From mboxrd@z Thu Jan  1 00:00:00 1970
From: Fergus Henderson <fjh@cs.mu.oz.au>
To: "John David Anglin" <dave@hiauly1.hia.nrc.ca>
Cc: gcc@gcc.gnu.org, gcc-bugs@gcc.gnu.org
Subject: Re: RFC: Jump to const_int
Date: Fri, 12 Jan 2001 21:10:00 -0000
Message-id: <20010113161041.A31163@hg.cs.mu.oz.au>
References: <no.id> <200101130340.WAA21616@hiauly1.hia.nrc.ca>
X-SW-Source: 2001-01/msg00851.html

On 12-Jan-2001, John David Anglin <dave@hiauly1.hia.nrc.ca> wrote:
> > I found the following testcase fails (991213-3.c) with the above abort:
> > 
> > int jump () { goto * (int (*) ()) 0xbabebec0; }
> 
> One further thought.  The test looks bogus to me because the address
> clearly can't be in the current function.  Thus, the behavior of such
> a jump is totally unpredictable.
>
> Gcc allows as an extension goto's to any void * expression.  Thus, the
> above is accepted but it will clearly cause problems when edges are
> to be calculated.

The *runtime* behaviour of such a jump is unpredictable.
It should be a runtime error, and a compile-time warning might be nice,
but it should not be a compile-time error and nor should the compiler
get an internal compiler error.

-- 
Fergus Henderson <fjh@cs.mu.oz.au>  |  "I have always known that the pursuit
                                    |  of excellence is a lethal habit"
WWW: < http://www.cs.mu.oz.au/~fjh >  |     -- the last words of T. S. Garp.