I'm not catching any exceptions with this code. What compiler options are you using to build, and how exactly are you determining that the __non_rtti_object exception is being thrown?

Vladimir, Brandon,

Did you compile the test-case without modifications? I could not compile... So, please take a look at amodified test-case:

     ...

     C *pC = new C;
     A *pA = dynamic_cast< A * >( pC );

     B *pB = dynamic_cast< B * >( pC );
     C *pCA = dynamic_cast< C * >( pA );

     C *pCB = dynamic_cast< C * >( pB );

     ...

Best regards,
Sergey

Hi Vladimir,

In your original post you've stated that the test case"...works fine with MSVC...". I understood that you've compiled it with
some version of Visual Studio. Did you use 2005, 2008, 2010 or 2012 vesrion?

In case ofMicrosoft C++ compiler and Visual Studio 2005 I can't compile
...
auto c = new C;
...
because it doesn't support C++11. I simply wanted to verify howthe testworks when it is compiled with Microsoft C++ compiler.

Could you provide more details on your software development environment? Thanks in advance.

Best regards,
Sergey

PS: Here are compilation errors I have:

..\PrtTests.cpp(5710) : error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
..\PrtTests.cpp(5710) : error C2440: 'initializing' : cannot convert from 'C *' to 'int'

Hi Vladimir,

I hope thata modified test-case for a 'dynamic_case' C++ operator will be useful for you ( it is amore generic ):

...
class A
{
public:
virtual void Method( void )
{
printf( "A::Method\n" );
};
};

class B: virtual public A
{
public:
virtual void Method( void )
{
printf( "B::Method\n" );
};
};

class C: virtual public A, public B
{
virtual void Method( void )
{
printf( "C::Method\n" );
};
};

class D
{
public:
virtual void Method( void )
{
printf( "D::Method\n" );
};
};
...
C *pC = new C;

A *pA = dynamic_cast< A * >( pC );
printf( "Object A is%sinitialized\n", ( pA !=NULL ) ? " " : " NOT " );

B *pB = dynamic_cast< B * >( pC );
printf( "Object B is%sinitialized\n", ( pB !=NULL ) ? " " : " NOT " );

C *pCA = dynamic_cast< C * >( pA );
printf( "Object C is%sinitialized\n", ( pCA !=NULL ) ? " " : " NOT " );

C *pCB = dynamic_cast< C * >( pB );
printf( "Object C is%sinitialized\n", ( pCB !=NULL ) ? " " : " NOT " );

D *pD = dynamic_cast< D * >( pC );
printf( "Object D is%sinitialized\n", ( pD !=NULL ) ? " " : " NOT " );
...

Hi Vladimir,

Have you noticed that I've added a new class D andthen tried to castthe pointerof the class Cto the pointer ofclassD?

A very important feature of the 'dynamic_cast'isthat itshould not cast fromtypeC to type D andthepointer to the object oftype D
must be equal toNULL.

However, I think that something is wrong with Intel C++ compiler because your original test-case is very generic even if it uses
some C++11 features. I wonder if thereissome problem related to support ofC++11 features in the compiler?

Best regards,
Sergey

An interesting point demonstrated by your code example is that the issue depends on the presence of virtual functions in different classes. I have tried a few combinations:

• Dynamic cast from B* to C* raises an exception when B does not declare/define any virtual functions, but does NOT fail if it does (concrete or pure functions, doesn't matter).
• Likewise, dynamic cast from C* to D* raises an exception when C declares/defines no virtual functions, and works fine otherwise.
  [SergeyK] It shouldn't raise any exceptions and it should assign a valueNULL to apointer of type D.

Quoting Sergey Kostrov ...
C *pC = new C;

A *pA = dynamic_cast< A * >( pC );
printf( "Object A is%sinitialized\n", ( pA !=NULL ) ? " " : " NOT " );

B *pB = dynamic_cast< B * >( pC );
printf( "Object B is%sinitialized\n", ( pB !=NULL ) ? " " : " NOT " );

C *pCA = dynamic_cast< C * >( pA );
printf( "Object C is%sinitialized\n", ( pCA !=NULL ) ? " " : " NOT " );

C *pCB = dynamic_cast< C * >( pB );
printf( "Object C is%sinitialized\n", ( pCB !=NULL ) ? " " : " NOT " );

D *pD = dynamic_cast< D * >( pC );
printf( "Object D is%sinitialized\n", ( pD !=NULL ) ? " " : " NOT " );
...

use a"default" cast, like:

...

