re PR middle-end/57366 (gcc.dg/lto/attr-weakref-1 FAILs)

	PR middle-end/57366
	* cgraphunit.c (compile): When weakref is not supported,
	set up transparent aliases before final output pass.
	* varasm.c (assemble_alias): Do not try to do it here.

From-SVN: r199583

gcc/ChangeLog

 2013-06-01  Jan Hubicka  <jh@suse.cz>
 
+	PR middle-end/57366
+	* cgraphunit.c (compile): When weakref is not supported,
+	set up transparent aliases before final output pass.
+	* varasm.c (assemble_alias): Do not try to do it here.
+
+2013-06-01  Jan Hubicka  <jh@suse.cz>
+
 	PR middle-end/57467
 	* passes.c (for_per_function): Skip unanalyzed functions.
 

gcc/cgraphunit.c

@@ -1996,6 +1996,32 @@ compile (void)
   bitmap_obstack_release (NULL);
   mark_functions_to_output ();
 
+  /* When weakref support is missing, we autmatically translate all
+     references to NODE to references to its ultimate alias target.
+     The renaming mechanizm uses flag IDENTIFIER_TRANSPARENT_ALIAS and
+     TREE_CHAIN.
+
+     Set up this mapping before we output any assembler but once we are sure
+     that all symbol renaming is done.
+
+     FIXME: All this uglyness can go away if we just do renaming at gimple
+     level by physically rewritting the IL.  At the moment we can only redirect
+     calls, so we need infrastructure for renaming references as well.  */
+#ifndef ASM_OUTPUT_WEAKREF
+  symtab_node node;
+
+  FOR_EACH_SYMBOL (node)
+    if (node->symbol.alias
+	&& lookup_attribute ("weakref", DECL_ATTRIBUTES (node->symbol.decl)))
+      {
+	IDENTIFIER_TRANSPARENT_ALIAS
+	   (DECL_ASSEMBLER_NAME (node->symbol.decl)) = 1;
+	TREE_CHAIN (DECL_ASSEMBLER_NAME (node->symbol.decl))
+	   = (node->symbol.alias_target ? node->symbol.alias_target
+	      : DECL_ASSEMBLER_NAME (symtab_alias_target (node)->symbol.decl));
+      }
+#endif
+
   cgraph_state = CGRAPH_STATE_EXPANSION;
   if (!flag_toplevel_reorder)
     output_in_order ();

gcc/varasm.c

@@ -5560,13 +5560,6 @@ assemble_alias (tree decl, tree target)
 
       if (alias == target)
 	error ("weakref %q+D ultimately targets itself", decl);
-      else
-	{
-#ifndef ASM_OUTPUT_WEAKREF
-	  IDENTIFIER_TRANSPARENT_ALIAS (alias) = 1;
-	  TREE_CHAIN (alias) = target;
-#endif
-	}
       if (TREE_PUBLIC (decl))
 	error ("weakref %q+D must have static linkage", decl);
     }