<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 --- - Profile Instrumentation and linker (gnu) garbage collection"
href="https://llvm.org/bugs/show_bug.cgi?id=25286">25286</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>Profile Instrumentation and linker (gnu) garbage collection
</td>
</tr>
<tr>
<th>Product</th>
<td>new-bugs
</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>new bugs
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>davidxl@google.com
</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>If you use the latest clang to build an instrumented executable or shared
library with garbage collection turned on, you will get a linker error if the
linker is gnu ld:
clang -fprofile-instr-generate -fdata-sections -ffunction-sections
-Wl,--gc-sections t.c
The affected platform is Linux and FreeBSD. This is basically a gnu linker bug:
<a href="https://sourceware.org/bugzilla/show_bug.cgi?id=19161">https://sourceware.org/bugzilla/show_bug.cgi?id=19161</a>
It is possible to workaround this by changing clang driver, but the solution is
hacky and temporary, so not desirable.
If you hit the problem, here are three solutions:
1) update the gnu linker (when the fix is released)
2) use gold linker: -fuse-ld=gold
3) use the following linker script -- name it prf_data.x
SECTIONS {
__llvm_prf_data : { KEEP(*(__llvm_prf_data)) }
}
and add the following link option: -Wl,-T,prf_data.x
Keep this bug open as a place holder to document the issue.</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>