https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114493
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |jakub at gcc dot gnu.org
--- Comment #8 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
This doesn't ICE in C++, because the C++ FE forcibly updates the corresponding
pointer types in:
#0 fixup_may_alias (klass=<record_type 0x7fffea2dec78 S>) at
../../gcc/cp/class.cc:2328
#1 0x0000000000456835 in fixup_attribute_variants (t=<record_type
0x7fffea2dec78 S>) at ../../gcc/cp/class.cc:2354
#2 0x00000000006f3024 in cp_parser_class_head (parser=0x7fffea2dea80,
nested_name_specifier_p=0x7fffffffd5ff) at ../../gcc/cp/parser.cc:27831
/* KLASS is a class that we're applying may_alias to after the body is
parsed. Fixup any POINTER_TO and REFERENCE_TO types. The
canonical type(s) will be implicitly updated. */
static void
fixup_may_alias (tree klass)
{
tree t, v;
for (t = TYPE_POINTER_TO (klass); t; t = TYPE_NEXT_PTR_TO (t))
for (v = TYPE_MAIN_VARIANT (t); v; v = TYPE_NEXT_VARIANT (v))
TYPE_REF_CAN_ALIAS_ALL (v) = true;
for (t = TYPE_REFERENCE_TO (klass); t; t = TYPE_NEXT_REF_TO (t))
for (v = TYPE_MAIN_VARIANT (t); v; v = TYPE_NEXT_VARIANT (v))
TYPE_REF_CAN_ALIAS_ALL (v) = true;
}
Now, fixup_attribute_variants also does:
for (variants = TYPE_NEXT_VARIANT (t);
variants;
variants = TYPE_NEXT_VARIANT (variants))
{
/* These are the two fields that check_qualified_type looks at and
are affected by attributes. */
TYPE_ATTRIBUTES (variants) = attrs;
unsigned valign = align;
if (TYPE_USER_ALIGN (variants))
valign = MAX (valign, TYPE_ALIGN (variants));
else
TYPE_USER_ALIGN (variants) = user_align;
SET_TYPE_ALIGN (variants, valign);
TYPE_PACKED (variants) = packed;
if (may_alias)
fixup_may_alias (variants);
}
I think the TYPE_ATTRIBUTES update isn't needed, because
decl_attributes (&t, attributes, (int) ATTR_FLAG_TYPE_IN_PLACE);
should update the variants already:
984 TYPE_ATTRIBUTES (*anode) = r;
985 /* If this is the main variant, also push the
attributes
986 out to the other variants. */
987 if (*anode == TYPE_MAIN_VARIANT (*anode))
988 {
989 for (tree variant = *anode; variant;
990 variant = TYPE_NEXT_VARIANT (variant))
991 {
992 if (TYPE_ATTRIBUTES (variant) == old_attrs)
993 TYPE_ATTRIBUTES (variant)
994 = TYPE_ATTRIBUTES (*anode);
995 else if (!find_same_attribute
996 (attr, TYPE_ATTRIBUTES (variant)))
997 TYPE_ATTRIBUTES (variant) = tree_cons
998 (name, args, TYPE_ATTRIBUTES (variant));
999 }
1000 }
Seems finish_struct doesn't actually call layout_type on the type variants,
wonder what does that, but I'd think that stuff like TYPE_USER_ALIGN,
TYPE_ALIGN would be finalized when layout_type is performed for those.
TYPE_PACKED is apparently done in
finish_record_layout even for the variants (called from layout_type).
