生成 .so 和使用 .so

是哟ing两个最简单的项目演示使用 c++ 项目生成 .so 和在 c++ 项目中使用 .so

项目1：生成 .so 文件 (maker_so)

项目结构

maker_so/ ├── include/ │ └── calculator.h ├── src/ │ └── calculator.cpp └── CMakeLists.txt

文件内容

include/calculator.h

#ifndefCALCULATOR_H#defineCALCULATOR_Hextern"C"{intadd(inta,intb);intsubtract(inta,intb);intmultiply(inta,intb);floatdivide(inta,intb);}#endif

src/calculator.cpp

#include"calculator.h"intadd(inta,intb){returna+b;}intsubtract(inta,intb){returna-b;}intmultiply(inta,intb){returna*b;}floatdivide(inta,intb){if(b==0)return0;return(float)a/b;}

CMakeLists.txt

cmake_minimum_required(VERSION 3.10) project(maker_so) # 设置库的输出目录为项目下的 lib set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${CMAKE_SOURCE_DIR}/lib) # 包含头文件目录 include_directories(${CMAKE_SOURCE_DIR}/include) # 创建动态库 add_library(calculator SHARED src/calculator.cpp) message(STATUS "Building calculator shared library")

构建项目1

# 创建并进入项目目录mkdir-pmaker_so/{include,src,build}cdmaker_so# 创建文件（使用上面的内容）# ... 创建 calculator.h, calculator.cpp, CMakeLists.txt# 构建cdbuild cmake..cmake--build.# 查看生成的 .sols-l../lib/# 应该看到: libcalculator.so

项目2：使用 .so 文件 (user_so)

项目结构

user_so/ ├── lib/ # 从项目1复制过来的 .so │ └── libcalculator.so ├── include/ # 从项目1复制过来的头文件 │ └── calculator.h ├── src/ │ └── main.cpp └── CMakeLists.txt

文件内容

include/calculator.h（从项目1复制）

#ifndefCALCULATOR_H#defineCALCULATOR_Hextern"C"{intadd(inta,intb);intsubtract(inta,intb);intmultiply(inta,intb);floatdivide(inta,intb);}#endif

src/main.cpp

#include<iostream>#include"calculator.h"intmain(){inta=15,b=4;std::cout<<"=== Using calculator library ===\n";std::cout<<a<<" + "<<b<<" = "<<add(a,b)<<std::endl;std::cout<<a<<" - "<<b<<" = "<<subtract(a,b)<<std::endl;std::cout<<a<<" * "<<b<<" = "<<multiply(a,b)<<std::endl;std::cout<<a<<" / "<<b<<" = "<<divide(a,b)<<std::endl;return0;}

CMakeLists.txt

cmake_minimum_required(VERSION 3.10) project(user_so) # 设置可执行文件输出目录 set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_SOURCE_DIR}/bin) # 设置 RPATH，让程序能在 lib 目录找到 .so set(CMAKE_INSTALL_RPATH "${CMAKE_SOURCE_DIR}/lib") set(CMAKE_BUILD_WITH_INSTALL_RPATH TRUE) # 包含头文件目录 include_directories(${CMAKE_SOURCE_DIR}/include) # 指定库文件目录 link_directories(${CMAKE_SOURCE_DIR}/lib) # 创建可执行文件 add_executable(calc_app src/main.cpp) # 链接动态库 target_link_libraries(calc_app calculator) message(STATUS "Building application that uses calculator.so")

完整的一键构建脚本

创建一个脚本build_all.sh来自动化整个过程：

#!/bin/bashecho"=== 项目1: 生成 libcalculator.so ==="# 创建项目1mkdir-pmaker_so/{include,src,build}# 创建项目1的文件cat>maker_so/include/calculator.h<<'EOF' #ifndef CALCULATOR_H #define CALCULATOR_H extern "C" { int add(int a, int b); int subtract(int a, int b); int multiply(int a, int b); float divide(int a, int b); } #endif EOFcat>maker_so/src/calculator.cpp<<'EOF' #include "calculator.h" int add(int a, int b) { return a + b; } int subtract(int a, int b) { return a - b; } int multiply(int a, int b) { return a * b; } float divide(int a, int b) { if (b == 0) return 0; return (float)a / b; } EOFcat>maker_so/CMakeLists.txt<<'EOF' cmake_minimum_required(VERSION 3.10) project(maker_so) set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${CMAKE_SOURCE_DIR}/lib) include_directories(${CMAKE_SOURCE_DIR}/include) add_library(calculator SHARED src/calculator.cpp) EOF# 构建项目1cdmaker_somkdir-pbuildcdbuild cmake..cmake--build.cd../..echo-e"\n=== 项目2: 使用 libcalculator.so ==="# 创建项目2mkdir-puser_so/{include,src,build,lib}# 从项目1复制 .so 和头文件到项目2cpmaker_so/lib/libcalculator.so user_so/lib/cpmaker_so/include/calculator.h user_so/include/# 创建项目2的文件cat>user_so/src/main.cpp<<'EOF' #include <iostream> #include "calculator.h" int main() { int a = 15, b = 4; std::cout << "=== Using calculator library ===\n"; std::cout << a << " + " << b << " = " << add(a, b) << std::endl; std::cout << a << " - " << b << " = " << subtract(a, b) << std::endl; std::cout << a << " * " << b << " = " << multiply(a, b) << std::endl; std::cout << a << " / " << b << " = " << divide(a, b) << std::endl; return 0; } EOFcat>user_so/CMakeLists.txt<<'EOF' cmake_minimum_required(VERSION 3.10) project(user_so) set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_SOURCE_DIR}/bin) set(CMAKE_INSTALL_RPATH "${CMAKE_SOURCE_DIR}/lib") set(CMAKE_BUILD_WITH_INSTALL_RPATH TRUE) include_directories(${CMAKE_SOURCE_DIR}/include) link_directories(${CMAKE_SOURCE_DIR}/lib) add_executable(calc_app src/main.cpp) target_link_libraries(calc_app calculator) EOF# 构建项目2cduser_somkdir-pbuildcdbuild cmake..cmake--build.cd../..echo-e"\n=== 运行结果 ==="./user_so/bin/calc_appecho-e"\n=== 项目文件列表 ==="echo"项目1生成的 .so:"ls-lmaker_so/lib/echo-e"\n项目2使用的 .so:"ls-luser_so/lib/echo-e"\n项目2生成的可执行文件:"ls-luser_so/bin/

手动构建步骤（如果没有脚本）

构建项目1

cdmaker_somkdirbuild&&cdbuild cmake..makecd../..

复制文件到项目2

mkdir-puser_so/lib user_so/includecpmaker_so/lib/libcalculator.so user_so/lib/cpmaker_so/include/calculator.h user_so/include/

构建项目2

cduser_somkdirbuild&&cdbuild cmake..makecd../..

运行

./user_so/bin/calc_app

验证 .so 文件

# 查看 .so 的符号nm-Duser_so/lib/libcalculator.so# 查看可执行文件的依赖ldd user_so/bin/calc_app# 运行程序./user_so/bin/calc_app

这样就完成了：

1. 项目1生成了libcalculator.so
2. 项目2使用了这个.so文件
3. 所有文件都放在各自的项目目录下，互不干扰