From: Sam Ravnborg <sam@ravnborg.org>
To: Josh Triplett <josh@joshtriplett.org>
Cc: linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org,
Linus Torvalds <torvalds@linux-foundation.org>,
Andrew Morton <akpm@linux-foundation.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Michal Marek <mmarek@suse.cz>,
Rashika Kheria <rashika.kheria@gmail.com>
Subject: Re: #pragma once?
Date: Tue, 7 Jan 2014 06:55:32 +0100 [thread overview]
Message-ID: <20140107055532.GA16581@ravnborg.org> (raw)
In-Reply-To: <20140106204706.GA16924@leaf>
On Mon, Jan 06, 2014 at 12:47:07PM -0800, Josh Triplett wrote:
> [CCing build-system folks and others likely to know about potential
> issues.]
>
> Does anyone have any objection to the use of "#pragma once" instead of
> the usual #ifndef-#define-...-#endif include guard? GCC, LLVM/clang,
> and the latest Sparse all support either method just fine. (I added
> support to Sparse myself.) Both have equivalent performance. "#pragma
> once" is simpler, and avoids the possibility of a typo in the defined
> guard symbol.
For kernel headers no concern.
For UAPI headers we should be more carefull - as we do not know which
compiler it ends up seeing - and what version.
Sam
next prev parent reply other threads:[~2014-01-07 6:03 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-06 20:47 #pragma once? Josh Triplett
2014-01-06 21:00 ` Andrew Morton
2014-01-06 21:09 ` Josh Triplett
2014-01-06 21:33 ` Theodore Ts'o
2014-01-06 21:50 ` Dave Jones
2014-01-07 5:55 ` Sam Ravnborg [this message]
2014-01-07 9:48 ` Geert Uytterhoeven
2014-01-07 10:09 ` Michal Marek
2014-01-07 10:38 ` Josh Triplett
2014-01-07 10:50 ` Josh Triplett
2014-01-07 10:50 ` Josh Triplett
2014-01-12 16:14 ` Patrick Palka
2014-01-13 5:53 ` Josh Triplett
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