Re: libstdc++ bootstrap failure after r261525

[François Dumont <frs dot dumont at gmail dot com>]

Here is the missing part of the can_advance patch.

    * include/debug/helper_functions.h
    (__gnu_debug::_Safe_iterator<>): Add declaration.
    (__can_advance(_Ite, _Size)): New.
    (__can_advance(const _Safe_iterator<>&, _Size)): Overload declaration.
    * include/debug/functions.h
    (__gnu_debug::_Safe_iterator<>): Remove declaration.
    * include/debug/stl_iterator.h
    (__can_advance(const _Safe_iterator<>&)): New definition.
    * include/debug/stl_iterator.h
    (__can_advance(const std::reverse_iterator<>&, _Size)): New.
    (__can_advance(const std::move_iterator<>&, _Size)): New.
    * include/debug/macros.h (__glibcxx_check_can_increment): New.
    * include/debug/debug.h (__glibcxx_requires_can_increment): New.
    * include/bits/stl_algobase.h (fill_n): Use latter.
    * testsuite/25_algorithms/fill_n/2.cc: New.
    * testsuite/25_algorithms/fill_n/debug/1_neg.cc: New.
    * testsuite/25_algorithms/fill_n/debug/2_neg.cc: New.
    * testsuite/25_algorithms/fill_n/debug/3_neg.cc: New.
    * testsuite/25_algorithms/fill_n/debug/4_neg.cc: New.

Tested under linux x86_64, normal and debug modes.

Now I understand why applying the patch in the first place failed.

François

On 13/06/2018 15:24, Jonathan Wakely wrote:
> On 13/06/18 13:42 +0200, Paolo Carlini wrote:
> > Hi,
> >
> > On 13/06/2018 08:11, François Dumont wrote:
> > > On 12/06/2018 23:26, Martin Sebor wrote:
> > > > Bootstrap fails in libstdc++ with the following error.
> > > > I haven't investigated it much except to take a peek
> > > > at recent libstdc++ commits where r261525 looks like it
> > > > introduced __glibcxx_check_can_increment_range, so it
> > > > seems like it might have something to do with it.  I don't
> > > > see a __glibcxx_requires_can_increment_range macro defined
> > > > anywhere in the patch so maybe it's a typo?  Francois, can
> > > > you please see what's going on?
> > > >
> > > > /opt/notnfs/msebor/build/gcc-86114/x86_64-pc-linux-gnu/libstdc++-v3/include/bits/stl_algobase.h:452:45: 
> > > > error: ‘__glibcxx_requires_can_increment_range’ was not declared in 
> > > > this scope
> > > >        __glibcxx_requires_can_increment_range(__first, __last, 
> > > > __result);
> > > >
> > > > Thanks
> > > > Martin
> > > > .
> > > I had missed the fact that the patch didn't apply correctly on 
> > > include/debug/debug.h as stated in the ChangeLog entry.
> > >
> > > It is fixed now.
> > But even after r261537 we are seeing the regressions:
> >
> > FAIL: g++.dg/warn/pr31246.C -std=gnu++11 (test for excess errors)
> > FAIL: g++.dg/warn/pr31246.C -std=gnu++14 (test for excess errors)
> > FAIL: g++.dg/warn/pr31246.C -std=gnu++98 (test for excess errors)
> >
> > Which definitely are related.
>
> And failing Debug Mode tests:
>
> FAIL: 20_util/hash/84998.cc (test for excess errors)
> FAIL: 23_containers/vector/cons/destructible_debug_neg.cc (test for 
> excess errors)
> FAIL: 25_algorithms/binary_search/partitioned.cc (test for excess errors)
> FAIL: 25_algorithms/equal_range/partitioned.cc (test for excess errors)
> FAIL: 25_algorithms/lexicographical_compare/71545.cc (test for excess 
> errors)
> FAIL: 25_algorithms/lower_bound/partitioned.cc (test for excess errors)
> FAIL: 25_algorithms/upper_bound/partitioned.cc (test for excess errors)
> FAIL: ext/profile/mutex_extensions_neg.cc (test for excess errors)
>
> The logs show:
>
> /home/jwakely/src/gcc/build/x86_64-pc-linux-gnu/libstdc++-v3/include/bits/stl_algobase.h:452: 
> error: '__can_advance' is not a member of '__gnu_debug'
> /home/jwakely/src/gcc/build/x86_64-pc-linux-gnu/libstdc++-v3/include/bits/stl_algobase.h:484: 
> error: '__can_advance' is not a member of '__gnu_debug'
> /home/jwakely/src/gcc/build/x86_64-pc-linux-gnu/libstdc++-v3/include/bits/stl_algobase.h:629: 
> error: '__can_advance' is not a member of '__gnu_debug'
> /home/jwakely/src/gcc/build/x86_64-pc-linux-gnu/libstdc++-v3/include/bits/stl_algobase.h:664: 
> error: '__can_advance' is not a member of '__gnu_debug'

