[Bug tree-optimization/41355] Type of ADDR_EXPR in CALL_EXPR not rebuilt when function is cloned

["baldrick at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org>]

------- Comment #1 from baldrick at gcc dot gnu dot org  2010-07-05 18:43 -------
It turns out that the problem is that when build_function_type_skip_args
creates
the new type, TYPE_POINTER_TO for the new type is still pointing to the old
type.
When gimple_call_set_fndecl is used to change the fndecl to one with less
arguments, an ADDR_EXPR is built.  The type of the ADDR_EXPR is obtained from
the
TYPE_POINTER_TO field of the new type, and thus has type pointer-to-old-type
rather than pointer-to-new-type.  I'm testing the following patch.  The idea
here is that calling copy_node has no advantage.  In spite of the comment,
build_distinct_type_copy preserves attributes etc too, so it might as well
be used always.  [I think the comment refers to some earlier logic, since
the change introducing build_distinct_type_copy post-dates it].

Index: gcc-4.5/gcc/tree.c
===================================================================
--- gcc-4.5.orig/gcc/tree.c     2010-07-05 20:26:21.349376337 +0200
+++ gcc-4.5/gcc/tree.c  2010-07-05 20:29:11.582730610 +0200
@@ -7208,24 +7208,10 @@
        new_reversed = void_list_node;
     }

-  /* Use copy_node to preserve as much as possible from original type
-     (debug info, attribute lists etc.)
-     Exception is METHOD_TYPEs must have THIS argument.
-     When we are asked to remove it, we need to build new FUNCTION_TYPE
-     instead.  */
-  if (TREE_CODE (orig_type) != METHOD_TYPE
-      || !bitmap_bit_p (args_to_skip, 0))
-    {
-      new_type = copy_node (orig_type);
-      TYPE_ARG_TYPES (new_type) = new_reversed;
-    }
-  else
-    {
-      new_type
-        = build_distinct_type_copy (build_function_type (TREE_TYPE
(orig_type),
-                                                        new_reversed));
-      TYPE_CONTEXT (new_type) = TYPE_CONTEXT (orig_type);
-    }
+  new_type
+    = build_distinct_type_copy (build_function_type (TREE_TYPE (orig_type),
+                                                     new_reversed));
+  TYPE_CONTEXT (new_type) = TYPE_CONTEXT (orig_type);

   /* This is a new type, not a copy of an old type.  Need to reassociate
      variants.  We can handle everything except the main variant lazily.  */


-- 

baldrick at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |hubicka at gcc dot gnu dot
                   |                            |org
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2010-07-05 18:43:39
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41355