<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/61063>61063</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            Clang++ modules: "Cannot compile this l-value expression yet," then crash
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            new issue
      </td>
    </tr>

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

    <tr>
      <th>Reporter</th>
      <td>
          csimon-bambecksystems
      </td>
    </tr>
</table>

<pre>
    This might be the same crash as issue #60981 but the diagnostic "cannot compile this l-value expression yet" is new. According to the C++ language status page, as I understand it, Clang 15 should totally be able to compile this l-value expression, as it's just a call to a void-returning member function of a struct, where the empty member function is defined in a module imported by the main translation unit. Anyway even if Clang++ could not compile some expression, it still should not crash... right? The attachment contains the minimal code needed to produce the diagnostic and crash. If I comment out the (already empty) definition of Message::ToChars() in message-rep.cppm, then compilation succeeds - seeming to show that the crash has to do with accessing the definition of ToChars() within the imported module...
[test.zip](https://github.com/llvm/llvm-project/files/10853504/test.zip)

</pre>
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