| // Copyright 2012-2013 The Rust Project Developers. See the COPYRIGHT |
| // file at the top-level directory of this distribution and at |
| // http://rust-lang.org/COPYRIGHT. |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| use ast::{self, Ident}; |
| use syntax_pos::{self, BytePos, CharPos, Pos, Span, NO_EXPANSION}; |
| use source_map::{SourceMap, FilePathMapping}; |
| use errors::{Applicability, FatalError, DiagnosticBuilder}; |
| use parse::{token, ParseSess}; |
| use str::char_at; |
| use symbol::{Symbol, keywords}; |
| use core::unicode::property::Pattern_White_Space; |
| |
| use std::borrow::Cow; |
| use std::char; |
| use std::mem::replace; |
| use rustc_data_structures::sync::Lrc; |
| |
| 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, |
| } |
| } |
| } |
| |
| 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<char>, |
| pub source_file: Lrc<syntax_pos::SourceFile>, |
| /// 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<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>, |
| /// Stack of open delimiters and their spans. Used for error message. |
| token: token::Token, |
| span: Span, |
| /// The raw source span which *does not* take `override_span` into account |
| span_src_raw: Span, |
| open_braces: Vec<(token::DelimToken, Span)>, |
| crate override_span: Option<Span>, |
| last_unclosed_found_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 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, ()>) -> 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) |
| } |
| |
| /// Return the next token. EFFECT: advances the string_reader. |
| pub fn try_next_token(&mut self) -> Result<TokenAndSpan, ()> { |
| 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) |
| } |
| |
| fn try_real_token(&mut self) -> Result<TokenAndSpan, ()> { |
| 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 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<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(), |
| // 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(), |
| override_span, |
| last_unclosed_found_span: None, |
| } |
| } |
| |
| pub fn new(sess: &'a ParseSess, |
| source_file: Lrc<syntax_pos::SourceFile>, |
| override_span: Option<Span>) -> 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 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.fm.start_pos != end.fm.start_pos { |
| span = span.shrink_to_lo(); |
| } |
| |
| let mut sr = StringReader::new_raw_internal(sess, begin.fm, 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.span_err(sp, m) |
| } |
| |
| |
| /// 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<T, F>(&self, start: BytePos, f: F) -> T |
| where F: FnOnce(&str) -> T |
| { |
| self.with_str_from_to(start, self.pos, f) |
| } |
| |
| /// Create 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<T, F>(&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 i = 0; |
| while i < s.len() { |
| let ch = char_at(s, i); |
| let next = i + ch.len_utf8(); |
| if ch == '\r' { |
| if next < s.len() && char_at(s, next) == '\n' { |
| return translate_crlf_(self, start, s, errmsg, i).into(); |
| } |
| let pos = start + BytePos(i as u32); |
| let end_pos = start + BytePos(next as u32); |
| self.err_span_(pos, end_pos, errmsg); |
| } |
| i = next; |
| } |
| return s.into(); |
| |
| fn translate_crlf_(rdr: &StringReader, |
| start: BytePos, |
| s: &str, |
| errmsg: &str, |
| mut i: usize) |
| -> String { |
| let mut buf = String::with_capacity(s.len()); |
| let mut j = 0; |
| while i < s.len() { |
| let ch = char_at(s, i); |
| let next = i + ch.len_utf8(); |
| if ch == '\r' { |
| if j < i { |
| buf.push_str(&s[j..i]); |
| } |
| j = next; |
| if next >= s.len() || char_at(s, next) != '\n' { |
| let pos = start + BytePos(i as u32); |
