# Support for CUDA & ClangCL on Windows

**URL:** https://discourse.cmake.org/t/support-for-cuda-clangcl-on-windows/1437
**Category:** Development
**Tags:** comp:clang, lang:cuda, os:windows
**Created:** [June 23, 2020, 8:43pm UTC](https://discourse.cmake.org/t/support-for-cuda-clangcl-on-windows/1437 "2020-06-23T20:43:32Z")
**Posts on this page:** 3
**Page:** 1

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### Author: ![mojca](https://discourse.cmake.org/user_avatar/discourse.cmake.org/mojca/32/610_2.png) [@mojca](https://discourse.cmake.org/u/mojca)
#### Post date: [June 23, 2020, 8:43pm UTC](https://discourse.cmake.org/t/support-for-cuda-clangcl-on-windows/1437/1 "2020-06-23T20:43:32Z")

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When trying to build a simple CUDA project on Windows and optimistically specifying `-T ClangCL`, CMake complains about unknown CUDA compiler

```auto
Selecting Windows SDK version 10.0.18362.0 to target Windows 10.0.19041.
The CXX compiler identification is Clang 10.0.0 with MSVC-like command-line
The CUDA compiler identification is unknown
Detecting CXX compiler ABI info
Detecting CXX compiler ABI info - done
Check for working CXX compiler: C:/Program Files (x86)/Microsoft Visual Studio/2019/Preview/VC/Tools/Llvm/bin/clang-cl.exe - skipped
Detecting CXX compile features
Detecting CXX compile features - done
CMake Error at CMakeLists.txt:7 (project):
  No CMAKE_CUDA_COMPILER could be found.

```

I’m aware that the support is still pretty sketchy, but I’m in principle able to compile [simple code](https://llvm.org/docs/CompileCudaWithLLVM.html#invoking-clang) with

```auto
> clang++ axpy.cu -o axpy --cuda-gpu-arch=sm_60 -lcudart_static --cuda-path="C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v10.2" -L"C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v10.2\lib\x64"
clang++: warning: Unknown CUDA version 10.2. Assuming the latest supported version 10.1 [-Wunknown-cuda-version]
   Creating library axpy.lib and object axpy.exp

```

Would it be possible to add at least some very basic support for CUDA compiled with clang on Windows?

---

<div class="post-metadata">

### Author: ![brad.king](https://discourse.cmake.org/user_avatar/discourse.cmake.org/brad.king/32/11_2.png) [@brad.king](https://discourse.cmake.org/u/brad.king)
#### Post date: [June 24, 2020, 9:57am UTC](https://discourse.cmake.org/t/support-for-cuda-clangcl-on-windows/1437/2 "2020-06-24T09:57:50Z")

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Work is ongoing. See [CMake Issue 20776](https://gitlab.kitware.com/cmake/cmake/-/issues/20776).

---

<div class="post-metadata">

### Author: ![mojca](https://discourse.cmake.org/user_avatar/discourse.cmake.org/mojca/32/610_2.png) [@mojca](https://discourse.cmake.org/u/mojca)
#### Post date: [June 25, 2020, 7:42am UTC](https://discourse.cmake.org/t/support-for-cuda-clangcl-on-windows/1437/3 "2020-06-25T07:42:50Z")

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Thank you, that’s very good news, I’ll be watching the ticket on GitLab.