# Copyright 2021 Google LLC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      https://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

cmake_policy(SET CMP0012 NEW)
cmake_policy(SET CMP0048 NEW)
project(ruy CXX)
cmake_minimum_required(VERSION 3.13)  # Copied from IREE
set(CMAKE_CXX_STANDARD 14)

include(GNUInstallDirs)

if (PROJECT_NAME STREQUAL CMAKE_PROJECT_NAME)
  set(RUY_IS_TOPLEVEL TRUE)
  set(RUY_MINIMAL_BUILD_DEFAULT_VALUE OFF)
else()
  set(RUY_IS_TOPLEVEL FALSE)
  set(RUY_MINIMAL_BUILD_DEFAULT_VALUE ON)
endif()

option(RUY_MINIMAL_BUILD "Disable ruy's tests, examples, etc. Build only ruy public libraries." ${RUY_MINIMAL_BUILD_DEFAULT_VALUE})
if (NOT RUY_MINIMAL_BUILD)
  enable_testing()
endif()

option(RUY_PROFILER "Enable ruy's built-in profiler (harms performance)" OFF)

option(RUY_ENABLE_INSTALL "Enable install rule" ${RUY_IS_TOPLEVEL})

include(cmake/ruy_add_all_subdirs.cmake)
include(cmake/ruy_cc_library.cmake)
include(cmake/ruy_cc_binary.cmake)
include(cmake/ruy_cc_test.cmake)

option(RUY_FIND_CPUINFO "Use find_package to find cpuinfo" OFF)

# Skip cpuinfo if it was already generated, which can happen when ruy is
# a subdirectory in a wider project that already uses cpuinfo.
if (NOT TARGET cpuinfo::cpuinfo)
  if (RUY_FIND_CPUINFO)
    find_package(cpuinfo REQUIRED)
  else()
    # Test if the third_party/cpuinfo submodule was checked out before
    # adding that subdirectory, so we can do more helpful things below in the
    # else() block when it's not.
    set(RUY_CPUINFO_CMAKELISTS_FILE "${CMAKE_CURRENT_SOURCE_DIR}/third_party/cpuinfo/CMakeLists.txt")
    if (EXISTS "${RUY_CPUINFO_CMAKELISTS_FILE}")
      # Disabling cpuinfo's tests and benchmarks to prevent a copy of its
      # googletest dependency getting downloaded into a 'deps' directory in the
      # source tree!
      set(CPUINFO_BUILD_BENCHMARKS OFF CACHE BOOL "" FORCE)
      set(CPUINFO_BUILD_UNIT_TESTS OFF CACHE BOOL "" FORCE)
      set(CPUINFO_BUILD_MOCK_TESTS OFF CACHE BOOL "" FORCE)
      add_subdirectory("third_party/cpuinfo" EXCLUDE_FROM_ALL)
    else()
      # third_party/cpuinfo is not checked out. That could be intentional when
      # ruy is a subdirectory in a wider project that is already providing
      # the cpuinfo target. Maybe that wider project's CMakeLists is ordered
      # in such a way that cpuinfo gets generated after ruy. In that case,
      # it's helpful that we continue silently. In the worst case if the cpuinfo
      # target never gets defined, ruy will fail to compile.
      # On the other hand, if ruy is the top-level project here (not part of a
      # wider project) then nothing will define the cpuinfo target for us,
      # so we will definitely fail to compile, so we may as well fail right here.
      if (RUY_IS_TOPLEVEL)
        message(FATAL_ERROR "This file does not exist:\n${RUY_CPUINFO_CMAKELISTS_FILE}\n"
                      "That typically means that the git submodules of the ruy "
                      "repository haven't been checked out. Try this in the ruy "
                      "git directory:\n  git submodule update --init")
      endif()
    endif()
  endif()
endif()

# googletest is only needed for tests. Projects embedding ruy as a subdirectory
# and not needing to build ruy tests may proceed without a local checkout of
# third_party/googletest.
if (NOT RUY_MINIMAL_BUILD
    AND NOT TARGET gtest
    AND EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/third_party/googletest/CMakeLists.txt")
  add_subdirectory("third_party/googletest" EXCLUDE_FROM_ALL)
endif()

add_subdirectory("ruy")

if (NOT RUY_MINIMAL_BUILD)
  add_subdirectory("example")
endif()

if (RUY_ENABLE_INSTALL)
  install(EXPORT ${PROJECT_NAME}Targets
    NAMESPACE ${PROJECT_NAME}::
    DESTINATION "${CMAKE_INSTALL_LIBDIR}/cmake/${PROJECT_NAME}"
  )

  include(CMakePackageConfigHelpers)

  configure_package_config_file(
    "cmake/${PROJECT_NAME}Config.cmake.in"
    "${PROJECT_BINARY_DIR}/${PROJECT_NAME}Config.cmake"
    INSTALL_DESTINATION "${CMAKE_INSTALL_LIBDIR}/cmake/${PROJECT_NAME}"
  )

  install(FILES "${PROJECT_BINARY_DIR}/${PROJECT_NAME}Config.cmake"
    DESTINATION "${CMAKE_INSTALL_LIBDIR}/cmake/${PROJECT_NAME}"
  )
endif()