re PR middle-end/47281 (error: non-trivial conversion at assignment)

2011-01-14  Richard Guenther  <rguenther@suse.de>

	PR middle-end/47281
	Revert
	2011-01-11  Richard Guenther  <rguenther@suse.de>

        PR tree-optimization/46076
        * tree-ssa.c (useless_type_conversion_p): Conversions from
        unprototyped to empty argument list function types are useless.

	* gcc.dg/torture/pr47281.c: New testcase.
	* gcc.dg/tree-ssa/pr46076.c: XFAIL.

From-SVN: r168781

gcc/ChangeLog

 2011-01-14  Richard Guenther  <rguenther@suse.de>
 
+	PR middle-end/47281
+	Revert
+	2011-01-11  Richard Guenther  <rguenther@suse.de>
+
+        PR tree-optimization/46076
+        * tree-ssa.c (useless_type_conversion_p): Conversions from
+        unprototyped to empty argument list function types are useless.
+
+2011-01-14  Richard Guenther  <rguenther@suse.de>
+
 	PR tree-optimization/47286
 	* tree-ssa-structalias.c (new_var_info): Register variables
 	are global.

gcc/testsuite/ChangeLog

 2011-01-14  Richard Guenther  <rguenther@suse.de>
 
+	PR middle-end/47281
+	* gcc.dg/torture/pr47281.c: New testcase.
+	* gcc.dg/tree-ssa/pr46076.c: XFAIL.
+
+2011-01-14  Richard Guenther  <rguenther@suse.de>
+
 	PR tree-optimization/47286
 	* gcc.dg/tree-ssa/pr47286.c: New testcase.
 

gcc/testsuite/gcc.dg/torture/pr47281.c

+/* { dg-do compile } */
+
+struct T;
+typedef void F(void);
+
+F* aux(void (*x)())
+{
+  return x;
+}
+
+void make_mess (int);
+
+F*
+get_funloc (void (*x)(int), F* (*y)())
+{
+  return y(x);
+}
+
+F*
+foo ()
+{
+  return get_funloc (make_mess, aux);
+}

gcc/testsuite/gcc.dg/tree-ssa/pr46076.c

 /* { dg-do link } */
 /* { dg-options "-O2" } */
 
-extern void link_error (void);
+extern void link_error (void) { /* XFAIL */ }
 
 typedef unsigned char(*Calculable)(void);
 

gcc/tree-ssa.c

@@ -1410,11 +1410,6 @@ useless_type_conversion_p (tree outer_type, tree inner_type)
       if (!prototype_p (outer_type))
 	return true;
 
-      /* A conversion between unprototyped and empty argument list is ok.  */
-      if (TYPE_ARG_TYPES (outer_type) == void_list_node
-	  && !prototype_p (inner_type))
-	return true;
-
       /* If the unqualified argument types are compatible the conversion
 	 is useless.  */
       if (TYPE_ARG_TYPES (outer_type) == TYPE_ARG_TYPES (inner_type))