grammar error in function call when missing comma between parameters

int test(int a, int b)
{
  return a + b;  
}

int main()
{
  int result;
  result = test(1 2);
  return 0;
}

  else if (tk == Id) {
    ...
--  while (tk != ')') { expr(Assign); *++e = PSH; ++t; if (tk == ',') next(); }
++  while (tk != ')') { 
++    expr(Assign); *++e = PSH; ++t;
++    if (tk == ',') { next(); if(tk == ')') { printf("%d: error unexpected comma in function call\n", line); exit(-1); }}
++    else if(tk != ')') { printf("%d: error missing comma in function call\n", line); exit(-1); }
++  }
    ...
}