diff --git a/libstdc++-v3/include/bits/stl_algobase.h b/libstdc++-v3/include/bits/stl_algobase.h
index 877f32b..022a3f1 100644
--- a/libstdc++-v3/include/bits/stl_algobase.h
+++ b/libstdc++-v3/include/bits/stl_algobase.h
@@ -783,6 +783,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     {
       // concept requirements
       __glibcxx_function_requires(_OutputIteratorConcept<_OI, _Tp>)
+      __glibcxx_requires_can_increment(__first, __n);
 
       return _OI(std::__fill_n_a(std::__niter_base(__first), __n, __value));
     }
diff --git a/libstdc++-v3/include/debug/debug.h b/libstdc++-v3/include/debug/debug.h
index d055dcb..f157a6d 100644
--- a/libstdc++-v3/include/debug/debug.h
+++ b/libstdc++-v3/include/debug/debug.h
@@ -62,6 +62,7 @@ namespace __gnu_debug
 
 # define __glibcxx_requires_cond(_Cond,_Msg)
 # define __glibcxx_requires_valid_range(_First,_Last)
+# define __glibcxx_requires_can_increment(_First,_Size)
 # define __glibcxx_requires_can_increment_range(_First1,_Last1,_First2)
 # define __glibcxx_requires_can_decrement_range(_First1,_Last1,_First2)
 # define __glibcxx_requires_sorted(_First,_Last)
@@ -88,6 +89,8 @@ namespace __gnu_debug
 # define __glibcxx_requires_cond(_Cond,_Msg) _GLIBCXX_DEBUG_VERIFY(_Cond,_Msg)
 # define __glibcxx_requires_valid_range(_First,_Last)	\
   __glibcxx_check_valid_range(_First,_Last)
+# define __glibcxx_requires_can_increment(_First,_Size)	\
+  __glibcxx_check_can_increment(_First,_Size)
 # define __glibcxx_requires_can_increment_range(_First1,_Last1,_First2)	\
   __glibcxx_check_can_increment_range(_First1,_Last1,_First2)
 # define __glibcxx_requires_can_decrement_range(_First1,_Last1,_First2)	\
diff --git a/libstdc++-v3/include/debug/functions.h b/libstdc++-v3/include/debug/functions.h
index 3a2ba74..41519b2 100644
--- a/libstdc++-v3/include/debug/functions.h
+++ b/libstdc++-v3/include/debug/functions.h
@@ -40,9 +40,6 @@
 
 namespace __gnu_debug
 {
-  template<typename _Iterator, typename _Sequence>
-    class _Safe_iterator;
-
   template<typename _Sequence>
     struct _Insert_range_from_self_is_safe
     { enum { __value = 0 }; };
diff --git a/libstdc++-v3/include/debug/helper_functions.h b/libstdc++-v3/include/debug/helper_functions.h
index 94d5016..2073df9 100644
--- a/libstdc++-v3/include/debug/helper_functions.h
+++ b/libstdc++-v3/include/debug/helper_functions.h
@@ -37,6 +37,9 @@
 
 namespace __gnu_debug
 {
+  template<typename _Iterator, typename _Sequence>
+    class _Safe_iterator;
+
   /** The precision to which we can calculate the distance between
    *  two iterators.
    */
@@ -164,6 +167,16 @@ namespace __gnu_debug
       return __valid_range(__first, __last, __dist);
     }
 
