What actions are performed in the stack when a function is called in a program?

When a function is called in a Go program (and in most languages with call stack support), the following happens on the stack:

1. A stack frame is allocated — a memory area for storing local variables, parameters, and the return address.
2. The return address is saved — so that after the function completes, execution can continue from the correct place.
3. Function parameters are copied — argument values are passed into the new frame.
4. Local variables are initialized — memory is allocated and, if necessary, initial values are set.

After the function executes, the stack frame is removed, and control returns to the saved address.

Example (simplified):

func add(a, b int) int {
    sum := a + b
    return sum
}

func main() {
    result := add(2, 3)
    fmt.Println(result) // 5
}

When add is called, a frame is created on the stack with parameters a=2, b=3, a local variable sum, and a return address in main.