Modifying the "address" format, which prints a pointer and a description of...

Modifying the "address" format, which prints a pointer and a description of what it points to, to detect when the deref of that pointer points to something valid. So if you have:

    % cat sp.cpp 
    #include <tr1/memory>

    class A
    {
    public:
        A (): m_i (12) {}
        virtual ~A() {}
    private:
        int m_i;
    };

    int main (int argc, char const *argv[], char const *envp[])
    {
        A *a_pointers[2] = { NULL, NULL };
        A a1;
        A a2;
        a_pointers[0] = &a1;
        a_pointers[1] = &a2;
        return 0;
    }


And you stop at the "return 0", you can now read memory using the "address" format and see:

(lldb) memory read --format address `&a_pointers`
0x7fff5fbff870: 0x00007fff5fbff860 -> 0x00000001000010b0 vtable for A + 16
0x7fff5fbff878: 0x00007fff5fbff850 -> 0x00000001000010b0 vtable for A + 16
0x7fff5fbff880: 0x00007fff5fbff8d0
0x7fff5fbff888: 0x00007fff5fbff8c0
0x7fff5fbff890: 0x0000000000000001
0x7fff5fbff898: 0x36d54c275add2294
0x7fff5fbff8a0: 0x00007fff5fbff8b0
0x7fff5fbff8a8: 0x0000000100000bb4 a.out`start + 52

Note the extra dereference that was applied to 0x00007fff5fbff860 and 0x00007fff5fbff850 so we can see that these are "A" classes.

llvm-svn: 160085