[Bug libstdc++/13864] stl_hastable.h Line 527

["greg dot bertin at solacesystems dot com" <gcc-bugzilla at gcc dot gnu dot org>]

------- Additional Comments From greg dot bertin at solacesystems dot com  2004-01-26 14:20 -------
Subject: RE:  stl_hastable.h Line 527

Hi pinskia ...

__n is initialized but the memory being pointed at by __n is not. It is
memory allocated via _M_get_node():

  _Node* _M_get_node() { return _M_node_allocator.allocate(1); } 

Allocators return uninitialized memory blocks. This is a problem because
_Construct():

  template <class _T1, class _T2>
    inline void
    _Construct(_T1* __p, const _T2& __value)
    { new (static_cast<void*>(__p)) _T1(__value); }

assumes that __p points to a properly initialized T1 object since it
invokes T1's copy constructor. T1's copy constructor will assume that
T1's members (e.g. pointer members that are not NULL and thus need to be
deallocate()'d/delete()'d/free()'d/whatever) have been properly
initialized. The other uses of _Construct() in the standard STL that I
checked all pass a properly initialized __p to _Construct and thus
behave correctly.


Thanks for looking at this!!

> -----Original Message-----
> From: pinskia at gcc dot gnu dot org [mailto:gcc-bugzilla@gcc.gnu.org]
> Sent: Monday, January 26, 2004 8:24 AM
> To: greg.bertin@solacesystems.com
> Subject: [Bug libstdc++/13864] stl_hastable.h Line 527
> 
> 
> ------- Additional Comments From pinskia at gcc dot gnu dot org
2004-01-
> 26 13:23 -------
> Here is the full source, n __n is initialized:
>   _Node* _M_new_node(const value_type& __obj)
>   {
>     _Node* __n = _M_get_node();
>     __n->_M_next = 0;
>     try {
>       _Construct(&__n->_M_val, __obj);
>       return __n;
>     }
>     catch(...)
>       {
>         _M_put_node(__n);
>         __throw_exception_again;
>       }
>   }
> 
> --
>            What    |Removed                     |Added
>
------------------------------------------------------------------------
--
> --
>              Status|UNCONFIRMED                 |RESOLVED
>          Resolution|                            |INVALID
> 
> 
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13864
> 
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> You reported the bug, or are watching the reporter.




-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13864