Re: mach_port_t vs task_t (really ipc_space_t) in Mach header files

[Farid Hajji]

Hi Marcus,

> I saw that the defs file have nice specific types like ipc_space_t and
> mach_port_name_t, but the C header files almost all have mach_port_t for
> them.  In the Hurd, we have a typedef for each of these types and keep
> them in the header.  We even use task_t in proc etc.
> 
> I am now using mach_port_t in mach.texi everywhere (where it is used in the
> generated C header file), rather than the more explicit type in the defs
> file.  But maybe we don't want that?
I've stumbled across this problem as I tried to convert some *.defs
to omg-idl. Since IDL is a strongly typed interface definition language,
keeping the more specific types seemed more sensible in a first try
(you could simply typedef those types away to mach_port_t).

Two questions:
  * are the more specific types at least _consistently_ used?
    I doubt this is the case: a lot of files simply fall back to
    mach_port_t later
  * are they really needed for architectural reasons, or, more
    precisely, for better readability? In the Mach case, I'd
    guess "maybe no," but on non-Mach VKs, that could well be
    a different matter.

Actually, I didn't find the specific types in the *.defs very helpful
for drawing clean lines of abstractions. They seem to have been added
as an afterthought, but were propagated to the bulk sources very
half-heartedly, if at all. So if you're going to remove them, that
would be okay with me (IMHO).

At least, as far as _mach.texi_ is concerned, it may be okay, but
please remain consistent with Mach headers ;-)

What do others think?

-Farid.

-- 
Farid Hajji -- Unix Systems and Network Admin | Phone: +49-2131-67-555
Broicherdorfstr. 83, D-41564 Kaarst, Germany  | farid.hajji@ob.kamp.net
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