[<prev] [next>] [<thread-prev] [thread-next>] [month] [year] [list]
Date: Mon, 1 Jan 2007 14:20:20 +0000
From: Christoph Hellwig <hch@...radead.org>
To: "Robert P. J. Day" <rpjday@...dspring.com>
Subject: Re: [PATCH] Documentation: Explain a second alternative for multi-line macros.
On Sun, Dec 31, 2006 at 02:32:25PM -0500, Robert P. J. Day wrote:
> + (a) Enclose those statements in a do - while block:
> +
> + #define macrofun(a, b, c) \
> + do { \
> + if (a == 5) \
> + do_this(b, c); \
> + } while (0)
nitpick, please don't add an indentaion level for the do {. Do this
should look like:
#define macrofun(a, b, c) \
do { \
if (a == 5) \
do_this(b, c); \
} while (0)
> + (b) Use the gcc extension that a compound statement enclosed in
> + parentheses represents an expression:
> +
> + #define macrofun(a, b, c) ({ \
> if (a == 5) \
> do_this(b, c); \
> - } while (0)
> + })
I'd rather document to not use this - it makes the code far less
redable. And it's a non-standard extension, something we only
use if it provides us a benefit which it doesn't here.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Hosted by DataForce ISP -
Powered by Openwall GNU/*/Linux