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From: "weilercdale at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/101566] gcc miscompiles lambda used as tuple-like object applied to function for call
Date: Wed, 21 Jul 2021 18:24:54 +0000	[thread overview]
Message-ID: <bug-101566-4-vzVQTqMLRI@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-101566-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101566

--- Comment #2 from Dale Weiler <weilercdale at gmail dot com> ---
(In reply to Andrew Pinski from comment #1)
>   f.0_1 = f_8(D);
>   tuple = t;
>   _11 = &tuple.__ts#2;
>   tuple ={v} {CLOBBER};
> 
> 
> template<Size N, typename T>
> constexpr decltype(auto) get(T tuple) { return *tuple(Get<N>{}); }
> 
> 
> I think the above function (get) is broken and is returning a reference to
> the argument and that would be invalid.

Ah, passing `T&` here instead of T does appear to avoid the issue, the question
now becomes why does -fsanitize=undefined find nothing, and is the return type,
i.e `declval(get<N>(t))` different in gcc compared to the other compiles. I
would expect similar issues in the other compilers if this is returning a
reference to the temporary given by the argument list of `get`

  parent reply	other threads:[~2021-07-21 18:24 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-21 18:07 [Bug c++/101566] New: " weilercdale at gmail dot com
2021-07-21 18:18 ` [Bug c++/101566] " pinskia at gcc dot gnu.org
2021-07-21 18:24 ` weilercdale at gmail dot com [this message]
2021-07-21 18:34 ` pinskia at gcc dot gnu.org
2021-07-21 18:42 ` weilercdale at gmail dot com
2021-07-21 18:51 ` weilercdale at gmail dot com
2021-07-21 19:22 ` weilercdale at gmail dot com
2021-07-21 19:23 ` weilercdale at gmail dot com
2021-07-21 19:56 ` redi at gcc dot gnu.org

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