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From: Tim Rentsch <tr.17687@z991.linuxsc.com>
Newsgroups: comp.lang.c
Subject: Re: Regarding assignment to struct
Date: Mon, 05 May 2025 22:57:14 -0700
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Kaz Kylheku <643-408-1753@kylheku.com> writes:

> On 2025-05-05, Keith Thompson <Keith.S.Thompson+u@gmail.com> wrote:
>
>> Michael S <already5chosen@yahoo.com> writes:
>>
>>> On Mon, 05 May 2025 01:34:16 -0700
>>> Keith Thompson <Keith.S.Thompson+u@gmail.com> wrote:
>>>
>>>> And more obviously, "%p" requires an argument of type void*, not
>>>> int*.
>>>
>>> That part of otherwise very good comment is unreasonably pedantic.
>>
>> I disagree.  I suggest it's a bad habit to use "%p" without
>> ensuring, by a cast if necessary, that the argument is of type
>> void*.
>>
>> In most implementations, it's likely that all pointers have the
>> same size and representation and are passed as arguments in the
>> same way, but getting the types right means one less thing to worry
>> about.
>
> If the codebade assumes all data pointers are the same size, bit
> pattern and are treated the same in the calling conventions / ABI,
> then it is probably moot.
>
> That code is doomed on a platform where the assumption doesn't
> hold, and the printf statemnts are probably not independently
> reusable.
>
> (I mostly put in these casts just to communicate to others that
> an ISO C language lawyer works here, if you happen to need one.)
>
> Also, it owuld be amazingly stupid of any such platform not just
> make those printfs work:  to promote variadic arguments of
> pointer-to-object type to a common representation which is the
> same as void *, combined with a matching behavior in the va_arg
> macro for extracting the value back into any pointer-to-object
> type.

This statement strikes me as would an utterance coming from a
resident of Fantasyland.