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* [Bug c++/108974] New: std::barrier except completion function which is not manifestly noexcept
@ 2023-02-28 19:23 oliver.rosten at googlemail dot com
2023-02-28 19:24 ` [Bug libstdc++/108974] " pinskia at gcc dot gnu.org
` (6 more replies)
0 siblings, 7 replies; 8+ messages in thread
From: oliver.rosten at googlemail dot com @ 2023-02-28 19:23 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108974
Bug ID: 108974
Summary: std::barrier except completion function which is not
manifestly noexcept
Product: gcc
Version: 12.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: oliver.rosten at googlemail dot com
Target Milestone: ---
std::barrier<std::function<void()>> b{1, [](){}};
is accepted by gcc (and clang).
However, it fails on MSVC - as I think it should - since std::function's call
operator isn't manifestly noexcept.
https://godbolt.org/z/7vfoa1qhn
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug libstdc++/108974] std::barrier except completion function which is not manifestly noexcept
2023-02-28 19:23 [Bug c++/108974] New: std::barrier except completion function which is not manifestly noexcept oliver.rosten at googlemail dot com
@ 2023-02-28 19:24 ` pinskia at gcc dot gnu.org
2023-02-28 21:16 ` redi at gcc dot gnu.org
` (5 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: pinskia at gcc dot gnu.org @ 2023-02-28 19:24 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108974
--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Created attachment 54558
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=54558&action=edit
Full testcase
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug libstdc++/108974] std::barrier except completion function which is not manifestly noexcept
2023-02-28 19:23 [Bug c++/108974] New: std::barrier except completion function which is not manifestly noexcept oliver.rosten at googlemail dot com
2023-02-28 19:24 ` [Bug libstdc++/108974] " pinskia at gcc dot gnu.org
@ 2023-02-28 21:16 ` redi at gcc dot gnu.org
2023-02-28 21:17 ` redi at gcc dot gnu.org
` (4 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: redi at gcc dot gnu.org @ 2023-02-28 21:16 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108974
Jonathan Wakely <redi at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Ever confirmed|0 |1
Last reconfirmed| |2023-02-28
CC| |rodgertq at gcc dot gnu.org
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug libstdc++/108974] std::barrier except completion function which is not manifestly noexcept
2023-02-28 19:23 [Bug c++/108974] New: std::barrier except completion function which is not manifestly noexcept oliver.rosten at googlemail dot com
2023-02-28 19:24 ` [Bug libstdc++/108974] " pinskia at gcc dot gnu.org
2023-02-28 21:16 ` redi at gcc dot gnu.org
@ 2023-02-28 21:17 ` redi at gcc dot gnu.org
2023-03-02 2:27 ` de34 at live dot cn
` (3 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: redi at gcc dot gnu.org @ 2023-02-28 21:17 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108974
--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
"is_nothrow_invocable_v<CompletionFunction&> shall be true."
Failing to meet that requirement is undefined, so we're not required to reject
it as ill-formed.
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug libstdc++/108974] std::barrier except completion function which is not manifestly noexcept
2023-02-28 19:23 [Bug c++/108974] New: std::barrier except completion function which is not manifestly noexcept oliver.rosten at googlemail dot com
` (2 preceding siblings ...)
2023-02-28 21:17 ` redi at gcc dot gnu.org
@ 2023-03-02 2:27 ` de34 at live dot cn
2023-03-02 2:38 ` rodgertq at gcc dot gnu.org
` (2 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: de34 at live dot cn @ 2023-03-02 2:27 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108974
Jiang An <de34 at live dot cn> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |de34 at live dot cn
--- Comment #3 from Jiang An <de34 at live dot cn> ---
> is_nothrow_invocable_v<CompletionFunction&> shall be true.
If implementation divergence is not intendedly permitted, I don't think it
makes much sense to introduce UB in this way.
I guess we should either turn it into a mandating requirement:
> Instantiation of barrier<CompletionFunction> is ill-formed
> if is_nothrow_invocable_v<CompletionFunction&> is not true.
