<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/78254>78254</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            Clang-tidy duplicate checks results in remarkable slowdowns
        </td>
    </tr>

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

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

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

<pre>
    When running clang-tidy (LLVM16) with --enable-check-profile on an internal file, I see that:
 - 10 seconds is spend on cert-dcl51-cpp
 - 10 seconds is spend on bugprone-reserved-identifier
 - 10 seconds is spend on cert-dcl37-c
 
I understand that preventing duplicate runs of checks is tricky due to multiple reasons. However, saving 20 seconds makes a lot of sense as well. Given that sensitivity, I think it makes sense to have small steps. A first step that I can see here is reporting to a user that we have these duplicates in the run, that way people can disable those checks in the .clang-tidy file.
</pre>
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