<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 static constexpr when compiling with -fprofile-instr-generate"
   href="https://bugs.llvm.org/show_bug.cgi?id=51883">51883</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>Undefined Reference to static constexpr when compiling with -fprofile-instr-generate
          </td>
        </tr>

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

        <tr>
          <th>Version</th>
          <td>trunk
          </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>C++14
          </td>
        </tr>

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

        <tr>
          <th>Reporter</th>
          <td>thoren.paulson@gmail.com
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>blitzrakete@gmail.com, erik.pilkington@gmail.com, llvm-bugs@lists.llvm.org, richard-llvm@metafoo.co.uk
          </td>
        </tr></table>
      <p>
        <div>
        <pre>Godbolt link: <a href="https://godbolt.org/z/vqEjKEKch">https://godbolt.org/z/vqEjKEKch</a>

When I compile the following code with `-Oz -std=c++14
-fprofile-instr-generate`, it refers to the undefined symbol kUndefined, which
causes "undefined reference" at link time.

```
#include <algorithm>


class Foo {
private:
    static constexpr int kUndefined = 4;
public:
    int Bar(int a);
};

int Foo::Bar(int a) {
    return std::max(a, kUndefined);
}
```

It seems this is because std::max takes its arguments by reference, so if it
doesn't get inlined (consequence of -Oz), code is generated referring to
kUndefined, but there is no code generated to define kUndefined.</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>