c++/2577: pure virtual destructors must not be called ?

[moyere at objectif dot fr]

>Number:         2577
>Category:       c++
>Synopsis:       pure virtual destructors must not be called ?
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Apr 18 03:36:00 PDT 2001
>Closed-Date:
>Last-Modified:
>Originator:     moyere@objectif.fr
>Release:        gcc version egcs-2.91.66 19990314/Linux (egcs-1.1.2 release)
>Organization:
>Environment:
RedHat Linux 6.2 on i586
>Description:
With inheritance, a destructor must call the destructor of
its parents.
In the following example, the class A (the parent) has a pure virtual destructor. This destructor must not be called
when the destructor of the B class (the child class) is called.
The generated code is wrong and the linker looks for a destructor that doesn't exist.

A solution is to give an empty implementation to the A destructor (ie write : virtual ~A() {} instead of virtual ~A() = 0;).

class A {
public:
        virtual ~A() = 0;

        virtual void method(void) = 0;
};

class B : public A {
public:
        virtual ~B() {};

        void method(void) {};
};

int main(int argc, char **argv) {
        B b;
        b.method();
}

This gives the following error:
gcc  -g3 t.cc -o t
/tmp/ccKjy7Ar.o: In function `A type_info function':
t.cc:21: undefined reference to `A::~A(void)'
t.cc:21: undefined reference to `A::~A(void)'
collect2: ld returned 1 exit status
>How-To-Repeat:

>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted: