CMakeLists.txt

cmake_minimum_required(VERSION 3.13)
project(MParT VERSION 2.2.1)

message(STATUS "Will install MParT to ${CMAKE_INSTALL_PREFIX}")

# Add the cmake folder as a search path and include files
LIST(APPEND CMAKE_MODULE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/cmake/)
Include(FetchContent)

# #############################################################
# Options
option(MPART_PYTHON "Build python bindings with pybind11" ON)
option(MPART_MATLAB "Build matlab bindings with pybind11" ON)
option(MPART_JULIA "Build julia bindings with CxxWrap.jl" ON)
option(MPART_FETCH_DEPS "If CMake should be allowed to fetch and build external dependencies that weren't found." ON)
option(MPART_ARCHIVE "If MParT should build with support to serialize data using the cereal library" ON)
option(MPART_OPT "Build MParT with NLopt optimization library" ON)

# #############################################################
# Installation path configuration
Include(SetInstallPaths)

# #############################################################
# Compiler configuration

# Set the C++ version
set(CMAKE_CXX_STANDARD 17 CACHE STRING "C++ version selection") # or 11, 14, 17, 20
set(CMAKE_CXX_STANDARD_REQUIRED ON) # optional, ensure standard is supported

# Set the build type to Release if it's not explicity set already
if(NOT CMAKE_BUILD_TYPE)
    set(CMAKE_BUILD_TYPE Release)
endif()

set(COMPILER_IS_NVCC OFF)

include(CheckCXXCompilerFlag)
check_cxx_compiler_flag("-Wno-deprecated-gpu-targets" COMPILER_IS_NVCC1)
check_cxx_compiler_flag("--expt-relaxed-constexpr" COMPILER_IS_NVCC2)

if(COMPILER_IS_NVCC1 AND COMPILER_IS_NVCC2)
    add_definitions(-DMPART_ENABLE_GPU)
    message(STATUS "GPU support detected")
    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-deprecated-gpu-targets --expt-relaxed-constexpr")
    add_compile_definitions(EIGEN_NO_CUDA)
    set(COMPILER_IS_NVCC ON)
endif()

set(CMAKE_CXX_FLAGS_DEBUG "-g")
set(CMAKE_CXX_FLAGS_RELEASE "-O3")

option(BUILD_SHARED_LIBS "Build using shared libraries" ON)

# #############################################################
# RPATH settings
# See https://gist.github.com/kprussing/db21614ca5b51cedff07dfb70059f280 for scikit-build example

# use, i.e. don't skip the full RPATH for the build tree
set(CMAKE_SKIP_BUILD_RPATH FALSE)

# when building, don't use the install RPATH already
# (but later on when installing)
set(CMAKE_BUILD_WITH_INSTALL_RPATH FALSE)

set(CMAKE_INSTALL_RPATH "${CMAKE_INSTALL_PREFIX}/lib")

# add the automatically determined parts of the RPATH
# which point to directories outside the build tree to the install RPATH
set(CMAKE_INSTALL_RPATH_USE_LINK_PATH TRUE)

# the RPATH to be used when installing, but only if it's not a system directory
list(FIND CMAKE_PLATFORM_IMPLICIT_LINK_DIRECTORIES "${CMAKE_INSTALL_PREFIX}/lib" isSystemDir)

# if("${isSystemDir}" STREQUAL "-1")
#     set(CMAKE_INSTALL_RPATH "${CMAKE_INSTALL_PREFIX}/lib")
# endif("${isSystemDir}" STREQUAL "-1")

# #############################################################
# Dependencies

# Add Kokkos
find_package(Kokkos QUIET)

if(NOT Kokkos_FOUND)
    IF(MPART_FETCH_DEPS)
        message(STATUS "Could not find Kokkos.  Fetching source.")

        FetchContent_Declare(
            kokkos
            GIT_REPOSITORY https://github.com/kokkos/kokkos
            GIT_TAG 3.7.00
            GIT_SHALLOW TRUE
        )
        FetchContent_MakeAvailable(kokkos)
    else()
        message(FATAL_ERROR "Could not find Kokkos library and MPART_FETCH_DEPS=OFF, so CMake will not attempt to fetch and install Kokkos itself.")
    endif()
else()
    message(STATUS "Found Kokkos!")
endif()

if(${COMPILER_IS_NVCC})
    message(STATUS "Searching for CUBLAS and CUSOLVER linear algebra libraries.")
    find_package(CUDAToolkit COMPONENTS cudart cublas cusolver REQUIRED)
    set(CUDA_LIBRARIES CUDA::cudart CUDA::cublas CUDA::cusolver)

else()
    message(STATUS "MParT is not compiled with CUDA support, so CUBLAS and CUSOLVER will not be used.")
    set(CUDA_LIBRARIES "")
endif()

# Add Eigen
find_package(Eigen3 QUIET)

if(NOT Eigen3_FOUND)
    if(MPART_FETCH_DEPS)
        message(STATUS "Could not find Eigen. Fetching source.")

