<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 --- - Uninitialized bytes from clang_createIndex"
href="https://llvm.org/bugs/show_bug.cgi?id=30410">30410</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>Uninitialized bytes from clang_createIndex
</td>
</tr>
<tr>
<th>Product</th>
<td>clang
</td>
</tr>
<tr>
<th>Version</th>
<td>3.9
</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>libclang
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>markus.zimmermann@nethead.at
</td>
</tr>
<tr>
<th>CC</th>
<td>klimek@google.com, llvm-bugs@lists.llvm.org
</td>
</tr>
<tr>
<th>Classification</th>
<td>Unclassified
</td>
</tr></table>
<p>
<div>
<pre>Created <span class=""><a href="attachment.cgi?id=17279" name="attach_17279" title="failure.c">attachment 17279</a> <a href="attachment.cgi?id=17279&action=edit" title="failure.c">[details]</a></span>
failure.c
We (<a href="https://github.com/go-clang">https://github.com/go-clang</a> automatic generated bindings for Clang's C API
for Go) are in the process of adding address sanitizer checks into our test
process. Before we do a public release, we want to make sure that we did
nothing wrong. However, by using the address sanitizer I found that an instance
of "uninitialized bytes".
The attached program compiled with
clang -I `llvm-config --includedir` -lclang -g -fsanitize=memory
-fsanitize-memory-track-origins -fno-omit-frame-pointer failing.c -o failing
produces the following output:
$ ./failing
Uninitialized bytes in __interceptor_memchr at offset 6 inside [0x70800000bf58,
7)
==1796==WARNING: MemorySanitizer: use-of-uninitialized-value
#0 0x7ff7dd302c85 (/usr/lib/x86_64-linux-gnu/libLLVM-3.9.so.1+0x653c85)
#1 0x7ff7dd3130a7 (/usr/lib/x86_64-linux-gnu/libLLVM-3.9.so.1+0x6640a7)
#2 0x7ff7e1242bbe (/usr/lib/x86_64-linux-gnu/libclang-3.9.so.1+0xc05bbe)
#3 0x7ff7e12524ca (/usr/lib/x86_64-linux-gnu/libclang-3.9.so.1+0xc154ca)
#4 0x7ff7e0acdf39 (/usr/lib/x86_64-linux-gnu/libclang-3.9.so.1+0x490f39)
#5 0x7ff7e0aab504 (/usr/lib/x86_64-linux-gnu/libclang-3.9.so.1+0x46e504)
#6 0x7ff7e08a078e (/usr/lib/x86_64-linux-gnu/libclang-3.9.so.1+0x26378e)
#7 0x7ff7dd2dd314 (/usr/lib/x86_64-linux-gnu/libLLVM-3.9.so.1+0x62e314)
#8 0x7ff7dd2dd393 (/usr/lib/x86_64-linux-gnu/libLLVM-3.9.so.1+0x62e393)
#9 0x7ff7dd3404bc (/usr/lib/x86_64-linux-gnu/libLLVM-3.9.so.1+0x6914bc)
#10 0x7ff7e0427183 (/lib/x86_64-linux-gnu/libpthread.so.0+0x8183)
#11 0x7ff7df82c37c (/lib/x86_64-linux-gnu/libc.so.6+0xfa37c)
Uninitialized value was stored to memory at
#0 0x421635 (/home/vagrant/go/src/github.com/go-clang/failing+0x421635)
#1 0x7ff7dca669bd (/usr/lib/x86_64-linux-gnu/libstdc++.so.6+0xbb9bd)
Uninitialized value was stored to memory at
#0 0x421635 (/home/vagrant/go/src/github.com/go-clang/failing+0x421635)
#1 0x7ff7dca65e2f (/usr/lib/x86_64-linux-gnu/libstdc++.so.6+0xbae2f)
Uninitialized value was created by a heap allocation
#0 0x41fc39 (/home/vagrant/go/src/github.com/go-clang/failing+0x41fc39)
#1 0x7ff7dca09dac (/usr/lib/x86_64-linux-gnu/libstdc++.so.6+0x5edac)
SUMMARY: MemorySanitizer: use-of-uninitialized-value
(/usr/lib/x86_64-linux-gnu/libLLVM-3.9.so.1+0x653c85)
Exiting
I am using the packages of <a href="http://llvm.org/apt/trusty/">http://llvm.org/apt/trusty/</a>
llvm-toolchain-trusty-3.9
Please let me know if I should try anything. It would be great if we could get
rid of this problem, so that we can enable the address sanitizer checks.</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>