C99: Suggestions for style(9)

[Marius Strobl]

On Fri, May 01, 2009 at 01:37:23PM +0200, Christoph Mallon wrote:
> Marius Strobl schrieb:
> >On Sun, Apr 26, 2009 at 09:02:36AM +0200, Christoph Mallon wrote:
> >>return with parentheses:
> >>Removed, because it does not improve maintainability in any way. There 
> >>is no source for confusion here, so the rule even contradicts the rule, 
> >>which states not to use redundant parentheses. Maybe, decades ago it was 
> >>just a workaround for a broken compiler, which does not exist anymore.
> >
> >FYI, the idea behind this rule is said to be to able to use
> >a macro return(), f.e. for debugging you then can do:
> >#define	return(x) do {						 \
> >	printf("returning from %s with %d\n", __func__, (x));		\
> >	return (x);							\
> >} while (0)
> >
> >Given the this is a nifty feature and parentheses around the
> >return value don't hurt maintainability in any way IMO this
> >rule should stay.
> 
> This is mentioned nowhere in style(9) (in general it is lacking reasons 
> why something is some way or the other).

I agree that style(9) lacks explanations, however this doesn't
necessarily mean that non-obvious rules are "silly" and should
be removed.

> Also I consider this as gross abuse: Macro names shall be in all 
> uppercase, so it is clear that there is a macro at work. Therefore 
> "return" is not a candidate. So this would violate yet another rule in 
> style(9) (the original return already violates the no-redundant 
> parentheses rule).
> Also I would not mention __func__: there were objections against using 
> it in the past (though I, logically, prefer its use).

In general this is correct, a return() macro (in which case
the parentheses are not redundant) would be for local debugging
only and not ever hit the tree just like any other printf()-
debugging should not, so neither is relevant here. Besides,
a macro without side effects, which a return() macro typically
shouldn't have, is fine to be named all lowercase according
to style(9).

Marius