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    <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 - c++ visibility for specialization is not correct"
   href="https://bugs.llvm.org/show_bug.cgi?id=36810">36810</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>c++ visibility for specialization is not correct
          </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>Severity</th>
          <td>enhancement
          </td>
        </tr>

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

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

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

        <tr>
          <th>Reporter</th>
          <td>stevenwu@apple.com
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>dgregor@apple.com, llvm-bugs@lists.llvm.org
          </td>
        </tr></table>
      <p>
        <div>
        <pre>Here is a reproducer:

$ cat test.ii

namespace std {
template <class>
class __attribute__((__type_visibility__("default"))) shared_ptr {
  template <class> friend class shared_ptr;
};
} // namespace std
struct dict;
std::shared_ptr<dict> g; // comment out this line will change the visibility
for foo
class __attribute__((visibility("default"))) Bar;
template <class = std::shared_ptr<Bar>>
class __attribute__((visibility("default"))) i {
  std::shared_ptr<int> foo() const;
};
template <> std::shared_ptr<int> i<>::foo() const {
  return std::shared_ptr<int>();
}

$ clang -x c++ -fvisibility=hidden test.ii -emit-llvm -S -o test.ll && grep foo
test.ll
define hidden void @_ZNK1iISt10shared_ptrI3BarEE3fooEv(%class.i* %this)

After commenting out the declaration for 'g':
define void @_ZNK1iISt10shared_ptrI3BarEE3fooEv(%class.i* %this)

It seems that when LinkageComputer try to compute the visibility for foo(), it
try to get the TemplateDecl specialized by shared_ptr<Bar>, it gets the
TemplateDecl for friend class shared_ptr which doesn't have type_visibility.</pre>
        </div>
      </p>


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