C *pC = new C;

A *pA = ( A * )pC;
printf( "Object A is%sinitialized\n", ( pA !=NULL ) ? " " : " NOT " );

B *pB = (B * )pC;
printf( "Object B is%sinitialized\n", ( pB !=NULL ) ? " " : " NOT " );

C *pCA = ( C * )pA;
printf( "Object C is%sinitialized\n", ( pCA !=NULL ) ? " " : " NOT " );

C *pCB = ( C * )pB;
printf( "Object C is%sinitialized\n", ( pCB !=NULL ) ? " " : " NOT " );

D *pD = (D * )pC;
printf( "Object D is%sinitialized\n", ( pD !=NULL ) ? " " : " NOT " );
...

Quoting vpozdyayev Hi Sergey. C-style casts work reasonably enough, with "(C*)pA" giving a "cannot convert" compile-time error, and "(D*)pC" resulting in an unusable pointer. The trouble is only with one particular dynamic_cast, whereFindCompleteObject(void**) encounters a null pCompleteLocatorand throws the "Access violation - no RTTI data!"__non_rtti_objectexception. ---- Best regards, Vladimir

I really don't understand whyIntel C++ compilerneeds RTTI for the test-case.

>>...the original test case still fails on ICC 2013 update 2, command line (with just "icl.exe test.cpp"), or under MSVS 2012,
>>x86 and x64

Hi Vladimir,

I regret to see that the problem is still not fixed. So, I'll do another set of tests with ICC 2013 Initial Release integrated with VS 2008 Professional Edition.

Best regards,
Sergey

>>...I'll do another set of tests with ICC 2013 Initial Release integrated with VS 2008 Professional Edition...

Here are results:

There is a problem with Intel C++ Composer XE 2013 ( 2013.0.089 / Initial Release ) when the following code is executed:
...
auto cb = dynamic_cast< C * >( b );
...
A 32-bit test application crashes in a malloc CRT-function ( Debug and Release configurations ) because nSize is equal to 3765269347 and this is exactly 3GB (!):
...
extern "C" _CRTIMP void * __cdecl malloc( size_t nSize )
{
void *res = _nh_malloc_dbg( nSize, _newmode, _NORMAL_BLOCK, NULL, 0 );

RTCCALLBACK( _RTC_Allocate_hook, ( res, nSize, 0 ) );

return res;
}
...
and the exception is thrown from _nh_malloc_dbg internal CRT-function. I think nSize should have a value 4.

I couldn't reproduce the problem with Microsoft C++ compiler of Visual Studio 2012 Express Edition.

Here is a screenshot:

>>In my case (ICC 13.1.0 on MSVS 2012), the exception has been originally caused by a nullptr dereference
>>in FindCompleteObject, just like with ICC 12.1.5.

I didn't repeat a test with ICC 12 but I confirm that I saw some processing with FindCompleteObject internal function when I was doing debugging with ICC 13 and VS 2008 PE.

Brandon,

I can see that some time ago you've made a statement "...I'm not catching any exceptions with this code....". So, what else should we do in order to prove that there is a problem? Please let us know.

Best regards,
Sergey

Hi all,

Sorry for missing the updates on this thread. With the extra information, I could reproduce the thrown RTTI exception, and I've submitted a problem report to our front-end team.  Interestingly, if class B contains its own virtual function, the exception no longer gets thrown.

What happened to the 1st original post? As soon as Brandon made his post the original post is re-formatted to almost unreadable form.

>>... Interestingly, if class B contains its own virtual function, the exception no longer gets thrown...

Hi Brandon, Do you mean a modification like this one:
...
class B : virtual public A
{
public:
virtual void _dummy() { }
};
...

>>>> Interestingly, if class B contains its own virtual function, the exception no longer gets thrown
>>
>>That's right; as I have mentioned earlier, this problem seems to depend on whether B has any additions to vtable. I am
>>currently using a virtual destructor in A as a workaround (which results in automatic generation of default virtual ~B() for
>>all B classes).

Even if both "tricks" could be considered as workarounds the initial test case ( in post #1 ) should work without throwing the exception.

Best regards,
Sergey