Or relax the preconditions:
> If any invocation to the completion function throws an exception,
> the behavior is undefined.
I've mailed to LWG Chair for this...
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug libstdc++/108974] std::barrier except completion function which is not manifestly noexcept
2023-02-28 19:23 [Bug c++/108974] New: std::barrier except completion function which is not manifestly noexcept oliver.rosten at googlemail dot com
` (3 preceding siblings ...)
2023-03-02 2:27 ` de34 at live dot cn
@ 2023-03-02 2:38 ` rodgertq at gcc dot gnu.org
2023-03-02 2:43 ` rodgertq at gcc dot gnu.org
2023-03-02 9:58 ` redi at gcc dot gnu.org
6 siblings, 0 replies; 8+ messages in thread
From: rodgertq at gcc dot gnu.org @ 2023-03-02 2:38 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108974
--- Comment #4 from Thomas Rodgers <rodgertq at gcc dot gnu.org> ---
(In reply to Jiang An from comment #3)
> > is_nothrow_invocable_v<CompletionFunction&> shall be true.
>
> If implementation divergence is not intendedly permitted, I don't think it
> makes much sense to introduce UB in this way.
>
> I guess we should either turn it into a mandating requirement:
> > Instantiation of barrier<CompletionFunction> is ill-formed
> > if is_nothrow_invocable_v<CompletionFunction&> is not true.
>
> Or relax the preconditions:
> > If any invocation to the completion function throws an exception,
> > the behavior is undefined.
>
> I've mailed to LWG Chair for this...
LWG Chair has already weighed in on this thread.
libstdc++ and libc++ have essentially the same implementation of std::barrier
(libstdc++'s implementation is derived from libc++'s). So that they behave
consistently and MSVC is different is not surprising.
I don't have a strong opinion on whether this should be UB ore mandated.
Raising an LWG issue seems reasonable.
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug libstdc++/108974] std::barrier except completion function which is not manifestly noexcept
2023-02-28 19:23 [Bug c++/108974] New: std::barrier except completion function which is not manifestly noexcept oliver.rosten at googlemail dot com
` (4 preceding siblings ...)
2023-03-02 2:38 ` rodgertq at gcc dot gnu.org
@ 2023-03-02 2:43 ` rodgertq at gcc dot gnu.org
2023-03-02 9:58 ` redi at gcc dot gnu.org
6 siblings, 0 replies; 8+ messages in thread
From: rodgertq at gcc dot gnu.org @ 2023-03-02 2:43 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108974
Thomas Rodgers <rodgertq at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |ASSIGNED
Assignee|unassigned at gcc dot gnu.org |rodgertq at gcc dot gnu.org
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug libstdc++/108974] std::barrier except completion function which is not manifestly noexcept
2023-02-28 19:23 [Bug c++/108974] New: std::barrier except completion function which is not manifestly noexcept oliver.rosten at googlemail dot com
` (5 preceding siblings ...)
2023-03-02 2:43 ` rodgertq at gcc dot gnu.org
@ 2023-03-02 9:58 ` redi at gcc dot gnu.org
6 siblings, 0 replies; 8+ messages in thread
From: redi at gcc dot gnu.org @ 2023-03-02 9:58 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108974
--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Jiang An from comment #3)
> I've mailed to LWG Chair for this...
Thanks, the new issue will be opened soon.
^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2023-03-02 9:58 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
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2023-02-28 19:23 [Bug c++/108974] New: std::barrier except completion function which is not manifestly noexcept oliver.rosten at googlemail dot com
2023-02-28 19:24 ` [Bug libstdc++/108974] " pinskia at gcc dot gnu.org
2023-02-28 21:16 ` redi at gcc dot gnu.org
2023-02-28 21:17 ` redi at gcc dot gnu.org
2023-03-02 2:27 ` de34 at live dot cn
2023-03-02 2:38 ` rodgertq at gcc dot gnu.org
2023-03-02 2:43 ` rodgertq at gcc dot gnu.org
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