PR c++/70979 - literal class and closure types

	* class.c (finalize_literal_type_property): Handle closures
	specifically.
	(explain_non_literal_class): Likewise.

From-SVN: r247814

gcc/cp/ChangeLog

 2017-05-09  Jason Merrill  <jason@redhat.com>
 
+	PR c++/70979 - literal class and closure types
+	* class.c (finalize_literal_type_property): Handle closures
+	specifically.
+	(explain_non_literal_class): Likewise.
+
 	PR c++/66297, DR 1684 - literal class and constexpr member fns
 	* constexpr.c (is_valid_constexpr_fn): Only complain about
 	non-literal enclosing class in C++11.

gcc/cp/class.c

@@ -5752,6 +5752,8 @@ finalize_literal_type_property (tree t)
   if (cxx_dialect < cxx11
       || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t))
     CLASSTYPE_LITERAL_P (t) = false;
+  else if (CLASSTYPE_LITERAL_P (t) && LAMBDA_TYPE_P (t))
+    CLASSTYPE_LITERAL_P (t) = (cxx_dialect >= cxx1z);
   else if (CLASSTYPE_LITERAL_P (t) && !TYPE_HAS_TRIVIAL_DFLT (t)
 	   && CLASSTYPE_NON_AGGREGATE (t)
 	   && !TYPE_HAS_CONSTEXPR_CTOR (t))
@@ -5794,10 +5796,14 @@ explain_non_literal_class (tree t)
     return;
 
   inform (0, "%q+T is not literal because:", t);
-  if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t))
+  if (cxx_dialect < cxx1z && LAMBDA_TYPE_P (t))
+    inform (0, "  %qT is a closure type, which is only literal in "
+	    "C++1z and later", t);
+  else if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t))
     inform (0, "  %q+T has a non-trivial destructor", t);
   else if (CLASSTYPE_NON_AGGREGATE (t)
 	   && !TYPE_HAS_TRIVIAL_DFLT (t)
+	   && !LAMBDA_TYPE_P (t)
 	   && !TYPE_HAS_CONSTEXPR_CTOR (t))
     {
       inform (0, "  %q+T is not an aggregate, does not have a trivial "

gcc/testsuite/g++.dg/cpp1z/constexpr-lambda15.C

 // PR c++/79461
-// { dg-options -std=c++1z }
+// { dg-do compile { target c++14 } }
 
 struct S {
   constexpr S(int i) {
-    auto f = [i]{};
+    auto f = [i]{};		// { dg-error "literal" "" { target c++14_only } }
   }
 };
 int main() {}