+  // Fallback method, always ok.
+  template<typename _InputIterator, typename _Size>
+    inline bool
+    __can_advance(_InputIterator, _Size)
+    { return true; }
+
+  template<typename _Iterator, typename _Sequence, typename _Size>
+    bool
+    __can_advance(const _Safe_iterator<_Iterator, _Sequence>&, _Size);
+
 #if __cplusplus < 201103L
   // Helper struct to detect random access safe iterators.
   template<typename _Iterator>
diff --git a/libstdc++-v3/include/debug/macros.h b/libstdc++-v3/include/debug/macros.h
index a88faf9..44f48b0 100644
--- a/libstdc++-v3/include/debug/macros.h
+++ b/libstdc++-v3/include/debug/macros.h
@@ -87,6 +87,13 @@ _GLIBCXX_DEBUG_VERIFY(_First != _Last,					\
 		      ._M_iterator(_First, #_First)			\
 		      ._M_iterator(_Last, #_Last))
 
+// Verify that [_First, _First + _Size) forms a valid range.
+#define __glibcxx_check_can_increment(_First,_Size)			\
+_GLIBCXX_DEBUG_VERIFY(__gnu_debug::__can_advance(_First, _Size),	\
+		      _M_message(__gnu_debug::__msg_iter_subscript_oob)	\
+		      ._M_iterator(_First, #_First)			\
+		      ._M_integer(_Size, #_Size))
+
 #define __glibcxx_check_can_increment_range(_First1,_Last1,_First2)	\
   do									\
   {									\
diff --git a/libstdc++-v3/include/debug/safe_iterator.h b/libstdc++-v3/include/debug/safe_iterator.h
index 3a53ab7..7ed2b93 100644
--- a/libstdc++-v3/include/debug/safe_iterator.h
+++ b/libstdc++-v3/include/debug/safe_iterator.h
@@ -862,6 +862,11 @@ namespace __gnu_debug
       return __res;
     }
 
+  template<typename _Iterator, typename _Sequence, typename _Size>
+    inline bool
+    __can_advance(const _Safe_iterator<_Iterator, _Sequence>& __it, _Size __n)
+    { return __it._M_can_advance(__n); }
+
 #if __cplusplus < 201103L
   template<typename _Iterator, typename _Sequence>
     struct __is_safe_random_iterator<_Safe_iterator<_Iterator, _Sequence> >
diff --git a/libstdc++-v3/include/debug/stl_iterator.h b/libstdc++-v3/include/debug/stl_iterator.h
index 21eac76..a6a2a76 100644
--- a/libstdc++-v3/include/debug/stl_iterator.h
+++ b/libstdc++-v3/include/debug/stl_iterator.h
@@ -47,6 +47,11 @@ namespace __gnu_debug
 		   const std::reverse_iterator<_Iterator>& __last)
     { return __get_distance(__last.base(), __first.base()); }
 
+  template<typename _Iterator, typename _Size>
+    inline bool
+    __can_advance(const std::reverse_iterator<_Iterator>& __it, _Size __n)
+    { return __can_advance(__it.base(), -__n); }
+
 #if __cplusplus < 201103L
   template<typename _Iterator>
     struct __is_safe_random_iterator<std::reverse_iterator<_Iterator> >
@@ -96,6 +101,11 @@ namespace __gnu_debug
 		   const std::move_iterator<_Iterator>& __last)
     { return __get_distance(__first.base(), __last.base()); }
 
