#include "testharness.h"

struct list {
  struct list* back;
  int i;
  struct list* next;
};

#define NULL 0
struct list node1 = {NULL, 29, NULL};
struct list node2 = {&node1, 30, &node1};

void foo() {
  struct list local = node2;
  if (local.next == 0 || local.i != 30) E(1);
  
  //Test that this is an "atomic" operation.
  //If we naively split this into two assignments, 
  // local.next will change and *(local.next) will get the wrong value for
  // the second half of the assigment.
  local = *(local.next);
  if (local.next != 0 || local.i != 29) E(2);

  //Likewise, check that writing local.back (the first field of the struct)
  //doesn't cause problems.
  local = node2;
  local = *(local.back);
  if (local.next != 0 || local.i != 29) E(3);

}


//make sure split args are passed in the right order
struct list node3 = {NULL, 40, &node2};
void equalToNode3(struct list arg){
  if ((arg.back != node3.back)
      ||(arg.i != node3.i)
      ||(arg.next != node3.next)) {
    E(10);
  }
}

int main() {
  struct list local_node3 = node3;

  foo();

  equalToNode3(local_node3);  //pass from a split var
  equalToNode3(node3);        //pass from a nonsplit var

  SUCCESS;
}