On Sep 29, 2005, at 8:32 PM, Daniel Berlin wrote:
Any suggestions how to fix this?
The easiest thing is to store a version of unsigned_char_type_node
somewhere that has it's TYPE_ALIAS_SET set to 0, and use it there.
Whether this is the best solution, i'll leave to others :)
Something like this will fix the issue with TYPE_REF_CAN_ALIAS_ALL
by removing the use. Maybe we could move may_alias to a bit in the
types and move TYPE_REF_CAN_ALIAS_ALL from the pointer type to the
type which is being accessed instead of this mess.
-- Pinski
Index: c-common.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/c-common.c,v
retrieving revision 1.653
diff -u -p -r1.653 c-common.c
--- c-common.c 27 Sep 2005 16:04:06 -0000 1.653
+++ c-common.c 30 Sep 2005 17:46:42 -0000
@@ -2668,9 +2668,6 @@ c_common_get_alias_set (tree t)
|| t == unsigned_char_type_node)
return 0;
- /* If it has the may_alias attribute, it can alias anything. */
- if (lookup_attribute ("may_alias", TYPE_ATTRIBUTES (t)))
- return 0;
/* The C standard specifically allows aliasing between signed and
unsigned variants of the same type. We treat the signed
Index: alias.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/alias.c,v
retrieving revision 1.254
diff -u -p -r1.254 alias.c
--- alias.c 21 Jul 2005 22:34:33 -0000 1.254
+++ alias.c 30 Sep 2005 17:46:42 -0000
@@ -587,6 +587,10 @@ get_alias_set (tree t)
/* Now all we care about is the type. */
t = TREE_TYPE (t);
}
+
+ /* If it has the may_alias attribute, it can alias anything. */
+ if (lookup_attribute ("may_alias", TYPE_ATTRIBUTES (t)))
+ return 0;
/* Variant qualifiers don't affect the alias set, so get the main
variant. If this is a type with a known alias set, return it. */
Index: tree.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/tree.c,v
retrieving revision 1.505
diff -u -p -r1.505 tree.c
--- tree.c 14 Sep 2005 15:04:56 -0000 1.505
+++ tree.c 30 Sep 2005 17:46:42 -0000
@@ -4705,6 +4705,17 @@ build_pointer_type_for_mode (tree to_typ
if (to_type == error_mark_node)
return error_mark_node;
+
+ if (can_alias_all)
+ {
+ to_type =
+ build_type_attribute_variant (ttype,
+ merge_attributes
+ (TYPE_ATTRIBUTES (to_type),
+ tree_cons (get_identifier
("may_alias"),
+ NULL_TREE, NULL_TREE)));
+
+ }
/* In some cases, languages will have things that aren't a POINTER_TYPE
(such as a RECORD_TYPE for fat pointers in Ada) as TYPE_POINTER_TO.
@@ -4721,14 +4732,13 @@ build_pointer_type_for_mode (tree to_typ
/* First, if we already have a type for pointers to TO_TYPE and it's
the proper mode, use it. */
for (t = TYPE_POINTER_TO (to_type); t; t = TYPE_NEXT_PTR_TO (t))
- if (TYPE_MODE (t) == mode && TYPE_REF_CAN_ALIAS_ALL (t) == can_alias_all)
+ if (TYPE_MODE (t) == mode)
return t;
t = make_node (POINTER_TYPE);
TREE_TYPE (t) = to_type;
TYPE_MODE (t) = mode;
- TYPE_REF_CAN_ALIAS_ALL (t) = can_alias_all;
TYPE_NEXT_PTR_TO (t) = TYPE_POINTER_TO (to_type);
TYPE_POINTER_TO (to_type) = t;
@@ -4754,6 +4764,18 @@ build_reference_type_for_mode (tree to_t
bool can_alias_all)
{
tree t;
+
+
+ if (can_alias_all)
+ {
+ to_type =
+ build_type_attribute_variant (ttype,
+ merge_attributes
+ (TYPE_ATTRIBUTES (to_type),
+ tree_cons (get_identifier
("may_alias"),
+ NULL_TREE, NULL_TREE)));
+
+ }
/* In some cases, languages will have things that aren't a REFERENCE_TYPE
(such as a RECORD_TYPE for fat pointers in Ada) as TYPE_REFERENCE_TO.
@@ -4770,14 +4792,13 @@ build_reference_type_for_mode (tree to_t
/* First, if we already have a type for pointers to TO_TYPE and it's
the proper mode, use it. */
for (t = TYPE_REFERENCE_TO (to_type); t; t = TYPE_NEXT_REF_TO (t))
- if (TYPE_MODE (t) == mode && TYPE_REF_CAN_ALIAS_ALL (t) == can_alias_all)
+ if (TYPE_MODE (t) == mode)
return t;
t = make_node (REFERENCE_TYPE);
TREE_TYPE (t) = to_type;
TYPE_MODE (t) = mode;
- TYPE_REF_CAN_ALIAS_ALL (t) = can_alias_all;
TYPE_NEXT_REF_TO (t) = TYPE_REFERENCE_TO (to_type);
TYPE_REFERENCE_TO (to_type) = t;
@@ -4809,12 +4830,12 @@ build_type_no_quals (tree t)
case POINTER_TYPE:
return build_pointer_type_for_mode (build_type_no_quals (TREE_TYPE (t)),
TYPE_MODE (t),
- TYPE_REF_CAN_ALIAS_ALL (t));
+ false);
case REFERENCE_TYPE:
return
build_reference_type_for_mode (build_type_no_quals (TREE_TYPE (t)),
TYPE_MODE (t),
- TYPE_REF_CAN_ALIAS_ALL (t));
+ false);
default:
return TYPE_MAIN_VARIANT (t);
}
