开源项目学习(6)---- CMake demo 分析

- 日理万妓 2024-02-26 07:48 29阅读 0赞

#### 目录 ####

*   *   *  常用的CMake demo
         *  libyuv 的CMake 参考

#### 常用的CMake demo ####

针对自己写的 C++ demo 的 CMakeLists.txt 如下：

# CMakeLists for stl_demo
    # 2023.8.6 first initialize
    
    # set(CMAKE_LEGACY_CYGWIN_WIN32 0)
    PROJECT ( stl_demo )	# "C" is required even for C++ projects
    CMAKE_MINIMUM_REQUIRED( VERSION 2.9 )
    
    OPTION( BUILSTATICLIB "Build static library" OFF )
    OPTION( BUILDDYNAMICLIB "Build dynamic library" OFF )
    OPTION( BUILONEBIN "Build single bin" ON )
    
    SET (  base_dir	${
        PROJECT_SOURCE_DIR} )
    FILE ( GLOB_RECURSE	demo_src ${
        base_dir}/source/*.cpp )
    LIST ( SORT			demo_src )
    
    SET ( inc_dir	${base_dir}/include )
    list(APPEND inc_dir ${base_dir}/Cdemo/include)
    
    SET ( lib_name	stldemo )
    SET ( lib_static	${lib_name} )
    SET ( lib_shared	${lib_name}_shared )
    
    add_definitions( -DBUILDTYPE_CMAKE )
    add_definitions( -DFLAGS )  
    
    INCLUDE_DIRECTORIES(${inc_dir})
    set(EXECUTABLE_OUTPUT_PATH  ${PROJECT_SOURCE_DIR}/output)
    set(LIBRARY_OUTPUT_PATH  ${PROJECT_SOURCE_DIR}/output)
    
    if(BUILONEBIN)
    message(WARNING "enter BUILONEBIN")
    list(APPEND demo_src )
    #this creates the conversion tool
    ADD_EXECUTABLE( stl_demo  ${demo_src})
    elseif(BUILSTATICLIB)
    message(WARNING "enter BUILSTATICLIB")
    ADD_LIBRARY( ${lib_static} STATIC ${demo_src} )
    ADD_EXECUTABLE			( stl_demo_staticlink ${base_dir}/demoMain.cpp )
    TARGET_LINK_LIBRARIES	( stl_demo_staticlink ${lib_static} )
    
    elseif(BUILDDYNAMICLIB)
    message(WARNING "enter BUILDDYNAMICLIB")
    ADD_LIBRARY(${lib_shared} SHARED ${demo_src} )
    TARGET_LINK_LIBRARIES	( stl_demo_dynamiclink ${lib_shared} )
    SET_TARGET_PROPERTIES	( ${ly_lib_shared} PROPERTIES OUTPUT_NAME "${ly_lib_name}" )
    SET_TARGET_PROPERTIES	( ${ly_lib_shared} PROPERTIES PREFIX "lib" )
    
    ADD_EXECUTABLE			( stl_demo_dynamiclink ${base_dir}/demoMain.cpp )
    endif()

分析：

*  Option 选项是可以配置的选项，注意如果是在 Linux 环境中，使用的是 ccmake 命令，ccmake 是Linux 下使用 ncurses 的图形化命令配置界面，需要单独安装，deepin 下安装命令如下：

sudo apt-get install cmake-curses-gui

*  使用 **INCLUDE\_DIRECTORIES** 设置头文件的包含目录，多个头文件路径可以使用变量的方式传入
 *  **add\_definitions** 添加宏定义和编译选项
 *  **ADD\_EXECUTABLE** 添加可执行文件，**ADD\_LIBRARY** 添加静态库和动态库
 *  **TARGET\_LINK\_LIBRARIES** 添加链接的静态库和动态库
 *  注意 if 语句中可以直接使用变量名，**不需要加引用的方式**
 *  使用下面的命令可以收集所有的 cpp 文件；

FILE ( GLOB_RECURSE	demo_src ${
        base_dir}/source/*.cpp )

*  使用 list 可以添加并收集一连串的变量集合

SET ( inc_dir	${
        base_dir}/include )
    # append C demo Header File
    list(APPEND inc_dir ${
        base_dir}/Cdemo/include)

#### libyuv 的CMake 参考 ####

开源第三方库 libyuv 的CMake 主体

PROJECT ( YUV C CXX )	# "C" is required even for C++ projects
    CMAKE_MINIMUM_REQUIRED( VERSION 2.8 )
    OPTION( TEST "Built unit tests" OFF )
    
    SET ( ly_base_dir	${
        PROJECT_SOURCE_DIR} )
    SET ( ly_src_dir	${
        ly_base_dir}/source )
    SET ( ly_inc_dir	${
        ly_base_dir}/include )
    SET ( ly_tst_dir	${
        ly_base_dir}/unit_test )
    SET ( ly_lib_name	yuv )
    SET ( ly_lib_static	${
        ly_lib_name} )
    SET ( ly_lib_shared	${
        ly_lib_name}_shared )
    
