c-common.c: Use NULL_TREE instead of 0 where appropriate.

	* c-common.c: Use NULL_TREE instead of 0 where appropriate.
	* c-warn.c: Likewise.

	* c-decl.c: Use NULL_TREE instead of 0 where appropriate.
	* c-typeck.c: Likewise.

From-SVN: r248161

gcc/c-family/ChangeLog

+2017-05-17  Marek Polacek  <polacek@redhat.com>
+
+	* c-common.c: Use NULL_TREE instead of 0 where appropriate.
+	* c-warn.c: Likewise.
+
 2017-05-17  Ville Voutilainen  <ville.voutilainen@gmail.com>
 
 	Implement new C++ intrinsics __is_assignable and __is_constructible.

gcc/c-family/c-common.c

@@ -2989,7 +2989,7 @@ shorten_compare (location_t loc, tree *op0_ptr, tree *op1_ptr,
       if (!real1 && !real2 && integer_zerop (primop1)
 	  && TYPE_UNSIGNED (*restype_ptr))
 	{
-	  tree value = 0;
+	  tree value = NULL_TREE;
 	  /* All unsigned values are >= 0, so we warn.  However,
 	     if OP0 is a constant that is >= 0, the signedness of
 	     the comparison isn't an issue, so suppress the
@@ -3022,7 +3022,7 @@ shorten_compare (location_t loc, tree *op0_ptr, tree *op1_ptr,
 	      break;
 	    }
 
-	  if (value != 0)
+	  if (value != NULL_TREE)
 	    {
 	      /* Don't forget to evaluate PRIMOP0 if it has side effects.  */
 	      if (TREE_SIDE_EFFECTS (primop0))
@@ -4651,10 +4651,10 @@ self_promoting_args_p (const_tree parms)
       if (type == error_mark_node)
 	continue;
 
-      if (TREE_CHAIN (t) == 0 && type != void_type_node)
+      if (TREE_CHAIN (t) == NULL_TREE && type != void_type_node)
 	return 0;
 
-      if (type == 0)
+      if (type == NULL_TREE)
 	return 0;
 
       if (TYPE_MAIN_VARIANT (type) == float_type_node)
@@ -5579,7 +5579,7 @@ check_function_arguments_recurse (void (*callback)
 	    format_num = tree_to_uhwi (format_num_expr);
 
 	    for (inner_arg = first_call_expr_arg (param, &iter), i = 1;
-		 inner_arg != 0;
+		 inner_arg != NULL_TREE;
 		 inner_arg = next_call_expr_arg (&iter), i++)
 	      if (i == format_num)
 		{

gcc/c-family/c-warn.c

@@ -1078,7 +1078,7 @@ match_case_to_enum_1 (tree key, tree type, tree label)
   else
     print_hex (key, buf);
 
-  if (TYPE_NAME (type) == 0)
+  if (TYPE_NAME (type) == NULL_TREE)
     warning_at (DECL_SOURCE_LOCATION (CASE_LABEL (label)),
 		warn_switch ? OPT_Wswitch : OPT_Wswitch_enum,
 		"case value %qs not in enumerated type",

gcc/c/ChangeLog

 2017-05-17  Marek Polacek  <polacek@redhat.com>
 
+	* c-decl.c: Use NULL_TREE instead of 0 where appropriate.
+	* c-typeck.c: Likewise.
+
+2017-05-17  Marek Polacek  <polacek@redhat.com>
+
 	PR sanitizer/80659
 	* c-decl.c (build_compound_literal): Set DECL_ARTIFICIAL and
 	DECL_IGNORED_P even for non-static compound literals.