        FetchContent_Declare(
            eigen3
            GIT_REPOSITORY https://gitlab.com/libeigen/eigen
            GIT_TAG 3.4.0
            GIT_SHALLOW TRUE
        )
        FetchContent_MakeAvailable(eigen3)
    else()
        message(FATAL_ERROR "Could not find Eigen3 library and MPART_FETCH_DEPS=OFF, so CMake will not attempt to fetch and install Eigen3 itself.")
    endif()
else()
    message(STATUS "Found Eigen: ${Eigen_DIR}")
endif()

# Add pybind11 if necessary
if(MPART_PYTHON)
    find_package(pybind11 CONFIG QUIET)

    if(NOT pybind11_FOUND)
        if(${MPART_FETCH_DEPS})
            message(STATUS "Could not find pybind11. Fetching source.")

            FetchContent_Declare(
                pybind11
                GIT_REPOSITORY https://github.com/pybind/pybind11
                GIT_TAG v2.10.0
                GIT_SHALLOW TRUE
            )
            FetchContent_MakeAvailable(pybind11)
        else()
            message(FATAL_ERROR "Could not find pybind11 library and MPART_FETCH_DEPS=OFF, so CMake will not attempt to fetch and install pybind11 itself.")
        endif()

    else()
        message(STATUS "Found pybind11: ${pybind11_DIR}")
    endif()
endif()

# Add Julia if necessary
if(MPART_JULIA)
    find_package(Julia)

    if(NOT Julia_FOUND)
        set(MPART_JULIA OFF)
        message(WARNING "Requested Julia bindings but CMake could not find Julia executable.  Setting MPART_JULIA=OFF.")
    else()
        # Get a hint for the location of JlCxx
        get_filename_component(PARENT_DIR ${Julia_LIBRARY_DIR} DIRECTORY)

        # Use JlCxx_DIR to tell where CxxWrap is located
        if(NOT DEFINED JlCxx_DIR)
            execute_process(COMMAND ${Julia_EXECUTABLE} -e "import CxxWrap; print(CxxWrap.prefix_path())" OUTPUT_VARIABLE cxxwrap_location)
            set(JlCxx_DIR "${cxxwrap_location}/lib/cmake/JlCxx/")
        endif()

        find_package(JlCxx)

        if(NOT JlCxx_FOUND)
            set(MPART_JULIA OFF)
            message(WARNING "Requested Julia bindings but CMake could not find JlCxx package.  Setting MPART_JULIA=OFF.")
        else()
            get_target_property(JlCxx_location JlCxx::cxxwrap_julia LOCATION)
            message(STATUS "Found JlCxx: ${JlCxx_location}")

            add_definitions(-DJULIA_ENABLE_THREADING)
            set(CMAKE_INSTALL_RPATH "${CMAKE_INSTALL_PREFIX}/lib;${Julia_LIBRARY_DIR}")
            set(CMAKE_INSTALL_RPATH_USE_LINK_PATH TRUE)
        endif()
    endif()
endif()

# Add cereal if necessary
if(MPART_ARCHIVE)
    find_package(cereal QUIET)
    if(NOT cereal_FOUND)
        if(${MPART_FETCH_DEPS})
            message(STATUS "Could not find Cereal. Fetching source.")

            FetchContent_Declare(
                cereal
                GIT_REPOSITORY https://github.com/USCiLab/cereal
                GIT_TAG v1.3.2
                GIT_SHALLOW TRUE
            )
            set(JUST_INSTALL_CEREAL ON)
            FetchContent_MakeAvailable(cereal)
        else()
            set(MPART_ARCHIVE OFF)
            message(FATAL_ERROR "Could not find cereal library and MPART_FETCH_DEPS=OFF, so CMake will not attempt to fetch and install cereal itself.")
        endif()
    else()
        message(STATUS "Found cereal: ${cereal_DIR}")
    endif()
endif()

if(MPART_ARCHIVE)
    add_definitions(-DMPART_HAS_CEREAL)
    set(EXT_LIBRARIES cereal::cereal)
else()
    set(EXT_LIBRARIES "")
endif()

# Add NLopt if necessary
if(MPART_OPT)
    find_package(NLopt QUIET)
    if(NOT NLopt_FOUND)
        if(${MPART_FETCH_DEPS})
            message(STATUS "Could not find NLopt. Fetching source.")