    FILE ( GLOB_RECURSE	ly_source_files ${
        ly_src_dir}/*.cc )
    LIST ( SORT			ly_source_files )
    
    FILE ( GLOB_RECURSE	ly_unittest_sources ${ly_tst_dir}/*.cc )
    LIST ( SORT			ly_unittest_sources )
    
    INCLUDE_DIRECTORIES( BEFORE ${ly_inc_dir} )
    
    # this creates the static library (.a)
    ADD_LIBRARY				( ${ly_lib_static} STATIC ${ly_source_files} )
    
    # this creates the shared library (.so)
    ADD_LIBRARY				( ${ly_lib_shared} SHARED ${ly_source_files} )
    SET_TARGET_PROPERTIES	( ${ly_lib_shared} PROPERTIES OUTPUT_NAME "${ly_lib_name}" )
    SET_TARGET_PROPERTIES	( ${ly_lib_shared} PROPERTIES PREFIX "lib" )
    
    # this creates the conversion tool
    ADD_EXECUTABLE			( yuvconvert ${ly_base_dir}/util/yuvconvert.cc )
    TARGET_LINK_LIBRARIES	( yuvconvert ${ly_lib_static} )

*  **ly\_source\_files** 收集后缀名为 cc 的源文件，**ly\_unittest\_sources** 收集后缀名为 cc 的单元测试源文件
 *  **ly\_inc\_dir** 表示要包含的头文件目录
 *  这里同时生成静态库和动态库文件，并且设置静态库和动态库的名称
 *  生成 yuvconvert 可执行文件用于测试

INCLUDE ( FindJPEG )
    if (JPEG_FOUND)
      include_directories( ${
        JPEG_INCLUDE_DIR} )
      target_link_libraries( yuvconvert ${
        JPEG_LIBRARY} )
      add_definitions( -DHAVE_JPEG )
    endif()

对系统是否包含 libjpeg 的库做判断，如果存在，则加入 yuvconvert 的依赖中

if(TEST)
      find_library(GTEST_LIBRARY gtest)
      if(GTEST_LIBRARY STREQUAL "GTEST_LIBRARY-NOTFOUND")
        set(GTEST_SRC_DIR /usr/src/gtest CACHE STRING "Location of gtest sources")
        if(EXISTS ${
        GTEST_SRC_DIR}/src/gtest-all.cc)
          message(STATUS "building gtest from sources in ${GTEST_SRC_DIR}")
          set(gtest_sources ${
        GTEST_SRC_DIR}/src/gtest-all.cc)
          add_library(gtest STATIC ${
        gtest_sources})
          include_directories(${
        GTEST_SRC_DIR})
          include_directories(${
        GTEST_SRC_DIR}/include)
          set(GTEST_LIBRARY gtest)
        else()
          message(FATAL_ERROR "TEST is set but unable to find gtest library")
        endif()
      endif()
    
      add_executable(libyuv_unittest ${
        ly_unittest_sources})
      target_link_libraries(libyuv_unittest ${
        ly_lib_name} ${
        GTEST_LIBRARY})
      find_library(PTHREAD_LIBRARY pthread)
      if(NOT PTHREAD_LIBRARY STREQUAL "PTHREAD_LIBRARY-NOTFOUND")
        target_link_libraries(libyuv_unittest pthread)
      endif()
      if (JPEG_FOUND)
        target_link_libraries(libyuv_unittest ${
        JPEG_LIBRARY})
      endif()
    
      if(NACL AND NACL_LIBC STREQUAL "newlib")
        target_link_libraries(libyuv_unittest glibc-compat)
      endif()

上面主要是对测试程序链接生成的判断，判断是否包含 gtest lib，pthread lib，jpeg lib，如果有则加入对 libyuv\_unittest 的链接库中  
注意上面使用了 **find\_library(GTEST\_LIBRARY gtest)** 函数用于查找是否存在相关的库

# install the conversion tool, .so, .a, and all the header files
    INSTALL ( PROGRAMS ${
        CMAKE_BINARY_DIR}/yuvconvert			DESTINATION bin )
    INSTALL ( TARGETS ${
        ly_lib_static}						DESTINATION lib )
    INSTALL ( TARGETS ${
        ly_lib_shared} LIBRARY				DESTINATION lib RUNTIME DESTINATION bin )
    INSTALL ( DIRECTORY ${
        PROJECT_SOURCE_DIR}/include/		DESTINATION include )
    
    # create the .deb and .rpm packages using cpack
    INCLUDE ( CM_linux_packages.cmake )

最后使用 install 函数将生成的静态库和动态库安装到相应的目录中，并且包含了 **CM\_linux\_packages.cmake** 用于保存一些通用信息