Comment by matheusmoreira

I suppose it would depend on the implementation. References could be implemented with absolute pointers, or with base pointers plus offsets.

Base pointers are trivially relocatable. Just set the base pointer and it's done. This is how my language supports stack expansion: just reallocate the memory, overwrite base pointers, elements always dereference base plus offset, done. The heap is also implemented this way. All objects are indexes into a massive object array, and the base pointer is implicit.

https://www.matheusmoreira.com/articles/lone-lisp-heap

Absolute pointer references are not easily relocatable. You'd need to rewrite every single pointer. I've never seen anyone actually do this in C since it'd hit the same problem conservative garbage collectors do: you might rewrite an integer variable that just happens to look like a pointer.

If you're audacious enough you can try to somehow remap the stacks in the exact same spot they used to be at in order to not invalidate the pointers to begin with:

https://langdev.stackexchange.com/a/4242

https://www.microsoft.com/en-us/research/wp-content/uploads/...

Some languages like Go manage to do it because they just know where all the pointers are in most circumstances. They tend to choke only on foreign code they can't introspect into.