<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 - .symver directive not properly handled with -flto=thin"
href="https://bugs.llvm.org/show_bug.cgi?id=37065">37065</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>.symver directive not properly handled with -flto=thin
</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>enhancement
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
<tr>
<th>Component</th>
<td>Driver
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>thomasanderson@google.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
</tr></table>
<p>
<div>
<pre>clang version 7.0.0 (trunk 328716)
Using .symver to bind an imported symbol to a specific version causes problems
with LTO. The symbol with the version appears to be defined when it shouldn't
be. This causes a build failure when linking multiple bitcode files that both
want to import the symbol as now the symbol is duplicated.
$ cat test.c
#include <math.h>
__asm__(".symver exp2f, <a href="mailto:exp2f@GLIBC_2.2.5">exp2f@GLIBC_2.2.5</a>");
float test(float f) {
return exp2f(f);
}
$ clang test.c -c -o test.o
$ nm test.o | grep exp2f
U <a href="mailto:exp2f@GLIBC_2.2.5">exp2f@GLIBC_2.2.5</a>
$ clang test.c -c -o test.o -flto=thin
$ llvm-nm-5.0 test.o | grep exp2f
U exp2f
U exp2f
---------------- T <a href="mailto:exp2f@GLIBC_2.2.5">exp2f@GLIBC_2.2.5</a></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>