CMake

CMake是什么

• Cross Platform Make，一款优秀的工程构建工具

CMake与其他编译工具的对比

• autotools，配置繁琐（autoscan+autoconf+automake）
• CMake，效率比autotools块40%
• GCC --> Makefile --> CMake(autotools)

示例程序

sample1

• 程序结构

include
  |__base.h
lib
  |__libbase.a
  |__libbase.so
src
  |__CMakeLists.txt
  |__main
    |__CMakeLists.txt
    |__main.cpp
  |__base
    |__CMakeLists.txt
    |__base.cpp

• src/CMakeLists.txt

# CMake 最低版本号要求
cmake_minimum_required(VERSION 3.8.0)

# 项目名称
project( demo )

# 项目版本
set (demo_VERSION_MAJOR 1)
set (demo_VERSION_MINOR 0)

# 打印信息
MESSAGE(STATUS "PROJECT BINARY DIR: " ${PROJECT_BINARY_DIR})
MESSAGE(STATUS "PROJECT SOURCE DIR: " ${PROJECT_SOURCE_DIR})

# 设置配置（Debug/Release）
set(CMAKE_BUILD_TYPE "Debug")

# 设置C++版本
set(CMAKE_CXX_STANDARD 14)
# 或
add_compile_options(-std=c++11)

# 设置编译参数
ADD_DEFINITIONS(-DLINUX)
SET(CMAKE_C_FILAGS "$ENV{CFLAGS} -O0 -Wall -g -ggdb")
SET(CMAKE_C_FLAGS_RELEASE "$ENV{CFLAGS} -O3 -Wall")
set(CMAKE_CXX_FLAGS_DEBUG "$ENV{CXXFLAGS} -O0 -Wall -g -ggdb")
set(CMAKE_CXX_FLAGS_RELEASE "$ENV{CXXFLAGS} -O3 -Wall")

add_subdirectories( base )
add_subdirectories( main )

• src/base/CMakeLists.txt

# CMake 最低版本号要求
cmake_minimum_required(VERSION 3.8.0)

# 项目名称
project( base )

# 项目版本
set (base_VERSION_MAJOR 1)
set (base_VERSION_MINOR 0)

# 打印信息
MESSAGE(STATUS "BINARY DIR: " ${CMAKE_BINARY_DIR})
MESSAGE(STATUS "SOURCE DIR: " ${CMAKE_SOURCE_DIR})
MESSAGE(STATUS "CURRENT BINARY DIR: " ${CMAKE_CURRENT_BINARY_DIR})
MESSAGE(STATUS "CURRENT SOURCE DIR: " ${CMAKE_CURRENT_SOURCE_DIR})

# 自动查找当前目录下的所有源文件, 并将名称保存到 DIR_SRCS 变量
aux_source_directory(. DIR_SRCS)
# 或
# 手动配置源文件, 并将名称保存到 DIR_SRCS 变量
set( DIR_SRCS
  ${CMAKE_CURRENT_SOURCE_DIR}/base.cpp
  ...
)

# 手动配置头文件目录
include_directories(
  ${CMAKE_SOURCE_DIR}/include
)

# 设置库文件输出目录
set(LIBRARY_OUTPUT_PATH $(PROJECT_SOURCE_DIR)/lib)

add_library( base STATIC # STATIC/SHARED/MODULE
  ${DIR_SRCS}
)

# 安装
set(CMAKE_INSTALL_PREFIX /usr)
install(FILES include/base.h DESTINATION include)
install(TARGETS base ARCHIVE DESTINATION lib)

• src/main/CMakeLists.txt

# CMake 最低版本号要求
cmake_minimum_required(VERSION 3.8.0)

# 项目名称
project( main )

# 项目版本
set (main_VERSION_MAJOR 1)
set (main_VERSION_MINOR 0)

# 打印信息
MESSAGE(STATUS "BINARY DIR: " ${CMAKE_BINARY_DIR})
MESSAGE(STATUS "SOURCE DIR: " ${CMAKE_SOURCE_DIR})
MESSAGE(STATUS "CURRENT BINARY DIR: " ${CMAKE_CURRENT_BINARY_DIR})
MESSAGE(STATUS "CURRENT SOURCE DIR: " ${CMAKE_CURRENT_SOURCE_DIR})

# 检查系统是否支持 pow 函数
include (${CMAKE_ROOT}/Modules/CheckFunctionExists.cmake)
check_function_exists (pow HAVE_POW)

# 加入一个配置头文件，用于处理 CMake 对源码的设置
configure_file (
  "${PROJECT_SOURCE_DIR}/config.h.in"
  "${PROJECT_BINARY_DIR}/config.h"
  )

# 是否加入 Math 库
if (NOT HAVE_POW)
  include_directories ("${PROJECT_SOURCE_DIR}/math")
  add_subdirectory (math)
  set (EXTRA_LIBS ${EXTRA_LIBS} math)
endif (NOT HAVE_POW)

# 自动查找当前目录下的所有源文件, 并将名称保存到 DIR_SRCS 变量
aux_source_directory(. DIR_SRCS)
# 或
# 手动配置源文件, 并将名称保存到 DIR_SRCS 变量
set( DIR_SRCS
  ${CMAKE_CURRENT_SOURCE_DIR}/main.cpp
  ...
)

# 手动配置头文件目录
include_directories(
  ${CMAKE_SOURCE_DIR}/include
)

# 手动配置库文件目录
link_directories(
  ${CMAKE_SOURCE_DIR}/lib
)

add_excutable( main
  ${DIR_SRCS}
)

target_link_libraries(
  main
  "base" # 双引号表示从库路径中查找libhello.a
)

# 构建一个 CPack 安装包
include (InstallRequiredSystemLibraries)
set (CPACK_RESOURCE_FILE_LICENSE
  "${CMAKE_CURRENT_SOURCE_DIR}/License.txt")
set (CPACK_PACKAGE_VERSION_MAJOR "${main_VERSION_MAJOR}")
set (CPACK_PACKAGE_VERSION_MINOR "${main_VERSION_MINOR}")
include (CPack)

# 启用测试
enable_testing()

# 测试程序是否成功运行
add_test (test_run main 5 2)

# 测试帮助信息是否可以正常提示
add_test (test_usage main)
set_tests_properties (test_usage
  PROPERTIES PASS_REGULAR_EXPRESSION "Usage: .* base exponent")

# 定义一个宏，用来简化测试工作
macro (do_test arg1 arg2 result)
  add_test (test_${arg1}_${arg2} main ${arg1} ${arg2})
  set_tests_properties (test_${arg1}_${arg2}
    PROPERTIES PASS_REGULAR_EXPRESSION ${result})
endmacro (do_test)
 
# 利用 do_test 宏，测试一系列数据
do_test (5 2 "is 25")
do_test (10 5 "is 100000")
do_test (2 10 "is 1024")

• build

mkdir build && cd build 
cmake ..
make
./hello