From: Florian Weimer <fweimer@redhat.com>
To: Sam James <sam@gentoo.org>
Cc: Richard Biener <richard.guenther@gmail.com>,
gcc@gcc.gnu.org, c-std-porting@lists.linux.dev
Subject: Re: More C type errors by default for GCC 14
Date: Tue, 09 May 2023 19:35:50 +0200 [thread overview]
Message-ID: <87fs854dc9.fsf@oldenburg.str.redhat.com> (raw)
In-Reply-To: <87h6sljurv.fsf@gentoo.org> (Sam James's message of "Tue, 09 May 2023 18:07:16 +0100")
* Sam James:
> Florian Weimer <fweimer@redhat.com> writes:
>
>> * Richard Biener:
>>
>>>> Am 09.05.2023 um 14:16 schrieb Florian Weimer via Gcc <gcc@gcc.gnu.org>:
>>>>
>>>> TL;DR: This message is about turning implicit-int,
>>>> implicit-function-declaration, and possibly int-conversion into errors
>>>> for GCC 14.
>>>
>>> I suppose the goal is to not need to rely on altering CFLAGS but
>>> change the default behavior with still being able to undo this using
>>> -Wno-error= or -Wno-?
>>
>> That's what Clang does (and the defaults chang along with -std=
>> settings). To me, -Werror by default for some warnings seems rather
>> hackish. But that's just my personal preference, I do not have a strong
>> objection to doing it that way.
>
> Not that we have to follow Clang, but deviating by adding -fpermissive
> (which is a GCC-only flag) for C may not be desirable, and following
> Clang would let people use the same method for silencing known-bad
> codebases for now.
I think Clang already accepts -fpermissive, so it's not *too* bad?
(Presumably it just ignores it.)
>> One downside with -Wno- is that some developers jump on this rather
>> quickly instead of fixing the real problem. So far, I've seen this in
>> both Chromium and the kernel, in fringe areas admittedly, but still.
>> The advantage is that there is a familiar workaround to get things
>> compiling quickly again, of course.
>
> I've not seen very much of this so far, FWIW. Only for the more annoying
> C23 warnings which have well-documented problems (and unrelated to this,
> so I won't go on about it anymore).
I think this could be a side effect of our different testing strategies.
The kernel -Wno-implicit-function-declaration change looks like it was
specifically added to build with Clang 15/16.
> But -fpermissive does have a nice property in that it's immediately
> obvious you're doing something *terrible* if you use it.
Right.
> In addition to this, this made me realise something similar to what
> Florian was saying wrt whitespace. Passing -Wno-error=... doesn't
> always work with some poorly-written build scripts because they split
> on '=' (this happens with some CMake when poorly written).
Hmm, maybe I've seen this as well but attributed it to whitespace.
The -std=gnu89 approach would run into problems with this, too.
