[olliej]

In the C abstract machine there is no restriction on the stack size, and the nature of the stack (or that pointers are involved in it) is opaque, so within the definition of the language the call stack is infinitely sized. So if we want to be pedants about what is or is not "in the language" (though I'll note that IO routines are in the language), there is our infinite storage that does not depend on limits to pointer size.