re PR libstdc++/61143 (Arithmetic exception on emplacing into unordered_map moved...

2014-05-21  François Dumont  <fdumont@gcc.gnu.org>

	PR libstdc++/61143
	* include/bits/hashtable.h: Fix move semantic to leave hashtable in a
	usable state.
	* testsuite/23_containers/unordered_set/61143.cc: New.
	* testsuite/23_containers/unordered_set/modifiers/swap.cc: New.

From-SVN: r210726

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 6dd9b785d4d9c9d439614ecb4795315237d56c2c..b53dfb457a8b684c67b41428d008f9832e942bdc 100644 (file)
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,11 @@
+2014-05-21  François Dumont  <fdumont@gcc.gnu.org>
+
+       PR libstdc++/61143
+       * include/bits/hashtable.h: Fix move semantic to leave hashtable in a
+       usable state.
+       * testsuite/23_containers/unordered_set/61143.cc: New.
+       * testsuite/23_containers/unordered_set/modifiers/swap.cc: New.
+
 2014-05-21  Jonathan Wakely  <jwakely@redhat.com>
 
        PR libstdc++/61269

diff --git a/libstdc++-v3/include/bits/hashtable.h b/libstdc++-v3/include/bits/hashtable.h
index 22e17d29d7b14ac1573265d0d5794ba364c58aca..9b6394c4e49965f22a317fd565f584742ff8eb97 100644 (file)
--- a/libstdc++-v3/include/bits/hashtable.h
+++ b/libstdc++-v3/include/bits/hashtable.h
@@ -316,14 +316,49 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       size_type                        _M_element_count;
       _RehashPolicy            _M_rehash_policy;
 
+      // A single bucket used when only need for 1 bucket. Especially
+      // interesting in move semantic to leave hashtable with only 1 buckets
+      // which is not allocated so that we can have those operations noexcept
+      // qualified.
+      // Note that we can't leave hashtable with 0 bucket without adding
+      // numerous checks in the code to avoid 0 modulus.
+      __bucket_type            _M_single_bucket;
+
+      bool
+      _M_uses_single_bucket(__bucket_type* __bkts) const
+      { return __builtin_expect(_M_buckets == &_M_single_bucket, false); }
+
+      bool
+      _M_uses_single_bucket() const
+      { return _M_uses_single_bucket(_M_buckets); }
+
       __hashtable_alloc&
       _M_base_alloc() { return *this; }
 
-      using __hashtable_alloc::_M_deallocate_buckets;
+      __bucket_type*
+      _M_allocate_buckets(size_type __n)
+      {
+       if (__builtin_expect(__n == 1, false))
+         {
+           _M_single_bucket = nullptr;
+           return &_M_single_bucket;
+         }
+
+       return __hashtable_alloc::_M_allocate_buckets(__n);
+      }
+
+      void
+      _M_deallocate_buckets(__bucket_type* __bkts, size_type __n)
+      {
+       if (_M_uses_single_bucket(__bkts))
+         return;
+
+       __hashtable_alloc::_M_deallocate_buckets(__bkts, __n);
+      }
 
       void
       _M_deallocate_buckets()
-      { this->_M_deallocate_buckets(_M_buckets, _M_bucket_count); }
+      { _M_deallocate_buckets(_M_buckets, _M_bucket_count); }
 
       // Gets bucket begin, deals with the fact that non-empty buckets contain
       // their before begin node.
@@ -703,11 +738,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
       size_type
       erase(const key_type& __k)
-      {
-       if (__builtin_expect(_M_bucket_count == 0, false))
-         return 0;
-       return _M_erase(__unique_keys(), __k);
-      }
+      { return _M_erase(__unique_keys(), __k); }
 
       iterator
       erase(const_iterator, const_iterator);
@@ -768,7 +799,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       _M_rehash_policy()
     {
       _M_bucket_count = _M_rehash_policy._M_next_bkt(__bucket_hint);
-      _M_buckets = this->_M_allocate_buckets(_M_bucket_count);
+      _M_buckets = _M_allocate_buckets(_M_bucket_count);
     }
 
   template<typename _Key, typename _Value,
@@ -796,7 +827,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
            std::max(_M_rehash_policy._M_bkt_for_elements(__nb_elems),
                     __bucket_hint));
 