Thanks,
Florian
next prev parent reply other threads:[~2023-05-09 17:35 UTC|newest]
Thread overview: 246+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-09 12:15 Florian Weimer
2023-05-09 14:16 ` Dave Blanchard
2023-05-09 15:03 ` David Edelsohn
2023-05-09 15:07 ` Sam James
2023-05-09 15:35 ` Dave Blanchard
2023-05-09 15:58 ` Jonathan Wakely
2023-05-09 16:26 ` Arsen Arsenović
2023-05-09 15:14 ` Jonathan Wakely
2023-05-09 15:22 ` Dave Blanchard
2023-05-09 16:38 ` Arsen Arsenović
2023-05-09 16:57 ` Eli Zaretskii
2023-05-09 17:05 ` Sam James
2023-05-09 18:55 ` Eli Zaretskii
2023-05-09 17:15 ` Jonathan Wakely
2023-05-09 19:04 ` Eli Zaretskii
2023-05-09 19:07 ` Jakub Jelinek
2023-05-09 19:22 ` Eli Zaretskii
2023-05-09 20:13 ` David Edelsohn
2023-05-09 20:21 ` Arsen Arsenović
2023-05-10 2:38 ` Eli Zaretskii
2023-05-10 8:36 ` Arsen Arsenović
2023-05-10 11:52 ` Eli Zaretskii
2023-05-10 11:56 ` Jonathan Wakely
2023-05-10 12:25 ` Eli Zaretskii
2023-05-10 12:30 ` Jonathan Wakely
2023-05-10 12:44 ` Eli Zaretskii
2023-05-15 12:28 ` Richard Earnshaw (lists)
2023-05-15 20:17 ` Eric Gallager
2023-05-16 7:05 ` Florian Weimer
2023-05-16 15:56 ` Jason Merrill
2023-05-09 20:40 ` Jonathan Wakely
2023-05-09 22:27 ` David Edelsohn
2023-05-09 22:37 ` Joel Sherrill
2023-05-09 22:45 ` Jonathan Wakely
2023-05-10 10:40 ` Eric Gallager
2023-05-10 10:45 ` Sam James
2023-05-10 10:56 ` Neal Gompa
2023-05-10 12:06 ` Eli Zaretskii
2023-05-10 12:10 ` Neal Gompa
2023-05-10 12:41 ` Eli Zaretskii
2023-05-10 10:48 ` Jonathan Wakely
2023-05-10 10:51 ` Jonathan Wakely
2023-05-10 12:00 ` Eli Zaretskii
2023-05-10 12:42 ` Sam James
2023-05-10 15:10 ` Joel Sherrill
2023-05-10 15:14 ` Jakub Jelinek
2023-05-10 16:36 ` Joel Sherrill
2023-05-10 16:44 ` Jakub Jelinek
2023-05-10 17:05 ` Jonathan Wakely
2023-05-10 18:37 ` James K. Lowden
2023-05-10 23:26 ` Jonathan Wakely
2023-05-11 18:47 ` Jason Merrill
2023-05-10 23:33 ` Sam James
2023-05-11 5:48 ` Eli Zaretskii
2023-05-11 2:28 ` Po Lu
2023-05-11 2:09 ` Po Lu
2023-05-11 2:14 ` Sam James
2023-05-11 2:23 ` Po Lu
2023-05-11 3:14 ` Eli Schwartz
2023-05-11 3:56 ` Po Lu
2023-05-11 4:46 ` Eli Schwartz
2023-05-11 4:49 ` Eli Schwartz
2023-05-11 6:23 ` Po Lu
2023-05-11 6:18 ` Po Lu
2023-05-11 22:41 ` Eli Schwartz
2023-05-12 2:08 ` Po Lu
2023-05-12 3:07 ` Eli Schwartz
2023-05-12 5:57 ` Po Lu
2023-05-12 11:05 ` Gabriel Ravier
2023-05-12 13:53 ` Po Lu
2023-05-12 14:03 ` Jonathan Wakely
2023-05-14 12:35 ` Mark Wielaard
2023-05-12 11:48 ` Is the GNUC dialect anything that GCC does when given source code containing UB? (Was: More C type errors by default for GCC 14) Eli Schwartz
2023-05-12 13:07 ` Is the GNUC dialect anything that GCC does when given source code containing UB? Po Lu
2023-05-12 6:56 ` More C type errors by default for GCC 14 Eli Zaretskii
