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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 --- - Type with no linkage in signature: symbols for unique entities link together"
href="https://llvm.org/bugs/show_bug.cgi?id=28662">28662</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>Type with no linkage in signature: symbols for unique entities link together
</td>
</tr>
<tr>
<th>Product</th>
<td>clang
</td>
</tr>
<tr>
<th>Version</th>
<td>trunk
</td>
</tr>
<tr>
<th>Hardware</th>
<td>All
</td>
</tr>
<tr>
<th>OS</th>
<td>All
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Keywords</th>
<td>miscompilation
</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++11
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>hstong@ca.ibm.com
</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>Clang produces symbols for entities which cannot possibly be referenced from
another translation unit in such a way that distinct entities link together.
In the following program, the templates in question are neither equivalent nor
functionally equivalent.
Online compiler: <a href="http://melpon.org/wandbox/permlink/okS5TiGDAVgd8tb0">http://melpon.org/wandbox/permlink/okS5TiGDAVgd8tb0</a>
### SOURCE (a.cc):
extern "C" void abort();
void bar();
namespace {
template <typename T> struct A { A(int); char sizer[1]; };
}
template <typename T> void foo(char (*)[sizeof A<T>(T(0))]) {
static unsigned cnt = 0;
if (cnt++) abort();
}
int main(void) { bar(); foo<int>(0); }
### SOURCE (b.cc):
extern "C" void abort();
namespace {
template <typename T> struct A { A(int); char sizer[2]; };
}
template <typename T> void foo(char (*)[sizeof A<T>(T(0))]) {
static unsigned cnt = 0;
if (cnt++) abort();
}
void bar() { foo<int>(0); }
### COMMANDS:
clang++ -c -o a.o -std=c++11 a.cc
clang++ -c -o b.o -std=c++11 b.cc
clang++ -o a.out a.o b.o
./a.out
### EXPECTED OUTPUT:
rc=0
### ACTUAL OUTPUT:
(aborts)
### COMPILER VERSION INFO (clang++ -v):
clang version 4.0.0 (trunk 276290)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /usr/local/llvm-head/bin
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.6
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.6.3
Selected GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.6
Candidate multilib: .;@m64
Candidate multilib: 32;@m32
Selected multilib: .;@m64</pre>
</div>
</p>
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