re PR debug/46796 (debug info missing builtin type names with lto)

2011-12-20  Richard Guenther  <rguenther@suse.de>

	PR lto/46796
	* dwarf2out.c (modified_type_die): When the type variant
	chain is corrupt use the types name, if available, instead
	of __unknown__.

From-SVN: r182524

gcc/ChangeLog

+2011-12-20  Richard Guenther  <rguenther@suse.de>
+
+	PR lto/46796
+	* dwarf2out.c (modified_type_die): When the type variant
+	chain is corrupt use the types name, if available, instead
+	of __unknown__.
+
 2011-12-20  Tristan Gingold  <gingold@adacore.com>
 
 	* config/alpha/alpha.c (alpha_start_function): Adjust condition to

gcc/dwarf2out.c

@@ -9873,7 +9873,14 @@ modified_type_die (tree type, int is_const_type, int is_volatile_type,
     }
   /* This probably indicates a bug.  */
   else if (mod_type_die && mod_type_die->die_tag == DW_TAG_base_type)
-    add_name_attribute (mod_type_die, "__unknown__");
+    {
+      name = TYPE_NAME (type);
+      if (name
+	  && TREE_CODE (name) == TYPE_DECL)
+	name = DECL_NAME (name);
+      add_name_attribute (mod_type_die,
+			  name ? IDENTIFIER_POINTER (name) : "__unknown__");
+    }
 
   if (qualified_type)
     equate_type_number_to_die (qualified_type, mod_type_die);