[Bug java/49258] -ffunction-sections and --gc-sectinons have no effect at gcj

[licheng.1212 at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49258

--- Comment #6 from licheng.1212 at gmail dot com <licheng.1212 at gmail dot com> 2012-04-09 11:14:56 UTC ---
(In reply to comment #5)
> (In reply to comment #4)
> > Yes,but why we can't remove the function notused() form vtable, since this
> > function will never used.
> 
> How can you tell?  Without the full exectuable and knowing the entry point,
> there is no way (-fwhole-program can help but it becomes a turning machine at
> that point).

class hello{
    public void notused()
    {
        System.out.println("not used");
    }
    public static void main(String argv[])
    {
        System.out.println("Hello");    
    }
}

this is a full execlutable program,and it hava only one entry point "main"!

and i test a c++ file,it will remove the unused funcitons "notused":
[licheng@Soft04 ~]$ cat hello.cpp 
#include <iostream>

class hello
{
public:
        hello()
        {
        }
        void notused()
        {
                std::cout << "not used";
        }
        void used()
        {
                std::cout << "used";
        }
        ~hello()
        {
        }
}hi;

int main()
{       hello t;
        t.used();
        return 0;
}
[licheng@Soft04 ~]$