From daaa6fcc70ffe66bd56f5819ad4ee78fecd54bb6 Mon Sep 17 00:00:00 2001
From: Jason Merrill <jason@redhat.com>
Date: Fri, 19 Jul 2019 03:29:15 -0400
Subject: [PATCH] PR c++/90101 - dependent class non-type parameter.

We shouldn't complain that a dependent type is incomplete.

	* pt.c (invalid_nontype_parm_type_p): Check for dependent class type.

From-SVN: r273592
---
 gcc/cp/ChangeLog                             |  5 +++++
 gcc/cp/pt.c                                  |  2 ++
 gcc/testsuite/g++.dg/cpp2a/nontype-class21.C | 10 ++++++++++
 gcc/testsuite/g++.dg/cpp2a/nontype-class22.C | 21 ++++++++++++++++++++
 4 files changed, 38 insertions(+)
 create mode 100644 gcc/testsuite/g++.dg/cpp2a/nontype-class21.C
 create mode 100644 gcc/testsuite/g++.dg/cpp2a/nontype-class22.C

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index cef36b2d1b2..c1fc980e287 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,8 @@
+2019-07-19  Jason Merrill  <jason@redhat.com>
+
+	PR c++/90101 - dependent class non-type parameter.
+	* pt.c (invalid_nontype_parm_type_p): Check for dependent class type.
+
 2019-07-18  Jason Merrill  <jason@redhat.com>
 
 	PR c++/90098 - partial specialization and class non-type parms.
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 53aaad1800a..e433413827a 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -25228,6 +25228,8 @@ invalid_nontype_parm_type_p (tree type, tsubst_flags_t complain)
 		 "with %<-std=c++2a%> or %<-std=gnu++2a%>");
 	  return true;
 	}
+      if (dependent_type_p (type))
+	return false;
       if (!complete_type_or_else (type, NULL_TREE))
 	return true;
       if (!literal_type_p (type))
diff --git a/gcc/testsuite/g++.dg/cpp2a/nontype-class21.C b/gcc/testsuite/g++.dg/cpp2a/nontype-class21.C
new file mode 100644
index 00000000000..c58fe05b9dd
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp2a/nontype-class21.C
@@ -0,0 +1,10 @@
+// PR c++/90101
+// { dg-do compile { target c++2a } }
+
+template<int N>
+struct A{};
+
+template<int N, A<N>>
+struct B {};
+
+B<2,A<2>{}> b;
diff --git a/gcc/testsuite/g++.dg/cpp2a/nontype-class22.C b/gcc/testsuite/g++.dg/cpp2a/nontype-class22.C
new file mode 100644
index 00000000000..026855f0bc6
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp2a/nontype-class22.C
@@ -0,0 +1,21 @@
+// PR c++/90100
+// { dg-do compile { target c++2a } }
+
+template<typename T>
+inline constexpr bool is_nontype_list = false;
+
+template<template<auto...> typename T, auto... NonTypes>
+inline constexpr bool is_nontype_list<T<NonTypes...>> = true;
+
+// works
+template<auto...>
+struct A {};
+
+static_assert(is_nontype_list<A<1, 2, 3>>);
+
+// fails
+struct X {
+    int v;
+};
+
+static_assert(is_nontype_list<A<X{1}, X{2}, X{3}>>);
-- 
2.30.2