re PR c++/50500 ([C++0x] [DR 1082] move constructor should cause copy constructor to be deleted, but still declared)

	PR c++/50500
	DR 1082
	* class.c (type_has_user_declared_move_constructor): New.
	(type_has_user_declared_move_assign): New.
	(add_implicitly_declared_members): Add lazy copy ops
	even if there's a move.
	* method.c (lazily_declare_fn): Delete implicit copies
	if there's a move.
	(maybe_explain_implicit_delete): Explain this.  Use inform rather
	than error.
	* cp-tree.h: Declare new fns.

From-SVN: r180159

4 files changed, 93 insertions, 9 deletions

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 407c684..ad46384 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,17 @@
+2011-10-18  Jason Merrill  <jason@redhat.com>
+
+	PR c++/50500
+	DR 1082
+	* class.c (type_has_user_declared_move_constructor): New.
+	(type_has_user_declared_move_assign): New.
+	(add_implicitly_declared_members): Add lazy copy ops
+	even if there's a move.
+	* method.c (lazily_declare_fn): Delete implicit copies
+	if there's a move.
+	(maybe_explain_implicit_delete): Explain this.  Use inform rather
+	than error.
+	* cp-tree.h: Declare new fns.
+
 2011-10-18   Diego Novillo  <dnovillo@google.com>
 
 	* parser.c: Remove ENABLE_CHECKING markers around debugging
diff --git a/gcc/cp/class.c b/gcc/cp/class.c
index 6185054..c8efc7e 100644
--- a/gcc/cp/class.c
+++ b/gcc/cp/class.c
@@ -2736,13 +2736,12 @@ add_implicitly_declared_members (tree t,
 
      If a class definition does not explicitly declare a copy
      constructor, one is declared implicitly.  */
-  if (! TYPE_HAS_COPY_CTOR (t) && ! TYPE_FOR_JAVA (t)
-      && !type_has_move_constructor (t))
+  if (! TYPE_HAS_COPY_CTOR (t) && ! TYPE_FOR_JAVA (t))
     {
       TYPE_HAS_COPY_CTOR (t) = 1;
       TYPE_HAS_CONST_COPY_CTOR (t) = !cant_have_const_cctor;
       CLASSTYPE_LAZY_COPY_CTOR (t) = 1;
-      if (cxx_dialect >= cxx0x)
+      if (cxx_dialect >= cxx0x && !type_has_move_constructor (t))
 	CLASSTYPE_LAZY_MOVE_CTOR (t) = 1;
     }
 
@@ -2750,13 +2749,12 @@ add_implicitly_declared_members (tree t,
      when it is needed.  For now, just record whether or not the type
      of the parameter to the assignment operator will be a const or
      non-const reference.  */
-  if (!TYPE_HAS_COPY_ASSIGN (t) && !TYPE_FOR_JAVA (t)
-      && !type_has_move_assign (t))
+  if (!TYPE_HAS_COPY_ASSIGN (t) && !TYPE_FOR_JAVA (t))
     {
       TYPE_HAS_COPY_ASSIGN (t) = 1;
       TYPE_HAS_CONST_COPY_ASSIGN (t) = !cant_have_const_assignment;
       CLASSTYPE_LAZY_COPY_ASSIGN (t) = 1;
-      if (cxx_dialect >= cxx0x)
+      if (cxx_dialect >= cxx0x && !type_has_move_assign (t))
 	CLASSTYPE_LAZY_MOVE_ASSIGN (t) = 1;
     }
 
