From 842562b4e1bdd7a7f98e6dcf352b86f96a4e0426 Mon Sep 17 00:00:00 2001
From: Jason Merrill <jason@redhat.com>
Date: Thu, 23 Mar 2017 14:23:25 -0400
Subject: [PATCH] PR c++/80150 - ICE with overloaded variadic deduction.

	* pt.c (try_one_overload): Remove asserts.

From-SVN: r246422
---
 gcc/cp/ChangeLog                              |  3 +++
 gcc/cp/pt.c                                   |  7 ++++---
 gcc/testsuite/g++.dg/cpp0x/variadic-unify-3.C | 20 +++++++++++++++++++
 3 files changed, 27 insertions(+), 3 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/cpp0x/variadic-unify-3.C

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 22b7dfae028..73a25f3f3cc 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,5 +1,8 @@
 2017-03-23  Jason Merrill  <jason@redhat.com>
 
+	PR c++/80150 - ICE with overloaded variadic deduction.
+	* pt.c (try_one_overload): Remove asserts.
+
 	PR c++/77563 - missing ambiguous conversion error.
 	* call.c (convert_like_real): Use LOOKUP_IMPLICIT.
 
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index a4bf890dbfb..5259dad72a0 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -19694,9 +19694,10 @@ try_one_overload (tree tparms,
 	     is equivalent to the corresponding explicitly specified argument.
 	     We may have deduced more arguments than were explicitly specified,
 	     and that's OK.  */
-	  gcc_assert (ARGUMENT_PACK_INCOMPLETE_P (oldelt));
-	  gcc_assert (ARGUMENT_PACK_ARGS (oldelt)
-		      == ARGUMENT_PACK_EXPLICIT_ARGS (oldelt));
+
+	  /* We used to assert ARGUMENT_PACK_INCOMPLETE_P (oldelt) here, but
+	     that's wrong if we deduce the same argument pack from multiple
+	     function arguments: it's only incomplete the first time.  */
 
 	  tree explicit_pack = ARGUMENT_PACK_ARGS (oldelt);
 	  tree deduced_pack = ARGUMENT_PACK_ARGS (elt);
diff --git a/gcc/testsuite/g++.dg/cpp0x/variadic-unify-3.C b/gcc/testsuite/g++.dg/cpp0x/variadic-unify-3.C
new file mode 100644
index 00000000000..45f4d636c45
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/variadic-unify-3.C
@@ -0,0 +1,20 @@
+// PR c++/80150
+// { dg-do compile { target c++11 } }
+
+template <typename R, typename... Args>
+bool compare_functions(R(*funcA)(Args...), R(*funcB)(Args...), Args... args) {
+  return false;
+}
+
+int foo(int x) {
+  return x;
+}
+
+float foo(float x) {
+ return x;
+}
+
+int main() {
+  int a = 10;
+  compare_functions<int>(foo, foo, a);
+}
-- 
2.30.2