            FetchContent_Declare(
                NLopt
                GIT_REPOSITORY https://github.com/stevengj/nlopt/
                GIT_TAG v2.7.1
                GIT_SHALLOW TRUE
            )
            FetchContent_MakeAvailable(NLopt)
            add_library(NLopt::nlopt ALIAS nlopt)
        else()
            set(MPART_OPT OFF)
            message(FATAL_ERROR "Could not find NLopt library and MPART_FETCH_DEPS=OFF, so CMake will not attempt to fetch and install NLopt itself.")
        endif()
    else()
        message(STATUS "Found NLopt: ${NLopt_DIR}")
    endif()
endif()

if(MPART_OPT)
    add_definitions(-DMPART_HAS_NLOPT)
    set(EXT_LIBRARIES ${EXT_LIBRARIES} NLopt::nlopt)
endif()

# #############################################################
# MParT library
add_library(mpart "")
add_library(MParT::mpart ALIAS mpart)


target_link_libraries(mpart PRIVATE Kokkos::kokkos Eigen3::Eigen ${CUDA_LIBRARIES} ${EXT_LIBRARIES})

target_include_directories(mpart
    PUBLIC
    $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>
    $<INSTALL_INTERFACE:include>
)

add_subdirectory(src)

if(MPART_PYTHON)
    add_subdirectory(bindings/python)
endif()

if(MPART_JULIA)
    add_subdirectory(bindings/julia)
endif()

# Add matlab if necessary
if(MPART_MATLAB)
    find_package(Matlab)

    if(Matlab_FOUND)
        add_subdirectory(bindings/matlab)
    else()
        message(STATUS "Could not find matlab.  Matlab bindings will not be built.")
    endif()
endif()

# #############################################################
# Testing
option(MPART_BUILD_TESTS "If ON, unit tests will be built." ON)

if(MPART_BUILD_TESTS)
    # Install Catch2
    find_package(Catch2 QUIET)

    if(NOT Catch2_FOUND)
        IF(MPART_FETCH_DEPS)
            message(STATUS "Could not find Catch2.  Fetching Catch2 source.")

            FetchContent_Declare(
                Catch2
                GIT_REPOSITORY https://github.com/catchorg/Catch2.git
                GIT_TAG v3.2.1
            )

            FetchContent_MakeAvailable(Catch2)
        else()
            message(WARNING "Could not find Catch library and MPART_FETCH_DEPS=OFF, so CMake will not attempt to fetch and install Catch2 itself.  Tests will not be built.")
            set(MPART_BUILD_TESTS OFF)
        endif()

    else()
        message(STATUS "Found Catch2: ${Catch2_DIR}")
    endif()
endif()

if(MPART_BUILD_TESTS)
    # Define test sources
    add_subdirectory(tests)
    add_executable(RunTests ${TEST_SOURCES})
    target_link_libraries(RunTests PRIVATE mpart Catch2::Catch2 Kokkos::kokkos Eigen3::Eigen ${CUDA_LIBRARIES} ${EXT_LIBRARIES})
endif()

add_executable(PrintKokkosInfo tests/KokkosInfo.cpp)
target_link_libraries(PrintKokkosInfo Kokkos::kokkos)

# #############################################################
# Installation
install(TARGETS mpart
    EXPORT MParTTargets
    DESTINATION lib)

install(DIRECTORY MParT
    DESTINATION include
    FILES_MATCHING PATTERN "*.h")

include(CMakePackageConfigHelpers)

configure_package_config_file(${CMAKE_CURRENT_SOURCE_DIR}/Config.cmake.in
    "${CMAKE_CURRENT_BINARY_DIR}/MParTConfig.cmake"
    INSTALL_DESTINATION "${CMAKE_INSTALL_PREFIX}/lib/cmake"
    NO_SET_AND_CHECK_MACRO
    NO_CHECK_REQUIRED_COMPONENTS_MACRO
)

write_basic_package_version_file(
    ${CMAKE_CURRENT_BINARY_DIR}/MParTConfigVersion.cmake
    VERSION "${PROJECT_VERSION}"
    COMPATIBILITY SameMajorVersion
)

install(FILES
    ${CMAKE_CURRENT_BINARY_DIR}/MParTConfig.cmake
    ${CMAKE_CURRENT_BINARY_DIR}/MParTConfigVersion.cmake
    DESTINATION lib/cmake/MParT
)

export(TARGETS mpart ${KOKKOS_EXPORTS} NAMESPACE MParT:: FILE MParTTargets.cmake)
export(PACKAGE MParT)

install(EXPORT MParTTargets NAMESPACE MParT:: DESTINATION lib/cmake/MParT)

install(FILES ${CMAKE_CURRENT_BINARY_DIR}/MParTConfig.cmake
    ${CMAKE_CURRENT_BINARY_DIR}/MParTConfigVersion.cmake
    DESTINATION lib/cmake/MParT)

# #############################################################
# Documentation
Include(BuildDocs)

# #############################################################