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From: Jan Beulich <jbeulich@suse.com>
To: Ian Jackson <iwj@xenproject.org>
Cc: Wei Liu <wl@xen.org>, Anthony PERARD <anthony.perard@citrix.com>,
	Andrew Cooper <andrew.cooper3@citrix.com>,
	George Dunlap <george.dunlap@citrix.com>,
	Julien Grall <julien@xen.org>,
	Stefano Stabellini <sstabellini@kernel.org>,
	xen-devel@lists.xenproject.org,
	Manuel Bouyer <bouyer@antioche.eu.org>
Subject: Re: [PATCH] Fix error: array subscript has type 'char' [and 1 more messages]
Date: Wed, 27 Jan 2021 15:33:17 +0100	[thread overview]
Message-ID: <d3796603-20a7-2c81-a446-0d0a75cd52d5@suse.com> (raw)
In-Reply-To: <24593.28738.216430.891500@mariner.uk.xensource.com>

On 27.01.2021 14:53, Ian Jackson wrote:
> Jan Beulich writes ("Re: [PATCH] Fix error: array subscript has type 'char'"):
>> On 27.01.2021 09:31, Jan Beulich wrote:
>>> But yes, I'm not the maintainer of this code, so if you're
>>> happy with such risks, so be it.
>>
>> And actually I was only partly right here - there's one hunk
>> here affecting code I'm the maintainer just as much as you
>> are. At least there I'd like to ask that ...
>>
>>> For the record, to me the less risky approach here would seem
>>> to have been to make use of compilers allowing to choose
>>> whether plain char is signed or unsigned, and force it to
>>> unsigned for at least the affected components.
>>
>> ... this be considered as an alternative, before I maybe
>> withdraw my de-facto nak.
> 
> Whether char is signed or unsigned is generally specified in the
> platform API/ABI.  Deviating from this for userland code is not
> possible or reasonable since it would involve processing the system
> headers with a deviant langauge definition!

I don't think I've ever come across that part of a platform
API/ABI spec. Instead my understanding so far was that good
platform headers would be ignorant of the user's choice of
char's signed-ness (wherever compilers offer such a choice,
but I think all that I've ever worked with did). At the very
least gcc's doc doesn't warn about any possible
incompatibilities resulting from use of -fsigned-char or
-funsigned-char (or their bitfield equivalents, for that
matter).

Jan


  reply	other threads:[~2021-01-27 14:33 UTC|newest]

