To return a result of type String, the caller pushes a pointer to a temporary string before pushing the parameters, and the callee places the returned string value at that location.

• 为了返回一个字符串类型的结果，调用函数将在压入参数前首先把指向临时串的一个指针压入堆栈，接着被调用函数在此位置返回字符串值。