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

["Jörn Engel" <joern@wohnheim.fh-wedel.de>]

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