<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 - undefined reference to '__atomic_is_lock_free' with libstdc++"
   href="https://bugs.llvm.org/show_bug.cgi?id=34044">34044</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>undefined reference to '__atomic_is_lock_free' with libstdc++
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>clang
          </td>
        </tr>

        <tr>
          <th>Version</th>
          <td>5.0
          </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>Severity</th>
          <td>normal
          </td>
        </tr>

        <tr>
          <th>Priority</th>
          <td>P
          </td>
        </tr>

        <tr>
          <th>Component</th>
          <td>C++11
          </td>
        </tr>

        <tr>
          <th>Assignee</th>
          <td>unassignedclangbugs@nondot.org
          </td>
        </tr>

        <tr>
          <th>Reporter</th>
          <td>raj.khem@gmail.com
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>dgregor@apple.com, llvm-bugs@lists.llvm.org
          </td>
        </tr></table>
      <p>
        <div>
        <pre>Compile this sample with clang++ results in error while g++ works fine

#include <atomic>
#include <iostream>

struct Simple1 { int i; };

int main()
{
    std::atomic<Simple1> s1;
    std::cout << std::boolalpha << s1.is_lock_free() << '\n';
    return 0;
}


clang++ test.cpp -std=c++11                                                    
                          (08-03 06:47)
/tmp/tmp.Ro4Nz5NMoq/test-5d79a3.o: In function
`std::atomic<Simple1>::is_lock_free() const':
test.cpp:(.text._ZNKSt6atomicI7Simple1E12is_lock_freeEv[_ZNKSt6atomicI7Simple1E12is_lock_freeEv]+0x1b):
undefined reference to `__atomic_is_lock_free'


if I use -stdlib=libc++ it links successfully, it seems to be only a problem
when
using libstdc++</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>