[Bug c++/42063] New: g++ violate [class.dtor] when explicit destructor call

["pi3orama at gmail dot com" <gcc-bugzilla@gcc.gnu.org>]

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This bug is related to the example in [class.dtor]/12 of standard N2960.

according to the example, in the following program:

#include <iostream>
struct B {
        virtual ~B() { std::cout << "~B" << std::endl; }
};

struct D : B {
        ~D ()  { std::cout << "~D" << std::endl; }
};

typedef B B_alias;
int main()
{
        D D_object;
        B* B_ptr = &D_object;
        std::cout << "begin" << std::endl;
        D_object.B::~B();
        B_ptr->~B();
        std::cout << "end" << std::endl;
        return 0;
}

D_object .B::~B () should call B¡¯s destructor, and
B_ptr ->~B () should call D's destructor.

However the actual result is

begin
~B
~B
end
...

the strange thing is when D_object.B::~B() be removed, or be swapped between
B_ptr->~B(), everything is OK.

Another problem: according to the spec, 'Once a destructor is invoked for an
object, the object no longer exists'. However, the following code shows that
g++ doesn't respect it:

#include <iostream>
struct C {
        ~C() { std::cout << "XXX" << std::endl; }
};
int main()
{
        C * c = new C();
        c->C::~C();
        delete c;
        return 0;
}

the program ends normally. Shouldn't it generate a double free fault?


-- 
           Summary: g++ violate [class.dtor] when explicit destructor call
           Product: gcc
           Version: 4.3.4
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: pi3orama at gmail dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42063