> On 03/30/2015 01:23 PM, Jan Hubicka wrote:
> >Jason probably knows better, but I think only real C++ types comply the One
> >Defintion
> >Type and should be merged. Anything we create artifically in compiler is
> >probably
> >not covered by this.
>
> Agreed, compiler internals are outside the scope of the language. :)
:)
Hi,
this patch adds the ARTIFICIAL flag check to avoid ODR merging to these.
I oriignally tested DECL_ARTIFICIAL (decl) (that is TYPE_NAME) that randomly
dropped type names on some classes but not all.
Jason, please do you know what is meaning of DECL_ARTIFICIAL on class type
names? Perhaps we can drop them to 0 in free lang data?
With this bug I triggered wrong devirtualization because we no longer insert
non-odr types into a type inheritance graph. This is fixed by the
lto_read_decls
change and finally I triggered an ICE in ipa-devirt that due to the bug
output a warning late and ICEd on streamer cache being NULL. I guess it is
better to guard it even though all wanrings should be output early.
Bootsrapped/regtested x86_64-linux, will commit it after chromium rebuild.
Honza
* tree.c (need_assembler_name_p): Artificial types have no ODR
names.
* ipa-devirt.c (warn_odr): Do not try to apply ODR cache when
no caching is done.
* lto.c (lto_read_decls): Move code registering odr types out
of TYPE_CANONICAL conditional and also register polymorphic types.
Index: tree.c
===================================================================
--- tree.c (revision 221777)
@@ -5139,6 +5145,7 @@ need_assembler_name_p (tree decl)
&& decl == TYPE_NAME (TREE_TYPE (decl))
&& !is_lang_specific (TREE_TYPE (decl))
&& AGGREGATE_TYPE_P (TREE_TYPE (decl))
+ && !TYPE_ARTIFICIAL (TREE_TYPE (decl))
&& !variably_modified_type_p (TREE_TYPE (decl), NULL_TREE)
&& !type_in_anonymous_namespace_p (TREE_TYPE (decl)))
return !DECL_ASSEMBLER_NAME_SET_P (decl);
Index: lto/lto.c
===================================================================
--- lto/lto.c (revision 221777)
+++ lto/lto.c (working copy)
@@ -1944,13 +1944,24 @@ lto_read_decls (struct lto_file_decl_dat
lto_fixup_prevailing_type (t);
}
/* Compute the canonical type of all types.
- ??? Should be able to assert that !TYPE_CANONICAL. */
+
+ Inside a strongly connected component
+ gimple_register_canonical_type may recurse and insert
+ main variant ahead of time. Thus the need to check
+ TYPE_CANONICAL. */
if (TYPE_P (t) && !TYPE_CANONICAL (t))
- {
- gimple_register_canonical_type (t);
- if (odr_type_p (t))
- register_odr_type (t);
- }
+ gimple_register_canonical_type (t);
+
+ /* Reigster types to ODR hash. If we compile unit w/o
+ -fno-lto-odr-type-merging, also insert types with virtual
+ tables to keep type inheritance graph complete on
+ polymorphic types. */
+ if (TYPE_P (t)
+ && (odr_type_p (t)
+ || (TYPE_MAIN_VARIANT (t) == t
+ && TREE_CODE (t) == RECORD_TYPE
+ && TYPE_BINFO (t) && BINFO_VTABLE (TYPE_BINFO (t)))))
+ register_odr_type (t);
/* Link shared INTEGER_CSTs into TYPE_CACHED_VALUEs of its
type which is also member of this SCC. */
if (TREE_CODE (t) == INTEGER_CST
Index: ipa-devirt.c
===================================================================
--- ipa-devirt.c (revision 221777)
+++ ipa-devirt.c (working copy)
@@ -939,7 +939,8 @@ warn_odr (tree t1, tree t2, tree st1, tr
/* ODR warnings are output druing LTO streaming; we must apply location
cache for potential warnings to be output correctly. */
- lto_location_cache::current_cache->apply_location_cache ();
+ if (lto_location_cache::current_cache)
+ lto_location_cache::current_cache->apply_location_cache ();
if (!warning_at (DECL_SOURCE_LOCATION (TYPE_NAME (t1)), OPT_Wodr,
"type %qT violates one definition rule",
