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From: Jonathan Wakely <jwakely@redhat.com>
To: "libstdc++" <libstdc++@gcc.gnu.org>
Cc: Matthias Kretz <m.kretz@gsi.de>,
	Marc Glisse <marc.glisse@inria.fr>,
	 gcc Patches <gcc-patches@gcc.gnu.org>
Subject: Re: [PATCH] libstdc++: Implement std::unreachable() for C++23 (P0627R6)
Date: Thu, 31 Mar 2022 17:05:48 +0100	[thread overview]
Message-ID: <CACb0b4k-t6LQo_nGC=+QQwybTnr444m30mioP28Ag8BoLaHQ6A@mail.gmail.com> (raw)
In-Reply-To: <48cc3e77-8f70-a4a7-ad16-22ba11d883b4@grove.saclay.inria.fr>

On Thu, 31 Mar 2022 at 17:03, Marc Glisse via Libstdc++
<libstdc++@gcc.gnu.org> wrote:
>
> On Thu, 31 Mar 2022, Matthias Kretz via Gcc-patches wrote:
>
> > I like it. But I'd like it even more if we could have
> >
> > #elif defined _UBSAN
> >    __ubsan_invoke_ub("reached std::unreachable()");
> >
> > But to my knowledge UBSAN has no hooks for the library like this (yet).
>
> -fsanitize=undefined already replaces __builtin_unreachable with its own
> thing, so I was indeed going to ask if the assertion / trap provide a
> better debugging experience compared to plain __builtin_unreachable, with
> the possibility to get a stack trace (UBSAN_OPTIONS=print_stacktrace=1),
> etc? Detecting if (the right subset of) ubsan is enabled sounds like a
> good idea.

Does UBsan define a macro that we can use to detect it?


  reply	other threads:[~2022-03-31 16:06 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-03-31 15:30 Jonathan Wakely
2022-03-31 15:50 ` Matthias Kretz
2022-03-31 15:59   ` Xi Ruoyao
2022-03-31 16:01   ` Marc Glisse
2022-03-31 16:05     ` Jonathan Wakely [this message]
2022-03-31 18:21       ` Marc Glisse
2022-04-01 11:33         ` Jonathan Wakely
2022-04-01 11:56           ` Matthias Kretz
2022-04-01 13:01             ` Jonathan Wakely
2022-03-31 16:02   ` Jonathan Wakely

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