fix libstdc++/56170

diff --git a/libstdc++-v3/include/ext/debug_allocator.h b/libstdc++-v3/include/ext/debug_allocator.h
index 8190d2a..9bb73f0 100644
--- a/libstdc++-v3/include/ext/debug_allocator.h
+++ b/libstdc++-v3/include/ext/debug_allocator.h
@@ -43,6 +43,8 @@ 
 #define _DEBUG_ALLOCATOR_H 1
 
 #include <stdexcept>
+#include <bits/functexcept.h>
+#include <ext/alloc_traits.h>
 
 namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
 {
@@ -51,24 +53,35 @@  _GLIBCXX_BEGIN_NAMESPACE_VERSION
   using std::size_t;
 
   /**
-   *  @brief  A meta-allocator with debugging bits, as per [20.4].
+   *  @brief  A meta-allocator with debugging bits.
    *  @ingroup allocators
    *
-   *  This is precisely the allocator defined in the C++ Standard. 
-   *    - all allocation calls operator new
-   *    - all deallocation calls operator delete
+   *  This is precisely the allocator defined in the C++03 Standard.
    */
   template<typename _Alloc>
     class debug_allocator
     {
+      template<typename> friend class debug_allocator;
+
+      typedef __alloc_traits<_Alloc> _Traits;
+
     public:
-      typedef typename _Alloc::size_type       	size_type;
-      typedef typename _Alloc::difference_type	difference_type;
-      typedef typename _Alloc::pointer       	pointer;
-      typedef typename _Alloc::const_pointer    const_pointer;
-      typedef typename _Alloc::reference       	reference;
-      typedef typename _Alloc::const_reference  const_reference;
-      typedef typename _Alloc::value_type       value_type;
+      typedef typename _Traits::size_type       	size_type;
+      typedef typename _Traits::difference_type	difference_type;
+      typedef typename _Traits::pointer       	pointer;
+      typedef typename _Traits::const_pointer    const_pointer;
+      typedef typename _Traits::reference       	reference;
+      typedef typename _Traits::const_reference  const_reference;
+      typedef typename _Traits::value_type       value_type;
+
+      template<typename _Up>
+	class rebind
+	{
+	  typedef typename _Traits::template rebind<_Up>::other __other;
+
+	public:
+	  typedef debug_allocator<__other> other;
+	};
 
     private:
       // _M_extra is the number of objects that correspond to the
@@ -77,13 +90,34 @@  _GLIBCXX_BEGIN_NAMESPACE_VERSION
       
       _Alloc			_M_allocator;
 
-    public:
-      debug_allocator()
+      template<typename _Alloc2,
+	       typename = typename _Alloc2::template rebind<value_type>::other>
+	struct __convertible
+	{ };
+
+      template<typename _Alloc2>
+	struct __convertible<_Alloc2, _Alloc>
+	{
+	  typedef void* __type;
+	};
+
+      size_type _S_extra()
       {
 	const size_t __obj_size = sizeof(value_type);
-	_M_extra = (sizeof(size_type) + __obj_size - 1) / __obj_size; 
+	return (sizeof(size_type) + __obj_size - 1) / __obj_size; 
       }
-      
+
+    public:
+      debug_allocator() : _M_extra(_S_extra()) { }
+
+      template<typename _Alloc2>
+	debug_allocator(const debug_allocator<_Alloc2>& __a2,
+			typename __convertible<_Alloc2>::__type = 0)
+	: _M_allocator(__a2._M_allocator), _M_extra(_S_extra()) { }
+
+      debug_allocator(const _Alloc& __a)
+      : _M_allocator(__a), _M_extra(_S_extra()) { }
+
       pointer
       allocate(size_type __n)
       {
@@ -105,21 +139,52 @@  _GLIBCXX_BEGIN_NAMESPACE_VERSION
       void
       deallocate(pointer __p, size_type __n)
       {
+	using std::__throw_runtime_error;
 	if (__p)
 	  {
 	    pointer __real_p = __p - _M_extra;
 	    if (*reinterpret_cast<size_type*>(__real_p) != __n)
-	      {
-		throw std::runtime_error("debug_allocator::deallocate"
-					 " wrong size");
-	      }
+	      __throw_runtime_error("debug_allocator::deallocate wrong size");
 	    _M_allocator.deallocate(__real_p, __n + _M_extra);
 	  }
 	else
-	  throw std::runtime_error("debug_allocator::deallocate null pointer");
+	  __throw_runtime_error("debug_allocator::deallocate null pointer");
       }
+
+      void
+      construct(pointer __p, const value_type& __val)
+      { _Traits::construct(_M_allocator, __p, __val); }
+
+#if __cplusplus >= 201103L
+      template<typename _Tp, typename... _Args>
+	void
+	construct(_Tp* __p, _Args&&... __args)
+	{
+	  _Traits::construct(_M_allocator, __p,
+			     std::forward<_Args>(__args)...);
+	}
+#endif
+
+      template<typename _Tp>
+	void
+	destroy(_Tp* __p)
+	{ _Traits::destroy(_M_allocator, __p); }
+
+      size_type
+      max_size() const throw()
+      { return _Traits::max_size(_M_allocator) - _M_extra; }
+
+      friend bool
+      operator==(const debug_allocator& __lhs, const debug_allocator& __rhs)
+      { return __lhs._M_allocator == __rhs._M_allocator; }
     };
 
+  template<typename _Alloc>
+    inline bool
+    operator!=(const debug_allocator<_Alloc>& __lhs,
+	       const debug_allocator<_Alloc>& __rhs)
+    { return !(__lhs == __rhs); }
+
 _GLIBCXX_END_NAMESPACE_VERSION
 } // namespace
 
diff --git a/libstdc++-v3/testsuite/ext/debug_allocator/56170.cc b/libstdc++-v3/testsuite/ext/debug_allocator/56170.cc
new file mode 100644
index 0000000..217fc32
--- /dev/null
+++ b/libstdc++-v3/testsuite/ext/debug_allocator/56170.cc
@@ -0,0 +1,27 @@ 
+// Copyright (C) 2013 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-do compile }
+
+#include <list>
+#include <vector>
+#include <ext/debug_allocator.h>
+
+using __gnu_cxx::debug_allocator;
+
+template class std::list<int, debug_allocator<std::allocator<int> > >;
+template class std::vector<int, debug_allocator<std::allocator<int> > >;