[Bug rtl-optimization/21402] wrong-code with inlining and type-punned pointer

["pinskia at physics dot uc dot edu" <gcc-bugzilla at gcc dot gnu dot org>]

------- Additional Comments From pinskia at physics dot uc dot edu  2005-05-05 18:41 -------
Subject: Re:  wrong-code with inlining and type-punned pointer


On May 5, 2005, at 1:19 PM, schlie at comcast dot net wrote:

>
> ------- Additional Comments From schlie at comcast dot net  2005-05-05 
> 17:19 -------
> (In reply to comment #2)
>> "unsigned char *" and "char *" are in two different aliasing sets 
>> while char
>> and unsigned char are in the same one, well char is every aliasing 
>> set.
>
> Then I can't help but wonder if it may make sense to reconsider placing
> char *, and (un)signed char * in different aliasing sets, as there 
> seems
> little if any justifiable reason to generate incorrect code for 
> references to
> types which are considered be compatible for assignment. (Just as 
> arguably
> it likely makes little sense to generate warnings for the comparison 
> between
> pointers to types which differ only in signness for the same reason). 
> As
> neither seem particularly useful, and the former is clearly needlessly
> potentially dangerious.

Because this is what the standard says is allowed.  The standard also
says the comparisons and assignment between pointers without a case is
invalid code and should be diagnostic.  Again this is what the standard
says for these things and GCC follows the C standard.

-- Pinski



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21402