<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/54447>54447</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            Make setjmp uninlinable
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            backend:WebAssembly
      </td>
    </tr>

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

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

<pre>
    When EH is used with SjLj, Emscripten currently provides three ways of doing it:
1. Emscripten EH + Wasm EH
2. Wasm EH + Emscripten SjLj
3. Wasm EH + Wasm SjLj

[Emscripten EH/SjLj](https://emscripten.org/docs/porting/exceptions.html#javascript-based-exception-support) is an old way of emulating EH and SjLj using JavaScript from Emscripten. [Wasm EH/SjLj](https://emscripten.org/docs/porting/exceptions.html#webassembly-exception-handling-proposal) is a new faster way, which uses  [Wasm exception handling instructions](https://github.com/WebAssembly/exception-handling).

The eventual recommended way of doing EH and SjLj together is 3. 2 was provided as an interim solution while Wasm SjLj was not implemented. But there are restrictions in 2 and 3. In 2, you cannot call `setjmp` in a function that uses EH (`catchpad` or `cleanuppad` instruction). In 3, you can have `setjmp` calls in the function that uses EH, but you cannot call it within the `catch` clause of `try`-`catch`.

Users can get around this restriction by modifying source code, but sometimes it is not easy because `setjmp` calls can be inlined. One way to fix this is to make `setjmp` calls uninlinable in Clang. (This issue is labeled with "backend:WebAssembly" because there's no separate WebAssembly label for Clang.)
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJytVMuO2zgQ_Br50rAgU34edJhJMkgWu9hDspgzRbUsOhQp8GFHf79NauSRF4OcFvBDErurq7pLXZtmrF471PDlK0gHwWEDN-k7-H7585KxT_Cld8LKwVOICNai9mqEwZqrbNCB7ywi3PjowLTQGKnPIH1WPmXF56x42uTLfCqRsWd45a6n6ymC5fN9OltEJwIppnyMSdfvp2-_u-eHShl7SSG7zxk7dt4PLpJiL_TBe1xu7JkeNEY4-huM9cQ_RvwSOHhptMs736uMlRd-5VPWuubUo_U9ZO3CEDMzdooN5BqMamJHYkOwD4pH0Mid6ybRpibHJ38Q5PcECa01_UJ6DqRm7tL_q-OGRN9hX6txIaEjaopS1jTXwTiuZjGg8QYtdx5tlBT9cOuk6KJPHNxp3pFgRgKpnbdBpOIfkT-Tx0KdC9PTzSvWT2-slqzvvIhOvhz2jw4Br2TFwBVYJJAedYP3tk8-XLbcmzP6jlSQKrITo0g3u7gBnuYmNcmUPTijQhJDUhW-2y3laONB9oNCquixyeE5eIjICJy-Fkm2nGQTIBWKFKjiN7qO7RtNAMF1hBFcKcj2hUN_6Qe6iAkc2qBTPqFyPzU6Gf9IEYJ70Q28icHGxmShkGty4PRs0fXYs1i1XFSl8VzxsWQkkZiSho9Lx_yaRP6XufRpUbylzuQSpuKUGwdBd96O9LtenD-M8h-H1iVuNCBqoQnUL0J1y1ZCPUJvGtmOca7OBCsQhGlw5uZMj172xJdYyWlKyN0INYrE5QPNsWaNJJ0cFgf5t06LjKwCrfw1caAP3fb854cIQadkXqsIA58U1-c8TurHlOsCRgTFa1TzWs0Yq7n4SXalV-HB9-xONtkpY4eoAxwO3HJPPnwPniChJQtMRWnYq6Yqm1N54isvvcLqr0h6YrwkugpWVb95FZW6zn9xG1xQ0GZ7SVribtltt9vDqquOJ6wP7WFzOCKr6z2Wbblpjs2uboptvSlPq8TQVbQhfqOYFsNKVqxgrCg3R7bZsvKU77Dc7Phe7IvTvjieDtm2wJ5LlUdOcdOtbJXo1eHs6FBJ5937Ia03edaIqTTh8-A7YyveIV6kXiUlVZLxLzJMWRE">