re PR lto/61886 (LTO breaks fread with _FORTIFY_SOURCE=2)

	PR ipa/61886
	* varpool.c (varpool_node::get_availability): Recurse only on
	weakrefs with definition in the target.
	(symbol_table::remove_unreferenced_decls): Keep aliases in the boundary.

From-SVN: r231429

gcc/ChangeLog

 2015-12-08  Jan Hubicka  <hubicka@ucw.cz>
 
 	PR ipa/61886
-	* ipa-visibility.c (can_replace_by_local_alias): Look through transparent
-	aliaes; refuse weakrefs.
+	* varpool.c (varpool_node::get_availability): Recurse only on
+	weakrefs with definition in the target.
+	(symbol_table::remove_unreferenced_decls): Keep aliases in the boundary.
+
+2015-12-08  Jan Hubicka  <hubicka@ucw.cz>
+
+	PR ipa/61886
+	* ipa-visibility.c (can_replace_by_local_alias): Look through
+	transparent aliases; refuse weakrefs.
 	(update_visibility_by_resolution_info): Skip transparent aliases in the
 	analysis part
 

gcc/varpool.c

@@ -490,7 +490,7 @@ varpool_node::get_availability (void)
   if (DECL_IN_CONSTANT_POOL (decl)
       || DECL_VIRTUAL_P (decl))
     return AVAIL_AVAILABLE;
-  if (transparent_alias)
+  if (transparent_alias && definition)
     {
       enum availability avail;
 
@@ -667,11 +667,11 @@ symbol_table::remove_unreferenced_decls (void)
 	    enqueue_node (vnode, &first);
 	  else
 	    {
-	      referenced.add (node);
-	      while (node->alias && node->definition)
+	      referenced.add (vnode);
+	      while (vnode && vnode->alias && vnode->definition)
 		{
-		  node = node->get_alias_target ();
-	          referenced.add (node);
+		  vnode = vnode->get_alias_target ();
+	          referenced.add (vnode);
 		}
 	    }
 	}