[Bug fortran/50718] [4.6/4.7 Regression] ICE (fold_convert) with -fcheck=pointer

["burnus at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50718

Tobias Burnus <burnus at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.6.2

--- Comment #1 from Tobias Burnus <burnus at gcc dot gnu.org> 2011-10-13 18:36:44 UTC ---
The backtrace above is bogus. The actual issue is at gfc_conv_procedure_call
for:
              cond = fold_build2_loc (input_location, EQ_EXPR,
                                      boolean_type_node, parmse.expr,
                                      fold_convert (TREE_TYPE (parmse.expr),
                                                    null_pointer_node));

The problem is that the formal argument uses VALUE. Hence, the actual argument
is passed by value and it not an address expression.

Hence, the test  "if (*actual == NULL)" does not make sense - one would need to
use  "if (actual == NULL)" - hence, the "*" needs to be stripped away before
the comparison.


Simplified test case:


type t
  integer :: p
end type t

interface
  subroutine sub (x)
    import t
    type(t), value :: x
  end subroutine
end interface

type(t), pointer :: y
call sub(y)
end