[Bug c++/55385] New: g++ failed to call final overrider of a virtual function.

[Bug c++/55385] New: g++ failed to call final overrider of a virtual function.

[meng at g dot clemson.edu]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55385

             Bug #: 55385
           Summary: g++ failed to call final overrider of a virtual
                    function.
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: meng@g.clemson.edu


The code below is adapted from the example code given in 10.3/2 of the current
standard.

--------------- BEGIN ---------------
#include <iostream>

struct A {
 virtual void f() { std::cout << "A::f" << std::endl; }
};
struct B : virtual A {
 virtual void f() { std::cout << "B::f" << std::endl; }
};
struct C : B , virtual A {
 using A::f;
};
void foo() {
 C c;
 c.f();    // (1) calls B::f, the final overrider
 c.C::f(); // (2) calls A::f because of the using-declaration
}

int main ()
{
 foo();
 return 0;
}
---------------  END  ---------------

The standard says that c.f() should call B::f because it is the final overrider
in C of the virtual function f. According to my test on g++-4.7.0, however,
both call A::f.

My compile command line is: ~/gcc/4.7.0/bin/c++ -O3 -Wall -Wextra t.cc
My compiler version is: 
Reading specs from /home/meng/gcc/4.7.0/lib/gcc/i686-pc-linux-gnu/4.7.0/specs
COLLECT_GCC=/home/meng/gcc/4.7.0/bin/c++
COLLECT_LTO_WRAPPER=/home/meng/gcc/4.7.0/libexec/gcc/i686-pc-linux-gnu/4.7.0/lto-wrapper
Target: i686-pc-linux-gnu
Configured with: ./configure --prefix=/home/meng/gcc/4.7.0/
--enable-languages=c,c++
Thread model: posix
gcc version 4.7.0 (GCC)

[Bug c++/55385] g++ failed to call final overrider of a virtual function.

[daniel.kruegler at googlemail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55385

Daniel Krügler <daniel.kruegler at googlemail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |daniel.kruegler at
                   |                            |googlemail dot com

--- Comment #1 from Daniel Krügler <daniel.kruegler at googlemail dot com> 2012-11-19 19:16:43 UTC ---
I can see the exact same behaviour in gcc 4.8.0 20121104 (experimental).

I agree that the current behaviour looks like a defect defect and my tentative
guess is that this might be due to

http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#608

[Bug c++/55385] g++ failed to call final overrider of a virtual function.

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=55385

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |wrong-code
         Resolution|---                         |DUPLICATE
             Status|UNCONFIRMED                 |RESOLVED

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
This is an exact dup of bug 11750 which has been fixed since GCC 4.8; in fact a
few days before this bug was filed, Nov 14, 2012 :).

*** This bug has been marked as a duplicate of bug 11750 ***