Re: libstdc++/6090: Problem with copy of std_valarray

Re: libstdc++/6090: Problem with copy of std_valarray

[gdr]

Synopsis: Problem with copy of std_valarray

State-Changed-From-To: analyzed->closed
State-Changed-By: gdr
State-Changed-When: Sat Aug  3 13:44:35 2002
State-Changed-Why:
    Not a bug

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=6090

Re: libstdc++/6090: Problem with copy of std_valarray

[Gabriel Dos Reis]

The following reply was made to PR libstdc++/6090; it has been noted by GNATS.

From: Gabriel Dos Reis <gdr@codesourcery.com>
To: Benjamin Kosnik <bkoz@redhat.com>
Cc: gdr@gcc.gnu.org, gcc-gnats@gcc.gnu.org
Subject: Re: libstdc++/6090: Problem with copy of std_valarray
Date: 12 Apr 2002 01:53:10 +0200

 Benjamin Kosnik <bkoz@redhat.com> writes:
 
 | The following reply was made to PR libstdc++/6090; it has been noted by GNATS.
 | 
 | From: Benjamin Kosnik <bkoz@redhat.com>
 | To: Gabriel Dos Reis <gdr@codesourcery.com>
 | Cc: erwan.goasdoue@ipsis.fr, gcc-bugs@gcc.gnu.org, gdr@gcc.gnu.org,
 |         gcc-gnats@gcc.gnu.org
 | Subject: Re: libstdc++/6090: Problem with copy of std_valarray
 | Date: Wed, 10 Apr 2002 09:49:17 -0700 (PDT)
 | 
 |  > That is the mandated behaviour, in particular if the source and the
 |  > target don't have the same length then the behaviour is undefined.
 |  
 |  I think the problem is that the assignment and copy ctor do different 
 |  things. Why is that?
 
 (I'm not sure that is really a problem).
 
 The copy constructor is supposed to construct a new object out of an
 existing one, whereas the assignment operator is supposed to assign
 values to components of an existing object.  Those two operations are
 fundamentally semantically different.  Valarray<>'s design is more
 driven by speed than by security; the assignement operator is more
 memcpy()-like than std::vector<>::operator=()-like.  That was a design
 choice explained by the fact that valarray<>s are meant to be basic
 blocks with "basic" operations. 
 
 -- Gaby

Re: libstdc++/6090: Problem with copy of std_valarray

[Benjamin Kosnik]

The following reply was made to PR libstdc++/6090; it has been noted by GNATS.

From: Benjamin Kosnik <bkoz@redhat.com>
To: Gabriel Dos Reis <gdr@codesourcery.com>
Cc: erwan.goasdoue@ipsis.fr, gcc-bugs@gcc.gnu.org, gdr@gcc.gnu.org,
        gcc-gnats@gcc.gnu.org
Subject: Re: libstdc++/6090: Problem with copy of std_valarray
Date: Wed, 10 Apr 2002 09:49:17 -0700 (PDT)

 > That is the mandated behaviour, in particular if the source and the
 > target don't have the same length then the behaviour is undefined.
 
 I think the problem is that the assignment and copy ctor do different 
 things. Why is that?
 
 -benjamin

Re: libstdc++/6090: Problem with copy of std_valarray

[Gabriel Dos Reis]

The following reply was made to PR libstdc++/6090; it has been noted by GNATS.

From: Gabriel Dos Reis <gdr@codesourcery.com>
To: bkoz@gcc.gnu.org
Cc: erwan.goasdoue@ipsis.fr, gcc-bugs@gcc.gnu.org, gdr@gcc.gnu.org,
   gcc-gnats@gcc.gnu.org
Subject: Re: libstdc++/6090: Problem with copy of std_valarray
Date: 08 Apr 2002 13:06:42 +0200

 bkoz@gcc.gnu.org writes:
 
