<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/80613>80613</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            llvm crash - segfault during member init or function definition instantiation
        </td>
    </tr>

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

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

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

<pre>
    llvm crashes for the following reduced code:

```c++
class a {
  using size_type = long;
  template < typename Self > void at( this Self&&, size_type );
};
template < typename > class b : a{};
template < typename T = int > class d : b< T > {
  using some_type = T;

  some_type f = at( f );
};
d i e
```
if ``some_type`` does not depend on ``T``, llvm reports ``use of underclared identifier 'at'``, no crash

[full preprocessed input](https://github.com/eddieavd/llvm_crash_report_24_2_4/blob/master/repro/main-f875aa.cpp)
[reproducing compile command](https://github.com/eddieavd/llvm_crash_report_24_2_4/blob/master/repro/main-f875aa.sh)

[compiler explorer 1](https://godbolt.org/z/EWe6fP7b7), [compiler explorer 2](https://godbolt.org/z/Kxx3Y34Yq)
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJy8lEtv4zYQxz8NdRnEkEeSZR902MSrSy8FGqDYk8HH0GZBkSpJZbP76QtSTuy26eO0ACFpXn_-RhyQx2jOjmhg3SPrjhVf0sWHgZQyxF9UJbz6Nlj7MoEMPF4ogvYB0oVAe2v9V-POEEgtkhRIr4g1n1h9ZPXbc1evSzJ8zKt4peUxAgfWXx0AS8xK0XynU_o2E7DmCNa7M2veUxJNs-Upx54gJzk-EfxCVgNrPsOLNwp4YriHdDGxBBjuynq6V8bDuyjrj-_fH8tn5RVXAGs-Ac_M_1n1XPiNS3f1qtSLnPdc3H_v3k933T_fKK9Zt7guGWuz-h87UmCA_nIOq2k0rOa75GqC8hTB-QSKZnIKvLsmPl_L8QnKNASafUjxGl0igdewOEVBWh5IgVHkktGGAjDsM2p_k3B-Hac_jUr3qBdrYQ40By8pxqzi5iWx7shwf0lpjnm8cGQ4nk26LGIj_cRwfJtWhmOGOxXt04p4wvaEp5bhKKwXDMeJx0SB4Vj2KQ7jHvS-7zjfyHnOf_MNqKSoRebTkX6ajaX8nrhTPxAqXm5Mb2RXmgD0OlsfKMD2QyKvhLdp48OZ4fid4fj5V9rpn3vRZ018gg-18P9p_fT62nxp2i-_MzxUamjUoTnwioZtX_d13-z2TXUZOiKx11Ij36pmRyiF3rYd1bzjNWrRVGbAGtsa63Z7qPd1s2mJxBaFUqKXXVdL1tY0cWM3-T_m7SsT40LDvt5tm8pyQTaW-wvR0VcoQYa5hyqUu-tBLOfI2tqamOJNJZlk6e5ygweIdNZ8sQnUEvKhTzQJCmCcSeAD6MXJZLwDRTr78qdxMXGXDM9WtQQ7_MtQ5M2ur4c5-N9IJoZjIY4Mx9LRHwEAAP__ZLy4mA">