[Bug fortran/64921] [4.9/5/6 Regression] FAIL: gfortran.dg/class_allocate_18.f90

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64921

Mikael Morin <mikael at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |mikael at gcc dot gnu.org

--- Comment #20 from Mikael Morin <mikael at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #19)
> So the question is whether the frontend emits the correct test against zero:
> 
>                     offset = offset * byte_stride;
>                     D.3466 = (void *) array->data;
>                     D.3467 = D.3466;
>                     D.3465 = 8;
>                     D.3469 = 8;
>                     __builtin_memcpy ((void *) &transfer.4, (void *)
> &D.3467, (unsigned long) MAX_EXPR <MIN_EXPR <D.3469, D.3465>, 0>);
>                     ptr2 = (struct t4 *) (transfer.4 + offset);
>                     if (ptr2 != 0B)
>                       {
>                         {
>                           integer(kind=4) stat.5;
> 
>                           if (ptr2->k == 0B)
> 
> to me it looks like if we really want to test transfer.4 (array->data)
> against
> zero.

transfer.4 + offset calculates the address of an element of an array.
I believe that if that code is executed, array.data is non-zero, and  of course
array.data + offset as well.

I think the the test should check for ptr2%j's nullness before deallocating
ptr2%j, instead of testing ptr2.

With a patch like this:

diff --git a/gcc/fortran/class.c b/gcc/fortran/class.c
index 218973d..1ff7437 100644
--- a/gcc/fortran/class.c
+++ b/gcc/fortran/class.c
@@ -967,7 +967,7 @@ finalize_component (gfc_expr *expr, gfc_symbol *derived,
gfc_component *comp,
       cond->block->expr1->ts.kind = gfc_default_logical_kind;
       cond->block->expr1->value.function.isym = gfc_intrinsic_function_by_id
(GFC_ISYM_ASSOCIATED);
       cond->block->expr1->value.function.actual = gfc_get_actual_arglist ();
-      cond->block->expr1->value.function.actual->expr = gfc_copy_expr (expr);
+      cond->block->expr1->value.function.actual->expr = gfc_copy_expr (e);
       cond->block->expr1->value.function.actual->next = gfc_get_actual_arglist
();
       cond->block->next = dealloc;


Unfortunately, it doesn't seem to fix the problem.