From: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: David Laight <David.Laight@aculab.com>,
Tom Tromey <tom@tromey.com>,
Alexey Dobriyan <adobriyan@gmail.com>,
Luc Van Oostenryck <luc.vanoostenryck@gmail.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Sparse Mailing-list <linux-sparse@vger.kernel.org>
Subject: Re: [PATCH 00/11] pragma once: treewide conversion
Date: Sat, 6 Mar 2021 14:07:27 +0100 [thread overview]
Message-ID: <CANiq72k-_ORGU+tCVhBGnr0QtH4hQ45ayzDtoHND8JZa2jYYPA@mail.gmail.com> (raw)
In-Reply-To: <CAHk-=whh3fiL7FcLD_r1rfx-gP9W4HWS7vTPM9LKUH+0xzF2=A@mail.gmail.com>
On Fri, Mar 5, 2021 at 10:25 PM Linus Torvalds
<torvalds@linux-foundation.org> wrote:
>
> And regardless of even _those_ issues, you still should do all the
> other syntactic tokenization stuff (ie all the quoting, the the
> character handling: 'a' is a valid C token, but if you see the string
> "it's" outside of a comment, that's a syntax error even if it's inside
> a disabled region. IOW, this is an incorrect file:
>
> #if 0
> it's a bug to do this, and the compiler should scream
> #endif
>
> because it's simply not a valid token sequence. The fact that it's
> inside a "#if 0" region doesn't change that fact at all. So you did
> need to do all the tokenization logic.
Compilers don't scream that much, only GCC seems to give a warning. I
assume it is because it is just undefined rather than a required
error/diagnostic, i.e. the "If a ’ or a " character matches the last
category, the behavior is undefined." in 6.4.
Concerning #pragma once: I actually would like to have a standard
#once directive if what is a "seen file" could be defined a bit more
precisely. Even if just says it creates a guard with something similar
to the result of `__FILE__` would be good enough for many projects out
there, and one can still use guards when flexibility is needed and/or
corner cases are expected (which, if detected, the compiler could also
warn about).
Cheers,
Miguel
next prev parent reply other threads:[~2021-03-06 13:08 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-28 16:57 [PATCH 00/11] pragma once: treewide conversion Alexey Dobriyan
2021-02-28 16:58 ` [PATCH 01/11] pragma once: delete include/linux/atm_suni.h Alexey Dobriyan
2021-02-28 19:05 ` Jakub Kicinski
2021-02-28 16:59 ` [PATCH 02/11] pragma once: convert arch/arm/tools/gen-mach-types Alexey Dobriyan
2021-02-28 16:59 ` Alexey Dobriyan
2021-03-01 10:19 ` Russell King - ARM Linux admin
2021-03-01 10:19 ` Russell King - ARM Linux admin
2021-03-02 15:15 ` Alexey Dobriyan
2021-03-02 15:15 ` Alexey Dobriyan
2021-02-28 16:59 ` [PATCH 03/11] pragma once: convert arch/s390/tools/gen_facilities.c Alexey Dobriyan
2021-02-28 17:00 ` [PATCH 04/11] pragma once: convert drivers/gpu/drm/pl111/pl111_nomadik.h Alexey Dobriyan
2021-03-01 14:41 ` Linus Walleij
2021-02-28 17:01 ` [PATCH 05/11] pragma once: convert drivers/scsi/qla2xxx/qla_target.h Alexey Dobriyan
2021-02-28 22:07 ` Bart Van Assche
2021-02-28 17:02 ` [PATCH 06/11] pragma once: convert include/linux/cb710.h Alexey Dobriyan
2021-03-03 23:13 ` Michał Mirosław
2021-02-28 17:02 ` [PATCH 07/11] pragma once: convert kernel/time/timeconst.bc Alexey Dobriyan
2021-02-28 17:03 ` [PATCH 08/11] pragma once: convert scripts/atomic/ Alexey Dobriyan
2021-03-01 7:55 ` Peter Zijlstra
2021-02-28 17:04 ` [PATCH 09/11] pragma once: convert scripts/selinux/genheaders/genheaders.c Alexey Dobriyan
2021-02-28 18:37 ` Paul Moore
2021-02-28 18:57 ` Alexey Dobriyan
2021-02-28 17:05 ` [PATCH 10/11] pragma once: delete few backslashes Alexey Dobriyan
2021-02-28 17:05 ` Alexey Dobriyan
2021-03-01 8:54 ` Ido Schimmel
2021-03-01 8:54 ` Ido Schimmel
2021-03-02 19:00 ` Vineet Gupta
2021-03-02 19:00 ` Vineet Gupta
2021-03-04 14:22 ` Edward Cree
2021-03-04 14:22 ` Edward Cree
2021-03-23 10:09 ` Pavel Machek
2021-03-23 10:09 ` Pavel Machek
2021-02-28 17:05 ` [PATCH 11/11] pragma once: conversion script (in Python 2) Alexey Dobriyan
2021-02-28 17:11 ` [PATCH 12/11] pragma once: scripted treewide conversion Alexey Dobriyan
2021-02-28 17:11 ` Alexey Dobriyan
2021-03-01 17:35 ` Darrick J. Wong
2021-02-28 17:46 ` [PATCH 00/11] pragma once: " Linus Torvalds
2021-02-28 19:34 ` Alexey Dobriyan
2021-02-28 20:00 ` Linus Torvalds
[not found] ` <877dmo10m3.fsf@tromey.com>
2021-03-03 20:17 ` Linus Torvalds
2021-03-04 13:55 ` David Laight
2021-03-04 20:16 ` Linus Torvalds
2021-03-05 9:19 ` David Laight
2021-03-05 21:23 ` Linus Torvalds
2021-03-06 13:07 ` Miguel Ojeda [this message]
2021-03-06 21:33 ` Linus Torvalds
2021-03-23 10:03 ` Pavel Machek
2021-03-01 0:29 ` Luc Van Oostenryck
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