目的

熟悉使用cmakelists编译c++代码过程
编译动态库so给其他语言调用

操练

准备

环境：mac环境上测试

安装cmake
安装vscode
配置includePath：首选项->settings->搜索includePath

第三方库安装

$ brew install opencv # apt install opencv # ubuntu
$ brew install curl # apt install curl # ubuntu

构建项目

src/addsum.h

extern "C"
{
    int addsum(int a, int b);
}

src/addsum.cpp

int addsum(int a, int b)
{
    return a + b;
}

src/so_test.c

#include "addsum.cpp"

src/main.cpp

#include "iostream"
#include "stdio.h"
#include <curl/curl.h>
#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/highgui/highgui.hpp>
#include "addsum.h"

int main(int argc, char const *argv[])
{
    printf("hello wolrd");
    cv::Mat img = cv::imread("./aaa.jpeg");
    int su = addsum(1, 3);
    std::cout << su << std::endl;
    cv::imshow("test", img);
    cv::waitKey(0);

    return 0;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.9) #最低版本
#设置项目名称
SET(PROJECT_NAME Test1)
project(Test1 VERSION 1.0) #项目名称及自定义版本号

FIND_PACKAGE(OpenCV REQUIRED)
INCLUDE_DIRECTORIES(${OpenCV_INCLUDE_DIRS})

AUX_SOURCE_DIRECTORY(src DIR_SRCS)
SET(TEST_MATH ${DIR_SRCS})

ADD_EXECUTABLE(${PROJECT_NAME} ${TEST_MATH})



add_library(utils SHARED src/so_test.c)
TARGET_LINK_LIBRARIES(${PROJECT_NAME} ${OpenCV_LIBS})

编译

生成makefile

$ cmake .

编译

$ make

结果

$ ls -l
-rw-r--r--   1 root  staff   14362  5 10 12:58 CMakeCache.txt
drwxr-xr-x  13 root  staff     416  5 10 15:33 CMakeFiles
-rw-r--r--   1 root  staff     436  5 10 14:35 CMakeLists.txt
-rw-r--r--   1 root  staff    6773  5 10 14:35 Makefile
-rwxr-xr-x   1 root  staff  118784  5 10 15:33 Test1 # 生成的可执行文件
-rw-r--r--   1 root  staff  146304  5 10 11:16 aaa.jpeg
drwxr-xr-x   8 root  staff     256  5 10 14:35 build
-rw-r--r--   1 root  staff    1542  5 10 12:27 cmake_install.cmake
-rwxr-xr-x   1 root  staff   16472  5 10 14:55 libutils.dylib # 生成的动态库，用于给其他语言调用
drwxr-xr-x   6 root  staff     192  5 10 14:54 src

执行可执行文件

$ ./Test1
hello wolrd4 # 还有一张图

其他语言调用案例

案例

from ctypes import cdll


def main():
    so = cdll.LoadLibrary('./libutils.dylib')
    res = so.addsum(1, 3)
    print(res)


if __name__ == '__main__':
    main()