CMake 使用介绍

apt install cmake gcc -y

find_package(Python3 COMPONENTS Interpreter REQUIRED)

mkdir build && cd build
cmake ..
make

set(CMAKE_VERBOSE_MAKEFILE ON)

# 方式一
make VERBOSE=1

# 方式二
export VERBOSE=1
make

cmake -DCMAKE_EXPORT_COMPILE_COMMANDS=ON --build .
make

# 1. 要求的cmake最低版本
cmake_minimum_required(VERSION 3.2)

# 2. 添加c++11标准支持
#set( CMAKE_CXX_FLAGS "-std=c++11" )

# 3. 指定项目的名称，一般和项目的文件夹名称对应
PROJECT(test_sqrt)

# 4. 头文件
INCLUDE_DIRECTORIES(
include
)

# 源文件目录
AUX_SOURCE_DIRECTORY(src DIR_SRCS)

# 5. 通过设定SRC变量，将源代码路径都给SRC，如果有多个，可以直接在后面继续添加。若不添加编译能够通过，但是执行的时候会出现各种问题，比如 "symbol lookup error xxxxx , undefined symbol"
SET(SRC
${DIR_SRCS}
)

# 6. 编译主函数，生成可执行文件
# 设置路径
set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${PROJECT_SOURCE_DIR}/build/bin)

# 可执行文件生成
ADD_EXECUTABLE(${PROJECT_NAME} ${SRC})

# 7. 创建共享库/静态库
# 设置路径
set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${PROJECT_SOURCE_DIR}/build/lib)

set(LIB_NAME test_sqrt_lib)
# 创建共享库（把工程内的cpp文件都创建成共享库文件，方便通过头文件来调用）
# 这时候只需要cpp，不需要有主函数
# ${PROJECT_NAME}是生成的库名 表示生成的共享库文件就叫做 lib工程名.so
# 也可以专门写cmakelists来编译一个没有主函数的程序来生成共享库，供其它程序使用
# SHARED为生成动态库，STATIC为生成静态库
add_library(${LIB_NAME} STATIC ${SRC})

# 8. 链接库文件
# 把刚刚生成的${PROJECT_NAME}库和所需的其它库链接起来
# 如果需要链接其他的动态库，-l后接去除lib前缀和.so后缀的名称，以链接 libtestsqrt.so 为例,-ltestsqrt
TARGET_LINK_LIBRARIES(${PROJECT_NAME} m)

# 容器内编译
$ docker run --rm -it gcc:9.5.0 bash

# 安装依赖
$ sed "s#http://deb.debian.org/debian#https://mirrors.tuna.tsinghua.edu.cn/debian/#g" -i /etc/apt/sources.list
$ apt update
$ apt install cmake -y

# 源码初始化，CMakeLists.txt 参考示例文件
mkdir -p test_sqrt/src/ test_sqrt/include/

cat << EOF > test_sqrt/src/main.c
#include "../include/m.h"
#include <stdio.h>
int main(int argc, char** argv)
{
    double a = 81.0;
    double b = 0.0;

    printf("input a: %f\n", a);
    b = cal_sqrt(a);
    printf("sqrt result: %f\n",b);
    return 0;
}
EOF

cat << EOF > test_sqrt/src/m.c
#include "../include/m.h"

double cal_sqrt(double value)
{
    return sqrt(value);
}
EOF

cat << EOF > test_sqrt/include/m.h
#ifndef B_FILE_HEADER_INC
#define B_FIEL_HEADER_INC

#include<math.h>

double cal_sqrt(double value);

#endif
EOF

root@2f5346b34906:/# mkdir build && cd build
root@2f5346b34906:/test_sqrt/build# cmake ..
-- The C compiler identification is GNU 9.5.0
-- The CXX compiler identification is GNU 9.5.0
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Check for working CXX compiler: /usr/local/bin/c++
-- Check for working CXX compiler: /usr/local/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Configuring done
-- Generating done
-- Build files have been written to: /test_sqrt/build
root@2f5346b34906:/test_sqrt/build# make
Scanning dependencies of target test_sqrt
[ 16%] Building C object CMakeFiles/test_sqrt.dir/src/m.c.o
[ 33%] Building C object CMakeFiles/test_sqrt.dir/src/main.c.o
[ 50%] Linking C executable bin/test_sqrt
[ 50%] Built target test_sqrt
Scanning dependencies of target test_sqrt_lib
[ 66%] Building C object CMakeFiles/test_sqrt_lib.dir/src/m.c.o
[ 83%] Building C object CMakeFiles/test_sqrt_lib.dir/src/main.c.o
[100%] Linking C static library libtest_sqrt_lib.a
[100%] Built target test_sqrt_lib

# 二进制
root@2f5346b34906:/test_sqrt/build# bin/test_sqrt
input a: 81.000000
sqrt result: 9.000000