re PR c++/77338 (ICE on invalid C++11 code on x86_64-linux-gnu: Segmentation fault)

	PR c++/77338
	* constexpr.c (cxx_eval_constant_expression) <case PARM_DECL>: Only
	call is_really_empty_class on complete types.

	* g++.dg/cpp0x/decltype-77338.C: New test.

From-SVN: r240196

gcc/cp/ChangeLog

 2016-09-16  Jakub Jelinek  <jakub@redhat.com>
 
+	PR c++/77338
+	* constexpr.c (cxx_eval_constant_expression) <case PARM_DECL>: Only
+	call is_really_empty_class on complete types.
+
 	PR c++/77375
 	* class.c (check_bases): Set CLASSTYPE_HAS_MUTABLE if any
 	TYPE_HAS_MUTABLE_P for any bases.

gcc/cp/constexpr.c

@@ -3744,7 +3744,8 @@ cxx_eval_constant_expression (const constexpr_ctx *ctx, tree t,
 	/* Defer in case this is only used for its type.  */;
       else if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
 	/* Defer, there's no lvalue->rvalue conversion.  */;
-      else if (is_really_empty_class (TREE_TYPE (t)))
+      else if (COMPLETE_TYPE_P (TREE_TYPE (t))
+	       && is_really_empty_class (TREE_TYPE (t)))
 	{
 	  /* If the class is empty, we aren't actually loading anything.  */
 	  r = build_constructor (TREE_TYPE (t), NULL);

gcc/testsuite/ChangeLog

 2016-09-16  Jakub Jelinek  <jakub@redhat.com>
 
+	PR c++/77338
+	* g++.dg/cpp0x/decltype-77338.C: New test.
+
 	PR c++/77375
 	* g++.dg/cpp0x/mutable1.C: New test.
 

gcc/testsuite/g++.dg/cpp0x/decltype-77338.C

+// PR c++/77338
+// { dg-do compile { target c++11 } }
+
+struct S;
+
+template <typename>
+auto f (S s) -> decltype (s (s));	// { dg-error "no match for call to" }