From: David Laight <David.Laight@ACULAB.COM>
To: "'Moore, Robert'" <robert.moore@intel.com>, Qian Cai <cai@lca.pw>,
"Wysocki, Rafael J" <rafael.j.wysocki@intel.com>
Cc: "Schmauss, Erik" <erik.schmauss@intel.com>,
"jkim@FreeBSD.org" <jkim@FreeBSD.org>,
"lenb@kernel.org" <lenb@kernel.org>,
"ndesaulniers@google.com" <ndesaulniers@google.com>,
"linux-acpi@vger.kernel.org" <linux-acpi@vger.kernel.org>,
"devel@acpica.org" <devel@acpica.org>,
"clang-built-linux@googlegroups.com"
<clang-built-linux@googlegroups.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH v2] acpica: fix -Wnull-pointer-arithmetic warnings
Date: Mon, 29 Jul 2019 10:24:27 +0000 [thread overview]
Message-ID: <c98fa373a004472b979255a93b414fe1@AcuMS.aculab.com> (raw)
In-Reply-To: <94F2FBAB4432B54E8AACC7DFDE6C92E3B9661CBD@ORSMSX110.amr.corp.intel.com>
From: Moore, Robert
> Sent: 26 July 2019 20:36
...
> This is because pointer arithmetic
> on a pointer not pointing to an array is an undefined behavior (C11 6.5.6, constraint 8).
...
The standards committee as smoking dope again :-)
If that is enforced as a compiler warning/error a lot of code 'breaks'.
Anything that does:
struct foo *foo = ...;
struct bar *bar = (void *)(foo + 1);
suddenly becomes 'invalid'.
David
-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
next prev parent reply other threads:[~2019-07-29 10:24 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-18 19:48 [PATCH v2] acpica: fix -Wnull-pointer-arithmetic warnings Qian Cai
2019-07-26 19:35 ` Moore, Robert
2019-07-29 10:24 ` David Laight [this message]
2019-07-29 12:23 ` Qian Cai
2019-08-01 19:16 ` Qian Cai
2019-08-01 20:17 ` Schmauss, Erik
2019-08-01 20:28 ` Moore, Robert
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