re PR c++/81013 (ICE with invalid union in class hierarchy)

/cp
2018-01-18  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/81013
	* decl.c (xref_basetypes): Early return upon error about derived
	union.

/testsuite
2018-01-18  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/81013
	* g++.dg/inherit/union3.C: New.

From-SVN: r256856

gcc/cp/ChangeLog

+2018-01-18  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/81013
+	* decl.c (xref_basetypes): Early return upon error about derived
+	union.
+
 2018-01-18  Nathan Sidwell  <nathan@acm.org>
 
 	PR c++/83160

gcc/cp/decl.c

@@ -13801,7 +13801,10 @@ xref_basetypes (tree ref, tree base_list)
       CLASSTYPE_NON_LAYOUT_POD_P (ref) = true;
 
       if (TREE_CODE (ref) == UNION_TYPE)
-	error ("derived union %qT invalid", ref);
+	{
+	  error ("derived union %qT invalid", ref);
+	  return;
+	}
     }
 
   if (max_bases > 1)

gcc/testsuite/ChangeLog

+2018-01-18  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/81013
+	* g++.dg/inherit/union3.C: New.
+
 2018-01-18  Christophe Lyon <christophe.lyon@linaro.org>
 
 	* gcc.dg/rtl/arm/stl-cond.c: Enable on arm*.

gcc/testsuite/g++.dg/inherit/union3.C

+// PR c++/81013
+
+struct A
+{
+  virtual void foo() const;
+};
+
+union B : A  // { dg-error "derived union 'B' invalid" }
+{
+  void foo() const;
+};
+
+void bar(const B& b)
+{
+  b.foo();
+}