re PR c++/63362 (The c++11 triviality-traits need front-end help)

PR c++/63362
	* class.c (type_has_non_user_provided_default_constructor): Rename
	from type_has_user_provided_default_constructor, reverse sense.
	(default_init_uninitialized_part, explain_non_literal_class): Adjust.
	(check_bases_and_members): Set TYPE_HAS_COMPLEX_DFLT.
	* call.c (build_new_method_call_1): Adjust.
	* cp-tree.h: Adjust.
	* decl.c (grok_special_member_properties): Don't set
	TYPE_HAS_COMPLEX_DFLT.
	* init.c (build_value_init_noctor): Don't use
	type_has_user_provided_default_constructor.

From-SVN: r215771

gcc/cp/ChangeLog

@@ -1,3 +1,17 @@
+2014-10-01  Jason Merrill  <jason@redhat.com>
+
+	PR c++/63362
+	* class.c (type_has_non_user_provided_default_constructor): Rename
+	from type_has_user_provided_default_constructor, reverse sense.
+	(default_init_uninitialized_part, explain_non_literal_class): Adjust.
+	(check_bases_and_members): Set TYPE_HAS_COMPLEX_DFLT.
+	* call.c (build_new_method_call_1): Adjust.
+	* cp-tree.h: Adjust.
+	* decl.c (grok_special_member_properties): Don't set
+	TYPE_HAS_COMPLEX_DFLT.
+	* init.c (build_value_init_noctor): Don't use
+	type_has_user_provided_default_constructor.
+
 2014-09-30  Jason Merrill  <jason@redhat.com>
 
 	* cp-tree.h (cp_trait_kind): Add CPTK_IS_TRIVIALLY_ASSIGNABLE and

gcc/cp/call.c

@@ -7941,7 +7941,7 @@ build_new_method_call_1 (tree instance, tree fns, vec<tree, va_gc> **args,
 	  && TYPE_HAS_DEFAULT_CONSTRUCTOR (basetype)
 	  /* For a user-provided default constructor, use the normal
 	     mechanisms so that protected access works.  */
-	  && !type_has_user_provided_default_constructor (basetype)
+	  && type_has_non_user_provided_default_constructor (basetype)
 	  && !processing_template_decl)
 	init = build_value_init (basetype, complain);
 

gcc/cp/class.c

@@ -4937,21 +4937,25 @@ type_has_user_provided_constructor (tree t)
   return false;
 }
 
-/* Returns true iff class T has a user-provided default constructor.  */
+/* Returns true iff class T has a non-user-provided (i.e. implicitly
+   declared or explicitly defaulted in the class body) default
+   constructor.  */
 
 bool
-type_has_user_provided_default_constructor (tree t)
+type_has_non_user_provided_default_constructor (tree t)
 {
   tree fns;
 
-  if (!TYPE_HAS_USER_CONSTRUCTOR (t))
+  if (!TYPE_HAS_DEFAULT_CONSTRUCTOR (t))
     return false;
+  if (CLASSTYPE_LAZY_DEFAULT_CTOR (t))
+    return true;
 
   for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns))
     {
       tree fn = OVL_CURRENT (fns);
       if (TREE_CODE (fn) == FUNCTION_DECL
-	  && user_provided_p (fn)
+	  && !user_provided_p (fn)
 	  && sufficient_parms_p (FUNCTION_FIRST_USER_PARMTYPE (fn)))
 	return true;
     }
@@ -5009,7 +5013,7 @@ default_init_uninitialized_part (tree type)
   type = strip_array_types (type);
   if (!CLASS_TYPE_P (type))
     return type;
-  if (type_has_user_provided_default_constructor (type))
+  if (!type_has_non_user_provided_default_constructor (type))
     return NULL_TREE;
   for (binfo = TYPE_BINFO (type), i = 0;
        BINFO_BASE_ITERATE (binfo, i, t); ++i)
@@ -5383,8 +5387,7 @@ explain_non_literal_class (tree t)
       inform (0, "  %q+T is not an aggregate, does not have a trivial "
 	      "default constructor, and has no constexpr constructor that "
 	      "is not a copy or move constructor", t);
-      if (TYPE_HAS_DEFAULT_CONSTRUCTOR (t)
-	  && !type_has_user_provided_default_constructor (t))
+      if (type_has_non_user_provided_default_constructor (t))
 	{
 	  /* Note that we can't simply call locate_ctor because when the
 	     constructor is deleted it just returns NULL_TREE.  */
@@ -5528,6 +5531,13 @@ check_bases_and_members (tree t)
   TYPE_HAS_COMPLEX_MOVE_ASSIGN (t) |= TYPE_CONTAINS_VPTR_P (t);
   TYPE_HAS_COMPLEX_DFLT (t) |= TYPE_CONTAINS_VPTR_P (t);
 
