<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=http://email.email.llvm.org/c/eJylkt1unDAQhZ_G3IyCwAR2ufDFJlGU3vcFxngWHBkb2WZXefsMpD-Rum2lVjLy2GOdOd8wOpg39XWyCYZgSDQnUT2J6iS66tvajxUI-cDf0fos5EnIvrr5zhGaBDn8TueK0Vs_choWiucQZz7BEliWImC0eZop2wGCBwS_OvcjOWGC1Rs6W08GNE14sSHerPISrnShKOQj5L-RfWbieIE7WDjceW8zmkDJC3nI5S_V2OKX3WRMGb3ZrxghTwTWb7SYLZN5IsMMOYAhRuMeENeTf8LnNDAJXtA61I4AM2PNi-Uw25lKeCE_0AcygbE4-pBYiunRc7tgicGsA5myMKoxfdNjgWueQlTLHGLdFGt0asp5SVur5DOvkf2suuQ6fHDu8n27Y61XGrhrzzallRIHbdP3TTEpWevmYNqu09qcdXt_7rq67Wo8aKPxqHXB9sklJdoHZvJ0hV2CY9E-Ff_vwCpZyW3J-tjwXsq6q6kxg6mrdtDtQdxXNHMXy02nDHEsotol9TomTjqbcvqZxJTsyD9sN8wOs82O1KPDjymeufw2wp8avl3_-5wXO4_aYd4BYUghew>53993</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            Clang: missing diagnostics: warning: performing pointer arithmetic on a null pointer
        </td>
    </tr>

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

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

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

<pre>
    This code:
```
0 + (int*)0
```
leads to:
```
warning: performing pointer arithmetic on a null pointer has undefined behavior
```
However, this code:
```
(int*)(p - p) + 0
```
doesn't.
However, as I understand, all the information needed to determine "arithmetic on a null pointer" is available at compile time. Hence, the diagnostics can be produced.
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJydkc1upDAMx58mXKwiSAZmOOQwbVW1930BQzyQVUhQEma0b19D96PSzu5KKxnFjoP9_9l9MN_0l8kmGIIhoc6iehbVWbTVd9vDCoR85O9kfRbyLGRX3X3nCE2CHP5U54bRWz9yGhaKlxBnjmAJXJYiYLR5minbAYIHBL869zM5YYLVG7pYTwZ6mvBqQ7zb5TXc6EpRyCfI_yL7zMT-Ag-wsLvz3mc0gZIX8pjL37qxxLddZEwZvdmvGCFPBNZvtJgtk3kiwww5gCFG4xkQ95N_w-c0MAle0TrsHQFmxpoXy262M5XwSn6gD2QCY3H0IXEppkfP44IlBrMOZMrCaGU61WGRbXaknxx-bGS2KW3r-PTzdv3_OyvW6PSU87LVEfKFbeTXa1-ydA6cu_44HljeVxp4ES-sYqXETqO6ThWTxkOr8HQ6XIyRtVSNqtoLHQ9Dfemkaeu24ImQS1o0jzwmTzfYS7AvmufCalnJzWR9UnyWsm5rUmYwddUMfXMUh4pmHmu56ShDHIuod0n9OiZOOpty-pVEHtLIG9zbcX1c8xSiXuYQa1XsnfWu_B3mQwsZ">