[Opencxx-users] Re: [opencxx] Another question regarding double inheritance

[Francois T. <fra...@la...>]

Hi Grzegorz

I'm using OpenC++ version 2.5.12, along with gcc 2.95.4, libc6 2.2.5,
and libstdc++ 2.10. My machine runs Linux kernel 2.4.18 on a pentium
III.

Cheers

Francois

On Mon, 2002-11-04 at 10:05, Grzegorz Jakacki wrote:
> 
> Hi,
> 
> Which version of OpenC++ does it?
> 
> Regards
> Grzegorz
> 
> On 1 Nov 2002, Francois Taiani wrote:
> 
> > Hi again,
> >
> > I'm applying OpenC++ on a program with namespaces and double
> > inheritance, and occ seems to have troubles when it encounters the
> > following pattern: (which compile correctly with "g++ -c".)
> > --
> > class A{};
> > namespace N
> > {
> >   class B { };
> >   class A : virtual public ::A, virtual public B
> >   {};
> > }
> > --
> > If I launch occ on this bit of code (here for instance with the default
> > metaclass Class), I get a segmentation fault:
> > --
> > $ /usr/bin/occ -E -SClass test2.cc
> > zsh: segmentation fault  /usr/bin/occ -SClass test2.cc
> > --
> > I've used gdb to investigate what was going on and it seems occ is
> > trapped in an infinite recursion. Below is what the bottom of the stack
> > looks like just after the segfault. Environment::SearchBaseOrUsing ()
> > and Environment::LookupType() recursively call each other until the
> > memory space available to the stack gets exhausted.
> > ---
> > <--snip-- Infinite recursion leading to segmentation fault-->
> > ..
> > #32640 0x08069434 in Environment::SearchBaseOrUsing ()
> > #32641 0x080693c9 in Environment::LookupType ()
> > #32642 0x08069434 in Environment::SearchBaseOrUsing ()
> > #32643 0x080693c9 in Environment::LookupType ()
> > #32644 0x08069434 in Environment::SearchBaseOrUsing ()
> > #32645 0x080693c9 in Environment::LookupType ()
> > #32646 0x08069434 in Environment::SearchBaseOrUsing ()
> > #32647 0x080693c9 in Environment::LookupType ()
> > #32648 0x080692bb in Environment::LookupClassMetaobject ()
> > #32649 0x0806af6f in Walker::RecordBaseclassEnv ()
> > #32650 0x08085764 in ClassWalker::RecordMembers ()
> > #32651 0x08085245 in ClassWalker::TranslateClassSpec ()
> > #32652 0x0806c799 in Walker::TranslateClassSpec ()
> > #32653 0x08062904 in PtreeClassSpec::Translate ()
> > #32654 0x0806b014 in Walker::Translate ()
> > #32655 0x0806d72d in Walker::TranslateTypespecifier ()
> > #32656 0x0806b8d3 in Walker::TranslateDeclaration ()
> > #32657 0x08062440 in PtreeDeclaration::Translate ()
> > #32658 0x0806b014 in Walker::Translate ()
> > #32659 0x0806c3a8 in Walker::TranslateBrace ()
> > #32660 0x08062244 in PtreeBrace::Translate ()
> > #32661 0x0806b014 in Walker::Translate ()
> > #32662 0x0806b765 in Walker::TranslateNamespaceSpec ()
> > #32663 0x08062394 in PtreeNamespaceSpec::Translate ()
> > #32664 0x0806b014 in Walker::Translate ()
> > #32665 0x0805de0a in Compile ()
> > #32666 0x0805db2a in Compile ()
> > #32667 0x0805d941 in Compile ()
> > #32668 0x0805d834 in Compile ()
> > #32669 0x0805d7b4 in main ()
> > #32670 0x400ca0bf in __libc_start_main () from /lib/libc.so.6
> > ---
> > Interstingly, the segfault disappears if I remove any of the base
> > classes of N::A. For instance occ works fine on
> > --
> > class A{};
> >
> > namespace N
> > {
> >   class B { };
> >   class A : virtual public ::A // , virtual public B
> >   {};
> > }
> > --
> > The problem also disappears if I use another name for N::A (one that
> > does not mask ::A). I think this is a bug, but I'm not sure. Would
> > someone have any comment on it ?
> >
> > Thanks in advance
> >
> > Francois
> >
> > --
> > Francois Taiani                 +33 (0) 5 6133 6406
> > LAAS-CNRS (http://www.laas.fr)  Dependable Computing
> > http://www.laas.fr/~ftaiani     and Fault Tolerance
> >
> >
> >
> 
> ##################################################################
> # Grzegorz Jakacki                       Huada Electronic Design #
> # Senior Engineer, CAD Dept.              1 Gaojiayuan, Chaoyang #
> # tel. +86-10-64365577 x2074               Beijing 100015, China #
> # Copyright (C) 2002 Grzegorz Jakacki, HED. All Rights Reserved. #
> ##################################################################
-- 
Francois Taiani                 +33 (0) 5 6133 6406
LAAS-CNRS (http://www.laas.fr)  Dependable Computing 
http://www.laas.fr/~ftaiani     and Fault Tolerance