-       _M_buckets = this->_M_allocate_buckets(_M_bucket_count);
+       _M_buckets = _M_allocate_buckets(_M_bucket_count);
        __try
          {
            for (; __f != __l; ++__f)
@@ -833,9 +864,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
              {
                // Replacement allocator cannot free existing storage.
                this->_M_deallocate_nodes(_M_begin());
-               if (__builtin_expect(_M_bucket_count != 0, true))
-                 _M_deallocate_buckets();
-               _M_reset();
+               _M_before_begin._M_nxt = nullptr;
+               _M_deallocate_buckets();
+               _M_buckets = nullptr;
                std::__alloc_on_copy(__this_alloc, __that_alloc);
                __hashtable_base::operator=(__ht);
                _M_bucket_count = __ht._M_bucket_count;
@@ -867,7 +898,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
        if (_M_bucket_count != __ht._M_bucket_count)
          {
            __former_buckets = _M_buckets;
-           _M_buckets = this->_M_allocate_buckets(__ht._M_bucket_count);
+           _M_buckets = _M_allocate_buckets(__ht._M_bucket_count);
            _M_bucket_count = __ht._M_bucket_count;
          }
        else
@@ -885,8 +916,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
                      [&__roan](const __node_type* __n)
                      { return __roan(__n->_M_v()); });
            if (__former_buckets)
-             this->_M_deallocate_buckets(__former_buckets,
-                                         __former_bucket_count);
+             _M_deallocate_buckets(__former_buckets, __former_bucket_count);
          }
        __catch(...)
          {
@@ -917,7 +947,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       {
        __bucket_type* __buckets = nullptr;
        if (!_M_buckets)
-         _M_buckets = __buckets = this->_M_allocate_buckets(_M_bucket_count);
+         _M_buckets = __buckets = _M_allocate_buckets(_M_bucket_count);
 
        __try
          {
@@ -964,8 +994,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     _M_reset() noexcept
     {
       _M_rehash_policy._M_reset();
-      _M_bucket_count = 0;
-      _M_buckets = nullptr;
+      _M_bucket_count = 1;
+      _M_single_bucket = nullptr;
+      _M_buckets = &_M_single_bucket;
       _M_before_begin._M_nxt = nullptr;
       _M_element_count = 0;
     }
@@ -980,12 +1011,16 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     _M_move_assign(_Hashtable&& __ht, std::true_type)
     {
       this->_M_deallocate_nodes(_M_begin());
-      if (__builtin_expect(_M_bucket_count != 0, true))
-       _M_deallocate_buckets();
-
+      _M_deallocate_buckets();
       __hashtable_base::operator=(std::move(__ht));
       _M_rehash_policy = __ht._M_rehash_policy;
-      _M_buckets = __ht._M_buckets;
+      if (!__ht._M_uses_single_bucket())
+       _M_buckets = __ht._M_buckets;
+      else
+       {
+         _M_buckets = &_M_single_bucket;
+         _M_single_bucket = __ht._M_single_bucket;
+       }
       _M_bucket_count = __ht._M_bucket_count;
       _M_before_begin._M_nxt = __ht._M_before_begin._M_nxt;
       _M_element_count = __ht._M_element_count;
@@ -1019,7 +1054,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
          if (_M_bucket_count != __ht._M_bucket_count)
            {
              __former_buckets = _M_buckets;
-             _M_buckets = this->_M_allocate_buckets(__ht._M_bucket_count);
+             _M_buckets = _M_allocate_buckets(__ht._M_bucket_count);
              _M_bucket_count = __ht._M_bucket_count;
            }
          else
@@ -1093,10 +1128,18 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       _M_element_count(__ht._M_element_count),
       _M_rehash_policy(__ht._M_rehash_policy)
     {
+      // Update, if necessary, buckets if __ht is using its single bucket.
+      if (__ht._M_uses_single_bucket())
+       {
+         _M_buckets = &_M_single_bucket;
+         _M_single_bucket = __ht._M_single_bucket;
+       }
+
       // Update, if necessary, bucket pointing to before begin that hasn't
       // moved.
       if (_M_begin())
        _M_buckets[_M_bucket_index(_M_begin())] = &_M_before_begin;
+
       __ht._M_reset();
     }
 
