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<base href="https://llvm.org/bugs/" />
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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - False positive warning of -Waddress-of-packed-member"
href="https://llvm.org/bugs/show_bug.cgi?id=31050">31050</a>
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</tr>
<tr>
<th>Summary</th>
<td>False positive warning of -Waddress-of-packed-member
</td>
</tr>
<tr>
<th>Product</th>
<td>clang
</td>
</tr>
<tr>
<th>Version</th>
<td>unspecified
</td>
</tr>
<tr>
<th>Hardware</th>
<td>PC
</td>
</tr>
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<th>OS</th>
<td>Linux
</td>
</tr>
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<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>normal
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
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<th>Component</th>
<td>C++
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>yunlian@chromium.org
</td>
</tr>
<tr>
<th>CC</th>
<td>dgregor@apple.com, llvm-bugs@lists.llvm.org
</td>
</tr>
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<th>Classification</th>
<td>Unclassified
</td>
</tr></table>
<p>
<div>
<pre>#include <stdio.h>
typedef struct __attribute__ ((packed, aligned(4)))
{
short a;
short b;
int c;
} A;
int main() {
A s;
s.c = 0;
int* ptr = &s.c;
printf("%d", *ptr);
return 0;
}
Struct A is explictly requested to be aligned to 4 bytes. Therefore, A.c is
also aligned to 4 bytes.
However clang incorrectly complains:
taking address of packed member 'c' of class or structure 'A' may result in an
unaligned pointer value
[-Waddress-of-packed-member]
int* ptr = &s.c;
Thanks,</pre>
</div>
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