xref: /openbsd-src/gnu/gcc/libstdc++-v3/include/ext/debug_allocator.h (revision 404b540a9034ac75a6199ad1a32d1bbc7a0d4210)
1*404b540aSrobert // Allocators -*- C++ -*-
2*404b540aSrobert 
3*404b540aSrobert // Copyright (C) 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
4*404b540aSrobert //
5*404b540aSrobert // This file is part of the GNU ISO C++ Library.  This library is free
6*404b540aSrobert // software; you can redistribute it and/or modify it under the
7*404b540aSrobert // terms of the GNU General Public License as published by the
8*404b540aSrobert // Free Software Foundation; either version 2, or (at your option)
9*404b540aSrobert // any later version.
10*404b540aSrobert 
11*404b540aSrobert // This library is distributed in the hope that it will be useful,
12*404b540aSrobert // but WITHOUT ANY WARRANTY; without even the implied warranty of
13*404b540aSrobert // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14*404b540aSrobert // GNU General Public License for more details.
15*404b540aSrobert 
16*404b540aSrobert // You should have received a copy of the GNU General Public License along
17*404b540aSrobert // with this library; see the file COPYING.  If not, write to the Free
18*404b540aSrobert // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
19*404b540aSrobert // USA.
20*404b540aSrobert 
21*404b540aSrobert // As a special exception, you may use this file as part of a free software
22*404b540aSrobert // library without restriction.  Specifically, if other files instantiate
23*404b540aSrobert // templates or use macros or inline functions from this file, or you compile
24*404b540aSrobert // this file and link it with other files to produce an executable, this
25*404b540aSrobert // file does not by itself cause the resulting executable to be covered by
26*404b540aSrobert // the GNU General Public License.  This exception does not however
27*404b540aSrobert // invalidate any other reasons why the executable file might be covered by
28*404b540aSrobert // the GNU General Public License.
29*404b540aSrobert 
30*404b540aSrobert /*
31*404b540aSrobert  * Copyright (c) 1996-1997
32*404b540aSrobert  * Silicon Graphics Computer Systems, Inc.
33*404b540aSrobert  *
34*404b540aSrobert  * Permission to use, copy, modify, distribute and sell this software
35*404b540aSrobert  * and its documentation for any purpose is hereby granted without fee,
36*404b540aSrobert  * provided that the above copyright notice appear in all copies and
37*404b540aSrobert  * that both that copyright notice and this permission notice appear
38*404b540aSrobert  * in supporting documentation.  Silicon Graphics makes no
39*404b540aSrobert  * representations about the suitability of this software for any
40*404b540aSrobert  * purpose.  It is provided "as is" without express or implied warranty.
41*404b540aSrobert  */
42*404b540aSrobert 
43*404b540aSrobert /** @file ext/debug_allocator.h
44*404b540aSrobert  *  This file is a GNU extension to the Standard C++ Library.
45*404b540aSrobert  *  You should only include this header if you are using GCC 3 or later.
46*404b540aSrobert  */
47*404b540aSrobert 
48*404b540aSrobert #ifndef _DEBUG_ALLOCATOR_H
49*404b540aSrobert #define _DEBUG_ALLOCATOR_H 1
50*404b540aSrobert 
51*404b540aSrobert #include <stdexcept>
52*404b540aSrobert 
53*404b540aSrobert _GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
54*404b540aSrobert 
55*404b540aSrobert   using std::size_t;
56*404b540aSrobert 
57*404b540aSrobert   /**
58*404b540aSrobert    *  @brief  A meta-allocator with debugging bits, as per [20.4].
59*404b540aSrobert    *
60*404b540aSrobert    *  This is precisely the allocator defined in the C++ Standard.
61*404b540aSrobert    *    - all allocation calls operator new
62*404b540aSrobert    *    - all deallocation calls operator delete
63*404b540aSrobert    */
64*404b540aSrobert   template<typename _Alloc>
65*404b540aSrobert     class debug_allocator
66*404b540aSrobert     {
67*404b540aSrobert     public:
68*404b540aSrobert       typedef typename _Alloc::size_type       	size_type;
69*404b540aSrobert       typedef typename _Alloc::difference_type	difference_type;
70*404b540aSrobert       typedef typename _Alloc::pointer       	pointer;
71*404b540aSrobert       typedef typename _Alloc::const_pointer    const_pointer;
72*404b540aSrobert       typedef typename _Alloc::reference       	reference;
73*404b540aSrobert       typedef typename _Alloc::const_reference  const_reference;
74*404b540aSrobert       typedef typename _Alloc::value_type       value_type;
75*404b540aSrobert 
76*404b540aSrobert     private:
77*404b540aSrobert       // _M_extra is the number of objects that correspond to the
78*404b540aSrobert       // extra space where debug information is stored.
79*404b540aSrobert       size_type 		_M_extra;
80*404b540aSrobert 
81*404b540aSrobert       _Alloc			_M_allocator;
82*404b540aSrobert 
83*404b540aSrobert     public:
debug_allocator()84*404b540aSrobert       debug_allocator()
85*404b540aSrobert       {
86*404b540aSrobert 	const size_t __obj_size = sizeof(value_type);
87*404b540aSrobert 	_M_extra = (sizeof(size_type) + __obj_size - 1) / __obj_size;
88*404b540aSrobert       }
89*404b540aSrobert 
90*404b540aSrobert       pointer
allocate(size_type __n)91*404b540aSrobert       allocate(size_type __n)
92*404b540aSrobert       {
93*404b540aSrobert         pointer __res = _M_allocator.allocate(__n + _M_extra);
94*404b540aSrobert 	size_type* __ps = reinterpret_cast<size_type*>(__res);
95*404b540aSrobert 	*__ps = __n;
96*404b540aSrobert         return __res + _M_extra;
97*404b540aSrobert       }
98*404b540aSrobert 
99*404b540aSrobert       pointer
allocate(size_type __n,const void * __hint)100*404b540aSrobert       allocate(size_type __n, const void* __hint)
101*404b540aSrobert       {
102*404b540aSrobert         pointer __res = _M_allocator.allocate(__n + _M_extra, __hint);
103*404b540aSrobert 	size_type* __ps = reinterpret_cast<size_type*>(__res);
104*404b540aSrobert 	*__ps = __n;
105*404b540aSrobert         return __res + _M_extra;
106*404b540aSrobert       }
107*404b540aSrobert 
108*404b540aSrobert       void
deallocate(pointer __p,size_type __n)109*404b540aSrobert       deallocate(pointer __p, size_type __n)
110*404b540aSrobert       {
111*404b540aSrobert 	if (__p)
112*404b540aSrobert 	  {
113*404b540aSrobert 	    pointer __real_p = __p - _M_extra;
114*404b540aSrobert 	    if (*reinterpret_cast<size_type*>(__real_p) != __n)
115*404b540aSrobert 	      {
116*404b540aSrobert 		throw std::runtime_error("debug_allocator::deallocate"
117*404b540aSrobert 					 " wrong size");
118*404b540aSrobert 	      }
119*404b540aSrobert 	    _M_allocator.deallocate(__real_p, __n + _M_extra);
120*404b540aSrobert 	  }
121*404b540aSrobert 	else
122*404b540aSrobert 	  throw std::runtime_error("debug_allocator::deallocate null pointer");
123*404b540aSrobert       }
124*404b540aSrobert     };
125*404b540aSrobert 
126*404b540aSrobert _GLIBCXX_END_NAMESPACE
127*404b540aSrobert 
128*404b540aSrobert #endif
129