<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/130057>130057</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [C++20][Modules] Compile Error with static template function.
        </td>
    </tr>

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

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

    <tr>
      <th>Reporter</th>
      <td>
          jaehyuck0103
      </td>
    </tr>
</table>

<pre>
    Hello. LLVM.

I encountered an incomprehensible compilation error related to a static template function while using C++ modules.
I provide the minimal code below to reproduce the issue.
It's my first bug report to LLVM. Please let me know if there's anything wrong.

#### Environment
Ubuntu clang version 21.0.0 (++20250305083430+f4878cb91612-1~exp1~20250305083603.767)
Target: x86_64-pc-linux-gnu

#### Codes
``` c++
// main.cpp
#include "dummy_cuda_runtime.h"
#include <cstdint>

import MyModule;

int main() {

    uint16_t *buffer;
    cudaMalloc(&buffer, 100 * sizeof(uint16_t));  // No Compile Error

    MyClass aaa;

 cudaMalloc(&buffer, 100 * sizeof(uint16_t));  // Compile Error
}
```

``` c++
// a.cppm
module;

#include "dummy_cuda_runtime.h"
#include <cstdint>

export module MyModule;

export class MyClass {

  public:
 MyClass() {
        // If below line is not in constructor, No Compile Error
        cudaMalloc(&buffer_, 100 * sizeof(uint16_t));
    }

 uint16_t *buffer_;
};
```

``` c++
// dummy_cuda_runtime.h
template <class T> static void cudaMalloc(T **devPtr, int size) {
    // dummy
}
```

```
# CMakeLists.txt
cmake_minimum_required(VERSION 3.30)

set(CMAKE_C_COMPILER clang)
set(CMAKE_CXX_COMPILER clang++)

project(modules-example)

set(CMAKE_EXPORT_COMPILE_COMMANDS ON)

set(CMAKE_CXX_STANDARD 20)

add_executable(demo main.cpp)
target_sources(demo PUBLIC FILE_SET all_my_modules TYPE CXX_MODULES FILES
                           a.cppm)
```

``` shell
mkdir build
cd build
cmake .. -G Ninja
ninja
```

``` terminal
FAILED: CMakeFiles/demo.dir/main.cpp.o
/usr/lib/llvm-21/bin/clang++   -std=gnu++20 -MD -MT CMakeFiles/demo.dir/main.cpp.o -MF CMakeFiles/demo.dir/main.cpp.o.d @CMakeFiles/demo.dir/main.cpp.o.modmap -o CMakeFiles/demo.dir/main.cpp.o -c /home/jae/Projects/cpp_modules3/main.cpp
/home/jae/Projects/cpp_modules3/main.cpp:15:5: error: no matching function for call to 'cudaMalloc'
   15 | cudaMalloc(&buffer, 100 * sizeof(uint16_t)); // Compile Error
      | ^~~~~~~~~~
1 error generated.
ninja: build stopped: subcommand failed.
```
</pre>
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