| let end_pos = start + BytePos(next as u32); |
| rdr.err_span_(pos, end_pos, errmsg); |
| } |
| } |
| i = next; |
| } |
| if j < s.len() { |
| buf.push_str(&s[j..]); |
| } |
| buf |
| } |
| } |
| |
| /// Advance the StringReader by one character. If a newline is |
| /// discovered, add it to the SourceFile's list of line start offsets. |
| 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<ast::Name> { |
| 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 \ |
| <https://github.com/rust-lang/rust/issues/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<TokenAndSpan> { |
| 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 cmap = SourceMap::new(FilePathMapping::empty()); |
| cmap.files.borrow_mut().file_maps.push(self.source_file.clone()); |
| let loc = cmap.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<TokenAndSpan> { |
| 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<TokenAndSpan> { |
| // 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, false otherwise. |
| 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); |
| self.sess.span_diagnostic |
| .struct_span_err(span, "incorrect unicode escape sequence") |
| .span_help(span, |
| "format of unicode escape sequences is \ |
| `\\u{…}`") |
| .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(); |
| } |
| } |
| } |
| |
| /// Check 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) |
| } |
| } |
| |
| /// Return the next token from the string, advances the input past that |
| /// token, and updates the interner |
| fn next_token_inner(&mut self) -> Result<token::Token, ()> { |
| 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.fatal_span_verbose(start_with_quote, self.next_pos, |
| String::from("character literal may only contain one codepoint")) |
| .raise(); |
| |
| } |
| |
| // 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_with_applicability( |
| 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::Str_(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<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 |
| } |
| |
| 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()) |
| } |
| |
| #[cfg(test)] |
| mod tests { |
| use super::*; |
| |
| use ast::{Ident, CrateConfig}; |
| use symbol::Symbol; |
| use syntax_pos::{BytePos, Span, NO_EXPANSION}; |
| use source_map::SourceMap; |
| use errors; |
| use feature_gate::UnstableFeatures; |
| use parse::token; |
| use std::collections::HashSet; |
| use std::io; |
| use std::path::PathBuf; |
| use diagnostics::plugin::ErrorMap; |
| use rustc_data_structures::sync::Lock; |
| use with_globals; |
| fn mk_sess(cm: Lrc<SourceMap>) -> ParseSess { |
| let emitter = errors::emitter::EmitterWriter::new(Box::new(io::sink()), |
| Some(cm.clone()), |
| false, |
| false); |
| ParseSess { |
| span_diagnostic: errors::Handler::with_emitter(true, false, Box::new(emitter)), |
| unstable_features: UnstableFeatures::from_environment(), |
| config: CrateConfig::new(), |
| included_mod_stack: Lock::new(Vec::new()), |
| code_map: cm, |
| missing_fragment_specifiers: Lock::new(HashSet::new()), |
| raw_identifier_spans: Lock::new(Vec::new()), |
| registered_diagnostics: Lock::new(ErrorMap::new()), |
| non_modrs_mods: Lock::new(vec![]), |
| buffered_lints: Lock::new(vec![]), |
| } |
| } |
| |
| // open a string reader for the given string |
| fn setup<'a>(cm: &SourceMap, |
| sess: &'a ParseSess, |
| teststr: String) |
| -> StringReader<'a> { |
| let fm = cm.new_source_file(PathBuf::from("zebra.rs").into(), teststr); |
| StringReader::new(sess, fm, None) |
| } |
| |
| #[test] |
| fn t1() { |
| with_globals(|| { |
| let cm = Lrc::new(SourceMap::new(FilePathMapping::empty())); |
| let sh = mk_sess(cm.clone()); |
| let mut string_reader = setup(&cm, |
| &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<token::Token>) { |
