使用#define宏处理函数定义

#include <stdio.h>

#define DEBUG

#ifdef DEBUG
  #define PRINT        printf
  // or
  //#define PRINT(...)   printf(__VA_ARGS__)
#else
  #define PRINT(...)
#endif


int main(int argc, char *argv[]) {
  PRINT("Hello");
  PRINT("Thanks %s", "Bye!");
}