Suspicious CMake code for generator tests.

[mcourteaux]

Halide/test/generator/CMakeLists.txt

Lines 238 to 245 in 0653b82

	if ("NVPTX" IN_LIST Halide_LLVM_COMPONENTS)
	if (Halide_TARGET MATCHES "cuda")
	target_link_libraries("${TARGET}" PRIVATE CUDA::cuda_driver CUDA::cudart)
	endif ()
	if (Halide_TARGET MATCHES "opencl")
	target_link_libraries("${TARGET}" PRIVATE OpenCL::OpenCL)
	endif ()
	endif ()

[alexreinking]

It looks from the discussion in #8711 that this is actually fine.

#8711 (comment)

[mcourteaux]

It looks from the discussion in #8711 that this is actually fine.

#8711 (comment)

That comment doesn't say anything about NVPTX.

My concern is that OpenCL is linked only if LLVM's NVPTX component is found. That's nonsensical, right?

[alexreinking]

That comment doesn't say anything about NVPTX.

Your issue description didn't say anything about NVPTX 🙂

It looks like I wrote that like five years ago during the CMake overhaul effort. I'm not sure how it ended up that way. The injection happened in #4644

The original code appears to have been tied somewhat strongly to aot_acquire_release which was perhaps the only test at the time to use OpenCL:

# Acquire-Release test requires CUDA
halide_define_aot_test(acquire_release)
if (TARGET_PTX AND HL_TARGET MATCHES "cuda")
    include(AddCudaToTarget)
    add_cuda_to_target(generator_aot_acquire_release PRIVATE)
endif ()
if (TARGET_PTX AND HL_TARGET MATCHES "opencl")
    find_package(OpenCL REQUIRED)
    target_link_libraries(generator_aot_acquire_release PRIVATE OpenCL::OpenCL)
endif ()

The second TARGET_PTX was likely a copy-paste oversight that got preserved over the years.