Re: bug in roundup(3) from <sys/param.h>

[Alejandro Colomar <alx.manpages@gmail.com>]

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Hi Paul!

On 1/17/23 21:11, Paul Eggert wrote:
> On 1/17/23 11:16, Wilco Dijkstra via Libc-alpha wrote:
>> So it seems best to state it only works on unsigned values (with y > 0 since 
>> division
>> by zero is undefined behaviour of course) and it's implementation defined whether
>> overflow wraps or saturates.
> 
> roundup works just fine on signed integers. Although x should be nonnegative and 
> y should be positive, there's no requirement that either x or y must be unsigned.
> 
> This sort of thing matters in the C style I prefer nowadays, which is to use 
> types like ptrdiff_t and idx_t instead of size_t, so that I can optionally 
> enable runtime overflow checking that works.

That's fair; I'll clarify, and anyway, will post the manual page for review 
before pushing.

If you happen to know od any other use cases for this function, it might be 
interesting.

Cheers,

Alex

-- 
<http://www.alejandro-colomar.es/>

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