<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/149185>149185</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            Diagnose vertical white space in single line comments
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            clang:frontend,
            clang:diagnostics
      </td>
    </tr>

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

    <tr>
      <th>Reporter</th>
      <td>
          cor3ntin
      </td>
    </tr>
</table>

<pre>
    The Unicode consortium and the C++ committee are interested in diagnosing Vertical whitespaces (VT, FF) that appear in single-line comments. We should explore a warning to guide this effort.

The motivation for this warning is that if an IDE treats such a vertical character as whitespace (which they are recommended to do), the divergence between the behavior of compilers and IDEs can lead to code spoofing, and therefore security concerns

https://www.unicode.org/reports/tr55/#Spoofing-LB
https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2025/p2843r2.pdf
</pre>
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