<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/75777>75777</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [clangd][include-cleaner] False warning: Included header X is not used directly
        </td>
    </tr>

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

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

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

<pre>
    ```shell
$ ./clangd --version
clangd version 17.0.3 (https://github.com/llvm/llvm-project 888437e1b60011b8a375dd30928ec925b448da57)
Features: linux+grpc
Platform: x86_64-unknown-linux-gnu
```

If I have a header file which defines a concept, and I include that header file and reuse that concept, I am getting a false `Included header X is not used directly`, i.e., by commenting out that header I get a compile error (because that concept was not previously defined.

I have a reproducible repo here, but will also type out below: https://github.com/tuero/clangd_include_example


util.h
```cpp
#ifndef UTIL_H_
#define UTIL_H_

#include <string>

// Concept for simple states for flat search
template <typename T>
concept SimpleEnv = requires(T t, const T ct, const std::string &s) {
    T(s);
    { ct.is_terminal() } -> std::same_as<bool>;
};

#endif    // UTIL_H_
```

main.cpp
```cpp
#include <iostream>
#include <string>

#include "util.h"   // Included header util.h is not used directly

struct X {
    X(const std::string &s) : s(s) {}
 bool is_terminal() const {
        return false;
    }
 std::string s;
};

template <typename T>
concept Env = SimpleEnv<T>;

template <Env T>
bool is_terminal(const T &t) {
 return t.is_terminal();
}

int main() {
    X x("hello");
 std::cout << is_terminal(x) << std::endl;
}
```
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJyUVlGPsjgU_TX15UaCBQUefJjRMWuyD5usm8ybKeUq3S0t25Zx5t9vWkDFMd9-32QCctuennvPuRRmrTgrxDVZvpLldsY6V2uzdh0aPSt19bUmq7j_tzVKSeItiV8ITSEidMclU-cK5vMPNFZo1Y8O0SEGiyyKowQIzWvnWkuSF0J3hO7OwtVdGXHdELqT8mO8zVuj_0buIM_zNMlwUa7ieLEoc5Zky6pK4oLmyAu6LNM0r9gyI7ToN94hc51BvwVIobpPQl_PpuX96B-SuZM2jR_9zFfHVTrv1D9KX9Q8TJ6fVTekN6Y8PIbr_gR7qNkHAoMaWYUGTkIiXGrBa6jwJBRaYMC14tg6QjfAVAV7EIrLrkJwNXOTlX7YYGeHobuFe2ANnNE5oc7A4MSkRSCreN9DVSPMOwgLSjvoLFZQCYPcyS9PnG5ARBj5e_kFXDcNqoCmOzdhsvf7BNpN60mhMdp4sUrk7JEbXFi_X2vwQ-jOyq8h8yqa1GoslMHW6KrjopToHzTUaDCw6hxchJTApNXgvloM1EqU-uIV-oFXgjmv7jsO9T3iJ2taifc8-mvnhIzqB2l5245eTsRJVXiCvw7734-_Ha_hPrOH8HXNoCpJNtYZoc4keZtO8bxhMxTupA1Y4fmBdcyhDZGTZA4sMsMHeg6bVjIXYH1NFGsQDlfoUYY_A9Kb-gCSbMHgv53wtqf5AYJ_uFbWwQH43ZN1lS9n8tLTBUJXltACSPbagwMAHAjNfZQkd0GSvQJ3kbBHh6YRiklC837pFuYkebvDZg0emSXJptRaet4jEMm2t99jEVFV4hS26Ks1LfWzLmyYUNFNu6dq3pQR2jqDrLlp8zPC3aZQOniH0hvJxybspzzvxDtc60zHHbxPC_5OaP4_-iQvYAdZwtpsOyz3JYbvqvRwk138n0HXGdW_Sx7kHQEfKdgfqPeTTh09enUsSTaHiS--ofklN6AnSY7uJnTlpg4ecnzi1UkmdxsL5cB76uroe23gM4SpP_g0oXTSGNdicf_eIsmGJJsHop-9fmHkOh1VJZ-wGZ08q9ZJVSQFm-F6kcU0LxZpms_qNS5SVuQZ0kW-yipesAJTFpdpgTFDvipmYk1jmizoIo8LmsZ5xOmJ8ZymeYlpSWlG0hgbJmTkT9lIm_NMWNvhOltmWTaTrERpw3cApQovEAZ91svtzKzDyVx2Z0vSWArr7A3FCSfDB0T_QibLLVm-Dj005xKZQkOWW9iFY-zCjApd9_Ktk54fZ7POyPWvfToQugvsLaG7kN1_AQAA__9tYKnQ">