do_while.cpp

#include <iostream>
#include <malloc.h>

using namespace std;
#define f1() cout << "f1()" << endl;
#define f2() cout << "f2()" << endl;

#define fun()                                                                  \
  {                                                                            \
    f1();                                                                      \
    f2();                                                                      \
  }
#define fun1()                                                                 \
  do {                                                                         \
    f1();                                                                      \
    f2();                                                                      \
  } while (0)

int f() {
  int *p = (int *)malloc(sizeof(int));
  *p = 10;
  cout << *p << endl;
#ifndef DEBUG
  int error = 1;
#endif
  if (error)
    goto END;

  // dosomething
END:
  cout << "free" << endl;
  free(p);
  return 0;
}

int ff() {

  int *p = (int *)malloc(sizeof(int));
  *p = 10;
  cout << *p << endl;

  do {
#ifndef DEBUG
    int error = 1;
#endif
    if (error)
      break;
    // dosomething
  } while (0);

  cout << "free" << endl;
  free(p);
  return 0;
}

int fc() {
  int k1 = 10;
  cout << k1 << endl;
  do {
    int k1 = 100;
    cout << k1 << endl;
  } while (0);
  cout << k1 << endl;
  return 0;
}

int main() {

  if (1 > 0)
    fun();

  if (2 > 0)
    fun1();

  f();
  ff();
  fc();
  return 0;
}