diff --git a/src/libsyntax/parse/lexer/comments.rs b/src/libsyntax/parse/lexer/comments.rs index 63aa5d28ce8dc..672b0b9bbd16d 100644 --- a/src/libsyntax/parse/lexer/comments.rs +++ b/src/libsyntax/parse/lexer/comments.rs @@ -238,7 +238,19 @@ fn read_block_comment(rdr: &mut StringReader, debug!(">>> block comment"); let p = rdr.pos; let mut lines: Vec = Vec::new(); - let col = rdr.col; + + // Count the number of chars since the start of the line by rescanning. + let mut src_index = rdr.src_index(rdr.filemap.line_begin_pos()); + let end_src_index = rdr.src_index(rdr.pos); + assert!(src_index <= end_src_index); + let mut n = 0; + while src_index < end_src_index { + let c = char_at(&rdr.src, src_index); + src_index += c.len_utf8(); + n += 1; + } + let col = CharPos(n); + rdr.bump(); rdr.bump(); diff --git a/src/libsyntax/parse/lexer/mod.rs b/src/libsyntax/parse/lexer/mod.rs index 22a0261d8c6b1..566e0c213b119 100644 --- a/src/libsyntax/parse/lexer/mod.rs +++ b/src/libsyntax/parse/lexer/mod.rs @@ -44,13 +44,11 @@ pub struct StringReader<'a> { pub next_pos: BytePos, /// The absolute offset within the codemap of the current character pub pos: BytePos, - /// The column of the next character to read - pub col: CharPos, /// The current character (which has been read from self.pos) pub ch: Option, pub filemap: Lrc, - /// If Some, stop reading the source at this position (inclusive). - pub terminator: Option, + /// Stop reading src at this index. + pub end_src_index: usize, /// Whether to record new-lines and multibyte chars in filemap. /// This is only necessary the first time a filemap is lexed. /// If part of a filemap is being re-lexed, this should be set to false. @@ -61,7 +59,7 @@ pub struct StringReader<'a> { pub fatal_errs: Vec>, // cache a direct reference to the source text, so that we don't have to // retrieve it via `self.filemap.src.as_ref().unwrap()` all the time. - source_text: Lrc, + src: Lrc, /// Stack of open delimiters and their spans. Used for error message. token: token::Token, span: Span, @@ -113,14 +111,7 @@ impl<'a> StringReader<'a> { self.unwrap_or_abort(res) } fn is_eof(&self) -> bool { - if self.ch.is_none() { - return true; - } - - match self.terminator { - Some(t) => self.next_pos > t, - None => false, - } + self.ch.is_none() } /// Return the next token. EFFECT: advances the string_reader. pub fn try_next_token(&mut self) -> Result { @@ -176,21 +167,20 @@ impl<'a> StringReader<'a> { filemap.name)); } - let source_text = (*filemap.src.as_ref().unwrap()).clone(); + let src = (*filemap.src.as_ref().unwrap()).clone(); StringReader { sess, next_pos: filemap.start_pos, pos: filemap.start_pos, - col: CharPos(0), ch: Some('\n'), filemap, - terminator: None, + end_src_index: src.len(), save_new_lines_and_multibyte: true, // dummy values; not read peek_tok: token::Eof, peek_span: syntax_pos::DUMMY_SP, - source_text, + src, fatal_errs: Vec::new(), token: token::Eof, span: syntax_pos::DUMMY_SP, @@ -222,7 +212,7 @@ impl<'a> StringReader<'a> { // Seek the lexer to the right byte range. sr.save_new_lines_and_multibyte = false; sr.next_pos = span.lo(); - sr.terminator = Some(span.hi()); + sr.end_src_index = sr.src_index(span.hi()); sr.bump(); @@ -326,9 +316,7 @@ impl<'a> StringReader<'a> { /// offending string to the error message fn fatal_span_verbose(&self, from_pos: BytePos, to_pos: BytePos, mut m: String) -> FatalError { m.push_str(": "); - let from = self.byte_offset(from_pos).to_usize(); - let to = self.byte_offset(to_pos).to_usize(); - m.push_str(&self.source_text[from..to]); + m.push_str(&self.src[self.src_index(from_pos)..self.src_index(to_pos)]); self.fatal_span_(from_pos, to_pos, &m[..]) } @@ -354,8 +342,9 @@ impl<'a> StringReader<'a> { Ok(()) } - fn byte_offset(&self, pos: BytePos) -> BytePos { - (pos - self.filemap.start_pos) + #[inline] + fn src_index(&self, pos: BytePos) -> usize { + (pos - self.filemap.start_pos).to_usize() } /// Calls `f` with a string slice of the source text spanning from `start` @@ -386,7 +375,7 @@ impl<'a> StringReader<'a> { fn with_str_from_to(&self, start: