From 6781e2af709464df449604e222514f2d613e7666 Mon Sep 17 00:00:00 2001
From: Jason Merrill <jason@redhat.com>
Date: Thu, 21 Jul 2016 23:45:54 -0400
Subject: [PATCH] PR c++/69223 - ICE with deduced template return type.

	* semantics.c (apply_deduced_return_type): Call
	complete_type_or_else before building the new RESULT_DECL.

From-SVN: r238624
---
 gcc/cp/ChangeLog                                   |  4 ++++
 gcc/cp/semantics.c                                 |  6 ++++--
 gcc/testsuite/g++.dg/cpp0x/lambda/lambda-deduce3.C | 15 +++++++++++++++
 3 files changed, 23 insertions(+), 2 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/cpp0x/lambda/lambda-deduce3.C

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 603758c..a3cc081 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,5 +1,9 @@
 2016-07-21  Jason Merrill  <jason@redhat.com>
 
+	PR c++/69223
+	* semantics.c (apply_deduced_return_type): Call
+	complete_type_or_else before building the new RESULT_DECL.
+
 	PR c++/71274
 	* decl2.c (maybe_instantiate_decl): Split out from mark_used.
 	(decl_constant_var_p): Use it instead.
diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c
index 19daeff..63063b8 100644
--- a/gcc/cp/semantics.c
+++ b/gcc/cp/semantics.c
@@ -9279,6 +9279,10 @@ apply_deduced_return_type (tree fco, tree return_type)
   if (TREE_TYPE (result) == return_type)
     return;
 
+  if (!processing_template_decl && !VOID_TYPE_P (return_type)
+      && !complete_type_or_else (return_type, NULL_TREE))
+    return;
+
   /* We already have a DECL_RESULT from start_preparsed_function.
      Now we need to redo the work it and allocate_struct_function
      did to reflect the new type.  */
@@ -9294,8 +9298,6 @@ apply_deduced_return_type (tree fco, tree return_type)
 
   if (!processing_template_decl)
     {
-      if (!VOID_TYPE_P (TREE_TYPE (result)))
-	complete_type_or_else (TREE_TYPE (result), NULL_TREE);
       bool aggr = aggregate_value_p (result, fco);
 #ifdef PCC_STATIC_STRUCT_RETURN
       cfun->returns_pcc_struct = aggr;
diff --git a/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-deduce3.C b/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-deduce3.C
new file mode 100644
index 0000000..68ac29c
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-deduce3.C
@@ -0,0 +1,15 @@
+// PR c++/69223
+// { dg-do compile { target c++11 } }
+
+template <class T> struct A
+{
+  T x[20];
+};
+
+int main()
+{
+  auto l = [](const A<int>& i){ return i; };
+  A<int> a;
+
+  l(a);
+}
-- 
2.7.4