From 7363fb1a2aad74d5edca742efff4828f6d4c6479 Mon Sep 17 00:00:00 2001
From: jason <jason@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Mon, 19 Nov 2012 14:05:59 +0000
Subject: [PATCH] 	* class.c (one_inheriting_sig): Don't inherit base
 copy ctors.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@193623 138bc75d-0d04-0410-961f-82ee72b054a4
---
 gcc/cp/ChangeLog                        |  2 ++
 gcc/cp/class.c                          | 18 +++++++++++-------
 gcc/testsuite/g++.dg/cpp0x/inh-ctor15.C | 15 +++++++++++++++
 3 files changed, 28 insertions(+), 7 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/cpp0x/inh-ctor15.C

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 088959f7f46..06eec9584ec 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,5 +1,7 @@
 2012-11-19  Jason Merrill  <jason@redhat.com>
 
+	* class.c (one_inheriting_sig): Don't inherit base copy ctors.
+
 	PR c++/55262
 	* method.c (implicitly_declare_fn): Set DECL_PARM_INDEX on
 	the parms of an inheriting ctor.
diff --git a/gcc/cp/class.c b/gcc/cp/class.c
index 04f9df5a23a..da511e2aad2 100644
--- a/gcc/cp/class.c
+++ b/gcc/cp/class.c
@@ -2886,15 +2886,19 @@ static void
 one_inheriting_sig (tree t, tree ctor, tree *parms, int nparms)
 {
   /* We don't declare an inheriting ctor that would be a default,
-     copy or move ctor.  */
-  if (nparms == 0
-      || (nparms == 1
-	  && TREE_CODE (parms[0]) == REFERENCE_TYPE
-	  && TYPE_MAIN_VARIANT (TREE_TYPE (parms[0])) == t))
+     copy or move ctor for derived or base.  */
+  if (nparms == 0)
     return;
-  int i;
+  if (nparms == 1
+      && TREE_CODE (parms[0]) == REFERENCE_TYPE)
+    {
+      tree parm = TYPE_MAIN_VARIANT (TREE_TYPE (parms[0]));
+      if (parm == t || parm == DECL_CONTEXT (ctor))
+	return;
+    }
+
   tree parmlist = void_list_node;
-  for (i = nparms - 1; i >= 0; i--)
+  for (int i = nparms - 1; i >= 0; i--)
     parmlist = tree_cons (NULL_TREE, parms[i], parmlist);
   tree fn = implicitly_declare_fn (sfk_inheriting_constructor,
 				   t, false, ctor, parmlist);
diff --git a/gcc/testsuite/g++.dg/cpp0x/inh-ctor15.C b/gcc/testsuite/g++.dg/cpp0x/inh-ctor15.C
new file mode 100644
index 00000000000..cc105581080
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/inh-ctor15.C
@@ -0,0 +1,15 @@
+// Discussions on the core reflector indicate that not inheriting base copy
+// constructors was a deliberate choice.
+
+// { dg-options -std=c++11 }
+
+struct A { A(int); };
+struct B: public A
+{
+  using A::A;
+};
+
+A a (42);
+
+B b1 (24);			// inherited
+B b2 (a);			// not inherited { dg-error "no match" }
-- 
2.11.4.GIT