项目结构如下

CMakeLists清单

最外层的主CMakeLists

cmake_minimum_required(VERSION 3.17)
project(cmakeMulPackage)

set(CMAKE_CXX_STANDARD 11)

#添加一个子目录并构建该子目录
add_subdirectory(proj1)
add_subdirectory(proj2)

#定义头文件路径
include_directories(proj1/include proj2/include)

#生成可执行exe
add_executable(cmakeMulPackage app/src/main.cpp)

#目标依赖要使用的库的路径
link_directories(./lib)
#指定链接给目标依赖要使用的库
target_link_libraries(cmakeMulPackage
        MyProj1
        MyProj2)

proj1的CMakeLists

#定义头文件路径
include_directories(./include)

#同时生成lib与DLL
set(CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS ON)

set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ../lib) #DLL生成路径
set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ../lib) #lib生成路径
set(CMAKE_COMPILE_PDB_OUTPUT_DIRECTORY ../pdb) #pdb生成路径

#把目录src下面的所有文件作为变量存储
aux_source_directory(./src SOURCES)

#生成库
add_library(MyProj1 STATIC ${SOURCES})

proj2的CMakeLists

#定义头文件路径
include_directories(./include)

#同时生成lib与DLL
set(CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS ON)

set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ../lib) #DLL生成路径
set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ../lib) #lib生成路径
set(CMAKE_COMPILE_PDB_OUTPUT_DIRECTORY ../pdb) #pdb生成路径

#把目录src下面的所有文件作为变量存储
aux_source_directory(./src SOURCES)

#生成库
add_library(MyProj2 STATIC ${SOURCES})

项目代码

main.cpp

#include <iostream>

#include "hello.h"
#include "world.h"

int main() {
    std::cout << "Hello, World!" << std::endl;

    hello();
    world();
    return 0;
}

proj1/hello.h

#pragma execution_character_set("utf-8")
void hello(void);

proj1/hello.cpp

#include <cstdio>
#include "hello.h"

void hello()
{
    printf("proj1. 111111111\n");
}

proj2/world.h

#pragma execution_character_set("utf-8")
void world(void);

proj2/world.cpp

#include <cstdio>
#include "world.h"

void world()
{
    printf("proj2. 22222222\n");
}

运行