[Bug c++/16018] New: dynamic_cast fail accross shared libraries

[amos at ilogix dot com]

dynamic_cast<> sometimes fail when declaring a class in one shared library, 
allocating an object (Base*in another shared library, passing a pointer of a 
base to the third shared library and using dynamic_cast to down cast.

Note (1): the base and the derived are defined in different shared libraries.

Note (2): the shared libraries are statically linked (e.g. loaded at the 
application initialization).

This is a critical issue since it breaks the ability to use RTTI in large 
applications.

-------------------
Illustration
-------------------
[libx1.so]
class B
{
  ...
};

[libx2.so]
class D : public B
{
  ...
};

[libx3.so]
B* b = new D;

[libx4.so]
D* d = dynamic_cast<D*>(b);
assert(d != 0); // FAIL

-- 
           Summary: dynamic_cast fail accross shared libraries
           Product: gcc
           Version: 3.2
            Status: UNCONFIRMED
          Severity: critical
          Priority: P2
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: amos at ilogix dot com
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: 3.2 20020903 (Red Hat Linux 8.0 3.2-7)
  GCC host triplet: Red Hat Linux 8.0
GCC target triplet: Red Hat Linux 8.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16018