kern/104436: [PATCH] sys/sem.h should include sys/types.h

[Bruce Evans]

The following reply was made to PR kern/104436; it has been noted by GNATS.

From: Bruce Evans <bde at zeta.org.au>
To: John Baldwin <jhb at FreeBSD.org>
Cc: Cheng-Lung Sung <clsung at FreeBSD.org>, FreeBSD-gnats-submit at FreeBSD.org
Subject: Re: kern/104436: [PATCH] sys/sem.h should include sys/types.h
Date: Wed, 18 Oct 2006 10:09:04 +1000 (EST)

 On Tue, 17 Oct 2006, John Baldwin wrote:
 
 > How's this, it removes extra includes of cdefs.h and _types.h (ipc.h
 > already includes them), moves the typedefs earlier and includes them
 > in the _KERNEL case (consistent with ipc.h) and fixes the whitespace
 > in the typedefs.
 
 OK.  POSIX actually requires the namespace pollution with everything in
 sys/ipc.h, so the include of this can't be cleaned up and we may as well
 depend on its internals.
 
 I did a quick review of symbols in sys/sem.h:
 - POSIX seems to overspecify the representation: "A semaphore shall be
    respresented by an anonymous struct containing the following members:"
    [semval, sempid, semncnt, semzcnt]".  FreeBSD doesn't declare any of
    these struct members.
 - FreeBSD declares several things that aren't required by POSIX and uses
    bad names for most of these.  The worst ones are the struct member
    names `val', `buf' and `array'.  POSIX cannot reserve these, and sem.h
    mostly uses a `sem' prefix to avoid such pollution.  These seem to be
    implementation details that don't belong in the header anyway.
 
 I didn't check the symbols imported from sys/ipc.h.  Both of these headers
 are XSI extensions, so they don't need many visibility ifdefs internally.
 
 Bruce