内附程序，求解决编译错误..error: #29: expected an expression

char *GsmUSARTReceive(char *str, INT16U str_len)
{
  char *str_bk = str; INT16U buf_length = 0;

  buf_length = CHARS(GsmAppBuf);

  if(buf_length == 0)
return NULL;
  if(str_len)
{
if(str_len > buf_length)
str_len = buf_length;

while(str_len--)
{
if(EMPTY(GsmAppBuf))
{
//缓冲区为空就不取数据
}
else
{
GETCH(GsmAppBuf, *str_bk++);
}
}
}
  else
{
str_len = buf_length;
while(str_len--)
{
if(EMPTY(GsmAppBuf))
{
//缓冲区为空就不取数据
}
else
{
GETCH(GsmAppBuf, *str_bk++);
}
}

}
  return str;
}


error: #29: expected an expression
error: #29: expected an expression
warning: #177-D: variable "str_bk" was declared but never referenced

大括号不对，匹配有问题

编写程序时注意缩进格式，就不会有这种问题了

函数没问题，附到帖子就是这样了
红色部分的问题，给看下下