Index: gcc/cp/call.c
===================================================================
--- gcc/cp/call.c	(revision 109692)
+++ gcc/cp/call.c	(working copy)
@@ -4201,10 +4201,10 @@ convert_like_real (conversion *convs, tr
       if (ARITHMETIC_TYPE_P (t) && expr == null_node)
 	{
 	  if (fn)
-	    warning (0, "passing NULL to non-pointer argument %P of %qD",
+	    warning (OPT_Wconversion, "passing NULL to non-pointer argument %P of %qD",
 		     argnum, fn);
 	  else
-	    warning (0, "converting to non-pointer type %qT from NULL", t);
+	    warning (OPT_Wconversion, "converting to non-pointer type %qT from NULL", t);
 	}
 
       /* Warn about assigning a floating-point type to an integer type.  */
@@ -4212,10 +4212,10 @@ convert_like_real (conversion *convs, tr
 	  && TREE_CODE (t) == INTEGER_TYPE)
 	{
 	  if (fn)
-	    warning (0, "passing %qT for argument %P to %qD",
+	    warning (OPT_Wconversion, "passing %qT for argument %P to %qD",
 		     TREE_TYPE (expr), argnum, fn);
 	  else
-	    warning (0, "converting to %qT from %qT", t, TREE_TYPE (expr));
+	    warning (OPT_Wconversion, "converting to %qT from %qT", t, TREE_TYPE (expr));
 	}
     }
 
Index: gcc/cp/cvt.c
===================================================================
--- gcc/cp/cvt.c	(revision 109692)
+++ gcc/cp/cvt.c	(working copy)
@@ -1058,7 +1058,7 @@ build_expr_type_conversion (int desires,
   if (expr == null_node
       && (desires & WANT_INT)
       && !(desires & WANT_NULL))
-    warning (0, "converting NULL to non-pointer type");
+    warning (OPT_Wconversion, "converting NULL to non-pointer type");
 
   basetype = TREE_TYPE (expr);
 
Index: gcc/testsuite/g++.old-deja/g++.warn/impint.C
===================================================================
--- gcc/testsuite/g++.old-deja/g++.warn/impint.C	(revision 109692)
+++ gcc/testsuite/g++.old-deja/g++.warn/impint.C	(working copy)
@@ -1,5 +1,5 @@
 // { dg-do assemble  }
-
+// { dg-options "-Wconversion" }
 // Copyright (C) 2000 Free Software Foundation, Inc.
 // Contributed by Nathan Sidwell 24 Feb 2000 <nathan@codesourcery.com>
 
@@ -54,4 +54,3 @@ void fn ()
   punk ();          // { dg-warning "" } double to int
   rock (1);         // { dg-warning "" } double to int
 }
-
Index: gcc/testsuite/g++.old-deja/g++.warn/impint2.C
===================================================================
--- gcc/testsuite/g++.old-deja/g++.warn/impint2.C	(revision 109692)
+++ gcc/testsuite/g++.old-deja/g++.warn/impint2.C	(working copy)
@@ -1,4 +1,5 @@
 // { dg-do assemble  }
+// { dg-options "-Wconversion" }
 
 // Copyright (C) 2000 Free Software Foundation, Inc.
 // Contributed by Nathan Sidwell 6 Mar 2000 <nathan@codesourcery.com>
Index: gcc/testsuite/g++.old-deja/g++.other/null1.C
===================================================================
--- gcc/testsuite/g++.old-deja/g++.other/null1.C	(revision 109692)
+++ gcc/testsuite/g++.old-deja/g++.other/null1.C	(working copy)
@@ -1,4 +1,5 @@
 // { dg-do link  }
+// { dg-options "-Wconversion" }
 
 #include <cstddef>
 
Index: gcc/testsuite/g++.dg/warn/conv2.C
===================================================================
--- gcc/testsuite/g++.dg/warn/conv2.C	(revision 109692)
+++ gcc/testsuite/g++.dg/warn/conv2.C	(working copy)
@@ -1,3 +1,4 @@
 // PR c++/13932
+// { dg-options "-Wconversion" }
 
 int i = 1.; // { dg-warning "converting" }