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      <base href="https://bugs.llvm.org/">
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    <body><table border="1" cellspacing="0" cellpadding="8">
        <tr>
          <th>Bug ID</th>
          <td><a class="bz_bug_link 
          bz_status_NEW "
   title="NEW - Assertion failure/wrong linkage for explicit specialisation of function templates, declared in an unnamed namespace"
   href="https://bugs.llvm.org/show_bug.cgi?id=42321">42321</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>Assertion failure/wrong linkage for explicit specialisation of function templates, declared in an unnamed namespace
          </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++11
          </td>
        </tr>

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

        <tr>
          <th>Reporter</th>
          <td>momchil.velikov@arm.com
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>blitzrakete@gmail.com, dgregor@apple.com, erik.pilkington@gmail.com, llvm-bugs@lists.llvm.org, richard-llvm@metafoo.co.uk
          </td>
        </tr></table>
      <p>
        <div>
        <pre>Testcase (<a href="https://gcc.godbolt.org/z/E85jsh">https://gcc.godbolt.org/z/E85jsh</a>):

inline namespace {
  template <typename T> int f() { return 0; }
  template <typename T> int g() { return 0; }
}

template<> int f<int>() { return 0; }
template int g<int>();

int (*pf)() = f<int>;
int (*pg)() = g<int>;


triggers assertion failure in debug builds:

$ ./bin/clang -S bb.cc -o - 
clang-9: /data/src/llvm-project/clang/lib/AST/Decl.cpp:1491: clang::LinkageInfo
clang::LinkageComputer::getLVForDecl(const clang::NamedDecl *,
clang::LVComputationKind): Assertion `!Old || Old->getCachedLinkage() ==
D->getCachedLinkage()' failed.


In release builds, the function `f<int>` has external linkage and filescope,
whereas `g<int>` has internal linkage and is in the unnamed namespace.

IIUC [temp.explicit] #6 and [temp.expl.spec] #8 both should be members of the
unnamed namespace and, following, [basic.link] #4, have internal linkage.</pre>
        </div>
      </p>


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