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

/cp
2017-02-10  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/71737
	* pt.c (tsubst_decl): Don't try to preserve a typedef that names
	an error_mark_node as type.

/testsuite
2017-02-10  Paolo Carlini  <paolo.carlini@oracle.com>

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

From-SVN: r245327

gcc/cp/ChangeLog

+2017-02-10  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/71737
+	* pt.c (tsubst_decl): Don't try to preserve a typedef that names
+	an error_mark_node as type.
+
 2017-02-09  Jakub Jelinek  <jakub@redhat.com>
 	    Jason Merrill  <jason@redhat.com>
 

gcc/cp/pt.c

@@ -12877,11 +12877,11 @@ tsubst_decl (tree t, tree args, tsubst_flags_t complain)
 					args, complain, in_decl);
 
 	/* Preserve a typedef that names a type.  */
-	if (is_typedef_decl (r))
+	if (is_typedef_decl (r) && type != error_mark_node)
 	  {
 	    DECL_ORIGINAL_TYPE (r) = NULL_TREE;
 	    set_underlying_type (r);
-	    if (TYPE_DECL_ALIAS_P (r) && type != error_mark_node)
+	    if (TYPE_DECL_ALIAS_P (r))
 	      /* An alias template specialization can be dependent
 		 even if its underlying type is not.  */
 	      TYPE_DEPENDENT_P_VALID (TREE_TYPE (r)) = false;

gcc/testsuite/ChangeLog

+2017-02-10  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/71737
+	* g++.dg/cpp0x/pr71737.C: New.
+
 2017-02-10  Prasad Ghangal  <prasad.ghangal@gmail.com>
-	Richard Biener  <rguenther@suse.de>
+	    Richard Biener  <rguenther@suse.de>
 
 	* gcc.dg/gimplefe-error-1.c: New testcase.
 	* gcc.dg/gimplefe-error-2.c: New testcase.

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>;