re PR c++/28656 (duplicated null argument warning on memcpy())

	PR c++/28656
	* tree-vrp.c (nonnull_arg_p): Handle all nonnull attributes instead
	of just the first one.

	* c-common.c (check_function_nonnull): Handle multiple nonnull
	attributes properly.

	* c-c++-common/pr28656.c: New test.

From-SVN: r189707

1 files changed, 24 insertions, 21 deletions

diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c
index 66cc406..68c449e 100644
--- a/gcc/tree-vrp.c
+++ b/gcc/tree-vrp.c
@@ -353,32 +353,35 @@ nonnull_arg_p (const_tree arg)
     return true;
 
   fntype = TREE_TYPE (current_function_decl);
-  attrs = lookup_attribute ("nonnull", TYPE_ATTRIBUTES (fntype));
+  for (attrs = TYPE_ATTRIBUTES (fntype); attrs; attrs = TREE_CHAIN (attrs))
+    {
+      attrs = lookup_attribute ("nonnull", attrs);
 
-  /* If "nonnull" wasn't specified, we know nothing about the argument.  */
-  if (attrs == NULL_TREE)
-    return false;
+      /* If "nonnull" wasn't specified, we know nothing about the argument.  */
+      if (attrs == NULL_TREE)
+	return false;
 
-  /* If "nonnull" applies to all the arguments, then ARG is non-null.  */
-  if (TREE_VALUE (attrs) == NULL_TREE)
-    return true;
+      /* If "nonnull" applies to all the arguments, then ARG is non-null.  */
+      if (TREE_VALUE (attrs) == NULL_TREE)
+	return true;
 
-  /* Get the position number for ARG in the function signature.  */
-  for (arg_num = 1, t = DECL_ARGUMENTS (current_function_decl);
-       t;
-       t = DECL_CHAIN (t), arg_num++)
-    {
-      if (t == arg)
-	break;
-    }
+      /* Get the position number for ARG in the function signature.  */
+      for (arg_num = 1, t = DECL_ARGUMENTS (current_function_decl);
+	   t;
+	   t = DECL_CHAIN (t), arg_num++)
+	{
+	  if (t == arg)
+	    break;
+	}
 
-  gcc_assert (t == arg);
+      gcc_assert (t == arg);
 
-  /* Now see if ARG_NUM is mentioned in the nonnull list.  */
-  for (t = TREE_VALUE (attrs); t; t = TREE_CHAIN (t))
-    {
-      if (compare_tree_int (TREE_VALUE (t), arg_num) == 0)
-	return true;
+      /* Now see if ARG_NUM is mentioned in the nonnull list.  */
+      for (t = TREE_VALUE (attrs); t; t = TREE_CHAIN (t))
+	{
+	  if (compare_tree_int (TREE_VALUE (t), arg_num) == 0)
+	    return true;
+	}
     }
 
   return false;