re PR c++/51413 (Broken diagnostic with __builtin_offsetof)

/cp
2013-06-14  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/51413
	* semantics.c (finish_offsetof): Handle INDIRECT_REF as expr.

/testsuite
2013-06-14  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/51413
	* g++.dg/ext/builtin-offsetof1.C: New.

From-SVN: r200110

gcc/cp/ChangeLog

 2013-06-14  Paolo Carlini  <paolo.carlini@oracle.com>
 
+	PR c++/51413
+	* semantics.c (finish_offsetof): Handle INDIRECT_REF as expr.
+
+2013-06-14  Paolo Carlini  <paolo.carlini@oracle.com>
+
 	PR c++/57599
 	* rtti.c (build_dynamic_cast_1): In case of cast to an unambiguous
 	accessible base simply forward to build_static_cast.

gcc/cp/semantics.c

@@ -3690,10 +3690,17 @@ finish_offsetof (tree expr)
       || TREE_CODE (TREE_TYPE (expr)) == METHOD_TYPE
       || TREE_TYPE (expr) == unknown_type_node)
     {
-      if (TREE_CODE (expr) == COMPONENT_REF
-	  || TREE_CODE (expr) == COMPOUND_EXPR)
-	expr = TREE_OPERAND (expr, 1);
-      error ("cannot apply %<offsetof%> to member function %qD", expr);
+      if (TREE_CODE (expr) == INDIRECT_REF)
+	error ("second operand of %<offsetof%> is neither a single "
+	       "identifier nor a sequence of member accesses and "
+	       "array references");
+      else
+	{
+	  if (TREE_CODE (expr) == COMPONENT_REF
+	      || TREE_CODE (expr) == COMPOUND_EXPR)
+	    expr = TREE_OPERAND (expr, 1);
+	  error ("cannot apply %<offsetof%> to member function %qD", expr);
+	}
       return error_mark_node;
     }
   if (REFERENCE_REF_P (expr))

gcc/testsuite/ChangeLog

+2013-06-14  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/51413
+	* g++.dg/ext/builtin-offsetof1.C: New.
+
 2013-06-14  Vidya Praveen <vidyapraveen@arm.com>
 
 	* gcc.target/aarch64/vect_smlal_1.c: New file.

gcc/testsuite/g++.dg/ext/builtin-offsetof1.C

+// PR c++/51413
+// { dg-options "-w" }
+
+struct A
+{
+  static void foo();
+};
+
+int i = __builtin_offsetof(A, foo[1]);  // { dg-error "neither a single identifier nor a sequence of member accesses and array references" }