<html>
<head>
<base href="http://llvm.org/bugs/" />
</head>
<body><table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - regex: regex_replace does not handle \b correctly"
href="http://llvm.org/bugs/show_bug.cgi?id=16240">16240</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>regex: regex_replace does not handle \b correctly
</td>
</tr>
<tr>
<th>Product</th>
<td>libc++
</td>
</tr>
<tr>
<th>Version</th>
<td>unspecified
</td>
</tr>
<tr>
<th>Hardware</th>
<td>PC
</td>
</tr>
<tr>
<th>OS</th>
<td>Linux
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>normal
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
<tr>
<th>Component</th>
<td>All Bugs
</td>
</tr>
<tr>
<th>Assignee</th>
<td>hhinnant@apple.com
</td>
</tr>
<tr>
<th>Reporter</th>
<td>buglibcxx@lancom.de
</td>
</tr>
<tr>
<th>CC</th>
<td>llvmbugs@cs.uiuc.edu
</td>
</tr>
<tr>
<th>Classification</th>
<td>Unclassified
</td>
</tr></table>
<p>
<div>
<pre>Example from cplusplus.org reference:
std::string s ("there is a subsequence in the string\n");
std::regex e ("\\b(sub)([^ ]*)"); // matches words beginning by "sub"
// using string/c-string (3) version:
std::cout << std::regex_replace (s,e,"sub-$2");
Testing this with valgrind results in the message: "Invalid read of size 1"
This is because of setting match_prev_avail-flag in a case when we are at the
beginning of a string. This leads to a read operation one byte before the
beginning of the string in "__word_boundary<_CharT, _Traits>::__exec(__state&
__s) const"
The flag is set in "regex_iterator<BidirectionalIterator, _CharT,
_Traits>::operator++()" called from "regex_replace(_OutputIterator __out,
_BiderctionalIterator __first, _BiderctionalIterator __last,
const basic_regex<_CharT, _Traits>& __e, const _CharT* __fmt,
regex_constants::match_flag_type __flags = regex::constants::match_default)"</pre>
</div>
</p>
<hr>
<span>You are receiving this mail because:</span>
<ul>
<li>You are on the CC list for the bug.</li>
</ul>
</body>
</html>