Re: mbuf initialization macros

[Robert Elz <kre%munnari.OZ.AU@localhost>]

    Date:        Tue, 19 Apr 2016 13:49:09 +0900
    From:        Kengo NAKAHARA <k-nakahara%iij.ad.jp@localhost>
    Message-ID:  <5715B8C5.2050407%iij.ad.jp@localhost>

  | Sorry, I was confused. I remove the declarations.

There is no need to apologise for any of this - the prototype declarations
are certainly not wrong, just unnecessary (probably ... upon further thought
I am wondering if perhaps some compiler somewhere might complain about the
existence of a static func definition (inline or not) which is included in
a source file that does not use the func - and that might be what the __unused
is for ... The gcc in current (5.3.0) and the one in NetBSD 7 (4.8.4) do
not need it, but perhaps some earlier version?   (Or clang?)

Maybe hold off on deleting the prototypes for another day - just in case...
(either that, or be prepared to put them in later if someone complains
about a build failure.)

  | Although, I think m_length() declaration may be removed (by separated
  | commit) on this occasion, since the declaration is not needed as long as
  | I read mbuf.h commit log.

I do not generally recommend the use of commit logs as a way to discover
the truth about the universe -- they sometimes give some info as to what was
in a developer's mind when they made some change - but here I do not see
that.

Nevertheless, I believe that that prototype is also not needed (again,
probably).   It might (and I stress, I am guessing) have been added
initially because mbuf.h contained references to m_length that preceded its
definition - however, they were all in macros, which means only really in
the source files that call the macros (macro definitions can contain any
random junk - it only matters where they are called) so the prototype was
never really needed for that (and in any case, no such macro remains now) -
or it may just be that the prototype was just converted from when m_length()
was a real (external) function and so needed the prototype, when it could
have just been deleted.

This one has been there over a decade now, and doing no apparent harm, so
leaving it another few days cannot hurt!

kre