re PR c++/24926 (gcc ignores access level violation for anonymous structs)

/cp
2013-09-04  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/24926
	* class.c (finish_struct_anon_r): New.
	(finish_struct_anon): Use it.

/testsuite
2013-09-04  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/24926
	* g++.dg/parse/access11.C: New.

From-SVN: r202266

1 files changed, 82 insertions, 50 deletions

diff --git a/gcc/cp/class.c b/gcc/cp/class.c
index bcd8076..3d34b92 100644
--- a/gcc/cp/class.c
+++ b/gcc/cp/class.c
@@ -2773,15 +2773,93 @@ warn_hidden (tree t)
     }
 }
 
+/* Recursive helper for finish_struct_anon.  */
+
+static void
+finish_struct_anon_r (tree field, bool complain)
+{
+  bool is_union = TREE_CODE (TREE_TYPE (field)) == UNION_TYPE;
+  tree elt = TYPE_FIELDS (TREE_TYPE (field));
+  for (; elt; elt = DECL_CHAIN (elt))
+    {
+      /* We're generally only interested in entities the user
+	 declared, but we also find nested classes by noticing
+	 the TYPE_DECL that we create implicitly.  You're
+	 allowed to put one anonymous union inside another,
+	 though, so we explicitly tolerate that.  We use
+	 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
+	 we also allow unnamed types used for defining fields.  */
+      if (DECL_ARTIFICIAL (elt)
+	  && (!DECL_IMPLICIT_TYPEDEF_P (elt)
+	      || TYPE_ANONYMOUS_P (TREE_TYPE (elt))))
+	continue;
+
+      if (TREE_CODE (elt) != FIELD_DECL)
+	{
+	  if (complain)
+	    {
+	      if (is_union)
+		permerror (input_location,
+			   "%q+#D invalid; an anonymous union can "
+			   "only have non-static data members", elt);
+	      else
+		permerror (input_location,
+			   "%q+#D invalid; an anonymous struct can "
+			   "only have non-static data members", elt);
+	    }
+	  continue;
+	}
+
+      if (complain)
+	{
+	  if (TREE_PRIVATE (elt))
+	    {
+	      if (is_union)
+		permerror (input_location,
+			   "private member %q+#D in anonymous union", elt);
+	      else
+		permerror (input_location,
+			   "private member %q+#D in anonymous struct", elt);
+	    }
+	  else if (TREE_PROTECTED (elt))
+	    {
+	      if (is_union)
+		permerror (input_location,
+			   "protected member %q+#D in anonymous union", elt);
+	      else
+		permerror (input_location,
+			   "protected member %q+#D in anonymous struct", elt);
+	    }
+	}
+
+      TREE_PRIVATE (elt) = TREE_PRIVATE (field);
+      TREE_PROTECTED (elt) = TREE_PROTECTED (field);
+
+      /* Recurse into the anonymous aggregates to handle correctly
+	 access control (c++/24926):
+
+	 class A {
+	   union {
+	     union {
+	       int i;
+	     };
+	   };
+	 };
+
+	 int j=A().i;  */
+      if (DECL_NAME (elt) == NULL_TREE
+	  && ANON_AGGR_TYPE_P (TREE_TYPE (elt)))
+	finish_struct_anon_r (elt, /*complain=*/false);
+    }
+}
+
 /* Check for things that are invalid.  There are probably plenty of other
    things we should check for also.  */
 
 static void
 finish_struct_anon (tree t)
 {
-  tree field;
-
-  for (field = TYPE_FIELDS (t); field; field = DECL_CHAIN (field))
+  for (tree field = TYPE_FIELDS (t); field; field = DECL_CHAIN (field))
     {
       if (TREE_STATIC (field))
 	continue;
@@ -2790,53 +2868,7 @@ finish_struct_anon (tree t)
 
       if (DECL_NAME (field) == NULL_TREE
 	  && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
-	{
-	  bool is_union = TREE_CODE (TREE_TYPE (field)) == UNION_TYPE;
-	  tree elt = TYPE_FIELDS (TREE_TYPE (field));
-	  for (; elt; elt = DECL_CHAIN (elt))
-	    {
-	      /* We're generally only interested in entities the user
-		 declared, but we also find nested classes by noticing
-		 the TYPE_DECL that we create implicitly.  You're
-		 allowed to put one anonymous union inside another,
-		 though, so we explicitly tolerate that.  We use
-		 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
-		 we also allow unnamed types used for defining fields.  */
-	      if (DECL_ARTIFICIAL (elt)
-		  && (!DECL_IMPLICIT_TYPEDEF_P (elt)
-		      || TYPE_ANONYMOUS_P (TREE_TYPE (elt))))
-		continue;
-
-	      if (TREE_CODE (elt) != FIELD_DECL)
-		{
-		  if (is_union)
-		    permerror (input_location, "%q+#D invalid; an anonymous union can "
-			       "only have non-static data members", elt);
-		  else
-		    permerror (input_location, "%q+#D invalid; an anonymous struct can "
-			       "only have non-static data members", elt);
-		  continue;
-		}
-
-	      if (TREE_PRIVATE (elt))
-		{
-		  if (is_union)
-		    permerror (input_location, "private member %q+#D in anonymous union", elt);
-		  else
-		    permerror (input_location, "private member %q+#D in anonymous struct", elt);
-		}
-	      else if (TREE_PROTECTED (elt))
-		{
-		  if (is_union)
-		    permerror (input_location, "protected member %q+#D in anonymous union", elt);
-		  else
-		    permerror (input_location, "protected member %q+#D in anonymous struct", elt);
-		}
-
-	      TREE_PRIVATE (elt) = TREE_PRIVATE (field);
-	      TREE_PROTECTED (elt) = TREE_PROTECTED (field);
-	    }
-	}
+	finish_struct_anon_r (field, /*complain=*/true);
     }
 }