Re: [PATCH] [condingstyle] Add chapter on tests

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Jan Engelhardt wrote:
> +	if (is_prime(number) == true)
> +		return 0;
> +	if (is_prime(number) == false)
> +		return 1;
> +
> +should be:
> +
> +	if (is_prime(number))
> +		return 0;
> +	if (!is_prime(number))
> +		return 1;
> +
> +As far as pointers or functions returning an integer are concerned,
> +using long form tests helps to distinguish between pointers and bools
> +or functions returning boolean or integer, respectively.
> +Examples are:
> +
> +	if (p == NULL)
> +		return 1;
> +	if (!p)
> +		return 0;
> +
> +	if (strcmp(haystack, needle) == 0)
> +		return 1;
> +	if (!strcmp(haystack, needle))
> +		return 0;

The latter two examples seem odd.  Didn't you mean the following?

	if (p == NULL)
		return 1;
	if (p)
		return 0;

	if (strcmp(haystack, needle) == 0)
		return 1;
	if (strcmp(haystack, needle))
		return 0;

Perhaps better:

	if (p == NULL)
		return NO_MEMORY;
	if (p)
		return MEMORY;

	if (strcmp(haystack, needle) == 0)
		return IS_SAME;
	if (strcmp(haystack, needle))
		return IS_DIFFERENT;

However, to follow your argument about non-boolean expressions, the
following would be more consequently going into your direction:

	if (p == NULL)
		return NO_MEMORY;
	if (p != NULL)
		return MEMORY;

	if (strcmp(haystack, needle) == 0)
		return IS_SAME;
	if (strcmp(haystack, needle) != 0)
		return IS_DIFFERENT;

I.e., why do the explicit comparison with 0 or NULL only when it is
tested for equality, but not when testing for inequality?

However, I agree with Scott Preece that these rules should be left out
of CodingStyle because they are contentious.

(Disclosure:  I am personally used to "if (p)" and "if (!p)" tests of
pointers and many integer expressions, but I tend to the longer form in
less obvious cases like "if (strcmp(a, b) != 0)".)
-- 
Stefan Richter
-=====-=-=== -=-= ==-==
http://arcgraph.de/sr/
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]
  Powered by Linux