Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!cornell!uw-beaver!rice!sun-spots-request
From: lloyd!wse@husc6.harvard.edu (Bill Edwards)
Newsgroups: comp.sys.sun
Subject: Pointer Alignment on Suns
Keywords: Software
Message-ID: <1082@brazos.Rice.edu>
Date: 24 Aug 89 18:59:53 GMT
Sender: root@rice.edu
Organization: Sun-Spots
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Approved: Sun-Spots@rice.edu
X-Sun-Spots-Digest: Volume 8, Issue 106, message 4 of 15

Let's say I have a pointer to a 'struct foo' which I have typedef'ed to
FOOPTR.  If I then do something like:

	FOOPTR foo_ptr = (FOOPTR) malloc ((unsigned) sizeof (struct foo));

at the start of a function, lint on a Sun 4 (SPARC) complains that this
line has " possible pointer alignment problems" (lint does *not* give me
this meesage on a Sun 3).  I wrote a short program to do a sizeof of
'struct foo'.  On the Sun 3, 'struct foo' has a size which is not
divisible by 4, but on the Sun 4 its size *is* divisible by 4 (has
evidently been padded to a long-word boundary).  So, my question is, how
do I placate lint in this instance?  How do I align the pointer?  I've
tried ensuring that I only malloc memory in chunks in multiple of 4 sizes,
but to no avail.

Thanks. -- Bill Edwards
-- 
---------------------------------------------------------------------------
Bill Edwards                           wse%lloyd@husc6.harvard.edu (ARPA)
Camex;75 Kneeland St. Boston MA 02111  wse@lloyd.UUCP;edwards@harvunxw.bitnet
Tel.: (617) 426-3577                   Standard disclaimers