<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/63210>63210</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [C++20] [Modules] Incorrect linkage of non-exported variables introduced by lambda-expression
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            clang:modules
      </td>
    </tr>

    <tr>
      <th>Assignees</th>
      <td>
      </td>
    </tr>

    <tr>
      <th>Reporter</th>
      <td>
          ChuanqiXu9
      </td>
    </tr>
</table>

<pre>
    Reproducer:

```
export module A;

static void f () {}

auto lam = []{ f{};};
```

>From https://eel.is/c++draft/basic.link#3， the linkage of `lam` should be `module linkage`. But currently in clang, the linkage of `lam` is `internal linkage`.

I can image the reason should be the way we implement `module linkage`. Currently we implement `module linkage` by degrading `extern linkage` with conditions. But we never thought to promote original `internal linkage`. And for some other reason, the linkage of `lam` is internal instead of external in clang. 

CC: @iains 


</pre>
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