CMake杂记

1. 在编译过程中打印编印信息

• 执行命令cmake时追加：-DCMAKE_VERBOSE_MAKEFILE=ON
• 在CMakeLists.txt中添加：set(CMAKE_VERBOSE_MAKEFILEON ON)

2. 打印自定义变量及其值

get_cmake_property(_variableNames VARIABLES)
foreach (_variableName ${_variableNames})
    message(STATUS "${_variableName}=${${_variableName}}")
endforeach()

3. 打印环境变量及其值

execute_process(COMMAND "${CMAKE_COMMAND}" "-E" "environment")

4. 多系统区分

if(WIN32)
    # todo: windows action
elseif(APPLE)
    # todo: mac action
elseif(UNIX)
    # todo: linux action
endif()

5. windows下x64和x86区分

if(WINDOWS)
    if(CMAKE_CL_64)
        target_link_libraries (BarcodeReader "DBRx64")
    else()
        target_link_libraries (BarcodeReader "DBRx86")
    endif()
else()
    target_link_libraries (BarcodeReader "DynamsoftBarcodeReader")
endif()

6. 将pthread作为默认线程库

# add pthread library
find_package (Threads)
target_link_libraries(smt-logger ${CMAKE_THREAD_LIBS_INIT})

由于pthread不是linux的默认线程库，需要手动制定。

7. 设置构建类型

#set(CMAKE_BUILD_TYPE "Release")
#set(CMAKE_BUILD_TYPE "Debug")
#set(CMAKE_BUILD_TYPE "MinSizeRel")
#set(CMAKE_BUILD_TYPE "RelWithDebInfo")

8. 编译选项

add_definitions(-Wall)

可以通过add_definitions(xxx)设置编译选项, 常见编译选项列表:

1. -w: 关闭编译时的警告，也就是编译后不显示任何warning，因为有时在编译之后编译器会显示一些例如数据转换之类的警告，这些警告是我们平时可以忽略的。
2. -Wall: 编译后显示所有警告。
3. -W: 类似-Wall，会显示警告，但是只显示编译器认为会出现错误的警告。

9. TARGET的库属性设置

• 仅仅有静态
  • IMPORT_LOCATION=lib路径
• 有动态库且静态库作为链接：
  • IMPORTED_IMPLIB=lib路径
  • IMPORTED_LOCATION=dll路径

// 区分操作系统cpu架构， include 得在project下面
project(smt-logger-test VERSION 0.1.0)
include(CMakeDetermineSystem)

10. 用于寻找依赖库

include(CMakeFindDependencyMacro)
find_dependency(Threads)

11. 给Window的Debug版本加后缀

if(MSVC)
	set(CMAKE_DEBUG_POSTFIX "d")
endif()

12. 判断系统版本

project(app)
include(CMakeDetermineSystem)

13. 生成带版本的so文件

SET_TARGET_PROPERTIES(taos PROPERTIES VERSION 1.6.0.0 SOVERSION 1)

此时会生成如下文件：

libtaos.so -> libtaos.so.1*
libtaos.so.1 -> libtaos.so.1.6.0.0*
libtaos.so.1.6.0.0

14. Copy Qt DLL

COMMAND ${CMAKE_COMMAND} -E copy_if_different
    $<TARGET_FILE:Qt5::Core>
    $<TARGET_FILE:Qt5::Widgets>
    ... etc ...

15. 打印CMake表达式的值

add_custom_command(TARGET Test POST_BUILD
    COMMAND ${CMAKE_COMMAND} -E echo "Runtime Dlls: $<TARGET_RUNTIME_DLLS:Test>")

add_custom_command(TARGET Test POST_BUILD
    COMMAND ${CMAKE_COMMAND} -E echo "Target File: $<TARGET_FILE:${PROJECT_NAME}>")

调试查看CMake的表达式值

16. 拷贝当前项目中别的模块生成的DLL库到example模块里

target_link_libraries(${PROJECT_NAME} PRIVATE
    library1
    library2)

# Copy the output dll files  from library1 and library2 to current module's exe path.
add_custom_command(TARGET ${PROJECT_NAME} POST_BUILD
    COMMAND ${CMAKE_COMMAND} -E copy
    $<TARGET_RUNTIME_DLLS:${PROJECT_NAME}>
    $<TARGET_FILE_DIR:${PROJECT_NAME}>)

这个功能必须cmake版本高于3.21以上才支持

17. QT部署（windeployqt）

if (WIN32)
    add_custom_command(TARGET ${PROJECT_NAME} POST_BUILD
            COMMAND "$ENV{Qt5_DIR}/bin/windeployqt.exe" "$<TARGET_FILE:${PROJECT_NAME}>")
endif ()

需要定义Qt5_DIR环境变量

18. CMake使用MSVC时支持UTF-8

if (WIN32)
    add_compile_options("$<$<C_COMPILER_ID:MSVC>:/utf-8>")
    add_compile_options("$<$<CXX_COMPILER_ID:MSVC>:/utf-8>")
endif ()

19. CMake 静态库与共享库生成

1. 新建XXX_global.h文件，定义XXX_EXPORT

   #ifndef XXX_GLOBAL_H
   #define XXX_GLOBAL_H
   
   #include <QtGlobal>
   
   // Define XXX_SHARED_LIB in you application if you want to link against the
   // sharted version of AppLog
   
   #if defined(_WIN32) && defined(XXX_SHARED_LIB)
   #  if defined(XXX_LIBRARY)
   #    define XXX_EXPORT Q_DECL_EXPORT
   #  else
   #    define XXX_EXPORT Q_DECL_IMPORT
   #  endif
   #else
   #   define XXX_EXPORT
   #endif
   
   #endif //XXX_GLOBAL_H

2. 使用XXX_EXPORT

   class XXX_EXPORT XXX
   {
   };

3. CMakeLists.txt，add_library的库类型由BUILD_SHARED_LIBS指定

   // BUILD_SHARED_LIBS默认为OFF
   option(BUILD_SHARED_LIBS "Specifies the type of libraries (SHARED or STATIC) to build" OFF)
   
   add_library(${PROJECT_NAME} ${XXX_HEADERS} ${XXX_SOURCES})
   
   if (BUILD_SHARED_LIBS)
       target_compile_definitions(${PROJECT_NAME} PUBLIC -DXXX_SHARED_LIB)
       target_compile_definitions(${PROJECT_NAME} PRIVATE -DXXX_LIBRARY)
   endif()

4. 如果使用了Conan，则在conanfile.py中加入

   def generate(self):    
       tc = CMakeToolchain(self)
       // ......
       if self.options.shared == True:
           tc.variables["BUILD_SHARED_LIBS"] = "ON"
       else:
           tc.variables["BUILD_SHARED_LIBS"] = "OFF"
   
       // ......
       tc.generate()
       tc = CMakeDeps(self)
       tc.generate()
           
   def package_info(self):
       // ......
       if self.options.shared:
           self.cpp_info.defines = ["XXX_SHARED_LIB"]

20. CMake设置程序图标

1. 在CMakeLists.txt同级目录下新建文件“XXX.rc”，并放入准备好的ico图标文件；在rc文件中添加以下内容

IDI_ICON1 ICON "product.ico"

2. 在cmake文件中添加

add_executable(PROJECT_NAME
        main.cpp
        resource.rc
)

3. 重新编译