Re: [C++ Patch] PR 53761

[Paolo Carlini]

Hi,

On 10/24/2012 06:57 PM, Jason Merrill wrote:

On 10/10/2012 11:13 AM, Paolo Carlini wrote:

-      error ("type transparent class %qT does not have any fields", t);
+      if (TREE_CODE (t) == UNION_TYPE)

+ error ("type transparent union %qT does not have any fields", t);

+      else

+ error ("type transparent class %qT does not have any fields", t);

If you use %q#T you don't need to repeat the class-key.

Indeed.

+ error ("type transparent union %qT cannot be made transparent", t);

Let's say why not.

Thus I tested the below.

Thanks,
Paolo.

//////////////////////

Index: cp/class.c
===================================================================
--- cp/class.c  (revision 192762)
+++ cp/class.c  (working copy)
@@ -6261,7 +6261,7 @@ finish_struct_1 (tree t)
       tree field = first_field (t);
       if (field == NULL_TREE || error_operand_p (field))
        {
-         error ("type transparent class %qT does not have any fields", t);
+         error ("type transparent %q#T does not have any fields", t);
          TYPE_TRANSPARENT_AGGR (t) = 0;
        }
       else if (DECL_ARTIFICIAL (field))
@@ -6275,6 +6275,12 @@ finish_struct_1 (tree t)
            }
          TYPE_TRANSPARENT_AGGR (t) = 0;
        }
+      else if (TYPE_MODE (t) != DECL_MODE (field))
+       {
+         error ("type transparent %q#T cannot be made transparent because "
+                "a field has neither pointer nor integer type", t);
+         TYPE_TRANSPARENT_AGGR (t) = 0;
+       }
     }
 }
 
Index: testsuite/g++.dg/ext/transparent-union.C
===================================================================
--- testsuite/g++.dg/ext/transparent-union.C    (revision 0)
+++ testsuite/g++.dg/ext/transparent-union.C    (working copy)
@@ -0,0 +1,5 @@
+// PR c++/53761
+
+typedef union {    // { dg-error "type transparent" }
+   double x;
+} __attribute__(( __transparent_union__ )) example_t;