On Mon, 13 Apr 2015, Jonathan Wakely wrote:
I don't have a preference, but I think the forward declarations should
work without problems. <list> includes bits/stl_iterator_base_funcs.h
so if the forward declarations didn't match the definitions for some
reason we'd know right away.
Here is a new version that also passes the tests. I guess we will have
plenty of time during stage1 to notice if it causes problems. We could
probably move the new definitions of __distance to
bits/stl_iterator_base_funcs.h, I don't have a clear preference.
2015-04-14 Marc Glisse <marc.gli...@inria.fr>
PR libstdc++/61347
* include/bits/stl_iterator_base_funcs.h (_List_iterator,
_List_const_iterator): Declare.
(__distance): Declare new overloads for _List_iterator and
_List_const_iterator.
* include/bits/stl_list.h (__distance): New overloads for
_List_iterator and _List_const_iterator.
* testsuite/23_containers/list/61347.cc: New testcase.
--
Marc GlisseIndex: include/bits/stl_iterator_base_funcs.h
===================================================================
--- include/bits/stl_iterator_base_funcs.h (revision 222076)
+++ include/bits/stl_iterator_base_funcs.h (working copy)
@@ -59,20 +59,26 @@
#ifndef _STL_ITERATOR_BASE_FUNCS_H
#define _STL_ITERATOR_BASE_FUNCS_H 1
#pragma GCC system_header
#include <bits/concept_check.h>
#include <debug/debug.h>
namespace std _GLIBCXX_VISIBILITY(default)
{
+_GLIBCXX_BEGIN_NAMESPACE_CONTAINER
+ // Forward declaration for the overloads of __distance.
+ template <typename> struct _List_iterator;
+ template <typename> struct _List_const_iterator;
+_GLIBCXX_END_NAMESPACE_CONTAINER
+
_GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _InputIterator>
inline typename iterator_traits<_InputIterator>::difference_type
__distance(_InputIterator __first, _InputIterator __last,
input_iterator_tag)
{
// concept requirements
__glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
@@ -89,20 +95,35 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
inline typename iterator_traits<_RandomAccessIterator>::difference_type
__distance(_RandomAccessIterator __first, _RandomAccessIterator __last,
random_access_iterator_tag)
{
// concept requirements
__glibcxx_function_requires(_RandomAccessIteratorConcept<
_RandomAccessIterator>)
return __last - __first;
}
+#if _GLIBCXX_USE_CXX11_ABI
+ // Forward declaration because of the qualified call in distance.
+ template<typename _Tp>
+ ptrdiff_t
+ __distance(_GLIBCXX_STD_C::_List_iterator<_Tp>,
+ _GLIBCXX_STD_C::_List_iterator<_Tp>,
+ input_iterator_tag);
+
+ template<typename _Tp>
+ ptrdiff_t
+ __distance(_GLIBCXX_STD_C::_List_const_iterator<_Tp>,
+ _GLIBCXX_STD_C::_List_const_iterator<_Tp>,
+ input_iterator_tag);
+#endif
+
/**
* @brief A generalization of pointer arithmetic.
* @param __first An input iterator.
* @param __last An input iterator.
* @return The distance between them.
*
* Returns @c n such that __first + n == __last. This requires
* that @p __last must be reachable from @p __first. Note that @c
* n may be negative.
*
Index: include/bits/stl_list.h
===================================================================
--- include/bits/stl_list.h (revision 222076)
+++ include/bits/stl_list.h (working copy)
@@ -1861,13 +1861,52 @@ _GLIBCXX_END_NAMESPACE_CXX11
operator>=(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
{ return !(__x < __y); }
/// See std::list::swap().
template<typename _Tp, typename _Alloc>
inline void
swap(list<_Tp, _Alloc>& __x, list<_Tp, _Alloc>& __y)
{ __x.swap(__y); }
_GLIBCXX_END_NAMESPACE_CONTAINER
+
+#if _GLIBCXX_USE_CXX11_ABI
+_GLIBCXX_BEGIN_NAMESPACE_VERSION
+
+ // Detect when distance is used to compute the size of the whole list.
+ template<typename _Tp>
+ inline ptrdiff_t
+ __distance(_GLIBCXX_STD_C::_List_iterator<_Tp> __first,
+ _GLIBCXX_STD_C::_List_iterator<_Tp> __last,
+ input_iterator_tag __tag)
+ {
+ typedef _GLIBCXX_STD_C::_List_const_iterator<_Tp> _CIter;
+ return std::__distance(_CIter(__first), _CIter(__last), __tag);
+ }
+
+ template<typename _Tp>
+ inline ptrdiff_t
+ __distance(_GLIBCXX_STD_C::_List_const_iterator<_Tp> __first,
+ _GLIBCXX_STD_C::_List_const_iterator<_Tp> __last,
+ input_iterator_tag)
+ {
+ typedef _GLIBCXX_STD_C::_List_node<size_t> _Sentinel;
+ _GLIBCXX_STD_C::_List_const_iterator<_Tp> __beyond = __last;
+ ++__beyond;
+ bool __whole = __first == __beyond;
+ if (__builtin_constant_p (__whole) && __whole)
+ return static_cast<const _Sentinel*>(__last._M_node)->_M_data;
+
+ ptrdiff_t __n = 0;
+ while (__first != __last)
+ {
+ ++__first;
+ ++__n;
+ }
+ return __n;
+ }
+
+_GLIBCXX_END_NAMESPACE_VERSION
+#endif
} // namespace std
#endif /* _STL_LIST_H */
Index: testsuite/23_containers/list/61347.cc
===================================================================
--- testsuite/23_containers/list/61347.cc (revision 0)
+++ testsuite/23_containers/list/61347.cc (working copy)
@@ -0,0 +1,49 @@
+// { dg-options "-std=gnu++11 -O2 -D_GLIBCXX_USE_CXX11_ABI" }
+
+// Copyright (C) 2015 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/>.
+
+#include <list>
+#include <iterator>
+#include <testsuite_hooks.h>
+
+__attribute__((__noinline__, __noclone__))
+void testm(std::list<short>& l)
+{
+ bool b = std::distance(l.begin(), l.end()) == l.size();
+ VERIFY( __builtin_constant_p(b) );
+ VERIFY( b );
+}
+
+__attribute__((__noinline__, __noclone__))
+void testc(const std::list<short>& l)
+{
+ bool b = std::distance(l.begin(), l.end()) == l.size();
+ VERIFY( __builtin_constant_p(b) );
+ VERIFY( b );
+}
+
+int main()
+{
+ bool test __attribute__((unused)) = true;
+
+#if _GLIBCXX_USE_DUAL_ABI
+ std::list<short> l;
+ testm(l);
+ testc(l);
+#endif
+}
