re PR c++/35315 (ICE with attribute transparent_union)

	PR c++/35315
	* c-common.c (handle_transparent_union_attribute): Don't
	make a duplicate type in C++.

From-SVN: r171145

gcc/c-family/ChangeLog

+2011-03-18  Jason Merrill  <jason@redhat.com>
+
+	PR c++/35315
+	* c-common.c (handle_transparent_union_attribute): Don't
+	make a duplicate type in C++.
+
 2011-03-15  Jason Merrill  <jason@redhat.com>
 
 	* c-common.c (max_constexpr_depth): New.

gcc/c-family/c-common.c

@@ -6152,6 +6152,7 @@ handle_transparent_union_attribute (tree *node, tree name,
       if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE))
 	{
 	  if (TYPE_FIELDS (type) == NULL_TREE
+	      || c_dialect_cxx ()
 	      || TYPE_MODE (type) != DECL_MODE (TYPE_FIELDS (type)))
 	    goto ignored;
 

gcc/testsuite/ChangeLog

+2011-03-18  Jason Merrill  <jason@redhat.com>
+
+	* g++.dg/ext/attrib32.C: Expect errors on the two-names case.
+
 2011-03-18  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>
 
 	PR middle-end/47405

gcc/testsuite/g++.dg/ext/attrib32.C

@@ -10,10 +10,10 @@ void bar()
   foo(0);
 }
 
-typedef union U1 { int i; } U2 __attribute__((transparent_union));
+typedef union U1 { int i; } U2 __attribute__((transparent_union)); // { dg-warning "ignored" }
 
-static void foo2(U1) {}
-static void foo2(U2) {}
+static void foo2(U1) {}		// { dg-error "previously defined" }
+static void foo2(U2) {}		// { dg-error "redefinition" }
 
 void bar2(U1 u1, U2 u2)
 {