+  /* If the only explicitly declared default constructor is user-provided,
+     set TYPE_HAS_COMPLEX_DFLT.  */
+  if (!TYPE_HAS_COMPLEX_DFLT (t)
+      && TYPE_HAS_DEFAULT_CONSTRUCTOR (t)
+      && !type_has_non_user_provided_default_constructor (t))
+    TYPE_HAS_COMPLEX_DFLT (t) = true;
+
   /* Warn if a public base of a polymorphic type has an accessible
      non-virtual destructor.  It is only now that we know the class is
      polymorphic.  Although a polymorphic base will have a already

gcc/cp/cp-tree.h

@@ -3484,7 +3484,7 @@ more_aggr_init_expr_args_p (const aggr_init_expr_arg_iterator *iter)
 /* Nonzero if there is a non-trivial X::X(X&&) for this class.  */
 #define TYPE_HAS_COMPLEX_MOVE_CTOR(NODE) (LANG_TYPE_CLASS_CHECK (NODE)->has_complex_move_ctor)
 
-/* Nonzero if there is a non-trivial default constructor for this class.  */
+/* Nonzero if there is no trivial default constructor for this class.  */
 #define TYPE_HAS_COMPLEX_DFLT(NODE) (LANG_TYPE_CLASS_CHECK (NODE)->has_complex_dflt)
 
 /* Nonzero if TYPE has a trivial destructor.  From [class.dtor]:
@@ -5195,7 +5195,7 @@ extern bool type_has_user_nondefault_constructor (tree);
 extern tree in_class_defaulted_default_constructor (tree);
 extern bool user_provided_p			(tree);
 extern bool type_has_user_provided_constructor  (tree);
-extern bool type_has_user_provided_default_constructor (tree);
+extern bool type_has_non_user_provided_default_constructor (tree);
 extern bool vbase_has_user_provided_move_assign (tree);
 extern tree default_init_uninitialized_part (tree);
 extern bool trivial_default_constructor_is_constexpr (tree);

gcc/cp/decl.c

@@ -11476,11 +11476,7 @@ grok_special_member_properties (tree decl)
 	    TYPE_HAS_CONST_COPY_CTOR (class_type) = 1;
 	}
       else if (sufficient_parms_p (FUNCTION_FIRST_USER_PARMTYPE (decl)))
-	{
-	  TYPE_HAS_DEFAULT_CONSTRUCTOR (class_type) = 1;
-	  if (user_provided_p (decl))
-	    TYPE_HAS_COMPLEX_DFLT (class_type) = 1;
-	}
+	TYPE_HAS_DEFAULT_CONSTRUCTOR (class_type) = 1;
       else if (move_fn_p (decl) && user_provided_p (decl))
 	TYPE_HAS_COMPLEX_MOVE_CTOR (class_type) = 1;
       else if (is_list_ctor (decl))

gcc/cp/init.c

@@ -343,13 +343,17 @@ build_value_init (tree type, tsubst_flags_t complain)
   if (CLASS_TYPE_P (type)
       && type_build_ctor_call (type))
     {
-      tree ctor = build_aggr_init_expr
-	(type,
+      tree ctor =
 	 build_special_member_call (NULL_TREE, complete_ctor_identifier,
 				    NULL, type, LOOKUP_NORMAL,
-				    complain));
-      if (ctor == error_mark_node
-	  || type_has_user_provided_default_constructor (type))
+				    complain);
+      if (ctor == error_mark_node)
+	return ctor;
+      tree fn = NULL_TREE;
+      if (TREE_CODE (ctor) == CALL_EXPR)
+	fn = get_callee_fndecl (ctor);
+      ctor = build_aggr_init_expr (type, ctor);
+      if (fn && user_provided_p (fn))
 	return ctor;
       else if (TYPE_HAS_COMPLEX_DFLT (type))
 	{

gcc/testsuite/g++.dg/ext/is_trivially_constructible2.C

@@ -0,0 +1,15 @@
+// { dg-do compile { target c++11 } }
+
+struct X {
+  X() = default;
+  template<class... U> X(U...);
+};
+
+struct Y {
+  template<class... U> Y(U...);
+};
+
+#define SA(X) static_assert((X),#X)
+
+SA(__is_trivially_constructible(X));
+SA(!__is_trivially_constructible(Y));