to be clear, in my example the result of oracle() cannot possibly alias with 'x' in C or C++ (and in fact gcc will optimize accordingly). In a different language where addresses are mere integers, things would be more complicated.
The numerical value returned by oracle might physically match the address of the stack slot for 'x', assuming that it exists, but it doesn't mean that, from a language point of view, it is a valid pointer.
If forging pointers had defined behaviour, it would be impossible to use the language sanely or perform any kind of optimization.
