re PR c++/30111 (Value-initialization of POD base class doesn't initialize members)

PR c++/30111
        * init.c (build_value_init_noctor): Split out from...
        (build_value_init): ...here.
        (expand_aggr_init_1): Handle value-initialization.
        * cp-tree.h: Add declaration.
        * class.c (type_has_user_provided_constructor):
        Handle non-class arguments.

From-SVN: r144112

gcc/cp/ChangeLog

@@ -1,3 +1,13 @@
+2009-02-11  Jason Merrill  <jason@redhat.com>
+
+	PR c++/30111
+	* init.c (build_value_init_noctor): Split out from...
+	(build_value_init): ...here.
+	(expand_aggr_init_1): Handle value-initialization.
+	* cp-tree.h: Add declaration.
+	* class.c (type_has_user_provided_constructor): 
+	Handle non-class arguments.
+
 2009-02-10  Jason Merrill  <jason@redhat.com>
 
 	PR c++/38649

gcc/cp/class.c

@@ -4090,6 +4090,9 @@ type_has_user_provided_constructor (tree t)
 {
   tree fns;
 
+  if (!CLASS_TYPE_P (t))
+    return false;
+
   if (!TYPE_HAS_USER_CONSTRUCTOR (t))
     return false;
 

gcc/cp/cp-tree.h

@@ -4476,6 +4476,7 @@ extern int is_class_type			(tree, int);
 extern tree get_type_value			(tree);
 extern tree build_zero_init			(tree, tree, bool);
 extern tree build_value_init			(tree);
+extern tree build_value_init_noctor		(tree);
 extern tree build_offset_ref			(tree, tree, bool);
 extern tree build_new				(tree, tree, tree, tree, int,
                                                  tsubst_flags_t);

gcc/cp/init.c

@@ -318,7 +318,21 @@ build_value_init (tree type)
 	  AGGR_INIT_ZERO_FIRST (ctor) = 1;
 	  return ctor;
 	}
-      else if (TREE_CODE (type) != UNION_TYPE)
+    }
+  return build_value_init_noctor (type);
+}
+
+/* Like build_value_init, but don't call the constructor for TYPE.  Used
+   for base initializers.  */
+
+tree
+build_value_init_noctor (tree type)
+{
+  if (CLASS_TYPE_P (type))
+    {
+      gcc_assert (!TYPE_NEEDS_CONSTRUCTING (type));
+	
+      if (TREE_CODE (type) != UNION_TYPE)
 	{
 	  tree field;
 	  VEC(constructor_elt,gc) *v = NULL;
@@ -800,11 +814,6 @@ emit_mem_initializers (tree mem_inits)
 		 "copy constructor",
 		 current_function_decl, BINFO_TYPE (subobject));
 
-      /* If an explicit -- but empty -- initializer list was present,
-	 treat it just like default initialization at this point.  */
-      if (arguments == void_type_node)
-	arguments = NULL_TREE;
-
       /* Initialize the base.  */
       if (BINFO_VIRTUAL_P (subobject))
 	construct_virtual_base (subobject, arguments);
@@ -1385,6 +1394,33 @@ expand_aggr_init_1 (tree binfo, tree true_exp, tree exp, tree init, int flags,
       return;
     }
 
+  /* If an explicit -- but empty -- initializer list was present,
+     that's value-initialization.  */
+  if (init == void_type_node)
+    {
+      /* If there's a user-provided constructor, we just call that.  */
+      if (type_has_user_provided_constructor (type))
+	/* Fall through.  */;
+      /* If there isn't, but we still need to call the constructor,
+	 zero out the object first.  */
+      else if (TYPE_NEEDS_CONSTRUCTING (type))
+	{
+	  init = build_zero_init (type, NULL_TREE, /*static_storage_p=*/false);
+	  init = build2 (INIT_EXPR, type, exp, init);
+	  finish_expr_stmt (init);
+	  /* And then call the constructor.  */
+	}
+      /* If we don't need to mess with the constructor at all,
+	 then just zero out the object and we're done.  */
+      else
+	{
+	  init = build2 (INIT_EXPR, type, exp, build_value_init_noctor (type));
+	  finish_expr_stmt (init);
+	  return;
+	}
+      init = NULL_TREE;
+    }
+
   /* We know that expand_default_init can handle everything we want
      at this point.  */
   expand_default_init (binfo, true_exp, exp, init, flags, complain);

gcc/testsuite/ChangeLog

@@ -1,3 +1,8 @@
+2009-02-11  Jason Merrill  <jason@redhat.com>
+
+	PR c++/30111
+	* g++.dg/init/value7.C: New test.
+
 2009-02-11  Paolo Bonzini  <bonzini@gnu.org>
 
 	* gcc.target/i386/pr38824.c: New testcase.

gcc/testsuite/g++.dg/init/value7.C

@@ -0,0 +1,17 @@
+// PR c++/30111
+// { dg-do run }
+
+struct pod {
+  int i;
+};
+
+struct inherit : pod {
+  inherit() : pod() {}
+};
+
+int main()
+{
+  inherit i;
+  return i.i != 0;
+}
+