span = self.mk_sp(raw_start, self.pos); self.sess.raw_identifier_spans.borrow_mut().push(span); } token::Ident(ident, is_raw_ident) })); } } if is_dec_digit(c) { let num = self.scan_number(c.unwrap()); let suffix = self.scan_optional_raw_name(); debug!("next_token_inner: scanned number {:?}, {:?}", num, suffix); return Ok(token::Literal(num, 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; // the eof will be picked up by the final `'` check below let c2 = self.ch.unwrap_or('\x00'); self.bump(); // If the character is an ident start not followed by another single // quote, then this is a lifetime name: if ident_start(Some(c2)) && !self.ch_is('\'') { 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('\'') { self.err_span_(start_with_quote, self.next_pos, "character literal may only contain one codepoint"); self.bump(); return Ok(token::Literal(token::Err(Symbol::intern("??")), None)) } // Include the leading `'` in the real identifier, for macro // expansion purposes. See #12512 for the gory details of why // this is necessary. let ident = self.with_str_from(start, |lifetime_name| { self.mk_ident(&format!("'{}", lifetime_name)) }); return Ok(token::Lifetime(ident)); } let valid = self.scan_char_or_byte(start, c2, /* ascii_only */ false, '\''); if !self.ch_is('\'') { let pos = self.pos; loop { self.bump(); if self.ch_is('\'') { let start = self.src_index(start); let end = self.src_index(self.pos); self.bump(); let span = self.mk_sp(start_with_quote, self.pos); self.sess.span_diagnostic .struct_span_err(span, "character literal may only contain one codepoint") .span_suggestion( span, "if you meant to write a `str` literal, use double quotes", format!("\"{}\"", &self.src[start..end]), Applicability::MachineApplicable ).emit(); return Ok(token::Literal(token::Err(Symbol::intern("??")), None)) } if self.ch_is('\n') || self.is_eof() || self.ch_is('/') { // Only attempt to infer single line string literals. If we encounter // a slash, bail out in order to avoid nonsensical suggestion when // involving comments. break; } } self.fatal_span_verbose(start_with_quote, pos, String::from("character literal may only contain one codepoint")).raise(); } let id = if valid { self.name_from(start) } else { Symbol::intern("0") }; self.bump(); // advance ch past token let suffix = self.scan_optional_raw_name(); Ok(token::Literal(token::Char(id), suffix)) } 'b' => { self.bump(); let lit = match self.ch { Some('\'') => self.scan_byte(), Some('"') => self.scan_byte_string(), Some('r') => self.scan_raw_byte_string(), _ => unreachable!(), // Should have been a token::Ident above. }; let suffix = self.scan_optional_raw_name(); Ok(token::Literal(lit, suffix)) } '"' => { let start_bpos = self.pos; let mut valid = true; self.bump(); while !self.ch_is('"') { if self.is_eof() { let last_bpos = self.pos; self.fatal_span_(start_bpos, last_bpos, "unterminated double quote string").raise(); } let ch_start = self.pos; let ch = self.ch.unwrap(); self.bump(); valid &= self.scan_char_or_byte(ch_start, ch, /* ascii_only */ false, '"'); } // adjust for the ASCII " at the start of the literal let id = if valid { self.name_from(start_bpos + BytePos(1)) } else { Symbol::intern("??") }; self.bump(); let suffix = self.scan_optional_raw_name(); Ok(token::Literal(token::Str_(id), suffix)) } 'r' => { 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; let mut valid = true; 'outer: loop { if self.is_eof() { self.fail_unterminated_raw_string(start_bpos, hash_count); } // if self.ch_is('"') { // content_end_bpos = self.pos; // for _ in 0..hash_count { // self.bump(); // if !self.ch_is('#') { // continue 'outer; let c = self.ch.unwrap(); match c { '"' => { content_end_bpos = self.pos; for _ in 0..hash_count { self.bump(); if !self.ch_is('#') { continue 'outer; } } break; } '\r' => { if !self.nextch_is('\n') { let last_bpos = self.pos; self.err_span_(start_bpos, last_bpos, "bare CR not allowed in raw string, use \\r \ instead"); valid = false; } } _ => (), } self.bump(); } self.bump(); let id = if valid { self.name_from_to(content_start_bpos, content_end_bpos) } else { Symbol::intern("??") }; let suffix = self.scan_optional_raw_name(); Ok(token::Literal(token::StrRaw(id, hash_count), 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 consume_whitespace(&mut self) { while is_pattern_whitespace(self.ch) && !self.is_eof() { self.bump(); } } 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_byte(&mut self) -> token::Lit { self.bump(); let start = self.pos; // the eof will be picked up by the final `'` check below let c2 = self.ch.unwrap_or('\x00'); self.bump(); let valid = self.scan_char_or_byte(start, c2, // ascii_only = true, '\''); if !self.ch_is('\'') { // Byte offsetting here is okay because the // character before position `start` are an // ascii single quote and ascii 'b'. let pos = self.pos; self.fatal_span_verbose(start - BytePos(2), pos, "unterminated byte constant".to_string()).raise(); } let id = if valid { self.name_from(start) } else { Symbol::intern("?") }; self.bump(); // advance ch past token token::Byte(id) } #[inline] fn scan_byte_escape(&mut self, delim: char, below_0x7f_only: bool) -> bool { self.scan_hex_digits(2, delim, below_0x7f_only) } fn scan_byte_string(&mut self) -> token::Lit { self.bump(); let start = self.pos; let mut valid = true; while !self.ch_is('"') { if self.is_eof() { let pos = self.pos; self.fatal_span_(start, pos, "unterminated double quote byte string").raise(); } let ch_start = self.pos; let ch = self.ch.unwrap(); self.bump(); valid &= self.scan_char_or_byte(ch_start, ch, // ascii_only = true, '"'); } let id = if valid { self.name_from(start) } else { Symbol::intern("??") }; self.bump(); token::ByteStr(id) } fn scan_raw_byte_string(&mut self) -> token::Lit { let start_bpos = self.pos; self.bump(); let mut hash_count = 0; while self.ch_is('#') { if hash_count == 65535 { let bpos = self.next_pos; self.fatal_span_(start_bpos, bpos, "too many `#` symbols: raw byte 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 pos = self.pos; let ch = self.ch.unwrap(); self.fatal_span_char(start_bpos, pos, "found invalid character; only `#` is allowed in raw \ string delimitation", ch).