@@ -1139,7 +1182,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     {
       if (__ht._M_node_allocator() == this->_M_node_allocator())
        {
-         _M_buckets = __ht._M_buckets;
+         if (__ht._M_uses_single_bucket())
+           {
+             _M_buckets = &_M_single_bucket;
+             _M_single_bucket = __ht._M_single_bucket;
+           }
+         else
+           _M_buckets = __ht._M_buckets;
+
          _M_before_begin._M_nxt = __ht._M_before_begin._M_nxt;
          // Update, if necessary, bucket pointing to before begin that hasn't
          // moved.
@@ -1189,15 +1239,34 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
       std::__alloc_on_swap(this->_M_node_allocator(), __x._M_node_allocator());
       std::swap(_M_rehash_policy, __x._M_rehash_policy);
-      std::swap(_M_buckets, __x._M_buckets);
+
+      // Deal properly with potentially moved instances.
+      if (this->_M_uses_single_bucket())
+       {
+         if (!__x._M_uses_single_bucket())
+           {
+             _M_buckets = __x._M_buckets;
+             __x._M_buckets = &__x._M_single_bucket;
+           }
+       }
+      else if (__x._M_uses_single_bucket())
+       {
+         __x._M_buckets = _M_buckets;
+         _M_buckets = &_M_single_bucket;
+       }       
+      else
+       std::swap(_M_buckets, __x._M_buckets);
+
       std::swap(_M_bucket_count, __x._M_bucket_count);
       std::swap(_M_before_begin._M_nxt, __x._M_before_begin._M_nxt);
       std::swap(_M_element_count, __x._M_element_count);
+      std::swap(_M_single_bucket, __x._M_single_bucket);
 
       // Fix buckets containing the _M_before_begin pointers that can't be
       // swapped.
       if (_M_begin())
        _M_buckets[_M_bucket_index(_M_begin())] = &_M_before_begin;
+
       if (__x._M_begin())
        __x._M_buckets[__x._M_bucket_index(__x._M_begin())]
          = &__x._M_before_begin;
@@ -1230,9 +1299,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
               _H1, _H2, _Hash, _RehashPolicy, _Traits>::
     find(const key_type& __k)
     {
-      if (__builtin_expect(_M_bucket_count == 0, false))
-       return end();
-
       __hash_code __code = this->_M_hash_code(__k);
       std::size_t __n = _M_bucket_index(__k, __code);
       __node_type* __p = _M_find_node(__n, __k, __code);
@@ -1250,9 +1316,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
               _H1, _H2, _Hash, _RehashPolicy, _Traits>::
     find(const key_type& __k) const
     {
-      if (__builtin_expect(_M_bucket_count == 0, false))
-       return end();
-      
       __hash_code __code = this->_M_hash_code(__k);
       std::size_t __n = _M_bucket_index(__k, __code);
       __node_type* __p = _M_find_node(__n, __k, __code);
@@ -1270,9 +1333,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
               _H1, _H2, _Hash, _RehashPolicy, _Traits>::
     count(const key_type& __k) const
     {
-      if (__builtin_expect(_M_bucket_count == 0, false))
-       return 0;
-
       __hash_code __code = this->_M_hash_code(__k);
       std::size_t __n = _M_bucket_index(__k, __code);
       __node_type* __p = _M_bucket_begin(__n);
@@ -1287,7 +1347,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
          else if (__result)
            // All equivalent values are next to each other, if we
            // found a non-equivalent value after an equivalent one it
-           // means that we won't find any more equivalent values.
+           // means that we won't find any new equivalent value.
            break;
          if (!__p->_M_nxt || _M_bucket_index(__p->_M_next()) != __n)
            break;
@@ -1311,9 +1371,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
               _H1, _H2, _Hash, _RehashPolicy, _Traits>::
     equal_range(const key_type& __k)
     {
-      if (__builtin_expect(_M_bucket_count == 0, false))
-       return std::make_pair(end(), end());
-
       __hash_code __code = this->_M_hash_code(__k);
       std::size_t __n = _M_bucket_index(__k, __code);
       __node_type* __p = _M_find_node(__n, __k, __code);
@@ -1347,9 +1404,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
               _H1, _H2, _Hash, _RehashPolicy, _Traits>::
     equal_range(const key_type& __k) const
     {
-      if (__builtin_expect(_M_bucket_count == 0, false))
-       return std::make_pair(end(), end());
-       
       __hash_code __code = this->_M_hash_code(__k);
       std::size_t __n = _M_bucket_index(__k, __code);
       __node_type* __p = _M_find_node(__n, __k, __code);
@@ -1944,7 +1998,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
               _H1, _H2, _Hash, _RehashPolicy, _Traits>::
     _M_rehash_aux(size_type __n, std::true_type)
     {
-      __bucket_type* __new_buckets = this->_M_allocate_buckets(__n);
+      __bucket_type* __new_buckets = _M_allocate_buckets(__n);
       __node_type* __p = _M_begin();
       _M_before_begin._M_nxt = nullptr;
       std::size_t __bbegin_bkt = 0;
@@ -1969,8 +2023,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
          __p = __next;
        }
 
