From a41bb2c947782287f983daac7807f0e0e4ef4b65 Mon Sep 17 00:00:00 2001
From: Jason Merrill <jason@redhat.com>
Date: Wed, 8 Oct 2014 17:05:50 -0400
Subject: [PATCH] re PR c++/63405 (ICE in cp_perform_integral_promotions, at
 cp/typeck.c:2084)

	PR c++/63405
	* pt.c (tsubst_pack_expansion): Limit simple expansion to type packs.

From-SVN: r216013
---
 gcc/cp/ChangeLog                         |  3 +++
 gcc/cp/pt.c                              |  8 +++++++-
 gcc/testsuite/g++.dg/cpp0x/variadic162.C | 14 ++++++++++++++
 3 files changed, 24 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/g++.dg/cpp0x/variadic162.C

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 975193d6a12..1f9f4121cd1 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,5 +1,8 @@
 2014-10-08  Jason Merrill  <jason@redhat.com>
 
+	PR c++/63405
+	* pt.c (tsubst_pack_expansion): Limit simple expansion to type packs.
+
 	PR c++/63485
 	* tree.c (build_cplus_array_type): Look for a type with no
 	typedef-name or attributes.
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index d1dddff3ac2..7d380e54b4a 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -9929,7 +9929,13 @@ tsubst_pack_expansion (tree t, tree args, tsubst_flags_t complain,
   /* If the expansion is just T..., return the matching argument pack.  */
   if (!unsubstituted_packs
       && TREE_PURPOSE (packs) == pattern)
-    return ARGUMENT_PACK_ARGS (TREE_VALUE (packs));
+    {
+      tree args = ARGUMENT_PACK_ARGS (TREE_VALUE (packs));
+      if (TREE_CODE (t) == TYPE_PACK_EXPANSION
+	  || pack_expansion_args_count (args))
+	return args;
+      /* Otherwise use the normal path so we get convert_from_reference.  */
+    }
 
   /* We cannot expand this expansion expression, because we don't have
      all of the argument packs we need.  */
diff --git a/gcc/testsuite/g++.dg/cpp0x/variadic162.C b/gcc/testsuite/g++.dg/cpp0x/variadic162.C
new file mode 100644
index 00000000000..9e5386deb47
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/variadic162.C
@@ -0,0 +1,14 @@
+// PR c++/63405
+// { dg-do compile { target c++11 } }
+
+template <typename _Tp> _Tp forward(_Tp);
+template <typename Args> struct Format { Format(int, Args); };
+template <typename... Args> auto format(Args &&... args) -> Format<Args...> {
+  return {0, args...};
+}
+
+template <typename... Args> void msg(Args... args) {
+  format(forward(args)...);
+}
+
+void some_function() { msg('x'); }
-- 
2.30.2