Thread overview: 96+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-12 18:12 [PATCH] Fix error: array subscript has type 'char' Manuel Bouyer
2021-01-12 18:12 ` [PATCH] NetBSD: Fix lock directory path Manuel Bouyer
2021-01-15 15:09   ` Roger Pau Monné
2021-01-15 15:13     ` Manuel Bouyer
2021-01-15 15:30       ` Andrew Cooper
2021-01-12 18:12 ` [PATCH] NetBSD hotplug: Introduce locking functions Manuel Bouyer
2021-01-27 15:57   ` Ian Jackson
2021-01-27 19:29     ` Manuel Bouyer
2021-01-28 14:05       ` Ian Jackson
2021-01-12 18:12 ` [PATCH] NetBSD hotplug: fix block unconfigure on destroy Manuel Bouyer
2021-01-15 15:27   ` Roger Pau Monné
2021-01-26 16:47     ` Manuel Bouyer
2021-01-27  9:40       ` Roger Pau Monné
2021-01-27  9:47         ` Manuel Bouyer
2021-01-12 18:12 ` [PATCH] NetBSD hotplug: handle case where vifname is not present Manuel Bouyer
2021-01-15 16:06   ` Roger Pau Monné
2021-01-26 16:49     ` Manuel Bouyer
2021-01-12 18:12 ` [PATCH] NetBSD: remove xenbackendd Manuel Bouyer
2021-01-15 15:31   ` Roger Pau Monné
2021-01-18 18:31     ` Andrew Cooper
2021-01-18 18:41       ` Manuel Bouyer
2021-01-12 18:12 ` [PATCH] NetBSD: use system-provided headers Manuel Bouyer
2021-01-15 16:01   ` Roger Pau Monné
2021-01-12 18:12 ` [PATCH] gdbsx: use right path for privcmd Manuel Bouyer
2021-01-18 18:03   ` Roger Pau Monné
2021-01-18 18:45     ` Andrew Cooper
2021-01-18 19:05       ` Manuel Bouyer
2021-01-12 18:12 ` [PATCH] libs/call: fix build on NetBSD Manuel Bouyer
2021-01-18 18:00   ` Roger Pau Monné
2021-01-12 18:12 ` [PATCH] libs/evtchn: " Manuel Bouyer
2021-01-18 18:01   ` Roger Pau Monné
2021-01-12 18:12 ` [PATCH] libs/foreignmemory: Implement " Manuel Bouyer
2021-01-18 17:49   ` Roger Pau Monné
2021-01-12 18:12 ` [PATCH] libs/gnttab: implement " Manuel Bouyer
2021-01-18 17:54   ` Roger Pau Monné
2021-01-26 17:05     ` Manuel Bouyer
2021-01-27  9:31       ` Roger Pau Monné
2021-01-12 18:12 ` [PATCH] libs/light: Switch NetBSD to QEMU_XEN Manuel Bouyer
2021-01-18 17:28   ` Roger Pau Monné
2021-01-12 18:12 ` [PATCH] libs/light: fix tv_sec printf format Manuel Bouyer
2021-01-18 18:19   ` Roger Pau Monné
2021-01-12 18:12 ` [PATCH] libs/light: fix uuid on NetBSD Manuel Bouyer
2021-01-15 17:27   ` Roger Pau Monné
2021-01-12 18:12 ` [PATCH] libs/light: make it build without setresuid() Manuel Bouyer
2021-01-18 18:16   ` Roger Pau Monné
2021-01-20 14:52     ` Ian Jackson
2021-01-20 15:13       ` Manuel Bouyer
2021-01-20 15:32         ` Ian Jackson
2021-01-20 16:56           ` Manuel Bouyer
2021-01-20 17:10             ` Ian Jackson
2021-01-20 17:20               ` Manuel Bouyer
2021-01-20 17:29                 ` Ian Jackson
2021-01-27 16:03                   ` Ian Jackson
2021-01-27 19:34                     ` Manuel Bouyer
2021-01-28 11:39                       ` Ian Jackson
2021-01-30 11:57                         ` Manuel Bouyer
2021-01-12 18:12 ` [PATCH] libs/light: pass some infos to qemu Manuel Bouyer
2021-01-16 10:16   ` Roger Pau Monné
2021-01-16 11:25     ` Manuel Bouyer
2021-01-18  8:36       ` Roger Pau Monné
2021-01-18  8:52         ` Manuel Bouyer
2021-01-18  9:07           ` Roger Pau Monné
2021-01-18  9:24             ` Manuel Bouyer
2021-01-26 22:42         ` Manuel Bouyer
2021-01-27  9:06           ` Roger Pau Monné
2021-01-27  9:49             ` Manuel Bouyer
2021-01-12 18:12 ` [PATCH] libs/store: make build without PTHREAD_STACK_MIN Manuel Bouyer
2021-01-18 18:18   ` Roger Pau Monné
2021-01-18 18:56   ` Andrew Cooper
2021-01-18 19:05     ` Manuel Bouyer
2021-01-12 18:12 ` [PATCH] ocaml/libs/eventchn: drop unneeded evtchn.h Manuel Bouyer
2021-01-13  9:22   ` Christian Lindig
2021-01-13  9:40     ` Manuel Bouyer
2021-01-12 18:12 ` [PATCH] xenpaging.c: include errno.h Manuel Bouyer
2021-01-15 16:08   ` Roger Pau Monné
2021-01-12 18:12 ` [PATCH] xenpmd.c: use dynamic allocation Manuel Bouyer
2021-01-27 15:57   ` Ian Jackson
2021-01-12 18:12 ` [PATCH] xenstat_netbsd: remove usused code Manuel Bouyer
2021-01-18 18:06   ` Roger Pau Monné
2021-01-14 10:53 ` [PATCH] Fix error: array subscript has type 'char' Jan Beulich
2021-01-14 12:29   ` Manuel Bouyer
2021-01-14 13:25     ` Jan Beulich
2021-01-14 14:16       ` Manuel Bouyer
2021-01-26 17:44         ` Manuel Bouyer
2021-01-26 17:59           ` Ian Jackson
2021-01-27  8:31             ` Jan Beulich
2021-01-27  8:37               ` Jan Beulich
2021-01-27 13:53                 ` [PATCH] Fix error: array subscript has type 'char' [and 1 more messages] Ian Jackson
2021-01-27 14:33                   ` Jan Beulich [this message]
2021-01-27 16:21                     ` Ian Jackson
2021-01-27 16:32                       ` Jan Beulich
2021-01-27 16:52                         ` George Dunlap
2021-01-27 17:00                           ` Jan Beulich
2021-01-27 17:00                           ` Ian Jackson
2021-01-18 19:08 ` NetBSD patches Andrew Cooper
2021-01-18 19:11   ` Manuel Bouyer

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