File gcc7-pr72764.patch of Package gcc7-testsuite.30293

From cffc4a68d759fdca588cdf9ece998862b76141e6 Mon Sep 17 00:00:00 2001
From: Jason Merrill <jason@redhat.com>
Date: Wed, 28 Jun 2017 17:06:35 -0400
Subject: [PATCH] PR c++/72764 - ICE with invalid template typename.
To: gcc-patches@gcc.gnu.org

	* decl.c (build_typename_type): No longer static.
	* tree.c (strip_typedefs): Use it instead of make_typename_type.

From-SVN: r249760
---
 gcc/cp/cp-tree.h                           |  1 +
 gcc/cp/decl.c                              |  2 +-
 gcc/cp/tree.c                              | 17 ++++++++++-------
 gcc/testsuite/g++.dg/cpp0x/alias-decl-60.C | 16 ++++++++++++++++
 5 files changed, 32 insertions(+), 8 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/cpp0x/alias-decl-60.C

diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index f82b1b6ae10..946a9167992 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -6087,6 +6087,7 @@ extern tree define_label			(location_t, tree);
 extern void check_goto				(tree);
 extern bool check_omp_return			(void);
 extern tree make_typename_type			(tree, tree, enum tag_types, tsubst_flags_t);
+extern tree build_typename_type			(tree, tree, tree, tag_types);
 extern tree make_unbound_class_template		(tree, tree, tree, tsubst_flags_t);
 extern tree build_library_fn_ptr		(const char *, tree, int);
 extern tree build_cp_library_fn_ptr		(const char *, tree, int);
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 93e24fc8984..3d96a3ea0fd 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -3594,7 +3594,7 @@ struct typename_hasher : ggc_ptr_hash<tree_node>
 
 static GTY (()) hash_table<typename_hasher> *typename_htab;
 
-static tree
+tree
 build_typename_type (tree context, tree name, tree fullname,
 		     enum tag_types tag_type)
 {
diff --git a/gcc/cp/tree.c b/gcc/cp/tree.c
index bb17278c611..4535af64dc6 100644
--- a/gcc/cp/tree.c
+++ b/gcc/cp/tree.c
@@ -1503,13 +1503,13 @@ strip_typedefs (tree t, bool *remove_attributes)
       break;
     case TYPENAME_TYPE:
       {
+	bool changed = false;
 	tree fullname = TYPENAME_TYPE_FULLNAME (t);
 	if (TREE_CODE (fullname) == TEMPLATE_ID_EXPR
 	    && TREE_OPERAND (fullname, 1))
 	  {
 	    tree args = TREE_OPERAND (fullname, 1);
 	    tree new_args = copy_node (args);
-	    bool changed = false;
 	    for (int i = 0; i < TREE_VEC_LENGTH (args); ++i)
 	      {
 		tree arg = TREE_VEC_ELT (args, i);
@@ -1533,12 +1533,15 @@ strip_typedefs (tree t, bool *remove_attributes)
 	    else
 	      ggc_free (new_args);
 	  }
-	result = make_typename_type (strip_typedefs (TYPE_CONTEXT (t),
-						     remove_attributes),
-				     fullname, typename_type, tf_none);
-	/* Handle 'typedef typename A::N N;'  */
-	if (typedef_variant_p (result))
-	  result = TYPE_MAIN_VARIANT (DECL_ORIGINAL_TYPE (TYPE_NAME (result)));
+	tree ctx = strip_typedefs (TYPE_CONTEXT (t), remove_attributes);
+	if (!changed && ctx == TYPE_CONTEXT (t) && !typedef_variant_p (t))
+	  return t;
+	tree name = fullname;
+	if (TREE_CODE (fullname) == TEMPLATE_ID_EXPR)
+	  name = TREE_OPERAND (fullname, 0);
+	/* Use build_typename_type rather than make_typename_type because we
+	   don't want to resolve it here, just strip typedefs.  */
+	result = build_typename_type (ctx, name, fullname, typename_type);
       }
       break;
     case DECLTYPE_TYPE:
diff --git a/gcc/testsuite/g++.dg/cpp0x/alias-decl-60.C b/gcc/testsuite/g++.dg/cpp0x/alias-decl-60.C
new file mode 100644
index 00000000000..6bf9b7b1666
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/alias-decl-60.C
@@ -0,0 +1,16 @@
+// PR c++/72764
+// { dg-do compile { target c++11 } }
+
+template < typename > struct A;
+template < typename > struct B {};
+
+template < typename T >
+using C = typename A < T >::template D < T >;
+
+template < typename T > struct A
+{ 
+  // should be: template < typename > struct D : B < C < T > > {};
+  struct D : B < C < T > > {};	// { dg-error "not a class template" }
+};
+
+A < int >::D a;			// { dg-message "required" }
-- 
2.35.3