Re: [tuples] dereference POINTER_PLUS_EXPR check

["Richard Guenther" <richard.guenther@gmail.com>]

On Nov 22, 2007 1:58 AM, Aldy Hernandez <aldyh@redhat.com> wrote:
> > now due to the transitiveness of u_t_c, we now simply need to check
> >
> >   useless_type_conversion (lhs, op0)
> >
> > which in your notation is lhs and rhs1.  Which is exactly what the code did
> > before your patch.
>
> ...
>
> > Why are the pointed-to types relevant at all?  Type relations for the
> > pointed-to types don't necessary translate to the relations of the
> > pointer types.
> > For example useless_type_conversion (void *, int *) == true but
> > useless_type_conversion (void, int) is certainly not true.
>
> This is the failed testcase that prompted the patch:
>
> (gdb) ptt lhs_type
>  <pointer_type 0x2aaaaf571600
>     type <integer_type 0x2aaaaf559240 character(kind=1) public unsigned string-flag QI
>
> ...
>
> (gdb) ptt rhs1_type
>  <reference_type 0x2aaaaf5e6240
>     type <array_type 0x2aaaaf5e6180
>         type <integer_type 0x2aaaaf559240 character(kind=1) public unsigned string-flag QI
>
> u_t_c(lhs_type, rhs1_type) fails because it doesn't look far enough
> down, but you're saying it shouldn't.  Is u_t_c wrong then?

Andrew is right, this is a type mismatch.

Richard.