<html>
<head>
<base href="https://bugs.llvm.org/">
</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 constructor does not throw an exception for invalid backreferences in basic/grep patterns"
href="https://bugs.llvm.org/show_bug.cgi?id=34297">34297</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>regex constructor does not throw an exception for invalid backreferences in basic/grep patterns
</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>All
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>enhancement
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
<tr>
<th>Component</th>
<td>All Bugs
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>arthur.j.odwyer@gmail.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org, mclow.lists@gmail.com
</td>
</tr></table>
<p>
<div>
<pre>#include <regex>
#include <stdio.h>
int main() {
std::regex rx("(cat)\\1", std::regex::basic);
puts("Constructed without throwing: oops!");
try {
std::regex_match("(cat)", rx);
} catch (std::exception& e) {
puts("regex_match threw instead: oops!");
puts(e.what());
}
}
The output is:
Constructed without throwing: oops!
regex_match threw instead: oops!
The expression contained an invalid back reference.
I claim that the constructor should detect and throw on this pattern, rather
than throwing at match time. The same issue happens with the "std::regex::grep"
dialect, too.</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>