<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/87971>87971</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            Crash when evaluating a constexpr static function template in an incomplete class context.
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            clang:frontend,
            regression,
            crash
      </td>
    </tr>

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

    <tr>
      <th>Reporter</th>
      <td>
          cor3ntin
      </td>
    </tr>
</table>

<pre>
    ```cpp
struct s{
  static constexpr auto f(auto extent) {
    return 0;
 }

  static constexpr auto a = f(0);
};
```

The following crashes after clang 17.

https://godbolt.org/z/o7zaK7qKq


I's unclear whether this should be well-formed (see #73232)



</pre>
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