<html>
<head>
<base href="https://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 --- - No warning for integer overflow in array size"
href="https://llvm.org/bugs/show_bug.cgi?id=27439">27439</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>No warning for integer overflow in array size
</td>
</tr>
<tr>
<th>Product</th>
<td>clang
</td>
</tr>
<tr>
<th>Version</th>
<td>trunk
</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>-New Bugs
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>cherepan@mccme.ru
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
</tr>
<tr>
<th>Classification</th>
<td>Unclassified
</td>
</tr></table>
<p>
<div>
<pre>While compiling this program:
#include <limits.h>
int main()
{
char a[INT_MAX * 3];
(void)(INT_MAX * 3);
}
clang 3.9.0 (trunk 266734) gives the following warnings:
$ clang example.c
example.c:6:18: warning: overflow in expression; result is 2147483645 with type
'int' [-Winteger-overflow]
(void)(INT_MAX * 3);
^
1 warning generated.
There is no warning for the integer overflow in the declaration of the array.
UBSAN doesn't help.
For comparison:
$ gcc example.c
example.c: In function ‘main’:
example.c:5:18: warning: integer overflow in expression [-Woverflow]
char a[INT_MAX * 3];
^
example.c:6:18: warning: integer overflow in expression [-Woverflow]
(void)(INT_MAX * 3);
^</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>