Virtual inheritance destruction issue

[oliver]

My code is as follow. I know that I should use virtual destructor in
A. Why the following code gave me the following complain.

*** glibc detected *** ./private: free(): invalid pointer:
0x0000000001a92018 ***

The environment is Ubuntu 10.10 amd64 with gcc "gcc version 4.4.5
(Ubuntu/Linaro 4.4.4-14ubuntu5)"

1 using namespace std;
2 #include <iostream>
3
4 class A
5 {
6 private:
7 int a;
8 };
9
10 class B : virtual public A
11 {
12
13 };
14
15 int main()
16 {
17 A *ptr = new B;
18 delete ptr;
19 return 0;
20 }

 

[Victor Bazarov]

My code is as follow. I know that I should use virtual destructor in
A. Why the following code gave me the following complain.

*** glibc detected *** ./private: free(): invalid pointer:
0x0000000001a92018 ***

The environment is Ubuntu 10.10 amd64 with gcc "gcc version 4.4.5
(Ubuntu/Linaro 4.4.4-14ubuntu5)"

1 using namespace std;
2 #include<iostream>
3
4 class A
5 {
6 private:
7 int a;
8 };
9
10 class B : virtual public A
11 {
12
13 };
14
15 int main()
16 {
17 A *ptr = new B;
18 delete ptr;
19 return 0;
20 }

And if you add a virtual d-tor to A, what happens?

Victor

 

[red floyd]

My code is as follow. I know that I should use virtual destructor in
A. Why the following code gave me the following complain.

*** glibc detected *** ./private: free(): invalid pointer:
0x0000000001a92018 ***

The environment is Ubuntu 10.10 amd64 with gcc "gcc version 4.4.5
(Ubuntu/Linaro 4.4.4-14ubuntu5)"

1 using namespace std;
  2 #include <iostream>
  3
  4 class A
  5 {
  6     private:
  7         int a;
  8 };
  9
 10 class B : virtual public A
 11 {
 12
 13 };
 14
 15 int main()
 16 {
 17     A *ptr = new B;
 18     delete ptr;
 19     return 0;
 20 }

Isn't that UB? Deleteing an object with no virtual destructor
through a pointer to the base class?