re PR c++/71737 (ICE following 2x pack expansion in non-pack with template alias)

/c-family
2017-01-16  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/71737
	* c-common.c (set_underlying_type): Always set DECL_ORIGINAL_TYPE.

/testsuite
2017-01-16  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/71737
	* g++.dg/cpp0x/pr71737.C: New.

From-SVN: r244486

gcc/c-family/ChangeLog

+2017-01-16  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/71737
+	* c-common.c (set_underlying_type): Always set DECL_ORIGINAL_TYPE.
+
 2017-01-12  Martin Sebor  <msebor@redhat.com>
 
 	(-Wformat-overflow): ...to this.

gcc/c-family/c-common.c

@@ -7419,17 +7419,19 @@ set_underlying_type (tree x)
       if (TYPE_NAME (TREE_TYPE (x)) == 0)
 	TYPE_NAME (TREE_TYPE (x)) = x;
     }
-  else if (TREE_TYPE (x) != error_mark_node
-	   && DECL_ORIGINAL_TYPE (x) == NULL_TREE)
+  else if (DECL_ORIGINAL_TYPE (x) == NULL_TREE)
     {
       tree tt = TREE_TYPE (x);
       DECL_ORIGINAL_TYPE (x) = tt;
+      if (tt != error_mark_node)
+	{
 	  tt = build_variant_type_copy (tt);
 	  TYPE_STUB_DECL (tt) = TYPE_STUB_DECL (DECL_ORIGINAL_TYPE (x));
 	  TYPE_NAME (tt) = x;
 	  TREE_USED (tt) = TREE_USED (x);
 	  TREE_TYPE (x) = tt;
 	}
+    }
 }
 
 /* Record the types used by the current global variable declaration

gcc/testsuite/ChangeLog

+2017-01-16  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/71737
+	* g++.dg/cpp0x/pr71737.C: New.
+
 2017-01-16  Eric Botcazou  <ebotcazou@adacore.com>
 
 	* gnat.dg/opt62.adb: New test.

gcc/testsuite/g++.dg/cpp0x/pr71737.C

+// PR c++/78765
+// { dg-do compile { target c++11 } }
+
+template <template <typename ...> class TT>
+struct quote {
+  template <typename ...Ts>
+  using apply = TT<Ts...>;  // { dg-error "pack expansion" }
+};
+
+template <typename>
+using to_int_t = int;
+
+using t = quote<quote<to_int_t>::apply>::apply<int>;