2023-05-12 7:28 ` Jonathan Wakely
2023-05-12 10:36 ` Eli Zaretskii
2023-05-12 13:19 ` Po Lu
2023-05-12 13:25 ` Gabriel Ravier
2023-05-13 0:45 ` Po Lu
2023-05-13 5:30 ` Thomas Koenig
2023-05-13 5:53 ` Po Lu
2023-05-14 5:10 ` Eli Schwartz
2023-05-14 5:38 ` Po Lu
2023-05-14 9:46 ` David Brown
2023-05-14 10:21 ` Jonathan Wakely
2023-05-14 10:23 ` Jonathan Wakely
2023-05-14 5:08 ` Eli Schwartz
2023-05-14 5:28 ` Po Lu
2023-05-14 5:56 ` Eli Schwartz
2023-05-14 11:55 ` Po Lu
2023-05-14 12:22 ` Arsen Arsenović
2023-05-15 1:05 ` Po Lu
2023-05-14 6:03 ` Eli Schwartz
2023-05-14 8:47 ` Jonathan Wakely
2023-05-14 12:05 ` Po Lu
2023-05-14 12:48 ` Nicholas Vinson
2023-05-14 10:29 ` David Brown
2023-05-12 15:51 ` Jason Merrill
2023-05-17 10:06 ` Florian Weimer
2023-05-12 11:26 ` David Brown
2023-05-11 6:24 ` Eli Zaretskii
2023-05-11 22:43 ` Eli Schwartz
2023-05-12 2:38 ` Po Lu
2023-05-12 2:55 ` Jason Merrill
2023-05-12 6:01 ` Po Lu
2023-05-12 6:40 ` Jonathan Wakely
2023-05-12 13:23 ` Po Lu
2023-05-12 10:49 ` Pedro Alves
2023-05-12 13:26 ` Po Lu
2023-05-12 11:55 ` Eli Schwartz
2023-05-12 13:54 ` Po Lu
2023-05-12 6:49 ` Eli Zaretskii
2023-05-12 2:56 ` Sam James
2023-05-12 6:03 ` Po Lu
2023-05-12 3:06 ` Sam James
2023-05-12 6:25 ` Eli Zaretskii
2023-05-12 11:23 ` Gabriel Ravier
2023-05-11 6:12 ` Eli Zaretskii
2023-05-11 7:04 ` Jonathan Wakely
2023-05-11 22:30 ` Eli Schwartz
2023-05-11 22:35 ` Sam James
2023-05-12 2:40 ` Po Lu
2023-05-12 2:52 ` Sam James
2023-05-12 5:32 ` Po Lu
2023-05-12 2:39 ` Po Lu
2023-05-12 3:18 ` Eli Schwartz
2023-05-12 6:17 ` Eli Zaretskii
2023-05-11 7:59 ` David Brown
2023-05-09 21:00 ` Thomas Koenig
2023-05-09 21:17 ` Arsen Arsenović
2023-05-10 13:57 ` Florian Weimer
2023-05-10 11:00 ` David Brown
2023-05-11 10:49 ` James K. Lowden
2023-05-11 1:38 ` Po Lu
2023-05-11 1:43 ` Sam James
2023-05-11 2:20 ` Po Lu
2023-05-09 20:57 ` Florian Weimer
2023-05-10 2:33 ` Eli Zaretskii
2023-05-10 8:04 ` Jonathan Wakely
2023-05-10 8:46 ` Richard Biener
2023-05-10 12:26 ` Florian Weimer
2023-05-10 11:30 ` Eli Zaretskii
2023-05-10 12:03 ` Jakub Jelinek
2023-05-10 12:36 ` Eli Zaretskii
2023-05-10 12:41 ` Gabriel Ravier
2023-05-10 14:14 ` Eli Zaretskii
2023-05-10 14:22 ` Jakub Jelinek
2023-05-10 15:30 ` Eli Zaretskii
2023-05-10 16:02 ` Jakub Jelinek
2023-05-10 16:31 ` Eli Zaretskii
2023-05-10 16:33 ` Richard Biener
2023-05-10 16:57 ` Eli Zaretskii
2023-05-10 17:08 ` Joseph Myers
2023-05-10 18:18 ` Eli Zaretskii
2023-05-12 15:02 ` Florian Weimer
2023-05-12 17:52 ` Florian Weimer
2023-05-12 17:55 ` Gabriel Ravier
2023-05-12 18:00 ` Florian Weimer
2023-05-12 18:08 ` Alexander Monakov
2023-05-12 18:14 ` Florian Weimer
2023-05-15 12:51 ` Michael Matz
2023-05-16 8:55 ` Florian Weimer
