# Try to detect in the system several dependencies required by the different
# components of libomptarget. These are the dependencies we have:
#
# libffi : required to launch target kernels given function and argument
#          pointers.

include (FindPackageHandleStandardArgs)

################################################################################
# Looking for LLVM...
################################################################################

if (OPENMP_STANDALONE_BUILD)
  # Complete LLVM package is required for building libomptarget
  # in an out-of-tree mode.
  find_package(LLVM REQUIRED)
  message(STATUS "Found LLVM ${LLVM_PACKAGE_VERSION}")
  message(STATUS "Using LLVM in: ${LLVM_DIR}")
  list(APPEND LIBOMPTARGET_LLVM_INCLUDE_DIRS ${LLVM_INCLUDE_DIRS})
  list(APPEND CMAKE_MODULE_PATH ${LLVM_CMAKE_DIR})
  include(AddLLVM)
  if(TARGET omptarget)
    message(FATAL_ERROR "CMake target 'omptarget' already exists. "
                        "Use an LLVM installation that doesn't expose its 'omptarget' target.")
  endif()
else()
  # Note that OPENMP_STANDALONE_BUILD is FALSE, when
  # openmp is built with -DLLVM_ENABLE_RUNTIMES="openmp" vs
  # -DLLVM_ENABLE_PROJECTS="openmp", but openmp build
  # is actually done as a standalone project build with many
  # LLVM CMake variables propagated to it.
  list(APPEND LIBOMPTARGET_LLVM_INCLUDE_DIRS
    ${LLVM_MAIN_INCLUDE_DIR} ${LLVM_BINARY_DIR}/include
    )
  message(STATUS
    "Using LLVM include directories: ${LIBOMPTARGET_LLVM_INCLUDE_DIRS}")
endif()

################################################################################
# Looking for libffi...
################################################################################
find_package(FFI QUIET)
set(LIBOMPTARGET_DEP_LIBFFI_FOUND ${FFI_FOUND})

################################################################################
# Looking for offload-arch...
################################################################################
if(TARGET offload-arch)
  get_property(LIBOMPTARGET_OFFLOAD_ARCH TARGET offload-arch PROPERTY LOCATION)
else()
  find_program(LIBOMPTARGET_OFFLOAD_ARCH NAMES offload-arch
               PATHS ${LLVM_TOOLS_BINARY_DIR})
endif()

################################################################################
# Looking for NVIDIA GPUs...
################################################################################
set(LIBOMPTARGET_DEP_CUDA_ARCH "sm_35")

if(TARGET nvptx-arch)
  get_property(LIBOMPTARGET_NVPTX_ARCH TARGET nvptx-arch PROPERTY LOCATION)
else()
  find_program(LIBOMPTARGET_NVPTX_ARCH NAMES nvptx-arch
               PATHS ${LLVM_TOOLS_BINARY_DIR})
endif()

if(LIBOMPTARGET_NVPTX_ARCH)
  execute_process(COMMAND ${LIBOMPTARGET_NVPTX_ARCH}
                  OUTPUT_VARIABLE LIBOMPTARGET_NVPTX_ARCH_OUTPUT
                  OUTPUT_STRIP_TRAILING_WHITESPACE)
  string(REPLACE "\n" ";" nvptx_arch_list "${LIBOMPTARGET_NVPTX_ARCH_OUTPUT}")
  if(nvptx_arch_list)
    set(LIBOMPTARGET_FOUND_NVIDIA_GPU TRUE)
    set(LIBOMPTARGET_NVPTX_DETECTED_ARCH_LIST "${nvptx_arch_list}")
    list(GET nvptx_arch_list 0 LIBOMPTARGET_DEP_CUDA_ARCH)
  endif()
endif()


################################################################################
# Looking for AMD GPUs...
################################################################################

if(TARGET amdgpu-arch)
  get_property(LIBOMPTARGET_AMDGPU_ARCH TARGET amdgpu-arch PROPERTY LOCATION)
else()
  find_program(LIBOMPTARGET_AMDGPU_ARCH NAMES amdgpu-arch
               PATHS ${LLVM_TOOLS_BINARY_DIR})
endif()

if(LIBOMPTARGET_AMDGPU_ARCH)
  execute_process(COMMAND ${LIBOMPTARGET_AMDGPU_ARCH}
                  OUTPUT_VARIABLE LIBOMPTARGET_AMDGPU_ARCH_OUTPUT
                  OUTPUT_STRIP_TRAILING_WHITESPACE)
  string(REPLACE "\n" ";" amdgpu_arch_list "${LIBOMPTARGET_AMDGPU_ARCH_OUTPUT}")
  if(amdgpu_arch_list)
    set(LIBOMPTARGET_FOUND_AMDGPU_GPU TRUE)
    set(LIBOMPTARGET_AMDGPU_DETECTED_ARCH_LIST "${amdgpu_arch_list}")
  endif()
endif()

################################################################################
# Looking for Level0
################################################################################
find_path(LIBOMPTARGET_DEP_LEVEL_ZERO_INCLUDE_DIR NAMES level_zero/ze_api.h)

if(NOT LIBOMPTARGET_DEP_LEVEL_ZERO_INCLUDE_DIR)
  set(LIBOMPTARGET_DEP_LEVEL_ZERO_FOUND FALSE)
else()
  set(LIBOMPTARGET_DEP_LEVEL_ZERO_FOUND TRUE)
  find_library(LIBOMPTARGET_DEP_LEVEL_ZERO_LIBRARY NAMES ze_loader)
endif()

if(LIBOMPTARGET_OFFLOAD_ARCH)
  execute_process(COMMAND ${LIBOMPTARGET_OFFLOAD_ARCH} "--only=intel"
                  OUTPUT_VARIABLE LIBOMPTARGET_INTELGPU_ARCH_OUTPUT
                  OUTPUT_STRIP_TRAILING_WHITESPACE)
  string(REPLACE "\n" ";" intelgpu_arch_list "${LIBOMPTARGET_INTELGPU_ARCH_OUTPUT}")
  if(intelgpu_arch_list)
    set(LIBOMPTARGET_FOUND_INTELGPU_GPU TRUE)
    set(LIBOMPTARGET_INTELGPU_DETECTED_ARCH_LIST "${intelgpu_arch_list}")
  endif()
endif()

set(OPENMP_PTHREAD_LIB ${LLVM_PTHREAD_LIB})