From mboxrd@z Thu Jan  1 00:00:00 1970
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
	ip-172-31-74-118.ec2.internal
X-Spam-Level: 
X-Spam-Status: No, score=-1.9 required=3.0 tests=BAYES_00,FREEMAIL_FROM
	autolearn=ham autolearn_force=no version=3.4.6
X-Received: by 2002:ad4:5dc8:: with SMTP id m8mr50412480qvh.71.1641399112493;
        Wed, 05 Jan 2022 08:11:52 -0800 (PST)
X-Received: by 2002:a25:ba05:: with SMTP id t5mr70633728ybg.675.1641399112316;
 Wed, 05 Jan 2022 08:11:52 -0800 (PST)
Path: eternal-september.org!reader02.eternal-september.org!news.misty.com!border2.nntp.dca1.giganews.com!nntp.giganews.com!news-out.google.com!nntp.google.com!postnews.google.com!google-groups.googlegroups.com!not-for-mail
Newsgroups: comp.lang.ada
Date: Wed, 5 Jan 2022 08:11:52 -0800 (PST)
In-Reply-To: <15ffbb15-6f0b-4f61-8740-f100d9e384bbn@googlegroups.com>
Injection-Info: google-groups.googlegroups.com; posting-host=2804:14c:4c1:8775:352d:ffd4:3db5:6282;
 posting-account=wgmHdgoAAAA-F7JItPEZjeXqFc0KdzEQ
NNTP-Posting-Host: 2804:14c:4c1:8775:352d:ffd4:3db5:6282
References: <3b7ba153-ebf1-4b85-a1b2-3ad5aaeca11en@googlegroups.com> <15ffbb15-6f0b-4f61-8740-f100d9e384bbn@googlegroups.com>
User-Agent: G2/1.0
MIME-Version: 1.0
Message-ID: <98855f15-6bc3-4575-8a89-709175b5f7b8n@googlegroups.com>
Subject: Re: Ada Pure or Preelaborate or ? in Adare_net
From: Daniel Norte Moraes <danielcheagle@gmail.com>
Injection-Date: Wed, 05 Jan 2022 16:11:52 +0000
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Xref: reader02.eternal-september.org comp.lang.ada:63343
List-Id: <comp.lang.ada>

Em segunda-feira, 3 de janeiro de 2022 =C3=A0s 22:11:37 UTC-3, Simon Belmon=
t escreveu:
> On Friday, December 31, 2021 at 11:13:33 AM UTC-5, daniel...@gmail.com wr=
ote:=20
> > Hi!=20
> >=20
> > I and a friend created an Ada network lib where,=20
> > from the begining, we tried very hard to make It a Ada Pure.=20
> >=20
> > From the examples dir, the lib worked as expected (in gcc-10.2 gcc-11.2=
 and gcc-12).=20
> > To our surprise, what most caught the attention of the group's friends =
was the fact that the lib was Ada Pure and if that was correct.=20
> >=20
> > For this reason, if really 'is' pure, not pure, preelaborate or what (?=
), pleeeeeeaaase, we ask the group's Ada Language Lawyers to help analyze a=
nd suggest modifications if necessary.=20
> >=20
> > link: https://gitlab.com/daresoft/network/adare_net/-/tree/202x=20
> > for Ada version use 2012 and or 202x.=20
> >=20
> > Best Wishes and Happy New Year,=20
> > Dani.
> It seems to be mostly just a thin binding to a bunch of C functions, so t=
he applicability of any Ada feature is mostly a moot point. The Ada compile=
r has no control or visibility into the C domain, so while on the one hand =
your packages are technically Pure, on the other hand the C functions can v=
iolate those "purity rules" all they want, which might be misleading to use=
rs expecting otherwise. You don't use 'Unchecked_Access either, but obvious=
ly that doesn't mean the C functions are somehow prevented from creating da=
ngling pointers. Personally, I would have the interfaces reflect the realit=
y of the actual behavior (which in the case of C code you don't control, is=
 usually assume-the-worst).=20
>=20
> -sb

Thanks !

The C pointers are only created in   c_initialize_socket.c (c_init_address(=
)  ) and data pointed copied=20
to an ada array, and then immediately free by c part.  this is the only tim=
e there is a dynamic allocation.=20
We managed to make libadare_net very close to 100% static allocation!
Because this, don=C2=B4t are dangling pointers.

There is still the problem of omitting the execution of subprograms by the =
compiler by pure packages.
would 'preelaborate' solve this?

Thanks!

Best Wishes,
Dani.