cmake_minimum_required (VERSION 3.2)
project (xgboost)
find_package(OpenMP)

option(PLUGIN_UPDATER_GPU "Build GPU accelerated tree construction plugin")
if(PLUGIN_UPDATER_GPU)
  cmake_minimum_required (VERSION 3.5)
endif()

set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${OpenMP_CXX_FLAGS}")

if(NOT MSVC)
  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fPIC -O3 -funroll-loops -msse2 -D_MWAITXINTRIN_H_INCLUDED -D_FORCE_INLINES")
endif()


# Make sure we are using C++11
# Visual Studio 12.0 and newer supports enough c++11 to make this work
if(MSVC)
  if(MSVC_VERSION LESS 1800)
    message(STATUS "The compiler ${CMAKE_CXX_COMPILER} has no C++11 support. Please use a different C++ compiler.")
  endif()
else()
  # GCC 4.6 with c++0x supports enough to make this work
  include(CheckCXXCompilerFlag)
  CHECK_CXX_COMPILER_FLAG("-std=c++11" COMPILER_SUPPORTS_CXX11)
  CHECK_CXX_COMPILER_FLAG("-std=c++0x" COMPILER_SUPPORTS_CXX0X)

  set(STD_FLAG "")
  if(COMPILER_SUPPORTS_CXX11)
    set(STD_FLAG "-std=c++11")
  elseif(COMPILER_SUPPORTS_CXX0X)
    set(STD_FLAG "-std=c++0x")
  else()
    message(STATUS "The compiler ${CMAKE_CXX_COMPILER} has no C++11 support. Please use a different C++ compiler.")
  endif()
  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${STD_FLAG}")
endif()

#Make sure we are using the static runtime
if(MSVC)
    set(variables
        CMAKE_C_FLAGS_DEBUG
        CMAKE_C_FLAGS_MINSIZEREL
        CMAKE_C_FLAGS_RELEASE
        CMAKE_C_FLAGS_RELWITHDEBINFO
        CMAKE_CXX_FLAGS_DEBUG
        CMAKE_CXX_FLAGS_MINSIZEREL
        CMAKE_CXX_FLAGS_RELEASE
        CMAKE_CXX_FLAGS_RELWITHDEBINFO
    )
    foreach(variable ${variables})
        if(${variable} MATCHES "/MD")
            string(REGEX REPLACE "/MD" "/MT" ${variable} "${${variable}}")
        endif()
    endforeach()
endif()

include_directories (
    ${PROJECT_SOURCE_DIR}/include
    ${PROJECT_SOURCE_DIR}/dmlc-core/include
    ${PROJECT_SOURCE_DIR}/rabit/include
)

file(GLOB SOURCES
    src/c_api/*.cc
    src/common/*.cc
    src/data/*.cc
    src/gbm/*.cc
    src/metric/*.cc
    src/objective/*.cc
    src/tree/*.cc
    src/*.cc
)

set(RABIT_SOURCES
    rabit/src/allreduce_base.cc
    rabit/src/allreduce_robust.cc
    rabit/src/engine.cc
    rabit/src/c_api.cc
)

file(GLOB CUDA_SOURCES
    plugin/updater_gpu/src/*.cu
    plugin/updater_gpu/src/exact/*.cu
)

add_subdirectory(dmlc-core)

add_library(rabit STATIC ${RABIT_SOURCES})

#Set library output directories
if(MSVC)
    #With MSVC shared library is considered runtime
    set(CMAKE_RUNTIME_OUTPUT_DIRECTORY_RELEASE ${PROJECT_SOURCE_DIR}/lib)
    set(CMAKE_LIBRARY_OUTPUT_DIRECTORY_RELEASE ${PROJECT_SOURCE_DIR}/lib)
    set(CMAKE_RUNTIME_OUTPUT_DIRECTORY_DEBUG ${PROJECT_SOURCE_DIR}/lib)
    set(CMAKE_LIBRARY_OUTPUT_DIRECTORY_DEBUG ${PROJECT_SOURCE_DIR}/lib)
else()
    set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${PROJECT_SOURCE_DIR}/lib)
    set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${PROJECT_SOURCE_DIR})
endif()

set(LINK_LIBRARIES dmlccore rabit)

if(PLUGIN_UPDATER_GPU)
  find_package(CUDA REQUIRED)
  
  # nccl
  add_subdirectory(nccl)
  set(NCCL_DIRECTORY ${PROJECT_SOURCE_DIR}/nccl)
  include_directories(${NCCL_DIRECTORY}/src)

  #Find cub
  set(CUB_DIRECTORY ${PROJECT_SOURCE_DIR}/cub/)
  include_directories(${CUB_DIRECTORY})

  #Find googletest
  set(GTEST_DIRECTORY "${CACHE_PREFIX}" CACHE PATH "Googletest directory")
  include_directories(${GTEST_DIRECTORY}/include)

  #gencode flags
  set(GPU_COMPUTE_VER 35;50;52;60;61 CACHE STRING
    "Space separated list of compute versions to be built against")
  
  set(GENCODE_FLAGS "")
  foreach(ver ${GPU_COMPUTE_VER})
    set(GENCODE_FLAGS "${GENCODE_FLAGS}-gencode arch=compute_${ver},code=sm_${ver};")
  endforeach()
  set(CUDA_NVCC_FLAGS "${CUDA_NVCC_FLAGS};--expt-extended-lambda;${GENCODE_FLAGS};-lineinfo;")
  if(NOT MSVC)
    set(CUDA_NVCC_FLAGS "${CUDA_NVCC_FLAGS};-Xcompiler -fPIC")
  endif()

  cuda_add_library(gpuxgboost ${CUDA_SOURCES} STATIC)
  target_link_libraries(gpuxgboost nccl)
  list(APPEND LINK_LIBRARIES gpuxgboost) 
  list(APPEND SOURCES plugin/updater_gpu/src/register_updater_gpu.cc) 
else()
  set(CUDA_OBJS "")
endif()

add_library(objxgboost OBJECT ${SOURCES})
set_target_properties(${objxgboost} PROPERTIES POSITION_INDEPENDENT_CODE 1)

add_executable(runxgboost $<TARGET_OBJECTS:objxgboost>)
set_target_properties(runxgboost PROPERTIES OUTPUT_NAME xgboost)
target_link_libraries(runxgboost ${LINK_LIBRARIES})

add_library(xgboost SHARED $<TARGET_OBJECTS:objxgboost>)
target_link_libraries(xgboost ${LINK_LIBRARIES})

#Ensure these two targets do not build simultaneously, as they produce outputs with conflicting names
add_dependencies(xgboost runxgboost)

option(JVM_BINDINGS "Build JVM bindings" OFF)

if(JVM_BINDINGS)
    find_package(JNI QUIET REQUIRED)

    include_directories(${JNI_INCLUDE_DIRS} jvm-packages/xgboost4j/src/native)

    add_library(xgboost4j SHARED
        $<TARGET_OBJECTS:objxgboost>
        jvm-packages/xgboost4j/src/native/xgboost4j.cpp)
    target_link_libraries(xgboost4j
        ${LINK_LIBRARIES}
        ${JAVA_JVM_LIBRARY})
endif()