https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62077
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |jason at gcc dot gnu.org
--- Comment #26 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #24)
> Or "real" fix for the type_hash_canon issue (untested)
>
> Index: gcc/tree.c
> ===================================================================
> --- gcc/tree.c (revision 213814)
> +++ gcc/tree.c (working copy)
> @@ -6593,7 +6593,9 @@ type_hash_eq (const void *va, const void
> || !attribute_list_equal (TYPE_ATTRIBUTES (a->type),
> TYPE_ATTRIBUTES (b->type))
> || (TREE_CODE (a->type) != COMPLEX_TYPE
> - && TYPE_NAME (a->type) != TYPE_NAME (b->type)))
> + && TYPE_NAME (a->type) != TYPE_NAME (b->type))
> + || ((TYPE_MAIN_VARIANT (a->type) == TYPE_MAIN_VARIANT (a->type))
> + != (TYPE_MAIN_VARIANT (b->type) == TYPE_MAIN_VARIANT (b->type))))
> return 0;
>
> /* Be careful about comparing arrays before and after the element type
Hmpf, that doesn't fix it. But the following makes us ICE:
Index: tree.c
===================================================================
--- tree.c (revision 213814)
+++ tree.c (working copy)
@@ -6759,6 +6761,7 @@ type_hash_canon (unsigned int hashcode,
t1 = type_hash_lookup (hashcode, type);
if (t1 != 0)
{
+ gcc_assert (TYPE_MAIN_VARIANT (t1) == t1);
if (GATHER_STATISTICS)
{
tree_code_counts[(int) TREE_CODE (type)]--;
which means somebody mangles TYPE_MAIN_VARIANT of a type already in
the type hash table.
build_cplus_array_type is it:
/* We want TYPE_MAIN_VARIANT of an array to strip cv-quals from the
element type as well, so fix it up if needed. */
if (elt_type != TYPE_MAIN_VARIANT (elt_type))
{
tree m = build_cplus_array_type (TYPE_MAIN_VARIANT (elt_type),
index_type);
...
TYPE_MAIN_VARIANT (t) = m;
Jason? Something like
Index: cp/tree.c
===================================================================
--- cp/tree.c (revision 213814)
+++ cp/tree.c (working copy)
@@ -824,7 +824,11 @@ build_cplus_array_type (tree elt_type, t
build_cplus_array_type
(TYPE_CANONICAL (elt_type),
index_type ? TYPE_CANONICAL (index_type) : index_type);
- t = build_array_type (elt_type, index_type);
+ if (elt_type != TYPE_MAIN_VARIANT (elt_type))
+ t = build_cplus_array_type (TYPE_MAIN_VARIANT (elt_type),
+ index_type);
+ else
+ t = build_array_type (elt_type, index_type);
}
/* Push these needs up so that initialization takes place
@@ -840,37 +844,19 @@ build_cplus_array_type (tree elt_type, t
element type as well, so fix it up if needed. */
if (elt_type != TYPE_MAIN_VARIANT (elt_type))
{
- tree m = build_cplus_array_type (TYPE_MAIN_VARIANT (elt_type),
- index_type);
-
- if (TYPE_MAIN_VARIANT (t) != m)
+ /* ??? We didn't even try to re-use existing types?
+ ??? Ah, we did via the type_hash_canon that this breaks. */
+ tree t1;
+ for (t1 = TYPE_MAIN_VARIANT (t); t1; t1 = TYPE_NEXT_VARIANT (t1))
+ if (TREE_TYPE (t1) == elt_type)
+ {
+ t = t1;
+ break;
+ }
+ if (!t1)
{
- if (COMPLETE_TYPE_P (TREE_TYPE (t)) && !COMPLETE_TYPE_P (m))
- {
- /* m was built before the element type was complete, so we
- also need to copy the layout info from t. We might
- end up doing this multiple times if t is an array of
- unknown bound. */
- tree size = TYPE_SIZE (t);
- tree size_unit = TYPE_SIZE_UNIT (t);
- unsigned int align = TYPE_ALIGN (t);
- unsigned int user_align = TYPE_USER_ALIGN (t);
- enum machine_mode mode = TYPE_MODE (t);
- for (tree var = m; var; var = TYPE_NEXT_VARIANT (var))
- {
- TYPE_SIZE (var) = size;
- TYPE_SIZE_UNIT (var) = size_unit;
- TYPE_ALIGN (var) = align;
- TYPE_USER_ALIGN (var) = user_align;
- SET_TYPE_MODE (var, mode);
- TYPE_NEEDS_CONSTRUCTING (var) = needs_ctor;
- TYPE_HAS_NONTRIVIAL_DESTRUCTOR (var) = needs_dtor;
- }
- }
-
- TYPE_MAIN_VARIANT (t) = m;
- TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (m);
- TYPE_NEXT_VARIANT (m) = t;
+ t = build_variant_type_copy (t);
+ TREE_TYPE (t) = elt_type;
}
}
fixes that - but eventually breaks whatever needed that odd type completion,
which we also can't allow on types that are recorded in the type_hash_canon
hashtable. Not sure how that code can trigger when we build m right
before using elt_type which is now either not complete or complete (and so is
t).
The above fixes the LTO miscompares. Let's see if it survives LTO bootstrap.
