hello.cpp
#include <iostream>
#include "hello.h"
#ifdef USE_ADD
#include "libtest.h"
#endif
int main(int argc, char** argv)
{
#ifdef USE_ADD
std::cout << add(1, 2) << std::endl;
#endif
return 0;
}
CMakeLists.txt
cmake_minimum_required(VERSION 3.10)
#直接使用project定义target或者指定下版本,再通过config_file设定版本宏配置自动写入指定头文件
#project(helloworld)
project(helloworld VERSION 1.0)
#option放在configure_file前面否则默认值不生效
option(USE_ADD "Use ADD provided math implementation" ON)
#cmake执行时将hello.h.in中定义的@${target}_VERSION_MAJOR@和@${target}_VERSION_MINOR@替换为VERSION的1和0
#并重新重定向到${PROJECT_BINARY_DIR}下的新文件hello.h
configure_file(hello.h.in hello.h)
#指定CXX的版本
set(CMAKE_CXX_STANDARD 14)
set(CMAKE_CXX_STANDARD_REQUIRED True)
#可选宏需要通过配置文件hello.h.in导入
#配置文件额外添加 #cmakedefine USE_ADD 从CMake导入到hello.h,在工程中可以使用
if(USE_ADD)
add_subdirectory(lib)
list(APPEND EXTRA_LIBS add)
list(APPEND EXTRA_INCLUDES "${PROJECT_SOURCE_DIR}/lib")
endif()
add_executable(helloworld hello.cpp)
#放在add_executable后面,否则找不到target
#${PROJECT_BINARY_DIR}为CMake的环境变量
target_include_directories(helloworld PUBLIC
"${PROJECT_BINARY_DIR}"
${EXTRA_INCLUDES}
)
target_link_libraries(helloworld PUBLIC ${EXTRA_LIBS})
hello.h.in
#define HELLO_VERSION_MAJOR @helloworld_VERSION_MAJOR@
#define HELLO_VERSION_MINOR @helloworld_VERSION_MINOR@
liblibtest.h
int add(int a, int b);
liblibtest.cpp
#include "libtest.h"
int add(int a, int b)
{
return a+b;
}
libCMakeLists.txt
cmake_minimum_required(VERSION 3.10)
project(helloworld VERSION 1.0)
set(CMAKE_CXX_STANDARD 14)
set(CMAKE_CXX_STANDARD_REQUIRED True)
add_library(add libtest.cpp)
target_include_directories(add PUBLIC
"."
)