libstdc++: Use RAII to replace try/catch blocks

Move _Guard into std::vector declaration and use it to guard all calls to
vector _M_allocate.

Doing so the compiler has more visibility on what is done with the pointers
and do not raise anymore the -Wfree-nonheap-object warning.

libstdc++-v3/ChangeLog:

	* include/bits/vector.tcc (_Guard): Move all the nested duplicated class...
	* include/bits/stl_vector.h (_Guard_alloc): ...here and rename.
	(_M_allocate_and_copy): Use latter.
	(_M_initialize_dispatch): Small code simplification.
	(_M_range_initialize): Likewise and set _M_finish first from the result
	of __uninitialize_fill_n_a that can throw.

2 files changed, 55 insertions, 100 deletions

diff --git a/libstdc++-v3/include/bits/stl_vector.h b/libstdc++-v3/include/bits/stl_vector.h
index 3116971..182ad41 100644
--- a/libstdc++-v3/include/bits/stl_vector.h
+++ b/libstdc++-v3/include/bits/stl_vector.h
@@ -1607,6 +1607,39 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       clear() _GLIBCXX_NOEXCEPT
       { _M_erase_at_end(this->_M_impl._M_start); }
 
+    private:
+      // RAII guard for allocated storage.
+      struct _Guard_alloc
+      {
+	pointer _M_storage;	    // Storage to deallocate
+	size_type _M_len;
+	_Base& _M_vect;
+
+	_GLIBCXX20_CONSTEXPR
+	_Guard_alloc(pointer __s, size_type __l, _Base& __vect)
+	: _M_storage(__s), _M_len(__l), _M_vect(__vect)
+	{ }
+
+	_GLIBCXX20_CONSTEXPR
+	~_Guard_alloc()
+	{
+	  if (_M_storage)
+	    _M_vect._M_deallocate(_M_storage, _M_len);
+	}
+
+	_GLIBCXX20_CONSTEXPR
+	pointer
+	_M_release()
+	{
+	  pointer __res = _M_storage;
+	  _M_storage = pointer();
+	  return __res;
+	}
+
+      private:
+	_Guard_alloc(const _Guard_alloc&);
+      };
+
     protected:
       /**
        *  Memory expansion handler.  Uses the member allocation function to
@@ -1618,18 +1651,10 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
 	_M_allocate_and_copy(size_type __n,
 			     _ForwardIterator __first, _ForwardIterator __last)
 	{
-	  pointer __result = this->_M_allocate(__n);
-	  __try
-	    {
-	      std::__uninitialized_copy_a(__first, __last, __result,
-					  _M_get_Tp_allocator());
-	      return __result;
-	    }
-	  __catch(...)
-	    {
-	      _M_deallocate(__result, __n);
-	      __throw_exception_again;
-	    }
+	  _Guard_alloc __guard(this->_M_allocate(__n), __n, *this);
+	  std::__uninitialized_copy_a
+	    (__first, __last, __guard._M_storage, _M_get_Tp_allocator());
+	  return __guard._M_release();
 	}
 
 
@@ -1642,13 +1667,14 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       // 438. Ambiguity in the "do the right thing" clause
       template<typename _Integer>
 	void
-	_M_initialize_dispatch(_Integer __n, _Integer __value, __true_type)
+	_M_initialize_dispatch(_Integer __int_n, _Integer __value, __true_type)
 	{
-	  this->_M_impl._M_start = _M_allocate(_S_check_init_len(
-		static_cast<size_type>(__n), _M_get_Tp_allocator()));
-	  this->_M_impl._M_end_of_storage =
-	    this->_M_impl._M_start + static_cast<size_type>(__n);
-	  _M_fill_initialize(static_cast<size_type>(__n), __value);
+	  const size_type __n = static_cast<size_type>(__int_n);
+	  pointer __start =
+	    _M_allocate(_S_check_init_len(__n, _M_get_Tp_allocator()));
+	  this->_M_impl._M_start = __start;
+	  this->_M_impl._M_end_of_storage = __start + __n;
+	  _M_fill_initialize(__n, __value);
 	}
 
