Question

I have a main project and a DLL project. The main executable links to the DLL.
In the main project I have a function:

int func(char *str)
{
    .....
}

In the DLL project, I want to use this function. Can I forward declare this function and use it? Like:

int func(char *str);

int dllFunc()
{
    ...
    status = func(str);
    ...
}

Answer 1

One (fairly common) way of doing it is to provide a callback from the application, i.e.

In DLL:

typedef void (*callback)();

callback my_callback;

void dll_register_callback(callback app_callback) { my_callback = app_callback; }

void do_things() { my_callback(); }

In application:

void cb() {}

dll_register_callback(cb);