+  template<typename _Iterator, typename _Size>
+    inline bool
+    __can_advance(const std::move_iterator<_Iterator>& __it, _Size __n)
+    { return __can_advance(__it.base(), __n); }
+
   template<typename _Iterator>
     inline auto
     __unsafe(const std::move_iterator<_Iterator>& __it)
diff --git a/libstdc++-v3/testsuite/25_algorithms/fill_n/2.cc b/libstdc++-v3/testsuite/25_algorithms/fill_n/2.cc
new file mode 100644
index 0000000..6e18032
--- /dev/null
+++ b/libstdc++-v3/testsuite/25_algorithms/fill_n/2.cc
@@ -0,0 +1,46 @@
+// Copyright (C) 2018 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/>.
+
+// 25.2.5 [lib.alg.fill] Fill_n.
+
+// { dg-require-debug-mode "" }
+
+#include <algorithm>
+#include <vector>
+
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+  std::vector<int> ref;
+  ref.push_back(1);
+  ref.push_back(2);
+
+  std::vector<std::vector<int>> vvect;
+  vvect.push_back(std::vector<int>());
+  vvect.push_back(std::vector<int>());
+
+  VERIFY( std::fill_n(vvect.begin(), 2, ref) == vvect.end() );
+}
+
+int
+main()
+{
+  test01();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/25_algorithms/fill_n/debug/1_neg.cc b/libstdc++-v3/testsuite/25_algorithms/fill_n/debug/1_neg.cc
new file mode 100644
index 0000000..45a88fe
--- /dev/null
+++ b/libstdc++-v3/testsuite/25_algorithms/fill_n/debug/1_neg.cc
@@ -0,0 +1,39 @@
+// Copyright (C) 2018 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/>.
+
+// 25.2.5 [lib.alg.fill] Fill_n.
+
+// { dg-do run { xfail *-*-* } }
+// { dg-require-debug-mode "" }
+
+#include <algorithm>
+#include <vector>
+
+void
+test01()
+{
+  std::vector<int> vect;
+  vect.push_back(1);
+  std::fill_n(vect.begin(), 2, 0);
+}
+
+int
+main()
+{
+  test01();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/25_algorithms/fill_n/debug/2_neg.cc b/libstdc++-v3/testsuite/25_algorithms/fill_n/debug/2_neg.cc
new file mode 100644
index 0000000..3738ae6
--- /dev/null
+++ b/libstdc++-v3/testsuite/25_algorithms/fill_n/debug/2_neg.cc
@@ -0,0 +1,39 @@
+// Copyright (C) 2018 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/>.
+
+// 25.2.5 [lib.alg.fill] Fill_n.
+
+// { dg-do run { xfail *-*-* } }
+// { dg-require-debug-mode "" }
+
+#include <algorithm>
+#include <vector>
+
+void
+test01()
+{
+  std::vector<int> vect;
+  vect.push_back(1);
+  std::fill_n(vect.rbegin(), 2, 0);
+}
+
+int
+main()
+{
+  test01();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/25_algorithms/fill_n/debug/3_neg.cc b/libstdc++-v3/testsuite/25_algorithms/fill_n/debug/3_neg.cc
new file mode 100644
index 0000000..1497dbb
--- /dev/null
+++ b/libstdc++-v3/testsuite/25_algorithms/fill_n/debug/3_neg.cc
@@ -0,0 +1,39 @@
+// Copyright (C) 2018 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/>.
+
+// 25.2.5 [lib.alg.fill] Fill_n.
+
+// { dg-do run { xfail *-*-* } }
+// { dg-require-debug-mode "" }
+
+#include <algorithm>
+#include <list>
+
+void
+test01()
+{
+  std::list<int> l;
+  l.push_back(1);
+  std::fill_n(l.begin(), 2, 0);
+}
+
+int
+main()
+{
+  test01();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/25_algorithms/fill_n/debug/4_neg.cc b/libstdc++-v3/testsuite/25_algorithms/fill_n/debug/4_neg.cc
new file mode 100644
index 0000000..70c4a29
--- /dev/null
+++ b/libstdc++-v3/testsuite/25_algorithms/fill_n/debug/4_neg.cc
@@ -0,0 +1,43 @@
+// Copyright (C) 2018 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/>.
+
+// 25.2.5 [lib.alg.fill] Fill_n.
+
+// { dg-do run { xfail *-*-* } }
+// { dg-require-debug-mode "" }
+
+#include <algorithm>
+#include <list>
+
+void
+test01()
+{
+  std::list<int> l;
+  l.push_back(1);
+  l.push_back(2);
+
+  std::list<int>::iterator it = l.begin();
+  ++it;
+  std::fill_n(it, 2, 0);
+}
+
+int
+main()
+{
+  test01();
+  return 0;
+}