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

@@ -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.

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;

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);
+}