Question

I am writing a generic test function that will accept a function address (read from a map file) and arguments as comma separated data as arguments from a socket.

I am able to implement it for known function pointers.

like

void iif(int a, int b, float f);
typedef void (*fn_t)(int a, int b, float f);

With above approach I would write function pointers for all types of function implementation in the code base. Is there any generic way to do this?

Answer 1

No, since the compiler needs to know how to represent the arguments. It can’t know that for a function pointer type that excludes the information, and thus it can’t generate the call.

Functions with a small number of parameters might pass them in CPU registers, “spilling over” to the stack when many parameters are called for, for instance.

You can use varargs to come around this, doing so essentially “locks down” the way the arguments are passed. Of course, it forces the called functions to deal with varargs, which is not very convenient.