系统编译：如何给Make命令来传递参数

int main()
      {
          int i=9;
      #ifdef DEBUG
          i=1;
      #else
          i=0;
      #endif
          printf("i=%d\n", i);
          return 0;
      }

CFLAGS=-g -Wall -DDEBUG 

object=myprog

all:$object

myprog:a.c 

gcc ${CFLAGS} a.c -o ${object}

CFLAGS=CFLAG

CFLAGS+=-g -Wall -DDEBUG 

object=myprog

all:$object

myprog:a.c 

gcc ${CFLAGS} a.c -o ${object}

[ychq@ICM3-2 net]$ make CFLAG=-DDEBUG 

gcc -g -Wall -DDEBUG a.c 

a.c: In function `main': 

a.c:9: warning: implicit declaration of function `printf' [ychq@ICM3-2 net]$