       // Called by the range constructor to implement [23.1.1]/9
@@ -1690,13 +1716,14 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
 			    std::forward_iterator_tag)
 	{
 	  const size_type __n = std::distance(__first, __last);
-	  this->_M_impl._M_start
-	    = this->_M_allocate(_S_check_init_len(__n, _M_get_Tp_allocator()));
-	  this->_M_impl._M_end_of_storage = this->_M_impl._M_start + __n;
-	  this->_M_impl._M_finish =
-	    std::__uninitialized_copy_a(__first, __last,
-					this->_M_impl._M_start,
-					_M_get_Tp_allocator());
+	  pointer __start =
+	    this->_M_allocate(_S_check_init_len(__n, _M_get_Tp_allocator()));
+	  _Guard_alloc __guard(__start, __n, *this);
+	  this->_M_impl._M_finish = std::__uninitialized_copy_a
+	    (__first, __last, __start, _M_get_Tp_allocator());
+	  this->_M_impl._M_start = __start;
+	  (void) __guard._M_release();
+	  this->_M_impl._M_end_of_storage = __start + __n;
 	}
 
       // Called by the first initialize_dispatch above and by the
diff --git a/libstdc++-v3/include/bits/vector.tcc b/libstdc++-v3/include/bits/vector.tcc
index 25df060..36b27dc 100644
--- a/libstdc++-v3/include/bits/vector.tcc
+++ b/libstdc++-v3/include/bits/vector.tcc
@@ -467,32 +467,8 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       pointer __new_start(this->_M_allocate(__len));
       pointer __new_finish(__new_start);
 
-      // RAII guard for allocated storage.
-      struct _Guard
       {
-	pointer _M_storage;	    // Storage to deallocate
-	size_type _M_len;
-	_Tp_alloc_type& _M_alloc;
-
-	_GLIBCXX20_CONSTEXPR
-	_Guard(pointer __s, size_type __l, _Tp_alloc_type& __a)
-	: _M_storage(__s), _M_len(__l), _M_alloc(__a)
-	{ }
-
-	_GLIBCXX20_CONSTEXPR
-	~_Guard()
-	{
-	  if (_M_storage)
-	    __gnu_cxx::__alloc_traits<_Tp_alloc_type>::
-	      deallocate(_M_alloc, _M_storage, _M_len);
-	}
-
-      private:
-	_Guard(const _Guard&);
-      };
-
-      {
-	_Guard __guard(__new_start, __len, _M_impl);
+	_Guard_alloc __guard(__new_start, __len, *this);
 
 	// The order of the three operations is dictated by the C++11
 	// case, where the moves could alter a new element belonging
@@ -596,32 +572,8 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       pointer __new_start(this->_M_allocate(__len));
       pointer __new_finish(__new_start);
 
-      // RAII guard for allocated storage.
-      struct _Guard
       {
-	pointer _M_storage;	    // Storage to deallocate
-	size_type _M_len;
-	_Tp_alloc_type& _M_alloc;
-
-	_GLIBCXX20_CONSTEXPR
-	_Guard(pointer __s, size_type __l, _Tp_alloc_type& __a)
-	: _M_storage(__s), _M_len(__l), _M_alloc(__a)
-	{ }
-
-	_GLIBCXX20_CONSTEXPR
-	~_Guard()
-	{
-	  if (_M_storage)
-	    __gnu_cxx::__alloc_traits<_Tp_alloc_type>::
-	      deallocate(_M_alloc, _M_storage, _M_len);
-	}
-
-      private:
-	_Guard(const _Guard&);
-      };
-
-      {
-	_Guard __guard(__new_start, __len, _M_impl);
+	_Guard_alloc __guard(__new_start, __len, *this);
 
 	// The order of the three operations is dictated by the C++11
 	// case, where the moves could alter a new element belonging
@@ -833,32 +785,8 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
 		_M_check_len(__n, "vector::_M_default_append");
 	      pointer __new_start(this->_M_allocate(__len));
 
-	      // RAII guard for allocated storage.
-	      struct _Guard
-	      {
-		pointer _M_storage;         // Storage to deallocate
-		size_type _M_len;
-		_Tp_alloc_type& _M_alloc;
-
-		_GLIBCXX20_CONSTEXPR
-		_Guard(pointer __s, size_type __l, _Tp_alloc_type& __a)
-		: _M_storage(__s), _M_len(__l), _M_alloc(__a)
-		{ }
-
-		_GLIBCXX20_CONSTEXPR
-		~_Guard()
-		{
-		  if (_M_storage)
-		    __gnu_cxx::__alloc_traits<_Tp_alloc_type>::
-		      deallocate(_M_alloc, _M_storage, _M_len);
-		}
-
-	      private:
-		_Guard(const _Guard&);
-	      };
-
 	      {
-		_Guard __guard(__new_start, __len, _M_impl);
+		_Guard_alloc __guard(__new_start, __len, *this);
 
 		std::__uninitialized_default_n_a(__new_start + __size, __n,
 						 _M_get_Tp_allocator());