From: Paul Eggert <eggert@cs.ucla.edu>
To: Sam James <sam@gentoo.org>, Gnulib bugs <bug-gnulib@gnu.org>
Cc: "Arsen Arsenović" <arsen@aarsen.me>
Subject: Re: Making _Noreturn a no-op in < Clang 16?
Date: Wed, 18 Jan 2023 20:17:39 -0800 [thread overview]
Message-ID: <575c1ae6-d77d-9001-9f9b-a803778446c6@cs.ucla.edu> (raw)
In-Reply-To: <F3CDF510-E88C-4BDC-99E9-E10004E6ADF3@gentoo.org>
The problem we found in Gawk was that this sort of function call:
(b ? f : g) (x)
is mishandled by Clang < 16 when one function is _Noreturn and the other
isn't, in that Clang mistakenly treats the call as if both functions are
_Noreturn.
I expect this sort of issue to be reasonably rare in practical C code,
as most people don't write code like the above, and when they do then
typically F is _Noreturn if and only if G is also _Noreturn. So I've
held off on doing the more-drastic "#define _Noreturn /*empty*/" for
Clang < 16 in Gnulib, as my guess has been that the advantages of
enabling _Noreturn on Clang < 16 are greater than the disadvantages
given the rarity of situations like the above.
Of course I could be wrong....
next prev parent reply other threads:[~2023-01-19 4:17 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-19 2:09 Making _Noreturn a no-op in < Clang 16? Sam James
2023-01-19 4:17 ` Paul Eggert [this message]
2023-01-19 20:44 ` Sam James
2023-01-19 21:20 ` Paul Eggert
2023-01-19 21:30 ` Sam James
2023-01-20 3:40 ` Paul Eggert
2023-01-20 4:20 ` Sam James
2023-01-20 9:16 ` Paul Eggert
2023-01-20 10:25 ` Bruno Haible
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