How to control one project from another project using CMake/ Use header and shared lib of one Project into another project

Question

I want to trigger the building process and use the header file & shared lib (.so file) from different project to another single project.

Here, my parents projects are proj_1 & proj_2. And the project where I am intended to use the information is new_proj.

Structure looks like as follows:

infos/
|-- New_Stuff
|   `-- new_proj
|       |-- CMakeLists.txt
|       |-- include
|       |   `-- foo_bar.h
|       `-- src
|           |-- foo_bar.cpp
|           `-- main.cpp
`-- Old_Stuff
    |-- proj_1
    |   |-- CMakeLists.txt
    |   |-- include
    |   |   `-- foo.h
    |   `-- src
    |       `-- foo.cpp
    `-- proj_2
        |-- CMakeLists.txt
        |-- include
        |   `-- bar.h
        `-- src
            `-- bar.cpp

Minimal Example of the header and Source file. Pseudo code

proj_1

• foo.h

#include <iostream>
using namespace std;
void print_foo();

• foo.cpp

#include "foo.h"
#include <iostream>
using namespace std;
void print_foo()
{
    cout << "foo is here" endl;
}

proj_2

• bar.h

#include <iostream>
using namespace std;
void print_bar();

• bar.cpp

#include "bar.h"
#include <iostream>
using namespace std;
void print_bar()
{
    cout << "bar is here" endl;
}

new_proj

• foo_bar.h

#include "foo.h"
#include "bar.h"
#include <iostream>
using namespace std;
void print_message();

• foo_bar.cpp

#include "foo_bar.h"
#include <iostream>
using namespace std;
void print_message()
{
    cout << "Combining project" endl;
}

• main.cpp

#include "foo_bar.h"

int main()
{
    void print_message();
    void print_foo();
    void print_bar();
    return 0;
}

preferred output

Combining project
foo is here
bar is here

I have no idea how can I write the CMakeLists.txt file of new_proj.

Some facts about the parents projects (examples are given on behalf of proj_1)

• Header files are always resides in /proj_1/include
• Executable resides in /proj_1/bin and shared lib in /proj_1/lib

My approach

• I have gone through 1 2 but didn't get a clear idea.
• proj_1 & proj_2 are already exist and they will in the same location. Besides, I can clone them too if needed.

Want idea how to organize the CMakeLists.txt for new_proj.