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From: Pierre Habouzit <madcoder@debian.org>
To: kernel-janitors@vger.kernel.org
Subject: Re: [KJ] for loops and variable declarations...
Date: Tue, 05 Jun 2007 11:37:21 +0000	[thread overview]
Message-ID: <20070605113721.GH10354@.intersec.eu> (raw)
In-Reply-To: <ab8e556c0706050422y1cf091a8n34313317a92a5afd@mail.gmail.com>


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On Tue, Jun 05, 2007 at 06:22:40PM +0700, Kevin Jackson wrote:
> Hi all,
> 
> I'm just looking at kernel code for basically the first time - so
> please be patient :)
> 
> I'm seeing this style of code:
> 
> uchar a
> ....
> ....
> ....
> ....
> ....
> ....(many lines later...)
> for(a=2; a< VALUE; a++)
> 
> 
> Why are loop variables declared so far away from where they are used?

  because C forbigs in-code variable declarations (unlike C++). GNU C
authorizes it though.

> Is this advantageous in some way?  It seems that the scope of the
> variables is much larger than having them declared just as they are to
> be used eg:
> 
> for(uchar a=2; a<VALUE; a++)

  This for is only allowed in C99, and is not well defined on some
compilers where a scope is not necessarily limited to the for loop as
common sense would suppose.

  So IMHO, kernel do not uses such kind of code (but I may be wrong).

-- 
·O·  Pierre Habouzit
··O                                                madcoder@debian.org
OOO                                                http://www.madism.org

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  reply	other threads:[~2007-06-05 11:37 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-06-05 11:22 [KJ] for loops and variable declarations Kevin Jackson
2007-06-05 11:37 ` Pierre Habouzit [this message]
2007-06-05 11:59 ` John Anthony Kazos Jr.
2007-06-05 12:23 ` Matthew Wilcox
2007-06-05 13:07 ` Robert P. J. Day

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