[LLVMdev] LLVM 2.4 problem? (resend)

David Vandevoorde daveed at vandevoorde.com
Wed Oct 15 13:09:44 PDT 2008

On Oct 15, 2008, at 3:53 PM, Mike Stump wrote:
> Objects are defined like so:
> Two pointers of
>   the same type compare equal if and only if they are  both  null,
> both
>   point  to  the same object or function, or both point one past the
> end
>   of the same array.
> This means they _must_ compare !=, if they are different objects.

Aha!  Thanks for quoting that: It's from an expired standard (1998,  
presumably).  The 2003 standard has changed the words for that, taking  
away the property under discussion (for a different reason -- see Core  
Issue 73).

> So, let me state is this way, the address _must_ be different.  If you
> can't tell they are not, you are free to have them be the same.

The changes to address Core issue 73 invalidates your reasoning in the  
current standard (and in the working paper for the next standard).   
However, I'll mention this history to the issues maintainer as support  
for my position that I want the dinstinct-address-guarantee (back).


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