git submodule 与cmake（以Gflags glog为例）

• 为当前项目添加submodule  （以Gflags glog为例）

git submodule add http://172.16.10.13/source_dir/gflags submodules/gflags
git submodule add http://172.16.10.13/source_dir/glog submodules/glog

• 首次clone 项目后，同步submodule

git submodule update --init --recursive

• 项目cmake配置submodule
  • 　　源项目cmake

cmake_minimum_required (VERSION 2.8)

if("${CMAKE_SOURCE_DIR}" STREQUAL "${CMAKE_BINARY_DIR}")
    message(FATAL_ERROR "
    FATAL: In-source builds are not allowed.
           You should create a separate directory for build files.
           ")
endif()

project (test_pro)
aux_source_directory(src DIR_SRCS)
add_executable(test_pro ${DIR_SRCS})
#target_link_libraries(test_pro)

• • 　　添加submodule后cmake

cmake_minimum_required (VERSION 2.8)

if("${CMAKE_SOURCE_DIR}" STREQUAL "${CMAKE_BINARY_DIR}")
    message(FATAL_ERROR "
    FATAL: In-source builds are not allowed.
           You should create a separate directory for build files.
           ")
endif()

project (test_pro)
aux_source_directory(src DIR_SRCS)

### LOCALCMAKE_TOOLCHAIN 编译平台选择 例如：cmake -DLOCALCMAKE_TOOLCHAIN:STRING=1804 ..
### 设置submodule编译输出的位置
set(CMAKE_BUILD_DIR ${CMAKE_CURRENT_SOURCE_DIR}/bld_${LOCALCMAKE_TOOLCHAIN})

#Glog Gflags 静态库位置
set(GLOG_LIBRARY
    ${CMAKE_BUILD_DIR}/glog/lib/libglog.a
    )
set(GFLAGS_LIBRARY
    ${CMAKE_BUILD_DIR}/gflags/lib/libgflags.a
    )

#Glog 自动化编译
add_dependencies(test_pro Glog)
add_custom_command(
        WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/submodules/glog/build.static
        OUTPUT ${CMAKE_BUILD_DIR}/glog/include
        OUTPUT ${CMAKE_BUILD_DIR}/glog/lib/libglog.a
        COMMAND rm CMake* cmake* Makefile -rf
        COMMAND cmake -DCMAKE_INSTALL_PREFIX=${CMAKE_BUILD_DIR}/glog -DCMAKE_PREFIX_PATH=${CMAKE_BUILD_DIR}/gflags/ ..
        COMMAND make -j$(nproc)
        COMMAND make install)
        
#Glog make install 安装输出文件
add_custom_target(Glog
        DEPENDS ${CMAKE_BUILD_DIR}/gflags/lib/libgflags.a
        DEPENDS ${CMAKE_BUILD_DIR}/glog/include
        DEPENDS ${CMAKE_BUILD_DIR}/glog/lib/libglog.a
        )

#Gflags 自动化编译
add_dependencies(test_pro Gflags)
add_custom_command(
        WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/submodules/gflags/build.static
        OUTPUT ${CMAKE_BUILD_DIR}/gflags/include
        OUTPUT ${CMAKE_BUILD_DIR}/gflags/lib/libgflags.a
        COMMAND rm CMake* cmake* Makefile -rf
        COMMAND cmake -DCMAKE_INSTALL_PREFIX=${CMAKE_BUILD_DIR}/gflags -DCMAKE_TOOLCHAIN_FILE=${CMAKE_TOOLCHAIN_FILE} ..
        COMMAND make -j$(nproc)
        COMMAND make install)
        
#Gflags make install 安装输出文件
add_custom_target(Gflags
        DEPENDS ${CMAKE_BUILD_DIR}/gflags/include
        DEPENDS ${CMAKE_BUILD_DIR}/gflags/lib/libgflags.a
        )
    
add_executable(test_pro ${DIR_SRCS})

#项目对Glog Gflags的依赖
target_link_libraries(test_pro
            ${GLOG_LIBRARY}
            ${GFLAGS_LIBRARY})