Implement N4258 noexcept for std::basic_string.

PR libstdc++/58265 * doc/xml/manual/intro.xml: Document LWG 2063 and 2064 resolutions. * doc/html/manual/bugs.html: Regenerate. * include/bits/basic_string.h (basic_string): Implement N4258. Add correct exception-specifications and propagate allocators correctly. * include/bits/basic_string.tcc (basic_string::swap): Propagate allocators correctly. * include/debug/string (__gnu_debug::basic_string): Add correct exceptions-specifications and allcoator-extended constructors. * testsuite/21_strings/basic_string/allocator/char/copy.cc: New. * testsuite/21_strings/basic_string/allocator/char/copy_assign.cc: New. * testsuite/21_strings/basic_string/allocator/char/minimal.cc: New. * testsuite/21_strings/basic_string/allocator/char/move.cc: New. * testsuite/21_strings/basic_string/allocator/char/move_assign.cc: New. * testsuite/21_strings/basic_string/allocator/char/noexcept.cc: New. * testsuite/21_strings/basic_string/allocator/char/swap.cc: New. * testsuite/21_strings/basic_string/allocator/wchar_t/copy.cc: New. * testsuite/21_strings/basic_string/allocator/wchar_t/copy_assign.cc: New. * testsuite/21_strings/basic_string/allocator/wchar_t/minimal.cc: New. * testsuite/21_strings/basic_string/allocator/wchar_t/move.cc: New. * testsuite/21_strings/basic_string/allocator/wchar_t/move_assign.cc: New. * testsuite/21_strings/basic_string/allocator/wchar_t/noexcept.cc: New. * testsuite/21_strings/basic_string/allocator/wchar_t/swap.cc: New. * testsuite/util/testsuite_allocator.h (tracker_allocator): Define defaulted assignment operators. git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@227681 138bc75d-0d04-0410-961f-82ee72b054a4
gcc-mirror · Sep 11, 2015 · b7aaabf · b7aaabf
1 parent c5dc0aa
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diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
@@ -1,5 +1,35 @@
 2015-09-11  Jonathan Wakely  <jwakely@redhat.com>
 
+	PR libstdc++/58265
+	* doc/xml/manual/intro.xml: Document LWG 2063 and 2064 resolutions.
+	* doc/html/manual/bugs.html: Regenerate.
+	* include/bits/basic_string.h (basic_string): Implement N4258. Add
+	correct exception-specifications and propagate allocators correctly.
+	* include/bits/basic_string.tcc (basic_string::swap): Propagate
+	allocators correctly.
+	* include/debug/string (__gnu_debug::basic_string): Add correct
+	exceptions-specifications and allcoator-extended constructors.
+	* testsuite/21_strings/basic_string/allocator/char/copy.cc: New.
+	* testsuite/21_strings/basic_string/allocator/char/copy_assign.cc:
+	New.
+	* testsuite/21_strings/basic_string/allocator/char/minimal.cc: New.
+	* testsuite/21_strings/basic_string/allocator/char/move.cc: New.
+	* testsuite/21_strings/basic_string/allocator/char/move_assign.cc:
+	New.
+	* testsuite/21_strings/basic_string/allocator/char/noexcept.cc: New.
+	* testsuite/21_strings/basic_string/allocator/char/swap.cc: New.
+	* testsuite/21_strings/basic_string/allocator/wchar_t/copy.cc: New.
+	* testsuite/21_strings/basic_string/allocator/wchar_t/copy_assign.cc:
+	New.
+	* testsuite/21_strings/basic_string/allocator/wchar_t/minimal.cc: New.
+	* testsuite/21_strings/basic_string/allocator/wchar_t/move.cc: New.
+	* testsuite/21_strings/basic_string/allocator/wchar_t/move_assign.cc:
+	New.
+	* testsuite/21_strings/basic_string/allocator/wchar_t/noexcept.cc: New.
+	* testsuite/21_strings/basic_string/allocator/wchar_t/swap.cc: New.
+	* testsuite/util/testsuite_allocator.h (tracker_allocator): Define
+	defaulted assignment operators.
+
 	PR libstdc++/65092
 	* include/bits/stl_queue.h (queue, priority_queue): Add
 	allocator-extended constructors.

