auto merge of #9335 : alexcrichton/rust/issue-7945, r=thestinger

As documented in issue #7945, these literal identifiers are all accepted by rust
today, but they should probably be disallowed (especially `'''`). This changes
all escapable sequences to being *required* to be escaped.

Closes #7945

I wanted to write the tests with more exact spans, but I think #9308 will be fixing that?
This commit is contained in:
bors 2013-09-24 19:06:01 -07:00
commit 512f7781fe
5 changed files with 89 additions and 21 deletions

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@ -747,27 +747,34 @@ fn next_token_inner(rdr: @mut StringReader) -> token::Token {
}
// Otherwise it is a character constant:
if c2 == '\\' {
// '\X' for some X must be a character constant:
let escaped = rdr.curr;
let escaped_pos = rdr.last_pos;
bump(rdr);
match escaped {
'n' => { c2 = '\n'; }
'r' => { c2 = '\r'; }
't' => { c2 = '\t'; }
'\\' => { c2 = '\\'; }
'\'' => { c2 = '\''; }
'"' => { c2 = '"'; }
'0' => { c2 = '\x00'; }
'x' => { c2 = scan_numeric_escape(rdr, 2u); }
'u' => { c2 = scan_numeric_escape(rdr, 4u); }
'U' => { c2 = scan_numeric_escape(rdr, 8u); }
c2 => {
fatal_span_char(rdr, escaped_pos, rdr.last_pos,
~"unknown character escape", c2);
}
match c2 {
'\\' => {
// '\X' for some X must be a character constant:
let escaped = rdr.curr;
let escaped_pos = rdr.last_pos;
bump(rdr);
match escaped {
'n' => { c2 = '\n'; }
'r' => { c2 = '\r'; }
't' => { c2 = '\t'; }
'\\' => { c2 = '\\'; }
'\'' => { c2 = '\''; }
'"' => { c2 = '"'; }
'0' => { c2 = '\x00'; }
'x' => { c2 = scan_numeric_escape(rdr, 2u); }
'u' => { c2 = scan_numeric_escape(rdr, 4u); }
'U' => { c2 = scan_numeric_escape(rdr, 8u); }
c2 => {
fatal_span_char(rdr, escaped_pos, rdr.last_pos,
~"unknown character escape", c2);
}
}
}
'\t' | '\n' | '\r' | '\'' => {
fatal_span_char(rdr, start, rdr.last_pos,
~"character constant must be escaped", c2);
}
_ => {}
}
if rdr.curr != '\'' {
fatal_span_verbose(rdr,
@ -973,7 +980,7 @@ mod test {
}
#[test] fn character_escaped() {
let env = setup(@"'\n'");
let env = setup(@"'\\n'");
let TokenAndSpan {tok, sp: _} =
env.string_reader.next_token();
assert_eq!(tok, token::LIT_CHAR('\n' as u32));

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@ -0,0 +1,15 @@
// Copyright 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.
fn main() {
// these literals are just silly.
''';
//~^ ERROR: character constant must be escaped
}

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@ -0,0 +1,16 @@
// Copyright 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.
fn main() {
// note that this is a literal "\n" byte
'
';
//~^^ ERROR: character constant must be escaped
}

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@ -0,0 +1,15 @@
// Copyright 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.
fn main() {
// note that this is a literal "\r" byte
' ';
//~^ ERROR: character constant must be escaped
}

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@ -0,0 +1,15 @@
// Copyright 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.
fn main() {
// note that this is a literal tab character here
' ';
//~^ ERROR: character constant must be escaped
}