2023-05-16 10:39 ` Alexander Monakov
2023-05-16 11:01 ` Jakub Jelinek
2023-05-16 11:09 ` Jonathan Wakely
2023-05-16 11:15 ` Florian Weimer
2023-05-12 19:44 ` Joseph Myers
2023-05-12 20:43 ` Florian Weimer
2023-05-12 20:18 ` Jason Merrill
2023-05-12 20:57 ` Florian Weimer
2023-05-12 21:20 ` Sam James
2023-05-12 21:21 ` Sam James
2023-05-12 21:37 ` Florian Weimer
2023-05-12 21:47 ` Sam James
2023-05-12 21:59 ` Florian Weimer
2023-05-10 15:58 ` David Brown
2023-05-10 16:28 ` Eli Zaretskii
2023-05-11 6:52 ` David Brown
2023-05-11 7:39 ` Eli Zaretskii
2023-05-10 14:31 ` Thomas Koenig
2023-05-10 15:37 ` Eli Zaretskii
2023-05-11 2:38 ` Po Lu
2023-05-11 7:38 ` Arsen Arsenović
2023-05-11 8:31 ` Po Lu
2023-05-11 8:44 ` Arsen Arsenović
2023-05-11 9:28 ` Po Lu
2023-05-11 21:10 ` Arsen Arsenović
2023-05-12 1:41 ` Po Lu
2023-05-11 10:35 ` Eli Zaretskii
2023-05-11 19:25 ` Arsen Arsenović
2023-05-12 2:36 ` Po Lu
2023-05-12 12:30 ` Gabriel Ravier
2023-05-12 13:56 ` Po Lu
2023-05-12 7:53 ` Eli Zaretskii
2023-05-12 8:15 ` Jakub Jelinek
2023-05-12 10:40 ` Eli Zaretskii
2023-05-12 8:45 ` Christian Groessler
2023-05-12 10:14 ` Jonathan Wakely
2023-05-12 9:11 ` Thomas Koenig
2023-05-11 8:53 ` Jonathan Wakely
2023-05-11 9:29 ` Po Lu
2023-05-10 8:49 ` David Brown
2023-05-10 11:37 ` Eli Zaretskii
2023-05-10 11:49 ` Jonathan Wakely
2023-05-10 12:22 ` Eli Zaretskii
2023-05-10 13:30 ` David Brown
2023-05-10 14:39 ` Eli Zaretskii
2023-05-10 15:21 ` Paul Koning
2023-05-10 16:20 ` David Brown
2023-05-10 16:48 ` Eli Zaretskii
2023-05-10 12:32 ` Sam James
2023-05-10 12:47 ` Eli Zaretskii
2023-05-09 19:33 ` Arsen Arsenović
2023-05-09 15:25 ` David Edelsohn
2023-05-11 1:25 ` Po Lu
2023-05-11 1:30 ` Sam James
2023-05-11 1:33 ` Sam James
2023-05-11 2:18 ` Po Lu
2023-05-11 6:44 ` Jonathan Wakely
2023-05-11 8:32 ` Po Lu
2023-05-11 8:52 ` Jonathan Wakely
2023-05-11 7:36 ` Arsen Arsenović
2023-05-11 8:23 ` Po Lu
2023-05-09 18:22 ` Florian Weimer
2023-05-11 21:32 ` Segher Boessenkool
2023-05-09 15:16 ` Richard Biener
2023-05-09 16:05 ` Jakub Jelinek
2023-05-09 16:11 ` Sam James
2023-05-09 16:13 ` David Edelsohn
[not found] ` <BBE9950C-28AA-4A1C-A4C5-7F486538004E@gmail.com>
2023-05-09 16:44 ` Florian Weimer
2023-05-09 16:58 ` Ian Lance Taylor
2023-05-09 17:08 ` Jason Merrill
2023-05-09 17:16 ` Sam James
2023-05-09 16:59 ` Florian Weimer
2023-05-09 17:07 ` Sam James
2023-05-09 17:35 ` Florian Weimer [this message]
2023-05-11 15:21 ` Peter0x44
2023-05-12 9:33 ` Martin Jambor
2023-05-12 12:30 ` Jakub Jelinek
2023-05-15 12:46 ` Michael Matz
2023-05-15 13:14 ` Richard Earnshaw (lists)
2023-05-10 12:41 Marcin Jaczewski
2023-05-10 14:19 ` Eli Zaretskii
2023-05-10 13:10 Basile Starynkevitch
2023-05-10 14:20 ` David Brown
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