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<base href="https://bugs.llvm.org/">
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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - string::size() use of uninitialized memory (MSan)"
href="https://bugs.llvm.org/show_bug.cgi?id=32387">32387</a>
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</tr>
<tr>
<th>Summary</th>
<td>string::size() use of uninitialized memory (MSan)
</td>
</tr>
<tr>
<th>Product</th>
<td>libc++
</td>
</tr>
<tr>
<th>Version</th>
<td>unspecified
</td>
</tr>
<tr>
<th>Hardware</th>
<td>PC
</td>
</tr>
<tr>
<th>OS</th>
<td>All
</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>All Bugs
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>gonzalobg88@gmail.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org, mclow.lists@gmail.com
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<pre>The following MWE produces a MemorySanitizer error:
MWE:
#include <vector>
#include <string>
int main()
{
auto vec = std::vector<std::string>{{"a"}, {"b"}, {"c"}};
auto it = std::find(std::begin(vec), std::end(vec), "b");
assert(it2 == vec.begin() + 1);
}
Error:
==25671==WARNING: MemorySanitizer: use-of-uninitialized-value
#0 0x49a8ca in std::__1::basic_string<char, std::__1::char_traits<char>,
std::__1::allocator<char> >::size() const
/home/gonzalo/pool/msan/include/c++/v1/string:894:17
#1 0x49a8ca in bool std::__1::operator==<char, std::__1::char_traits<char>,
std::__1::allocator<char> >(std::__1::basic_string<char,
std::__1::char_traits<char>, std::__1::allocator<char> > const&, char const*)
/home/gonzalo/pool/msan/include/c++/v1/string:3581
#2 0x49a8ca in std::__1::__wrap_iter<std::__1::basic_string<char,
std::__1::char_traits<char>, std::__1::allocator<char> >*>
std::__1::find<std::__1::__wrap_iter<std::__1::basic_string<char,
std::__1::char_traits<char>, std::__1::allocator<char> >*>, char
[2]>(std::__1::__wrap_iter<std::__1::basic_string<char,
std::__1::char_traits<char>, std::__1::allocator<char> >*>,
std::__1::__wrap_iter<std::__1::basic_string<char, std::__1::char_traits<char>,
std::__1::allocator<char> >*>, char const (&) [2])
/home/gonzalo/pool/msan/include/c++/v1/algorithm:891
#3 0x49a8ca in main test.cpp:7
#4 0x7f220bb66b04 in __libc_start_main (/lib64/libc.so.6+0x21b04)
#5 0x42384e in _start
/home/abuild/rpmbuild/BUILD/glibc-2.19/csu/../sysdeps/x86_64/start.S:122
SUMMARY: MemorySanitizer: use-of-uninitialized-value
/home/gonzalo/pool/msan/include/c++/v1/string:894:17 in
std::__1::basic_string<char, std::__1::char_traits<char>,
std::__1::allocator<char> >::size() const
Exiting</pre>
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