Questions that are bothering me:
When a function that returns void returns, is any value from the stack frame copied into the register?
Is the return address in the stack frame even allocated, or is it nullptr?
Could a void function theoretically return a value if you hacked one into the frame?
Does the register even know to expect a value from a void function? If so, where is the logic for this and what is difference between a void and non-void function return at the stack frame & register level?
Any good books on this stuff?