BytePos, end: BytePos, f: F) -> T where F: FnOnce(&str) -> T { - f(&self.source_text[self.byte_offset(start).to_usize()..self.byte_offset(end).to_usize()]) + 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. @@ -438,47 +427,39 @@ impl<'a> StringReader<'a> { } } - /// Advance the StringReader by one character. If a newline is /// discovered, add it to the FileMap's list of line start offsets. pub fn bump(&mut self) { - let new_pos = self.next_pos; - let new_byte_offset = self.byte_offset(new_pos).to_usize(); - let end = self.terminator.map_or(self.source_text.len(), |t| { - self.byte_offset(t).to_usize() - }); - if new_byte_offset < end { - let old_ch_is_newline = self.ch.unwrap() == '\n'; - let new_ch = char_at(&self.source_text, new_byte_offset); - let new_ch_len = new_ch.len_utf8(); - - self.ch = Some(new_ch); - self.pos = new_pos; - self.next_pos = new_pos + Pos::from_usize(new_ch_len); - if old_ch_is_newline { + 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(); + + if self.ch.unwrap() == '\n' { if self.save_new_lines_and_multibyte { - self.filemap.next_line(self.pos); + self.filemap.next_line(self.next_pos); } - self.col = CharPos(0); - } else { - self.col = self.col + CharPos(1); } - if new_ch_len > 1 { + if next_ch_len > 1 { if self.save_new_lines_and_multibyte { - self.filemap.record_multibyte_char(self.pos, new_ch_len); + self.filemap.record_multibyte_char(self.next_pos, next_ch_len); } } - self.filemap.record_width(self.pos, new_ch); + self.filemap.record_width(self.next_pos, next_ch); + + 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 = new_pos; + self.pos = self.next_pos; } } pub fn nextch(&self) -> Option { - let offset = self.byte_offset(self.next_pos).to_usize(); - if offset < self.source_text.len() { - Some(char_at(&self.source_text, offset)) + 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 } @@ -489,17 +470,15 @@ impl<'a> StringReader<'a> { } pub fn nextnextch(&self) -> Option { - let offset = self.byte_offset(self.next_pos).to_usize(); - let s = &self.source_text[..]; - if offset >= s.len() { - return None; - } - let next = offset + char_at(s, offset).len_utf8(); - if next < s.len() { - Some(char_at(s, next)) - } else { - None + 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 } pub fn nextnextch_is(&self, c: char) -> bool { @@ -1359,8 +1338,8 @@ impl<'a> StringReader<'a> { loop { self.bump(); if self.ch_is('\'') { - let start = self.byte_offset(start).to_usize(); - let end = self.byte_offset(self.pos).to_usize(); + 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 @@ -1369,8 +1348,7 @@ impl<'a> StringReader<'a> { .span_suggestion(span, "if you meant to write a `str` literal, \ use double quotes", - format!("\"{}\"", - &self.source_text[start..end])) + format!("\"{}\"", &self.src[start..end])) .emit(); return Ok(token::Literal(token::Str_(Symbol::intern("??")), None)) } diff --git a/src/libsyntax/str.rs b/src/libsyntax/str.rs index d0f47629b10e5..281861918fd8e 100644 --- a/src/libsyntax/str.rs +++ b/src/libsyntax/str.rs @@ -8,6 +8,7 @@ // option. This file may not be copied, modified, or distributed // except according to those terms. +#[inline] pub fn char_at(s: &str, byte: usize) -> char { s[byte..].chars().next().unwrap() } diff --git a/src/libsyntax_pos/lib.rs b/src/libsyntax_pos/lib.rs index d30d3d78ca540..26ab5d0a34ba5 100644 --- a/src/libsyntax_pos/lib.rs +++ b/src/libsyntax_pos/lib.rs @@ -971,6 +971,15 @@ impl FileMap { lines.push(pos); } + /// Return the BytePos of the beginning of the current line. + pub fn line_begin_pos(&self) -> BytePos { + let lines = self.lines.borrow(); + match lines.last() { + Some(&line_pos) => line_pos, + None => self.start_pos, + } + } + /// Add externally loaded source. /// If the hash of the input doesn't match or no input is supplied via None, /// it is interpreted as an error and the corresponding enum variant is set. @@ -1047,6 +1056,7 @@ impl FileMap { self.multibyte_chars.borrow_mut().push(mbc); } + #[inline] pub fn record_width(&self, pos: BytePos, ch: char) { let width = match ch { '\t' =>