svn commit: r222084 - head/contrib/gperf/src

[mdf at FreeBSD.org]

On Wed, May 18, 2011 at 2:31 PM, Dimitry Andric <dim at freebsd.org> wrote:
> On 2011-05-18 23:16, Pawel Jakub Dawidek wrote:
>>
>> On Wed, May 18, 2011 at 09:06:20PM +0000, Ben Laurie wrote:
>>>
>>> Author: benl
>>> Date: Wed May 18 21:06:20 2011
>>> New Revision: 222084
>>> URL: http://svn.freebsd.org/changeset/base/222084
>>>
>>> Log:
>>>   Fix clang warnings.
>>>
>>>   Approved by: philip (mentor)
>>
>> [...]
>>>
>>> -            fprintf (stderr, " by changing asso_value['%c'] (char #%d)
>>> to %d\n",
>>> +            fprintf (stderr, " by changing asso_value['%c'] (char #%zd)
>>> to %d\n",
>>>                       *p, p - union_set + 1, asso_values[(unsigned
>>> char)(*p)]);
>>
>> Hmm, both 'p' and 'union_set' are 'char *' and %zd is for ssize_t. It is
>> a bit strange that it fixes the warning.
>
> If you subtract two pointers, such as in this case, you get a ptrdiff_t.
>
> Strictly, this doesn't have to be exactly the same type as ssize_t, but
> in practice it will almost always be.
>
> You can also cast the result to intmax_t, and use %jd, then it will
> always be correct, but possibly have some small overhead.

Or you can use %td which is the C99 conversion specifier for ptrdiff_t.

Thanks,
matthew