libstdc++-v3/libsupc++/new_opnt.cc

   1 // Support routines for the -*- C++ -*- dynamic memory management.
   2 // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2004, 2009
   3 // Free Software Foundation
   4 //
   5 // This file is part of GCC.
   6 //
   7 // GCC is free software; you can redistribute it and/or modify
   8 // it under the terms of the GNU General Public License as published by
   9 // the Free Software Foundation; either version 3, or (at your option)
  10 // any later version.
  11 //
  12 // GCC is distributed in the hope that it will be useful,
  13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 // GNU General Public License for more details.
  16 //
  17 // Under Section 7 of GPL version 3, you are granted additional
  18 // permissions described in the GCC Runtime Library Exception, version
  19 // 3.1, as published by the Free Software Foundation.
  20
  21 // You should have received a copy of the GNU General Public License and
  22 // a copy of the GCC Runtime Library Exception along with this program;
  23 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  24 // <http://www.gnu.org/licenses/>.
  25
  26 #include <bits/c++config.h>
  27 #include <exception_defines.h>
  28 #include "new"
  29
  30 using std::new_handler;
  31 using std::bad_alloc;
  32
  33 extern "C" void *malloc (std::size_t);
  34 extern new_handler __new_handler;
  35
  36 _GLIBCXX_WEAK_DEFINITION void *
  37 operator new (std::size_t sz, const std::nothrow_t&) throw()
  38 {
  39   void *p;
  40
  41   /* malloc (0) is unpredictable; avoid it.  */
  42   if (sz == 0)
  43     sz = 1;
  44   p = (void *) malloc (sz);
  45   while (p == 0)
  46     {
  47       new_handler handler = __new_handler;
  48       if (! handler)
  49         return 0;
  50       try
  51         {
  52           handler ();
  53         }
  54       catch (bad_alloc &)
  55         {
  56           return 0;
  57         }
  58
  59       p = (void *) malloc (sz);
  60     }
  61
  62   return p;
  63 }