re PR c++/51290 (Bogus warning: zero as null pointer constant with static_cast)

/cp
2011-11-24  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/51290
	* class.c (build_base_path): For the null pointer check use
	nullptr_node instead of integer_zero_node.

/testsuite
2011-11-24  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/51290
	* g++.dg/warn/Wzero-as-null-pointer-constant-3.C: New.

From-SVN: r181690

gcc/cp/ChangeLog

+2011-11-24  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/51290
+	* class.c (build_base_path): For the null pointer check use
+	nullptr_node instead of integer_zero_node.
+
 2011-11-22  Dodji Seketeli  <dodji@redhat.com>
 
 	PR c++/51145

gcc/cp/class.c

@@ -338,7 +338,7 @@ build_base_path (enum tree_code code,
   /* Now that we've saved expr, build the real null test.  */
   if (null_test)
     {
-      tree zero = cp_convert (TREE_TYPE (expr), integer_zero_node);
+      tree zero = cp_convert (TREE_TYPE (expr), nullptr_node);
       null_test = fold_build2_loc (input_location, NE_EXPR, boolean_type_node,
 			       expr, zero);
     }

gcc/testsuite/ChangeLog

+2011-11-24  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/51290
+	* g++.dg/warn/Wzero-as-null-pointer-constant-3.C: New.
+
 2011-11-23  Jakub Jelinek  <jakub@redhat.com>
 
 	PR target/51261

gcc/testsuite/g++.dg/warn/Wzero-as-null-pointer-constant-3.C

+// PR c++/51290
+// { dg-options "-Wzero-as-null-pointer-constant" }
+
+class A { int a; };
+
+class B { int b; };
+
+class C : public A, public B
+{
+    private:
+        static void foo (A *x)
+        {
+            C *y = static_cast<C *>(x);
+            (void) y;
+        }
+
+        static void bar (B *x)
+        {
+            C *y = static_cast<C *>(x);
+            (void) y;
+        }
+};