Path: utzoo!utgpu!news-server.csri.toronto.edu!dgp.toronto.edu!flaps
Newsgroups: comp.std.c
From: flaps@dgp.toronto.edu (Alan J Rosenthal)
Subject: low-level knowledge of your friendly neighbourhood C compiler
Message-ID: <1990May2.150837.946@jarvis.csri.toronto.edu>
References: <1990Apr25.180007.13243@cunixf.cc.columbia.edu> <12694@smoke.BRL.MIL> <2647@mica6.UUCP> <1990Apr28.232221.20725@utzoo.uucp> <2700@mica6.UUCP> <1990May1.165701.4289@utzoo.uucp> <2746@mica6.UUCP>
Date: 2 May 90 19:08:37 GMT
Lines: 13

henley@motcid.UUCP (Aaron Henley) writes:
>I think people should and in many cases must be aware of how their compiler
>allocates memory for structures, what happens when you typecast a word from a
>memory location starting at a point that isn't word aligned, etc...  These and
>many other usages of C are ambiguously defined.

This is completely wrong.  These things are UNDEFINED, not at all ambiguous.
The following two statements are both unambiguously false:
	a) dereferencing a misaligned pointer in C dumps core; and
	b) dereferencing a misaligned pointer in C doesn't dump core.
That's what undefined means.  It doesn't mean that one of them is true.

ajr