Re: Clarifying confusion of our variable placement rules caused by cleanup.h

"H. Peter Anvin" <[email protected]>
Newsgroups dev.linux.lists.ksummit,org.kernel.vger.linux-kernel
Message-ID <[email protected]>
On 2025-11-18 08:39, James Bottomley wrote:
> 
> For myself I do find some value in the C89 declarations at the
> beginning of the block for readability, so I'm happy to relax the
> mixing rule to cases where it's strictly necessary and require
> documenting in the comment what the necessity is.  However, I do think
> we should, absent ordering problems, keep __free variables
> uninitialised and at the top of the block given we can detect any
> problem (and thus keep this rule absolutely for non-__free variables
> where there's no ordering issues).  But, again, I'm less attached to
> this position than I am to the consistency one: I really think it's a
> bad idea to change the rules for one class of variables but not for
> another, so whatever we do, we should do it for everything and if that
> means relaxing the rule mixing code and declarations for everthing, I
> can live with that.
> 

To me, a major win with pushing declarations down to first initialization or
thereabouts is that it implicitly reduces the scope of a variable (without
needing to create new blocks.)  This can sometimes catch some pretty serious
errors.

	-hpa
lmpx.com only provides a reader for public news (NNTP) servers. It is not affiliated with the servers or forums shown here and is not responsible for the content of articles, which is written by their respective authors.