/*
 * HBF
*/

#include<stdio.h>
#include "extern.h"

int a = 0; // global variable

void test1() {
  auto int b = 0;   // local and auto variable
  static int c = 0; // local and static variable, not auto 
  a += 2;
  b += 2; 
  c += 2;
  printf("global a=%d,&a=%lu, auto b=%d,&b=%lu, static c=%d,&c=%lu\n", a, &a, b, &b, c, &c);
}

void test2() {
  int b = 0;
  static int c = 0;
  a += 2;
  b += 2;
  c += 2;
  printf("global a=%d,&a=%lu, auto b=%d,&b=%lu, static c=%d,&c=%lu\n", a, &a, b, &b, c, &c);
}

int main()
{
  printf("test register variable\n");	
  register int j; // register variable
  for (j=0; j<2; j++) {
    printf("register variable k=%d, address:%lu\n", j, &k);
  }

  printf("\ntest global, auto and static variables\n");
  int i;
  for (i=0; i<2; i++) {
    test1();
  }

  printf("\ntest global, auto and static variables\n");
  for (i=0; i<2; i++) {
    test2();
  }
  
  printf("\ntest extern variable\n");
  extern int k;
  printf("extern variable k=%d\n", k);  
  test3();
  printf("extern variable k=%d\n", k);

  printf("\ntest local variable scope\n");
  {
    int d = 2;
    printf("scope1 d=%d,&d=%lu\n", d, &d);
  }
  
  //printf("scope1 d=%d,&d=\n", d, &d);  // out of scope, not allowed by compiler
  
  {
    int d = 3; 
    printf("scope1 d=%d,&d=%lu\n", d, &d);
    {
      volatile int e = 1;
      if (e == 1) {
        printf("scope d=%d\n", d);
        printf("scope e=%d\n", e); 
      }
    }
  }



  return 0;
}

/*
test register variable
register variable k=0, address:4202496
register variable k=1, address:4202496

test global, auto and static variables
global a=2,&a=4214816, auto b=2,&b=6422236, static c=2,&c=4214824
global a=4,&a=4214816, auto b=2,&b=6422236, static c=4,&c=4214824

test global, auto and static variables
global a=6,&a=4214816, auto b=2,&b=6422236, static c=2,&c=4214820
global a=8,&a=4214816, auto b=2,&b=6422236, static c=4,&c=4214820

test extern variable
extern variable k=5
extern variable k=7

test local variable scope
scope1 d=2,&d=6422280
scope1 d=3,&d=6422276
scope d=3
scope e=1
*/