用Gcc编译C文件时出现错误，提示用c99标准

#include<stdio.h>
#include<stdlib.h>

#define MAX(A,B) A>B?A:B        //返回A，B中的最大值

#define LOOP(FROM,TO,CONTENT) \
for(int index=FROM;index<TO;index++){\
CONTENT \
}\

int main(void)
{
printf("Max num is %d\n",MAX(2,5));
printf("Max num is %f\n",MAX(5.5,5.4));
printf("Max char is %c\n",MAX('a','c'));

LOOP(2,10,
printf("Current index is %d\n",index);
)

return 0;
}