Is it possible to get the address of a function reference in Go?
Something like
func myFunction() {
}
// ...
unsafe.Pointer(&myFunction)
Just that is does not work that way. My guess it's not possible, but I did not found any proof yet.
Edit: Background
The background of my question comes from dealing with CGO and C Function pointers. This works:
/*
void go_myFunction();
typedef void (*myFunction_f)();
myFunction_f pMyFunction;
*/
import "C"
//export go_myFunction
func go_myFunction() {
// ...
}
func SetupFp() {
C.pMyFunction = (*[0]byte)(unsafe.Pointer(C.go_myFunction))
}
I'm also aware that the documentation states that passing a pointer to a go function does not work. But the above code seems no to be that far from it. I was just wondering if one could somehow skip the export step.
function
type in Go is not addressable and not comparable because:
Function pointers denote the code of the function. And the code of an anonymous function created by function literal is only stored once in memory, no matter how many times the code that returns the anonymous function value runs.
If you need to compare addresses of a functions you can do it with reflect.Pointer
. But any way this operation is more senseless than impossible because:
If v's Kind is Func, the returned pointer is an underlying code pointer, but not necessarily enough to identify a single function uniquely. The only guarantee is that the result is zero if and only if v is a nil func Value.