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; } Some(c) => { if c > '\x7F' { let pos = self.pos; self.err_span_char(pos, pos, "raw byte string must be ASCII", c); } } } self.bump(); } self.bump(); token::ByteStrRaw(self.name_from_to(content_start_bpos, content_end_bpos), hash_count) } } // 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) -> bool { c.map_or(false, Pattern_White_Space) } #[inline] fn in_range(c: Option, lo: char, hi: char) -> bool { c.map_or(false, |c| lo <= c && c <= hi) } #[inline] fn is_dec_digit(c: Option) -> 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 } fn ident_start(c: Option) -> 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) -> 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::{Ident, CrateConfig}; use crate::symbol::Symbol; use crate::source_map::SourceMap; use crate::feature_gate::UnstableFeatures; use crate::parse::token; use crate::diagnostics::plugin::ErrorMap; use crate::with_globals; use std::io; use std::path::PathBuf; use syntax_pos::{BytePos, Span, NO_EXPANSION}; use rustc_data_structures::fx::FxHashSet; use rustc_data_structures::sync::Lock; fn mk_sess(sm: Lrc) -> ParseSess { let emitter = errors::emitter::EmitterWriter::new(Box::new(io::sink()), Some(sm.clone()), false, false); ParseSess { span_diagnostic: errors::Handler::with_emitter(true, false, 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![]), } } // 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); StringReader::new(sess, sf, None) } #[test] fn t1() { with_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()); let id = Ident::from_str("fn"); assert_eq!(string_reader.next_token().tok, token::Comment); assert_eq!(string_reader.next_token().tok, token::Whitespace); let tok1 = string_reader.next_token(); let tok2 = TokenAndSpan { tok: token::Ident(id, false), sp: Span::new(BytePos(21), BytePos(23), NO_EXPANSION), }; assert_eq!(tok1.tok, tok2.tok); assert_eq!(tok1.sp, tok2.sp); assert_eq!(string_reader.next_token().tok, 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 = TokenAndSpan { tok: mk_ident("main"), sp: Span::new(BytePos(24), BytePos(28), NO_EXPANSION), }; assert_eq!(tok3.tok, tok4.tok); assert_eq!(tok3.sp, tok4.sp); // 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) { for expected_tok in &expected { assert_eq!(&string_reader.next_token().tok, expected_tok); } } // make the identifier by looking up the string in the interner fn mk_ident(id: &str) -> token::Token { token::Token::from_ast_ident(Ident::from_str(id)) } #[test] fn doublecolonparsing() { with_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_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_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_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_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().tok, token::Literal(token::Char(Symbol::intern("a")), None)); }) } #[test] fn character_space() { with_globals(|| { let sm = Lrc::new(SourceMap::new(FilePathMapping::empty())); let sh = mk_sess(sm.clone()); assert_eq!(setup(&sm, &sh, "' '".to_string()).next_token().tok, token::Literal(token::Char(Symbol::intern(" ")), None)); }) } #[test] fn character_escaped() { with_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().tok, token::Literal(token::Char(Symbol::intern("\\n")), None)); }) } #[test] fn lifetime_name() { with_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().tok, token::Lifetime(Ident::from_str("'abc"))); }) } #[test] fn raw_string() { with_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() .tok, token::Literal(token::StrRaw(Symbol::intern("\"#a\\b\x00c\""), 3), None)); }) } #[test] fn literal_suffixes() { with_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", $input)).next_token().tok, token::Literal(token::$tok_type(Symbol::intern($tok_contents)), Some(Symbol::intern("suffix")))); // with a whitespace separator: assert_eq!(setup(&sm, &sh, format!("{} suffix", $input)).next_token().tok, token::Literal(token::$tok_type(Symbol::intern($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().tok, token::Literal(token::Integer(Symbol::intern("2")), Some(Symbol::intern("us")))); assert_eq!(setup(&sm, &sh, "r###\"raw\"###suffix".to_string()).next_token().tok, token::Literal(token::StrRaw(Symbol::intern("raw"), 3), Some(Symbol::intern("suffix")))); assert_eq!(setup(&sm, &sh, "br###\"raw\"###suffix".to_string()).next_token().tok, token::Literal(token::ByteStrRaw(Symbol::intern("raw"), 3), Some(Symbol::intern("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_globals(|| { let sm = Lrc::new(SourceMap::new(FilePathMapping::empty())); let sh = mk_sess(sm.clone()); let mut lexer = setup(&sm, &sh, "/* /* */ */'a'".to_string()); match lexer.next_token().tok { token::Comment => {} _ => panic!("expected a comment!"), } assert_eq!(lexer.next_token().tok, token::Literal(token::Char(Symbol::intern("a")), None)); }) } #[test] fn crlf_comments() { with_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.tok, token::Comment); assert_eq!((comment.sp.lo(), comment.sp.hi()), (BytePos(0), BytePos(7))); assert_eq!(lexer.next_token().tok, token::Whitespace); assert_eq!(lexer.next_token().tok, token::DocComment(Symbol::intern("/// test"))); }) } }