@@ -4495,6 +4493,54 @@ type_has_move_assign (tree t)
   return false;
 }
 
+/* Returns true iff class T has a move constructor that was explicitly
+   declared in the class body.  Note that this is different from
+   "user-provided", which doesn't include functions that are defaulted in
+   the class.  */
+
+bool
+type_has_user_declared_move_constructor (tree t)
+{
+  tree fns;
+
+  if (CLASSTYPE_LAZY_MOVE_CTOR (t))
+    return false;
+
+  if (!CLASSTYPE_METHOD_VEC (t))
+    return false;
+
+  for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns))
+    {
+      tree fn = OVL_CURRENT (fns);
+      if (move_fn_p (fn) && !DECL_ARTIFICIAL (fn))
+	return true;
+    }
+
+  return false;
+}
+
+/* Returns true iff class T has a move assignment operator that was
+   explicitly declared in the class body.  */
+
+bool
+type_has_user_declared_move_assign (tree t)
+{
+  tree fns;
+
+  if (CLASSTYPE_LAZY_MOVE_ASSIGN (t))
+    return false;
+
+  for (fns = lookup_fnfields_slot (t, ansi_assopname (NOP_EXPR));
+       fns; fns = OVL_NEXT (fns))
+    {
+      tree fn = OVL_CURRENT (fns);
+      if (move_fn_p (fn) && !DECL_ARTIFICIAL (fn))
+	return true;
+    }
+
+  return false;
+}
+
 /* Nonzero if we need to build up a constructor call when initializing an
    object of this class, either because it has a user-provided constructor
    or because it doesn't have a default constructor (so we need to give an
diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index bda18d9..d0e874b 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -4870,6 +4870,8 @@ extern bool type_has_constexpr_default_constructor (tree);
 extern bool type_has_virtual_destructor		(tree);
 extern bool type_has_move_constructor		(tree);
 extern bool type_has_move_assign		(tree);
+extern bool type_has_user_declared_move_constructor (tree);
+extern bool type_has_user_declared_move_assign(tree);
 extern bool type_build_ctor_call		(tree);
 extern void explain_non_literal_class		(tree);
 extern void defaulted_late_check		(tree);
diff --git a/gcc/cp/method.c b/gcc/cp/method.c
index 0718f47..bb58312 100644
--- a/gcc/cp/method.c
+++ b/gcc/cp/method.c
@@ -1375,18 +1375,31 @@ maybe_explain_implicit_delete (tree decl)
 	{
 	  informed = true;
 	  if (sfk == sfk_constructor)
-	    error ("a lambda closure type has a deleted default constructor");
+	    inform (DECL_SOURCE_LOCATION (decl),
+		    "a lambda closure type has a deleted default constructor");
 	  else if (sfk == sfk_copy_assignment)
-	    error ("a lambda closure type has a deleted copy assignment operator");
+	    inform (DECL_SOURCE_LOCATION (decl),
+		    "a lambda closure type has a deleted copy assignment operator");
 	  else
 	    informed = false;
 	}
+      else if (DECL_ARTIFICIAL (decl)
+	       && (sfk == sfk_copy_assignment
+		   || sfk == sfk_copy_constructor)
+	       && (type_has_user_declared_move_constructor (ctype)
+		   || type_has_user_declared_move_assign (ctype)))
+	{
+	  inform (0, "%q+#D is implicitly declared as deleted because %qT "
+		 "declares a move constructor or move assignment operator",
+		 decl, ctype);
+	  informed = true;
+	}
       if (!informed)
 	{
 	  tree parm_type = TREE_VALUE (FUNCTION_FIRST_USER_PARMTYPE (decl));
 	  bool const_p = CP_TYPE_CONST_P (non_reference (parm_type));
 	  tree scope = push_scope (ctype);
-	  error ("%qD is implicitly deleted because the default "
+	  inform (0, "%q+#D is implicitly deleted because the default "
 		 "definition would be ill-formed:", decl);
 	  pop_scope (scope);
 	  synthesized_method_walk (ctype, sfk, const_p,
@@ -1743,6 +1756,15 @@ lazily_declare_fn (special_function_kind sfk, tree type)
   /* Declare the function.  */
   fn = implicitly_declare_fn (sfk, type, const_p);
 
+  /* [class.copy]/8 If the class definition declares a move constructor or
+     move assignment operator, the implicitly declared copy constructor is
+     defined as deleted.... */
+  if ((sfk == sfk_copy_assignment
+       || sfk == sfk_copy_constructor)
+      && (type_has_user_declared_move_constructor (type)
+	  || type_has_user_declared_move_assign (type)))
+    DECL_DELETED_FN (fn) = true;
+
   /* For move variants, rather than declare them as deleted we just
      don't declare them at all.  */
   if (DECL_DELETED_FN (fn)