Hack in gcc/c-decl.c?

[Mike Stump]

On Dec 29, 2005, at 12:16 PM, Gabriel Dos Reis wrote:
> | > I guess we just have to wait till GCC is miscompiled (probably by
> | > itself) to see whether the Middle End would cite chapter and  
> verse :-)
>
> I suspect that humor does not travel well through emails :-)  Sorry.

As my 4 year old would say, that's not funny.  :-)

> I was under the impression that we got some core language issues

For our purposes, the issue was decided and resolved.  We welcome  
dissenters to take the issue up with the C committee and see if they  
want to clarify the language standard in the way that is yet more  
restrictive than what gcc currently does, if they did, then we can  
decide if we want to take advantage of the latitude granted by the  
language standard.

Another interesting issue would be:

struct S {
     int i;
     float j;
} s;

*(float *)((char*)&s + 4);

on a platform that generated the program by printf("%d", offsetof(s,  
j)) to get the 4.  My take, it is valid.  Reasonably, I can see  
people say, but I want the optimizer to be able to notice that field  
j isn't used, and optimize it out.  I'd counter with, the optimizer  
knows that j is at offset 4, and it can see the +4 and `know' the  
field is used.  I would love to see the language in the standard that  
makes this perfectly clear, one way, or the other.