diff --git a/libstdc++-v3/doc/html/manual/bugs.html b/libstdc++-v3/doc/html/manual/bugs.html
@@ -366,6 +366,12 @@
     </p></dd><dt><span class="term"><a class="link" href="../ext/lwg-defects.html#2059" target="_top">2059</a>:
 	<span class="emphasis"><em>C++0x ambiguity problem with map::erase</em></span>
     </span></dt><dd><p>Add additional overloads.
+    </p></dd><dt><span class="term"><a class="link" href="../ext/lwg-defects.html#2063" target="_top">2063</a>:
+	<span class="emphasis"><em>Contradictory requirements for string move assignment</em></span>
+    </span></dt><dd><p>Respect propagation trait for move assignment.
+    </p></dd><dt><span class="term"><a class="link" href="../ext/lwg-defects.html#2064" target="_top">2064</a>:
+	<span class="emphasis"><em>More noexcept issues in basic_string</em></span>
+    </span></dt><dd><p>Add noexcept to the comparison operators.
     </p></dd><dt><span class="term"><a class="link" href="../ext/lwg-defects.html#2067" target="_top">2067</a>:
 	<span class="emphasis"><em>packaged_task should have deleted copy c'tor with const parameter</em></span>
     </span></dt><dd><p>Fix signatures.

diff --git a/libstdc++-v3/doc/xml/manual/intro.xml b/libstdc++-v3/doc/xml/manual/intro.xml
@@ -850,6 +850,18 @@ requirements of the license of GCC.
     <listitem><para>Add additional overloads.
     </para></listitem></varlistentry>
 
+    <varlistentry><term><link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="../ext/lwg-defects.html#2063">2063</link>:
+	<emphasis>Contradictory requirements for string move assignment</emphasis>
+    </term>
+    <listitem><para>Respect propagation trait for move assignment.
+    </para></listitem></varlistentry>
+
+    <varlistentry><term><link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="../ext/lwg-defects.html#2064">2064</link>:
+	<emphasis>More noexcept issues in basic_string</emphasis>
+    </term>
+    <listitem><para>Add noexcept to the comparison operators.
+    </para></listitem></varlistentry>
+
     <varlistentry><term><link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="../ext/lwg-defects.html#2067">2067</link>:
 	<emphasis>packaged_task should have deleted copy c'tor with const parameter</emphasis>
     </term>

diff --git a/libstdc++-v3/include/bits/basic_string.h b/libstdc++-v3/include/bits/basic_string.h
@@ -379,17 +379,15 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
        *  @brief  Default constructor creates an empty string.
        */
       basic_string()
-#if __cplusplus >= 201103L
-      noexcept(is_nothrow_default_constructible<_Alloc>::value)
-#endif
+      _GLIBCXX_NOEXCEPT_IF(is_nothrow_default_constructible<_Alloc>::value)
       : _M_dataplus(_M_local_data())
       { _M_set_length(0); }
 
       /**
        *  @brief  Construct an empty string using allocator @a a.
        */
       explicit
-      basic_string(const _Alloc& __a)
+      basic_string(const _Alloc& __a) _GLIBCXX_NOEXCEPT
       : _M_dataplus(_M_local_data(), __a)
       { _M_set_length(0); }
 
@@ -398,7 +396,8 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
        *  @param  __str  Source string.
        */
       basic_string(const basic_string& __str)
-      : _M_dataplus(_M_local_data(), __str._M_get_allocator()) // TODO A traits
+      : _M_dataplus(_M_local_data(),
+		    _Alloc_traits::_S_select_on_copy(__str._M_get_allocator()))
       { _M_construct(__str._M_data(), __str._M_data() + __str.length()); }
 
