HW19
COP-3402

1. Are function-local variables (auto in C) allocated at compile-time or run-time?
2. If some function definition has a local variable x, will that variable always assigned a single memory location in any possible program that has such a function?
3. The following are the contents of a stack frame, label which ones are caller created and which are callee created in the x86 64 System V ABI:
   • Callee-saved registers
   • Stack parameters
   • Return address
   • Local variables
   • Register parameters
   • Old base pointer
4. What register in the x86 64 System V ABI is meant to hold a pointer to the currently-executing function's stack frame?

5. What are the most and least number of active stack frames for the factorial function will exist in memory at one time for the following program?

   #include <stdio.h>
   
   int factorial(int n) {
     if (n < 2) {
       return 1;
     } else {
       return n * factorial(n - 1);
     }
   }
   
   int main() {
     int n = 5;
     printf("factorial(%d) = %d\n", n, factorial(n));
   }