Re: does this dynamic_cast<> bug know?

[Alexander Nedotsukov <bland mail ru>]

Bowie Owens wrote:

> Hi Alexander,
>
> Nice work on the bug report. I was able to reproduce the problem with 
> your sample code. It looks like the problem might be easy to fix. 
> Deleting public virtual T from the X base list was sufficient to get 
> the sample working. I don't think IDLStruct needs to directly inherit 
> from IDLType. Please try commenting out the public virtual IDLType in 
> the IDLStruct base class list: 

Damn why I not tried that? :-)

> class IDLStruct: public IDLCompound, /*public virtual IDLType,*/ 
> public IDLCompoundSeqElem
>
> Can you confirm that this allows the idl compiler to function properly 
> or at least better. 

Yep. Now it function properly. Actually one more similar place to fix in 
orbitcpp/idl-compiller/types/IDLUnion.h

Thanks!

> Alexander Nedotsukov wrote:
>
> > Hi,
> >
> > I think this may be considered as serious bug in C++ idl compiller
> > backend when it built with gcc 2.95.x. Look at the file
> > orbitcpp/idl-compiller/types.cc. It contains following pice of code
> > (actually there is may be much more places like that).
> >
> > IDLType *
> > IDLTypeParser::parseTypeSpec(IDLScope &scope,IDL_tree typespec) {
> > ...
> >        case IDLN_IDENT:
> >            {
> >                IDLElement *item =
> > scope.lookup(idlGetQualIdentifier(typespec));
> >                if (!item) throw
> > IDLExUnknownIdentifier(typespec,idlGetQualIdentifier(typespec));
> >                if (!item->isType()) throw
> > IDLExTypeIdentifierExpected(typespec,IDL_IDENT(typespec).str);
> >                type = dynamic_cast<IDLType *>(item);
> >                break;
> >            }
> >
> > I believe gcc 2.95.x dynamic_cast<> implementation is buggy and if
> > scope.lookup() return IDLStruct* then dynamic_cast<> two lines bellow
> > will result in NULL pointer and .idl compilation will be aborted with
> > the "not yet implemented: idln_ident". Code compilled with gcc 3.2 works
> > just fine. Here is a small sample that reproduce classes hierarchy
> > involved in case.
> >
> > class T {};
> > class TI { public: virtual void m() {} };
> > class CS : public virtual T, public virtual TI {};
> > class E : public virtual TI {};
> > class S : public E {};
> > class C : public S {};
> > class X : public C, public virtual T, public CS {};
> >
> > int
> > main()
> > {
> >  E* e = new X;
> >  T* t = dynamic_cast<T*>(e);
> >  delete e;
> >  return 0;
> > }
> >
> > All the best,
> > Alexander.
> >
> >
> >
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