From mboxrd@z Thu Jan  1 00:00:00 1970
From: Axel Kittenberger <Anshil@gmx.net>
To: gcc@gcc.gnu.org
Subject: Re: Is this a gcc bug?
Date: Wed, 17 Jan 2001 23:30:00 -0000
Message-id: <30811.979802996@www30.gmx.net>
X-SW-Source: 2001-01/msg01104.html

Falk Hueffner wrote:
> > 
> > Michael Eager <eager@mvista.com> writes:
> > 
> > > My sugguestion:
> > >
> > >       undefined behavior:  value of expression using 'x' is undefined
> > 
> > This would seem to imply that the behaviour is undefined because one
> > uses an undefined value. But that's not the case: the standard says
> > program behaviour is undefined even if you say x = ++x and never look
> > at x again. (At least IIRC.)
> 
> It is the result of the expression (including any side effects) which is 
> undefined.  An expression has a value, even if you never use it.
> 
> There are many constructs with undefined behavior.  Some can be
> recognized at compile time; most cannot.  

How about the compile-error:
"detected undefined behaviour: [some actual explanation]"?

..if gcc is able to see it in this case?

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