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SubjectRe: [PATCH 11/13] nvdimm: Use more common logic testing styles and bare ; positions
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On Wed, 2019-09-11 at 19:54 -0700, Joe Perches wrote:
> Avoid using uncommon logic testing styles to make the code a
> bit more like other kernel code.
>
> e.g.:
> if (foo) {
> ;
> } else {
> <code>
> }
>
> is typically written
>
> if (!foo) {
> <code>
> }
>

A lot of times the excessive inversions seem to result in a net loss of
readability - e.g.:

<snip>

> diff --git a/drivers/nvdimm/region_devs.c
> b/drivers/nvdimm/region_devs.c
> index 65df07481909..6861e0997d21 100644
> --- a/drivers/nvdimm/region_devs.c
> +++ b/drivers/nvdimm/region_devs.c
> @@ -320,9 +320,7 @@ static ssize_t set_cookie_show(struct device *dev,
> struct nd_interleave_set *nd_set = nd_region->nd_set;
> ssize_t rc = 0;
>
> - if (is_memory(dev) && nd_set)
> - /* pass, should be precluded by region_visible */;

For one, the comment is lost

> - else
> + if (!(is_memory(dev) && nd_set))

And it takes a moment to resolve between things such as:

if (!(A && B))
vs.
if (!(A) && B)

And this is especially true if 'A' and 'B' are longer function calls,
split over multiple lines, or are themselves compound 'sections'.

I'm not opposed to /all/ such transformations -- for example, the ones
where the logical inversion can be 'consumed' by toggling a comparision
operator, as you have a few times in this patch, don't sacrifice any
readibility, and perhaps even improve it.

> return -ENXIO;
>
> /*
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