re PR c++/59082 (ICE with duplicate (virtual) base)

/cp
2014-01-31  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/59082
	* class.c (build_vfield_ref): Early return error_mark_node if
	TYPE_VFIELD (type) is null.
	(build_base_path): Check return value of build_vfield_ref.

/testsuite
2014-01-31  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/59082
	* g++.dg/inherit/crash4.C: New.

From-SVN: r207359

gcc/cp/ChangeLog

+2014-01-31  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/59082
+	* class.c (build_vfield_ref): Early return error_mark_node if
+	TYPE_VFIELD (type) is null.
+	(build_base_path): Check return value of build_vfield_ref.
+
 2014-01-31  Jason Merrill  <jason@redhat.com>
 
 	PR c++/59646

gcc/cp/class.c

@@ -432,6 +432,9 @@ build_base_path (enum tree_code code,
                                                             complain),
 				     TREE_TYPE (TREE_TYPE (expr)));
       
+      if (v_offset == error_mark_node)
+	return error_mark_node;
+
       v_offset = fold_build_pointer_plus (v_offset, BINFO_VPTR_FIELD (v_binfo));
       v_offset = build1 (NOP_EXPR,
 			 build_pointer_type (ptrdiff_type_node),
@@ -625,7 +628,9 @@ build_vfield_ref (tree datum, tree type)
 {
   tree vfield, vcontext;
 
-  if (datum == error_mark_node)
+  if (datum == error_mark_node
+      /* Can happen in case of duplicate base types (c++/59082).  */
+      || !TYPE_VFIELD (type))
     return error_mark_node;
 
   /* First, convert to the requested type.  */

gcc/testsuite/ChangeLog

+2014-01-31  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/59082
+	* g++.dg/inherit/crash4.C: New.
+
 2014-01-31  Maxim Ostapenko  <m.ostapenko@partner.samsung.com>
+
 	* c-c++-common/tsan/simple_race.c: Made test less flaky.
 
 2014-01-31  Ilya Tocar  <ilya.tocar@intel.com>

gcc/testsuite/g++.dg/inherit/crash4.C

+// PR c++/59082
+
+struct A {};
+
+struct B : virtual A, A {};  // { dg-error "duplicate base type" }
+
+A foo(const B &b)
+{
+  return b;
+}