CMAKE with RAJA CUDA backend

[yencal]

I get this error when building a project using the RAJA CUDA backend.

/home/cyenusah/Project/hpc-heterogeneous-computing/src/daxpy/raja/raja_example/main.cpp: In function ‘int main(int, char**)’:
/home/cyenusah/Project/hpc-heterogeneous-computing/src/daxpy/raja/raja_example/main.cpp:37:24: error: ‘cuda_exec’ in namespace ‘RAJA’ does not name a template type
   37 |   using policy = RAJA::cuda_exec<256>;

Here is my CMakeLists.txt file

cmake_minimum_required(VERSION 3.17)
set(CMAKE_CXX_STANDARD 17) 
set(CMAKE_CXX_STANDARD_REQUIRED TRUE)

set(THIS raja-example)

project(${THIS})

if (NOT CMAKE_BUILD_TYPE)
    set(CMAKE_BUILD_TYPE Release)
endif(NOT CMAKE_BUILD_TYPE)

find_package(RAJA REQUIRED)

set(SOURCE main.cpp)

add_executable(${THIS} ${SOURCE})

target_link_libraries(${THIS} PRIVATE RAJA)

I installed RAJA using the ENABLE_CUDA cmake build flag, and it appears to install correctly since the examples that come with RAJA run the cuda backend when I execute them.

Please help on how to correctly use cmake for a project that used RAJA CUDA backend. Thanks.

[rhornung67]

How did you run CMake to configure the build for your project? Did you pass -DENABLE_CUDA=On?

[yencal]

@rhornung67 thanks for the suggestion. However when I do cmake -DENABLE_CUDA=On ../, I get this warning from cmake

CMake Warning:
  Manually-specified variables were not used by the project:

    ENABLE_CUDA

If I go ahead and run make anyway, I get the same error:

/home/cyenusah/Project/hpc-heterogeneous-computing/src/daxpy/raja/raja_example/main.cpp: In function ‘int main(int, char**)’:
/home/cyenusah/Project/hpc-heterogeneous-computing/src/daxpy/raja/raja_example/main.cpp:37:24: error: ‘cuda_exec’ in namespace ‘RAJA’ does not name a template type
   37 |   using policy = RAJA::cuda_exec<256>;

[davidbeckingsale]

It looks like your example is using CUDA, so you will need to tell CMake to compile your main.cpp file with CUDA, e.g.:

set_source_files_properties(main.cpp PROPERTIES LANGUAGE CUDA)

You will also need to add enable_language(CUDA) to your CMakeLists

[yencal]

@davidbeckingsale. Thanks for the suggestions. I had to add set(CMAKE_CUDA_HOST_COMPILER gcc) and set(CMAKE_CUDA_FLAGS "${CMAKE_CUDA_FLAGS} --extended-lambda") in addition to your suggestions to get it working.

Here is the final CMakeLists.txt that worked for me.

cmake_minimum_required(VERSION 3.17)
set(CMAKE_CXX_STANDARD 17) 
set(CMAKE_CXX_STANDARD_REQUIRED TRUE)

set(THIS raja-example)

project(${THIS})
enable_language(CUDA)
set(CMAKE_CUDA_HOST_COMPILER gcc)
set(CMAKE_CUDA_FLAGS "${CMAKE_CUDA_FLAGS} --extended-lambda")

if (NOT CMAKE_BUILD_TYPE)
    set(CMAKE_BUILD_TYPE Release)
endif(NOT CMAKE_BUILD_TYPE)

find_package(RAJA REQUIRED)

set(SOURCE main.cpp)
set_source_files_properties(${SOURCE} PROPERTIES LANGUAGE CUDA)
add_executable(${THIS} ${SOURCE})

target_link_libraries(${THIS} PRIVATE RAJA)

I used cmake ../ and found that -DENABLE_CUDA=ON did nothing.