How to call a function in C++ from library(.so) created by code generation?

Hello, all.

I created a .so file by selecting the ert_shrlib.tlc option during the code generation.

This option sets the target language to C.

Anyway, I want to use this library in Cpp.

However, it is very difficult to use the library because of the difference between C and Cpp.

Does anyone know how to use libraries(.so) based on C in Cpp?

Answer 1

[Infinite_king]

Hi Hyunjun Hyung,

The C library can be used by a C++ program. In fact, many OS libraries are written in C. Therefore, whenever a system call is made by a C++ program, it is actually utilizing a C library.

However, to use a C library, C linkage should be used to link the C functions. In your C++ code, declare the functions from the C library as extern "C". This instructs the C++ compiler to use C linkage for those functions, preventing name mangling and ensuring compatibility with the C library.

Ideally, the header file should include the extern "C" keyword. If the header file does not contain this keyword, update the function declarations as follows

// Shift the function declaration inside the extern "C" scope
extern "C" {
    void doSomething();
}

Finally, link the library while compiling as follows,

% linking library named 'my_library.so'
g++ .. -lmy_library -L/custom_directory_path