[Bug fortran/50960] [OOP] vtables not marked as constant

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50960

--- Comment #16 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-11-03 14:29:29 UTC ---
(In reply to comment #11)
> (In reply to comment #9)
> > FAIL: gfortran.dg/extends_type_of_1.f03  -O0  (internal compiler error)
> > FAIL: gfortran.dg/extends_type_of_3.f90  -O  (internal compiler error)
> 
> These two fail with:
> 
> internal compiler error: in fold_convert_loc, at fold-const.c:1894
> 
> Not quite sure what goes wrong there. Some typing problem?
> 
> 
> Reduced test case:
> 
>  type :: t1
>  end type
> 
>  type, extends(t1) :: t2
>  end type
> 
>  class(t1), pointer :: c1
>  type(t2) :: y
> 
>  if (.not. extends_type_of (y, c1)) call abort()
> 
> end

Looks like you are converting struct __vtype_MAIN___T1 to
struct __vtype_MAIN___T1 *.  Thus probably too many TREE_TYPE ()
wrappers somewhere or a forgotten address-taking.

Called from

4608            {
4609              /* Scalar pointers.  */
4610              se.want_pointer = 1;
4611              gfc_conv_expr (&se, expr);
4612              gfc_add_block_to_block (&block, &se.pre);
4613              gfc_add_modify (&block, dest,
4614                                   fold_convert (TREE_TYPE (dest),
se.expr))

where se.want_pointer (whatever it means) is not honored and se.expr
is a variable of type struct __vtype_MAIN___T1.