gnuc与ansic

GNU c与标准c的区别

1) 零长度数组
struct var_data
{
int len;
char data[0];
}test；
int a;
test.data -->a

2）case语句
case 1:
case 2:
case 3:
xxx;
break;
GNU C
case 1 ... 100:
xxx
break;

3)宏定义
#define MIN(x,y) ((x)<(y):(x),(y))

int x = 10;
int y = 20;
int z = MIN(x++,y++);

副作用：

GNUC 支持宏定义局部变量

#define MIN(x,y) \
{
type _x = x; type _y =y; _x<_y?_x:_y}
MIN(int, x++,y++)
{int _x=x++; int _y=y++; _x<_y?_x:_y}