[Moved from gcc-patches@ to gcc@] Hi JeanHeyd, наб,
I see you (JeanHeyd) are developing yet another survey about the names
for this new operator. Let me ask you to be clear about my fear of
ambiguity with null-terminated strings which are stored within arrays
and the length of both entities differ, usually by exactly one, being a
potential cause of a confusion that might result in buffer overflows, or
other kinds of errors (and it would be interesting to mention that I've
presented a link to an actual bug of that class in shadow-utils, which I
fixed recently). I would also like the survey to be presented to
programmers that like programming in C; I would refuse to acknowledge
the results of any survey that is presented to C++ or rust programmers
who acknowledge not wanting to program in C ever again. They have a
clear conflict of interest. If this survey is conducted, it should
include the gcc and glibc communities, and the resons why each name is
considered good and bad should be clearly stated alongside the options,
in a detailed rationale.
For extentof(), my only caveat is that one might want to add a 2-args
operator (or macro) that has the C++ semantics, that is, allowing you to
specify the dimension of the array that you want. I don't see why it
would be useful, but didn't want to preclude it either. But other than
that, I'm okay with that name.
Another thing is that I'd prefer it to be based on email, or something
that doesn't impose a barrier to those who don't have an account in a
given platform, and don't want to create it.
Thanks for your interest in this operator!
Have a lovely day!
Alex
P.S.: наб, you asked why not array_size(). I agree with the defenders
of lengthof that size should not be overloaded to mean both the number
of bytes and the number of elements of an object (although I'm closer to
accepting overloading the term "size" than overloading the term
"length", since size at least doesn't promote off-by-one errors). Also,
I have a macro sizeof_array() which I define as
#define sizeof_array(a) (countof(a) * sizeof((a)[0]))
It would be very weird and confusing to have
#define sizeof_array(a) (array_size(a) * sizeof((a)[0]))
On Sat, Oct 26, 2024 at 12:10:56AM GMT, Alejandro Colomar wrote:
> Hi Joseph,
>
> On Fri, Oct 25, 2024 at 08:44:15PM GMT, Joseph Myers wrote:
> > I don't see the use of pedwarn_c23 and associated tests (error with
> > -std=c23 -pedantic-errors, warning with -std=c23 -pedantic, no diagnostic
> > with -std=c23 -pedantic-errors -Wno-c23-c2y-compat, no diagnostic with
> > -std=c2y -pedantic-errors, warning with -std=c2y -pedantic-errors
> > -Wc23-c2y-compat), previously discussed in comments on v13, that would be
> > appropriate before considering this for inclusion with an appropriate
> > substitution of names.
>
> I removed it because I renamed it to __countof__, which is a GNU
> extension, and thus should not be warned by -Wpedantic. As part of my
> opposition to _Lengthof, I will not provide you with that part, which
> would amount to basically giving you _Lengthof but not. As part of the
> editorialising process, you'll also have to add pedantic warnings, if
> that's what you want to do. Again, I will earnestly ask to once more to
> consider __countof__, but it's up to you.
>
> Have a lovely night!
> Alex
>
> --
> <https://www.alejandro-colomar.es/>
--
<https://www.alejandro-colomar.es/>
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