<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/140339>140339</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [OpenACC] UNREACHABLE executed at /root/llvm-project/llvm/tools/clang/lib/Sema/SemaOpenACCClause.cpp:1305!
        </td>
    </tr>

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

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

    <tr>
      <th>Reporter</th>
      <td>
          k-arrows
      </td>
    </tr>
</table>

<pre>
    Reproducer:
https://godbolt.org/z/d3xM5dYsv
```cpp
void foo() {
#pragma acc serial loop
  for (int i = 0; i < 10; i++) {
#pragma acc loop
    for (int j = 0; j < 10; j++) {
#pragma acc loop vector(length : 5)
      for (int k = 0; k < 10; k++)
        ;
    }
  }
}
```
</pre>
<img width="1" height="1" alt="" src="http://email.email.llvm.org/o/eJyEks9unDAQh59muFhZ2WO8xAcOsBvUQ_9IqXro0WDDete7RrbZpn36CkKySVSpkoVnJOb7pPFPxWiHizEliBrEPlNTOvhQnu5UCP5XzFqvf5ePZgxeT50JwCug1SGlMc4lNoDN4HXrXdr4MAA2fwAbzZ--CP0zXoFWsKXPpxtHoNXVW0167wHvASWBop7_QT4GNZwVUV1HoglWOeK8nwcI6X0ggPf2koglwPeEAq-XckfYcw1YL-ffwFfSO9bxxjq-YR3_zyJX0yUfAO-duQzpQIBXRADKVfJOc7ppTm80p1fN6xAhwOu1g2K_VM_3-n3ZZKZLriWXKjMlK_IiF0xKlh3KvGc53zKNWykk3cqOm7xnfcu4QcwVy2yJFAUVrKCcScE2RqLQJi9QFr3MOUJOzVlZt3Huep5fNLMxTqZkOeVcZk61xsUlK4idU5cBEOfYhHIeuGunIUJOnY0p3hDJJrcE7NtoLtVuB2JPfnx9fKh2n6r68wMxT6abktFEJQLYBO8TYLMAx-CPpntpAZvkvYuAzSpvnG0Bm-_mrNZrdeycmqLZzKHjFeNUALJsCq78kF2bDlO76fz5pvggXhYwK9cdXEv8GwAA__9uzepC">