-      if (__builtin_expect(_M_bucket_count != 0, true))
-       _M_deallocate_buckets();
+      _M_deallocate_buckets();
       _M_bucket_count = __n;
       _M_buckets = __new_buckets;
     }
@@ -1986,7 +2039,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
               _H1, _H2, _Hash, _RehashPolicy, _Traits>::
     _M_rehash_aux(size_type __n, std::false_type)
     {
-      __bucket_type* __new_buckets = this->_M_allocate_buckets(__n);
+      __bucket_type* __new_buckets = _M_allocate_buckets(__n);
 
       __node_type* __p = _M_begin();
       _M_before_begin._M_nxt = nullptr;
@@ -2060,8 +2113,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
            __new_buckets[__next_bkt] = __prev_p;
        }
 
-      if (__builtin_expect(_M_bucket_count != 0, true))
-       _M_deallocate_buckets();
+      _M_deallocate_buckets();
       _M_bucket_count = __n;
       _M_buckets = __new_buckets;
     }

diff --git a/libstdc++-v3/testsuite/23_containers/unordered_set/61143.cc b/libstdc++-v3/testsuite/23_containers/unordered_set/61143.cc
new file mode 100644 (file)
index 0000000..b946425
--- /dev/null
+++ b/libstdc++-v3/testsuite/23_containers/unordered_set/61143.cc
@@ -0,0 +1,38 @@
+// { dg-options "-std=gnu++11" }
+
+// Copyright (C) 2014 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/>.
+
+// libstdc++/61143
+
+#include <unordered_set>
+
+void test01()
+{
+  std::unordered_set<int> us1, us2;
+  us1.insert(1);
+
+  us2 = std::move(us1);
+
+  us1.insert(1);
+}
+
+int main()
+{
+  test01();
+  return 0;
+}

diff --git a/libstdc++-v3/testsuite/23_containers/unordered_set/modifiers/swap.cc b/libstdc++-v3/testsuite/23_containers/unordered_set/modifiers/swap.cc
new file mode 100644 (file)
index 0000000..d03fd1d
--- /dev/null
+++ b/libstdc++-v3/testsuite/23_containers/unordered_set/modifiers/swap.cc
@@ -0,0 +1,65 @@
+// Copyright (C) 2014 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-options "-std=gnu++11" }
+
+#include <unordered_set>
+#include <testsuite_hooks.h>
+
+void test01()
+{
+  bool test __attribute__((unused)) = true;
+  std::unordered_set<int> us1 { 0, 1 };
+  {
+    std::unordered_set<int> us2(std::move(us1));
+
+    us1.swap(us2);
+
+    VERIFY( us1.find(0) != us1.end() );
+
+    us1.insert(2);
+
+    VERIFY( us1.size() == 3 );
+
+    us2.swap(us1);
+
+    VERIFY( us2.size() == 3 );
+    VERIFY( us2.find(2) != us2.end() );
+
+    us1 = { 3, 4, 5 };
+
+    VERIFY( us1.size() == 3 );
+    VERIFY( us1.bucket_count() >= 3 );
+
+    std::unordered_set<int> us3(std::move(us1));
+    us3 = std::move(us2);
+
+    us1.swap(us2);
+
+    VERIFY( us1.empty() );
+    VERIFY( us2.empty() );
+  }
+
+  us1 = { 0, 1 };
+  VERIFY( us1.size() == 2 );
+}
+
+int main()
+{
+  test01();
+  return 0;
+}