<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/143486>143486</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            Clang -pedantic: non-ISO practices may not be diagnosed
        </td>
    </tr>

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

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

    <tr>
      <th>Reporter</th>
      <td>
          pmor13
      </td>
    </tr>
</table>

<pre>
    I do believe that per ISO C11 this code:
```
int x __attribute__ ((aligned (16))) = 0;
```
leads to syntax error.

A conforming implementation shall produce at least one diagnostic message.

Clang with options `-std=c11 -Wall -Wextra -pedantic` produces nothing.

@AaronBallman Any comments?
</pre>
<img width="1" height="1" alt="" src="http://email.email.llvm.org/o/eJxckkFr4zAQhX-NfBkcZMlx4oMPbkugpz3soccwlqa2Flky0rib_PtFbXYLCwPGIH3vzdPDnN0ciAZxfBLHlwp3XmIatjWmRldTtPfhFWyEibyjDwJekGGjBK8_f8Bz0wAvLoOJloQehRxFJx8jRxcYbnC9InNy0850vYJQZ6HO6IuoLX9NJ1T_NSD0C0ihn_7jeEKbgSPke2C8AaUU06EckuMIJob3mFYXZnDr5mmlwMguBsgLeg9binY3BMjgCTNDDATW4RxiZmdgpZxxpgfv2WOY4bfjBeJWKBlEJ-vMVugX0zRQvxVo_UY3Tgj1RhYDOyM6-VcpQ4i8uDA_kKKVI6YYntD7FQOM4Q4mrsVnFvpS2UHbXvdY0dCc2v7Yat331TIQkiJjNeJ00vp4tu27Ok1tg8acVNdPlRuUVEfZNVKem073h_7c9--mM73Rkz7Jo2glrej8wfuP9RDTXLmcdxqaVrfnrvI4kc-fL6-UKYsLpUoJ0lAu1NM-Z9FK7zLnbwQ79jR85fS9vh4hxFCXVmwJDbuSw4r3kgVM_wInW-3JDwvzlkth1EWoy-x42aeDiatQl6Lz-NRbir_IsFCXT99ZqMvD-seg_gQAAP__yXjeBg">