protobuf.cmake

include (FindProtobuf)

if(NOT COMMAND protobuf_generate_cpp)
   include(ExternalProject)
   set(PROTOBUF_TARGET external.protobuf)
   set(PROTOBUF_INSTALL_DIR ${CMAKE_CURRENT_BINARY_DIR}/${PROTOBUF_TARGET})
   set(PROTOBUF_INCLUDE_DIRS ${PROTOBUF_INSTALL_DIR}/include)
   include_directories(${PROTOBUF_INCLUDE_DIRS})
   include_directories(${CMAKE_CURRENT_BINARY_DIR})
   IF(CMAKE_BUILD_TYPE MATCHES Debug)
     set(PROTOBUF_LIBRARIES protobufd)
   ELSE()
     set(PROTOBUF_LIBRARIES protobuf)
   ENDIF()
   foreach(lib ${PROTOBUF_LIBRARIES})
     if (MSVC)
       set(LIB_PATH ${PROTOBUF_INSTALL_DIR}/lib/lib${lib}.lib)
     else()
       set(LIB_PATH ${PROTOBUF_INSTALL_DIR}/lib/lib${lib}.a)
     endif()
     list(APPEND PROTOBUF_BUILD_BYPRODUCTS ${LIB_PATH})
     add_library(${lib} STATIC IMPORTED)
     set_property(TARGET ${lib} PROPERTY IMPORTED_LOCATION
                  ${LIB_PATH})
     add_dependencies(${lib} ${PROTOBUF_TARGET})
   endforeach(lib)
   set(PROTOBUF_PROTOC_EXECUTABLE ${PROTOBUF_INSTALL_DIR}/bin/protoc)
   list(APPEND PROTOBUF_BUILD_BYPRODUCTS ${PROTOBUF_PROTOC_EXECUTABLE})
   if(${CMAKE_VERSION} VERSION_LESS "3.10.0")
     set(PROTOBUF_PROTOC_TARGET protoc)
   else()
     set(PROTOBUF_PROTOC_TARGET protobuf::protoc)
   endif()
   if(NOT TARGET ${PROTOBUF_PROTOC_TARGET})
     add_executable(${PROTOBUF_PROTOC_TARGET} IMPORTED)
   endif()
   set_property(TARGET ${PROTOBUF_PROTOC_TARGET} PROPERTY IMPORTED_LOCATION
                ${PROTOBUF_PROTOC_EXECUTABLE})
   add_dependencies(${PROTOBUF_PROTOC_TARGET} ${PROTOBUF_TARGET})

   ExternalProject_Add(${PROTOBUF_TARGET}
       PREFIX ${PROTOBUF_TARGET}
       GIT_REPOSITORY https://android.googlesource.com/platform/external/protobuf
       GIT_TAG ca15ad7fb89a626c0d2a98240b11a2523727f9be
       UPDATE_COMMAND ""
       CONFIGURE_COMMAND ${CMAKE_COMMAND} ${PROTOBUF_INSTALL_DIR}/src/${PROTOBUF_TARGET}/cmake
           -G${CMAKE_GENERATOR}
           -DCMAKE_INSTALL_PREFIX=${PROTOBUF_INSTALL_DIR}
           -DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE}
           -DCMAKE_POSITION_INDEPENDENT_CODE=ON
           -DCMAKE_C_COMPILER:FILEPATH=${CMAKE_C_COMPILER}
           -DCMAKE_CXX_COMPILER:FILEPATH=${CMAKE_CXX_COMPILER}
           -DCMAKE_C_FLAGS=${PROTOBUF_CFLAGS}
           -DCMAKE_CXX_FLAGS=${PROTOBUF_CXXFLAGS}
           -Dprotobuf_BUILD_TESTS=OFF
       BUILD_BYPRODUCTS ${PROTOBUF_BUILD_BYPRODUCTS}
   )

   # cmake 3.7 uses Protobuf_ when 3.5 PROTOBUF_ prefixes.
   set(Protobuf_INCLUDE_DIRS ${PROTOBUF_INCLUDE_DIRS})
   set(Protobuf_LIBRARIES ${PROTOBUF_LIBRARIES})
   set(Protobuf_PROTOC_EXECUTABLE ${PROTOBUF_PROTOC_EXECUTABLE})
endif()