From 8d79f003d366e17bb17a4b0a7aab01fea51ffa71 Mon Sep 17 00:00:00 2001
From: Jason Merrill <jason@redhat.com>
Date: Tue, 30 Jan 2018 14:05:12 -0500
Subject: [PATCH] PR c++/84098 - ICE with lambda in template NSDMI.

	* pt.c (instantiate_class_template_1): Ignore more lambdas.

From-SVN: r257199
---
 gcc/cp/ChangeLog                                |  5 +++++
 gcc/cp/pt.c                                     | 12 ++++++++----
 gcc/testsuite/g++.dg/cpp1z/constexpr-lambda19.C | 13 +++++++++++++
 3 files changed, 26 insertions(+), 4 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/cpp1z/constexpr-lambda19.C

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 973798769a4..536a3e36107 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,8 @@
+2018-01-30  Jason Merrill  <jason@redhat.com>
+
+	PR c++/84098 - ICE with lambda in template NSDMI.
+	* pt.c (instantiate_class_template_1): Ignore more lambdas.
+
 2018-01-29  Jason Merrill  <jason@redhat.com>
 
 	PR c++/68810 - wrong location for reinterpret_cast error.
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 6c5d06b9ebb..9516be893aa 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -10527,6 +10527,11 @@ instantiate_class_template_1 (tree type)
 	{
 	  if (TYPE_P (t))
 	    {
+	      if (LAMBDA_TYPE_P (t))
+		/* A closure type for a lambda in an NSDMI or default argument.
+		   Ignore it; it will be regenerated when needed.  */
+		continue;
+
 	      /* Build new CLASSTYPE_NESTED_UTDS.  */
 
 	      tree newtag;
@@ -10594,11 +10599,10 @@ instantiate_class_template_1 (tree type)
 		  && DECL_OMP_DECLARE_REDUCTION_P (r))
 		cp_check_omp_declare_reduction (r);
 	    }
-	  else if (DECL_CLASS_TEMPLATE_P (t)
+	  else if ((DECL_CLASS_TEMPLATE_P (t) || DECL_IMPLICIT_TYPEDEF_P (t))
 		   && LAMBDA_TYPE_P (TREE_TYPE (t)))
-	    /* A closure type for a lambda in a default argument for a
-	       member template.  Ignore it; it will be instantiated with
-	       the default argument.  */;
+	    /* A closure type for a lambda in an NSDMI or default argument.
+	       Ignore it; it will be regenerated when needed.  */;
 	  else
 	    {
 	      /* Build new TYPE_FIELDS.  */
diff --git a/gcc/testsuite/g++.dg/cpp1z/constexpr-lambda19.C b/gcc/testsuite/g++.dg/cpp1z/constexpr-lambda19.C
new file mode 100644
index 00000000000..a16d31c59eb
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1z/constexpr-lambda19.C
@@ -0,0 +1,13 @@
+// PR c++/84098
+// { dg-options -std=c++17 }
+
+struct A{};
+
+template < typename >
+struct Test{
+    static constexpr auto var = []{};
+};
+
+int main(){
+    (void)Test< A >::var;
+}
-- 
2.30.2