| 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 cm = Lrc::new(SourceMap::new(FilePathMapping::empty())); |
| let sh = mk_sess(cm.clone()); |
| check_tokenization(setup(&cm, &sh, "a b".to_string()), |
| vec![mk_ident("a"), token::Whitespace, mk_ident("b")]); |
| }) |
| } |
| |
| #[test] |
| fn dcparsing_2() { |
| with_globals(|| { |
| let cm = Lrc::new(SourceMap::new(FilePathMapping::empty())); |
| let sh = mk_sess(cm.clone()); |
| check_tokenization(setup(&cm, &sh, "a::b".to_string()), |
| vec![mk_ident("a"), token::ModSep, mk_ident("b")]); |
| }) |
| } |
| |
| #[test] |
| fn dcparsing_3() { |
| with_globals(|| { |
| let cm = Lrc::new(SourceMap::new(FilePathMapping::empty())); |
| let sh = mk_sess(cm.clone()); |
| check_tokenization(setup(&cm, &sh, "a ::b".to_string()), |
| vec![mk_ident("a"), token::Whitespace, token::ModSep, mk_ident("b")]); |
| }) |
| } |
| |
| #[test] |
| fn dcparsing_4() { |
| with_globals(|| { |
| let cm = Lrc::new(SourceMap::new(FilePathMapping::empty())); |
| let sh = mk_sess(cm.clone()); |
| check_tokenization(setup(&cm, &sh, "a:: b".to_string()), |
| vec![mk_ident("a"), token::ModSep, token::Whitespace, mk_ident("b")]); |
| }) |
| } |
| |
| #[test] |
| fn character_a() { |
| with_globals(|| { |
| let cm = Lrc::new(SourceMap::new(FilePathMapping::empty())); |
| let sh = mk_sess(cm.clone()); |
| assert_eq!(setup(&cm, &sh, "'a'".to_string()).next_token().tok, |
| token::Literal(token::Char(Symbol::intern("a")), None)); |
| }) |
| } |
| |
| #[test] |
| fn character_space() { |
| with_globals(|| { |
| let cm = Lrc::new(SourceMap::new(FilePathMapping::empty())); |
| let sh = mk_sess(cm.clone()); |
| assert_eq!(setup(&cm, &sh, "' '".to_string()).next_token().tok, |
| token::Literal(token::Char(Symbol::intern(" ")), None)); |
| }) |
| } |
| |
| #[test] |
| fn character_escaped() { |
| with_globals(|| { |
| let cm = Lrc::new(SourceMap::new(FilePathMapping::empty())); |
| let sh = mk_sess(cm.clone()); |
| assert_eq!(setup(&cm, &sh, "'\\n'".to_string()).next_token().tok, |
| token::Literal(token::Char(Symbol::intern("\\n")), None)); |
| }) |
| } |
| |
| #[test] |
| fn lifetime_name() { |
| with_globals(|| { |
| let cm = Lrc::new(SourceMap::new(FilePathMapping::empty())); |
| let sh = mk_sess(cm.clone()); |
| assert_eq!(setup(&cm, &sh, "'abc".to_string()).next_token().tok, |
| token::Lifetime(Ident::from_str("'abc"))); |
| }) |
| } |
| |
| #[test] |
| fn raw_string() { |
| with_globals(|| { |
| let cm = Lrc::new(SourceMap::new(FilePathMapping::empty())); |
| let sh = mk_sess(cm.clone()); |
| assert_eq!(setup(&cm, &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 cm = Lrc::new(SourceMap::new(FilePathMapping::empty())); |
| let sh = mk_sess(cm.clone()); |
| macro_rules! test { |
| ($input: expr, $tok_type: ident, $tok_contents: expr) => {{ |
| assert_eq!(setup(&cm, &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(&cm, &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(&cm, &sh, "2us".to_string()).next_token().tok, |
| token::Literal(token::Integer(Symbol::intern("2")), |
| Some(Symbol::intern("us")))); |
| assert_eq!(setup(&cm, &sh, "r###\"raw\"###suffix".to_string()).next_token().tok, |
| token::Literal(token::StrRaw(Symbol::intern("raw"), 3), |
| Some(Symbol::intern("suffix")))); |
| assert_eq!(setup(&cm, &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 cm = Lrc::new(SourceMap::new(FilePathMapping::empty())); |
| let sh = mk_sess(cm.clone()); |
| let mut lexer = setup(&cm, &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 cm = Lrc::new(SourceMap::new(FilePathMapping::empty())); |
| let sh = mk_sess(cm.clone()); |
| let mut lexer = setup(&cm, &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"))); |
| }) |
| } |
| } |
