From: Jonathan Wakely <jwakely@redhat.com>
To: libstdc++@gcc.gnu.org
Cc: gcc-patches@gcc.gnu.org
Subject: Re: [patch] libstdc++/65352 fix ubsan errors in std::array<T, 0>
Date: Thu, 28 May 2015 13:52:00 -0000 [thread overview]
Message-ID: <20150528133817.GP2985@redhat.com> (raw)
In-Reply-To: <alpine.DEB.2.11.1505281522500.11312@stedding.saclay.inria.fr>
On 28/05/15 15:26 +0200, Marc Glisse wrote:
>On Thu, 28 May 2015, Jonathan Wakely wrote:
>
>>Unsurprisingly ubsan doesn't like referencing a null pointer.
>>
>>With this change __array_traits::_S_ref is only used to access an
>>element, which is invalid for std::array<T, 0> anyway.
>
>Should
>
>return *static_cast<_Tp*>(nullptr);
>
>be replaced with
>
>__builtin_unreachable();
>
>then? It seems strange to keep an implementation that is never
>supposed to be used.
That's a good idea, I experimented with just not defining it but that
fails for explicit instantiations of array<T, 0>.
next prev parent reply other threads:[~2015-05-28 13:38 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-28 12:03 Jonathan Wakely
2015-05-28 12:37 ` Jonathan Wakely
2015-05-28 13:38 ` Marc Glisse
2015-05-28 13:52 ` Jonathan Wakely [this message]
2015-05-28 13:57 ` Jonathan Wakely
2015-05-28 14:06 ` Marc Glisse
2015-05-28 14:49 ` Jonathan Wakely
2015-05-28 15:08 ` Jonathan Wakely
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