Re: RFC: turn kmalloc+memset(,0,) into kcalloc

Jörn Engel
2005-04-06T11:28:36Z

On Tue, 5 April 2005 22:01:49 +0200, Jesper Juhl wrote:
> On Tue, 5 Apr 2005, Roland Dreier wrote:
>
> > > or simply
> > > if (!(ptr = kcalloc(n, size, ...)))
> > > goto out;
> > > and save an additional line of screen realestate while you are at it...
> >
> > No, please don't do that. The general kernel style is to avoid
> > assignments within conditionals.
> >
> It may be the prefered style to avoid assignments in conditionals, but in
> that case we have a lot of cleanup to do. What I wrote above is quite
> common in the current tree - a simple egrep -r "if\ *\(\!\(.+=" * in
> 2.6.12-rc2-mm1 will find you somewhere between 1000 and 2000 cases
> scattered all over the tree.
>
> Personally I don't see why thy should not be used. They are short, not any
> harder to read (IMHO), save screen space & are quite common in userspace
> code as well (so people should be used to seeing them).
>
> If such statements are generally frawned upon then I'd suggest an addition
> be made to Documentation/CodingStyle mentioning that fact, and I wonder if
> patches to clean up current users would be welcome?

I _do_ change them whenever they occur in code I maintain. And each
time, it is an improvement.

o Functional code always has the same indentation. I can mentally
ignore the error path by ignoring all indented code. Getting a
quick overview is quite nice.

o Rather often, your preferred variant violates the 80 columns rule.
If I need the line break anyway,...

o Keeping condition and functional code seperate avoids the Lisp-style
bracket maze. Some editors can help you here, but not needing any
help would be even better, no?

Jörn

--
Mundie uses a textbook tactic of manipulation: start with some
reasonable talk, and lead the audience to an unreasonable conclusion.
-- Bruce Perens