 | Synopsis: Problem with copy of std_valarray
 | 
 | State-Changed-From-To: feedback->analyzed
 | State-Changed-By: bkoz
 | State-Changed-When: Wed Apr  3 12:45:33 2002
 | State-Changed-Why:
 |     This looks like it is still an issue in gcc-3.1. 
 |     
 |     include/std/std_valarray.h: 342
 |     
 |      template<typename _Tp>
 |       inline valarray<_Tp>&
 |       valarray<_Tp>::operator= (const valarray<_Tp>& __v)
 |       {
 |           __valarray_copy(__v._M_data, _M_size, _M_data);
 |           return *this;
 |       }
 |     
 |     include/std/std_valarray.h: 284
 |       template<typename _Tp>
 |       inline valarray<_Tp>::valarray (const valarray<_Tp>& __v)
 |         : _M_size(__v._M_size), _M_data(__valarray_get_storage<_Tp>(__v._M_size))
 |       { __valarray_copy_construct (__v._M_data, __v._M_data + _M_size, _M_data); }
 
 I'm not sure I understand what the problem is about.  Is the submitter
 complaining that copying a valarray wasn't adjusting the target's size?
 That is the mandated behaviour, in particular if the source and the
 target don't have the same length then the behaviour is undefined.
 
 -- Gaby

Re: libstdc++/6090: Problem with copy of std_valarray

[bkoz]

Synopsis: Problem with copy of std_valarray

State-Changed-From-To: feedback->analyzed
State-Changed-By: bkoz
State-Changed-When: Wed Apr  3 12:45:33 2002
State-Changed-Why:
    This looks like it is still an issue in gcc-3.1. 
    
    include/std/std_valarray.h: 342
    
     template<typename _Tp>
      inline valarray<_Tp>&
      valarray<_Tp>::operator= (const valarray<_Tp>& __v)
      {
          __valarray_copy(__v._M_data, _M_size, _M_data);
          return *this;
      }
    
    include/std/std_valarray.h: 284
      template<typename _Tp>
      inline valarray<_Tp>::valarray (const valarray<_Tp>& __v)
        : _M_size(__v._M_size), _M_data(__valarray_get_storage<_Tp>(__v._M_size))
      { __valarray_copy_construct (__v._M_data, __v._M_data + _M_size, _M_data); }
    
    
    Gaby?

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=6090

Re: libstdc++/6090: Problem with copy of std_valarray

[bkoz]

Synopsis: Problem with copy of std_valarray

Responsible-Changed-From-To: unassigned->gdr
Responsible-Changed-By: bkoz
Responsible-Changed-When: Mon Apr  1 18:51:24 2002
Responsible-Changed-Why:
    Yours.....
State-Changed-From-To: analyzed->feedback
State-Changed-By: bkoz
State-Changed-When: Mon Apr  1 18:51:24 2002
State-Changed-Why:
    Can you make sure that this is still an issue with gcc-3_1?

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=6090

Re: libstdc++/6090: Problem with copy of std_valarray

[paolo]

Synopsis: Problem with copy of std_valarray

State-Changed-From-To: open->analyzed
State-Changed-By: paolo
State-Changed-When: Fri Mar 29 12:11:01 2002
State-Changed-Why:
    Could you please provide a short, self-contained testcase
    demonstrating the problem?
    
    Thanks, Paolo.

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=6090

libstdc++/6090: Problem with copy of std_valarray

[erwan.goasdoue]

>Number:         6090
>Category:       libstdc++
>Synopsis:       Problem with copy of std_valarray
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Mar 29 02:16:01 PST 2002
>Closed-Date:
>Last-Modified:
>Originator:     std_valarray.h
>Release:        happened with gcc 2.95.3
>Organization:
>Environment:
linux mandrake 8.1
>Description:
Problem with operator= :
valarray<_Tp>::operator= (const valarray<_Tp>& __v)
{
    __valarray_copy(__v._M_data, _M_size, _M_data);
    return *this;
}

contrary to :
template<typename _Tp>
inline valarray<_Tp>::valarray (const valarray<_Tp>& __v)
        : _M_size (__v._M_size), _M_data (new _Tp[__v._M_size])
{ __valarray_copy (__v._M_data, _M_size, _M_data); }

never modify size of target.
>How-To-Repeat:

>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted: