<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/133509>133509</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            musttail attribute on a function with not_tail_called attribute has no warning/error that musttail is ignored
        </td>
    </tr>

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

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

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

<pre>
    Take:
```
int __attribute__((not_tail_called)) foo1(int);

int foo2(int a) {
 [[clang::musttail]]
  return foo1(a);
}
```

There is NO diagnostic saying musttail is being ignored due to the conflict of not_tail_called attribute.
</pre>
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