[Bug c++/20647] New: Wrong typeid for incomplete types

["frederic dot riss at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

On linux x86, using the following 2 little sources files :

---------- 1.C --------------------
#include <typeinfo>

class A {
public:
        A() {}
};

extern void foo(const std::type_info&);

int main()
{
        foo(typeid(A*));
        return 0;
}
-----------------------------------

---------- 2.C --------------------
#include <iostream>
#include <typeinfo>

class A;

void foo(const std::type_info& t)
{
        if (t == typeid(A*))
        {
                std::cout << "OK\n";
        }
        else
        {
                std::cout << "KO\n";
        }
}
-----------------------------------

and compiling with "g++ 1.C 2.C" gives me KO output. This means that the
comparison of the type_info passed to foo and the one computed by typeid(A*)
where A* is an incomplete type failed. 

In the binary there are 2 type_info symbols for A* :
 % nm a.out| grep TIP1A
0804884c r _ZTIP1A
0804882c V _ZTIP1A

I tried this test with many compilers and it worked with g++ 3.2 and failed with
g++ 3.3, 3.4 and pre4.0 (with the same binutils). Precise versions :

 % gcc-3.2 --version
gcc-3.2 (GCC) 3.2.3 (Debian)

 % gcc-3.3 --version
gcc-3.3 (GCC) 3.3.5 (Debian 1:3.3.5-8ubuntu2)

 % gcc-3.4 --version
gcc-3.4 (GCC) 3.4.4 20050209 (prerelease) (Debian 3.4.3-9ubuntu3)

 % gcc-4.0 --version
gcc-4.0 (GCC) 4.0.0 20050301 (prerelease) (Debian 4.0-0pre6ubuntu6)

-- 
           Summary: Wrong typeid for incomplete types
           Product: gcc
           Version: 3.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: frederic dot riss at gmail dot com
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20647