新手，GDB调试C++程序时，watch的设置问题。
我在line8设置了断点，但是设置watch时始终不对，求指点
(gdb) file 练习34Load new symbol table from "/home/zhaoyu/文档/练习34"? (y or n) yReading symbols from /home/zhaoyu/文档/练习34...done.(gdb) runStarting program: /home/zhaoyu/文档/练习34 45[Inferior 1 (process 17429) exited normally](gdb) list6 for(;i!=n;i++)7 {8 sum+=i;9 }10 return sum;11 }12 int main(void)13 {14 int Sum(int n);15 cout<<Sum(10)<<endl;(gdb) list16 }(gdb) break 8Breakpoint 1 at 0x804860a: file 练习34.cpp, line 8.(gdb) watch sumNo symbol "sum" in current context.