       /**
@@ -511,10 +510,25 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
       { _M_construct(__str.begin(), __str.end()); }
 
       basic_string(basic_string&& __str, const _Alloc& __a)
+      noexcept(_Alloc_traits::_S_always_equal())
       : _M_dataplus(_M_local_data(), __a)
       {
-	if (__str.get_allocator() == __a)
-	  *this = std::move(__str);
+	if (__str._M_is_local())
+	  {
+	    traits_type::copy(_M_local_buf, __str._M_local_buf,
+			      _S_local_capacity + 1);
+	    _M_length(__str.length());
+	    __str._M_set_length(0);
+	  }
+	else if (_Alloc_traits::_S_always_equal()
+	    || __str.get_allocator() == __a)
+	  {
+	    _M_data(__str._M_data());
+	    _M_length(__str.length());
+	    _M_capacity(__str._M_allocated_capacity);
+	    __str._M_data(__str._M_local_buf);
+	    __str._M_set_length(0);
+	  }
 	else
 	  _M_construct(__str.begin(), __str.end());
       }
@@ -550,7 +564,23 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
        */
       basic_string&
       operator=(const basic_string& __str)
-      { return this->assign(__str); }
+      {
+#if __cplusplus >= 201103L
+	if (_Alloc_traits::_S_propagate_on_copy_assign())
+	  {
+	    if (!_Alloc_traits::_S_always_equal() && !_M_is_local()
+		&& _M_get_allocator() != __str._M_get_allocator())
+	      {
+		// replacement allocator cannot free existing storage
+		_M_destroy(_M_allocated_capacity);
+		_M_data(_M_local_data());
+		_M_set_length(0);
+	      }
+	    std::__alloc_on_copy(_M_get_allocator(), __str._M_get_allocator());
+	  }
+#endif
+	return this->assign(__str);
+      }
 
       /**
        *  @brief  Copy contents of @a s into this string.
@@ -587,8 +617,51 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
       // 2063. Contradictory requirements for string move assignment
       basic_string&
       operator=(basic_string&& __str)
+      noexcept(_Alloc_traits::_S_nothrow_move())
       {
-	this->swap(__str);
+	if (!_M_is_local() && _Alloc_traits::_S_propagate_on_move_assign()
+	    && !_Alloc_traits::_S_always_equal()
+	    && _M_get_allocator() != __str._M_get_allocator())
+	  {
+	    // Destroy existing storage before replacing allocator.
+	    _M_destroy(_M_allocated_capacity);
+	    _M_data(_M_local_data());
+	    _M_set_length(0);
+	  }
+	// Replace allocator if POCMA is true.
+	std::__alloc_on_move(_M_get_allocator(), __str._M_get_allocator());
+
+	if (!__str._M_is_local()
+	    && (_Alloc_traits::_S_propagate_on_move_assign()
+	      || _Alloc_traits::_S_always_equal()))
+	  {
+	    pointer __data = nullptr;
+	    size_type __capacity;
+	    if (!_M_is_local())
+	      {
+		if (_Alloc_traits::_S_always_equal())
+		  {
+		    __data = _M_data();
+		    __capacity = _M_allocated_capacity;
+		  }
+		else
+		  _M_destroy(_M_allocated_capacity);
+	      }
+
+	    _M_data(__str._M_data());
+	    _M_length(__str.length());
+	    _M_capacity(__str._M_allocated_capacity);
+	    if (__data)
+	      {
+		__str._M_data(__data);
+		__str._M_capacity(__capacity);
+	      }
+	    else
+	      __str._M_data(__str._M_local_buf);
+	  }
+	else
+	    assign(__str);
+	__str.clear();
 	return *this;
       }
 
