http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56557
--- Comment #9 from Jan Hubicka <hubicka at gcc dot gnu.org> 2013-03-11
18:10:57 UTC ---
I am testing the following that should prevent references from external vtables
to land in LTO symbol table.
Index: lto-streamer-out.c
===================================================================
--- lto-streamer-out.c (revision 196596)
+++ lto-streamer-out.c (working copy)
@@ -1265,17 +1265,36 @@ bool
output_symbol_p (symtab_node node)
{
struct cgraph_node *cnode;
- struct ipa_ref *ref;
-
if (!symtab_real_symbol_p (node))
return false;
/* We keep external functions in symtab for sake of inlining
and devirtualization. We do not want to see them in symbol table as
- references. */
+ references unless they are really used. */
cnode = dyn_cast <cgraph_node> (node);
- if (cnode && DECL_EXTERNAL (cnode->symbol.decl))
- return (cnode->callers
- || ipa_ref_list_referring_iterate (&cnode->symbol.ref_list, 0,
ref));
+ if (cnode && DECL_EXTERNAL (cnode->symbol.decl)
+ && cnode->callers)
+ return true;
+
+ /* Ignore all referrences from external vars initializers - they are not
really
+ part of the compilation unit until they are used by folding. Some
symbols,
+ like referneces to external construction vtables can not be referred to at
all.
+ We decide this at can_refer_decl_in_current_unit_p */
+ if (DECL_EXTERNAL (node->symbol.decl))
+ {
+ int i;
+ struct ipa_ref *ref;
+ for (i = 0; ipa_ref_list_referring_iterate (&node->symbol.ref_list,
+ i, ref); i++)
+ {
+ if (ref->use == IPA_REF_ALIAS)
+ continue;
+ if (is_a <cgraph_node> (ref->referring))
+ return true;
+ if (!DECL_EXTERNAL (ref->referring->symbol.decl))
+ return true;
+ }
+ return false;
+ }
return true;
}
