Re: A CodingStyle suggestion

[Theodore Tso <tytso@mit.edu>]

On Sat, Feb 03, 2007 at 01:59:51PM -0800, Randy Dunlap wrote:
> On Sat, 3 Feb 2007 23:58:48 +0200 Ahmed S. Darwish wrote:
> > 
> > In CodingStyle Chapter 16 "Function return value and names", why not
> > adding a comment about the favorable community way of checking the return
> > value. ie:
> > 
> > ret = do_method();
> > if (ret) {
> >    /* deal with error */
> > }
> > 
> > and not other ways like:
> > 
> > if (do_method()) or if ((ret = do_method()) > value) ...
> > 
> 
> I like it.  Please cc: Andrew Morton <akpm@osdl.org> on it.
> Hopefully he will merge it.
> 

I'm going to have to disagree.  Sometimes if the main flow of the code
is down, it's actually better to do this:

	if ((err = do_foo()) < 0)
		return (err);
	if ((err = do_bar(current, filp)) < 0)
		return (err);
	if ((err = do_quux(filp, buffer)) < 0) {
		close(filp);
		return (err);
	}

Than to do something like this:

	err = do_foo();
	if (err < 0)
		return (err);
	err = do_bar(current, filp);
	if (err < 0)
		return (err);
	err = do_quux(filp, buffer);
	if (err < 0) {
		close(filp);
		return (err);
	}

The first is more concise, and it draws the reader's eye to what's
really going on.  The cleanup/return error path is less important, and
and it's pretty clear what's going on just from glancing at it.

						- Ted