https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103662
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |burnus at gcc dot gnu.org,
| |jakub at gcc dot gnu.org
--- Comment #10 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
>From what I can see, for normal derived types resolve_symbol calls
resolve_fl_derived -> resolve_fl_derived0 -> add_dt_to_dt_list
which ensures that the derived type eventually makes it into ns->derived_types
and then gfc_get_derived_type will do:
/* The derived types from an earlier namespace can be used as the
canonical type. */
if (derived->backend_decl == NULL
&& !derived->attr.use_assoc
&& !derived->attr.used_in_submodule
&& gfc_global_ns_list)
{
for (ns = gfc_global_ns_list;
ns->translated && !got_canonical;
ns = ns->sibling)
{
if (ns->derived_types)
{
for (gfc_symbol *dt = ns->derived_types; dt && !got_canonical;
dt = dt->dt_next)
{
gfc_copy_dt_decls_ifequal (dt, derived, true);
if (derived->backend_decl)
got_canonical = true;
if (dt->dt_next == ns->derived_types)
break;
}
}
}
}
(ugh, linear walk of all namespaces and all derived types in them! A hash
table would be much better) will find matching derived type in some other
namespace
and if it has backend_decl, will use it as TYPE_CANONICAL.
All of resolve_symbol and resolve_fl_derived and resolve_fl_derived0 have an
early exit for sym->attr.unlimited_polymorphic,
so add_dt_to_dt_list isn't done for it but that isn't a big deal because
gfc_get_derived_type for derived->attr.unlimited_polymorphic just returns
ptr_type_node (the same in all namespaces).
But __class__STAR_p symbol isn't unlimited_polymorphic, but in
resolve_fl_derive we trigger:
if (sym->attr.is_class && sym->ts.u.derived == NULL)
{
/* Fix up incomplete CLASS symbols. */
gfc_component *data = gfc_find_component (sym, "_data", true, true,
NULL);
gfc_component *vptr = gfc_find_component (sym, "_vptr", true, true,
NULL);
/* Nothing more to do for unlimited polymorphic entities. */
if (data->ts.u.derived->attr.unlimited_polymorphic)
return true;
and so don't call resolve_fl_derived0, neither for sym nor for vptr, so never
call add_dt_to_dt_list for __class__STAR_p
and so gfc_get_derived_type for those will always set TYPE_CANONICAL to itself,
so each namespace's __class__STAR_p is considered to be private for TBAA
purposes.
--- gcc/fortran/resolve.cc.jj 2022-03-21 11:00:06.447824689 +0100
+++ gcc/fortran/resolve.cc 2022-03-22 12:35:38.381250338 +0100
@@ -15138,7 +15138,10 @@ resolve_fl_derived (gfc_symbol *sym)
/* Nothing more to do for unlimited polymorphic entities. */
if (data->ts.u.derived->attr.unlimited_polymorphic)
- return true;
+ {
+ add_dt_to_dt_list (sym);
+ return true;
+ }
else if (vptr->ts.u.derived == NULL)
{
gfc_symbol *vtab = gfc_find_derived_vtab (data->ts.u.derived);
doesn't help much though, while it registers __class_STAR_p,
gfc_get_derived_type -> gfc_copy_dt_decls_ifequal -> gfc_compare_derived_types
considers them unequal.