@@ -1119,6 +1192,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
        */
       basic_string&
       assign(basic_string&& __str)
+      noexcept(_Alloc_traits::_S_nothrow_move())
       {
 	// _GLIBCXX_RESOLVE_LIB_DEFECTS
 	// 2063. Contradictory requirements for string move assignment
@@ -4961,13 +5035,14 @@ _GLIBCXX_END_NAMESPACE_CXX11
     inline bool
     operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
 	       const basic_string<_CharT, _Traits, _Alloc>& __rhs)
+    _GLIBCXX_NOEXCEPT
     { return __lhs.compare(__rhs) == 0; }
 
   template<typename _CharT>
     inline
     typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value, bool>::__type
     operator==(const basic_string<_CharT>& __lhs,
-	       const basic_string<_CharT>& __rhs)
+	       const basic_string<_CharT>& __rhs) _GLIBCXX_NOEXCEPT
     { return (__lhs.size() == __rhs.size()
 	      && !std::char_traits<_CharT>::compare(__lhs.data(), __rhs.data(),
 						    __lhs.size())); }
@@ -5007,6 +5082,7 @@ _GLIBCXX_END_NAMESPACE_CXX11
     inline bool
     operator!=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
 	       const basic_string<_CharT, _Traits, _Alloc>& __rhs)
+    _GLIBCXX_NOEXCEPT
     { return !(__lhs == __rhs); }
 
   /**
@@ -5044,6 +5120,7 @@ _GLIBCXX_END_NAMESPACE_CXX11
     inline bool
     operator<(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
 	      const basic_string<_CharT, _Traits, _Alloc>& __rhs)
+    _GLIBCXX_NOEXCEPT
     { return __lhs.compare(__rhs) < 0; }
 
   /**
@@ -5081,6 +5158,7 @@ _GLIBCXX_END_NAMESPACE_CXX11
     inline bool
     operator>(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
 	      const basic_string<_CharT, _Traits, _Alloc>& __rhs)
+    _GLIBCXX_NOEXCEPT
     { return __lhs.compare(__rhs) > 0; }
 
   /**
@@ -5118,6 +5196,7 @@ _GLIBCXX_END_NAMESPACE_CXX11
     inline bool
     operator<=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
 	       const basic_string<_CharT, _Traits, _Alloc>& __rhs)
+    _GLIBCXX_NOEXCEPT
     { return __lhs.compare(__rhs) <= 0; }
 
   /**
@@ -5155,6 +5234,7 @@ _GLIBCXX_END_NAMESPACE_CXX11
     inline bool
     operator>=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
 	       const basic_string<_CharT, _Traits, _Alloc>& __rhs)
+    _GLIBCXX_NOEXCEPT
     { return __lhs.compare(__rhs) >= 0; }
 
   /**
@@ -5192,6 +5272,7 @@ _GLIBCXX_END_NAMESPACE_CXX11
     inline void
     swap(basic_string<_CharT, _Traits, _Alloc>& __lhs,
 	 basic_string<_CharT, _Traits, _Alloc>& __rhs)
+    _GLIBCXX_NOEXCEPT_IF(noexcept(__lhs.swap(__rhs)))
     { __lhs.swap(__rhs); }
 
 

diff --git a/libstdc++-v3/include/bits/basic_string.tcc b/libstdc++-v3/include/bits/basic_string.tcc
@@ -61,11 +61,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       if (this == &__s)
 	return;
 
-      // _GLIBCXX_RESOLVE_LIB_DEFECTS
-      // 431. Swapping containers with unequal allocators.
-      // TODO propagation traits
-      std::__alloc_swap<allocator_type>::_S_do_it(_M_get_allocator(),
-						  __s._M_get_allocator());
+      _Alloc_traits::_S_on_swap(_M_get_allocator(), __s._M_get_allocator());
 
       if (_M_is_local())
 	if (__s._M_is_local())
@@ -404,7 +400,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
       if (__new_size <= this->capacity())
 	{
-	  _CharT* __p = this->_M_data() + __pos1;
+	  pointer __p = this->_M_data() + __pos1;
 
 	  const size_type __how_much = __old_size - __pos1 - __n1;
 	  if (__how_much && __n1 != __n2)
@@ -433,7 +429,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
       if (__new_size <= this->capacity())
 	{
-	  _CharT* __p = this->_M_data() + __pos;
+	  pointer __p = this->_M_data() + __pos;
 
 	  const size_type __how_much = __old_size - __pos - __len1;
 	  if (_M_disjunct(__s))