[Libclc-developers] Re: libclc questions

[Michael B.A. <mb...@io...>]

I subscribed to the libclc-developers list and sent this message there.

On Sun, 16 Mar 2003 22:18:58 +0100
Bj=F8rn Augestad <bo...@me...> wrote:

> >>>Why does libclc define it's own error codes? What libclc function could
> >>>possibly return CLC_ENODEV? If a platform does not have ISO C and POSIX
> >>>error codes available there is probably a reason for it.
> >>
> >>As an example, malloc() doesn't have to set errno to ENOMEM. If we have=
=20
> >>a function which can fail for 2 or more reasons and one of them is "Out=
=20
> >>of memory", we must set errno to ENOMEM and CLC_EFOO. Since we cannot=20
> >>rely on the precense of ENOMEM, we need to use CLC_ENOMEM. We try to=20
> >=20
> >=20
> > A malloc() implementation with no ENOMEM? Interesting! Which platform
> > is that?
>=20
> The DeathStation 9000 :-)
> Seriously, malloc is not, prior to e.g. Unix98, required to set errno to=
=20
> ENOMEM. This means that we cannot assume that errno contains a=20
> reasonable value if malloc() fails. We must therefore set it ourselves.=20
> Since we don't know about POSIX (we're pure ANSI C, remember) we must=20
> set it to CLC_ENOMEM. Oh well...

But the standards do not say that malloc will not set errno to
ENOMEM and every malloc ever written _does_ use ENOMEM. Same goes
for probably every other ISO function you'll use. You're introducing a
technically unncessary level of indirection that contributes to an overall
non-standard experience for the sake of a standard. Why are you going to
make 99.9999% of the users deal with two different namespaces of error
codes for some imaginary platform that doesn't exist?  Following the
letter of the law for this is just being pedantic.

Mike

--=20
A  program should be written to model the concepts of the task it
performs rather than the physical world or a process because this
maximizes  the  potential  for it to be applied to tasks that are
conceptually  similar and, more important, to tasks that have not
yet been conceived.=20