<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/148370>148370</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [clangd] clangd doesn't work with some file names with --experimental-modules-support option
        </td>
    </tr>

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

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

    <tr>
      <th>Reporter</th>
      <td>
          FSK-idk
      </td>
    </tr>
</table>

<pre>
    Here I have an example repo: https://github.com/FSK-idk/clangd-test

When I build the project and look at the file `somefile.cppm` in particular, I don't see any clangd info:

<img width="1332" height="306" alt="Image" src="https://github.com/user-attachments/assets/4c239d9c-95cf-4970-930b-62a59affeb72" />
&nbsp;

However, if I do one of the following, the info will come back:
- comment `import std;` in the file `types.cppm`
- rename the file `somefile.cppm`, for example, to `asd.cppm` (or to some other name, but there is a chance that clangd will not work with the new name either)
- add a new file `asd.cppm` with the content `export module asd;` (same here, maybe some other name)
- remove `--experimental-modules-support` option (but then module info won't be available, but at least highlight will work)

Here is what it looks like if I rename `somefile.cppm` to `asd.cppm`:

<img width="1331" height="310" alt="Image" src="https://github.com/user-attachments/assets/544df3f1-65bd-4836-94d9-e56a712c1291" />
&nbsp;

Versions
```
❯ clangd --version
clangd version 20.1.7
Features: linux
Platform: x86_64-pc-linux-gnu
❯ clang --version 
clang version 20.1.7
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/bin
```

I also tested it with 21.0.0git version I built today and got the same result.
</pre>
<img width="1" height="1" alt="" src="http://email.email.llvm.org/o/eJy0VcFu4zYQ_Rr6MpBBUZZkHXzwbtbYoJcCXbTHghJHEhuKFEjKTv6-GEpOFk3rW4EAsR7JmTeP84YyBD1YxBMrv7DyaSeXODp_uvz2S6bVy6516u30HT3CM4zyiiAt4KucZoPgcXasOMMY4xxYcWbiwsRl0HFc2n3nJiYuWxgmLp2RdlBZxBAZPzN-_mNEC8_QLtooiCPC7N1f2EWQVoFx7gVkTHivDQKreHAT0u99N88TqzhoC7P0UXeLkZ6Jr_AMylkm6ggBiekbrFlB256YrolZ8VVPA9y0iiMrnpgQeVEIJgSMqIcxrljBK4Kk2b6fJzkgIcF3K_Kg7CWgz2SMshsntDEwcZEhYPpx6ETRqKbLmrLrs0NT86wpeJtVQpaN7Hts60SGwhbfiK-obBtmVnxZ-X93N7xiKlj3qWZwFsH1q1rOGHfTdqB1Aqh2uGljoHMTQiu7l1WKjACiR-LqaXY-QoiK8qzi_ix-fJsx3JVPhz1aOeHDGyIKvfP3hkmMHG2UQb3fIhNH5wmn0-DiiB4oMu1ul9QCHkEHkNCN0naUUsb7zabCrItwc_4FbjqOiZHFWwoCqOk8E03iLJUCmRbvlH9m8n66czZuuuBr0mVyajEIMtzlYeIYKD6RI6aTfGvxcwnNJtXkrildluHrjF6T7NJka9iQhWWmNBTYzVE7S_G34u09-XqRW4O3CPIqtZGteVdKRjAoQ4RRD6OhVl7lIWlWKtQ9m5o3ElHH5LQARr_g2k3btf6b3z7d3WNL5Z8slfP_x1Ll4aD6os-zqmxVdjgWVdYcVJNhWck6F10umvyhpX5HH7Szgb4qvv3xM_smWPPEzpd7t2XZdd3J-HmDNgAE3-f7mvHzBWVcPFIZYLRdXhk__2pk7J2fCHs9Vn9Wh2zusrSaDXb5nOojE9xTfc70Q_oB43_H_DF6lIraBw3tml3QxObZhiiNQfWkPeFJXc_EpdX2nwrw8zNIExzQ4EZFHZNsIvI93_NBx3da6yiPEJ2Sb2mID24d4MkoHsNi4n6nToVqikbu8JTXpShEzXmxG0-HUlTqKKqGl0XblsdDnee9amtVV0XXt2qnT4KLktc59RbnxV40WApel1XdYs2FYAeOk9Rmb8x12js_7HQIC57yw7Go-c7IFk1Iz5wQNALSKhOCXj1_okNZuwyBHbjRIYaPMFFHk97H9cpZ-XTvB-UwrH78GD9pBqTxQkYKK_jY95vpd4s3pwcWIELbv2x7LJm4pDLIBVud15P4OwAA__-lE3rx">