Variable: max-lisp-eval-depth

Limit on depth in `eval', `apply' and `funcall' before error.

This limit serves to catch infinite recursions for you before they cause
actual stack overflow in C, which would be fatal for Emacs.
You can safely make it considerably larger than its default value,
if that proves inconveniently small. However, if you increase it too far,
Emacs could overflow the real C stack, and crash.