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

   1 // Support routines for the -*- C++ -*- dynamic memory management.
   2 // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2004 Free Software Foundation
   3 //
   4 // This file is part of GCC.
   5 //
   6 // GCC is free software; you can redistribute it and/or modify
   7 // it under the terms of the GNU General Public License as published by
   8 // the Free Software Foundation; either version 2, or (at your option)
   9 // any later version.
  10 //
  11 // GCC is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15 //
  16 // You should have received a copy of the GNU General Public License
  17 // along with GCC; see the file COPYING.  If not, write to
  18 // the Free Software Foundation, 51 Franklin Street, Fifth Floor,
  19 // Boston, MA 02110-1301, USA.
  20 //
  21 // As a special exception, you may use this file as part of a free software
  22 // library without restriction.  Specifically, if other files instantiate
  23 // templates or use macros or inline functions from this file, or you compile
  24 // this file and link it with other files to produce an executable, this
  25 // file does not by itself cause the resulting executable to be covered by
  26 // the GNU General Public License.  This exception does not however
  27 // invalidate any other reasons why the executable file might be covered by
  28 // the GNU General Public License.
  29
  30 #include "new"
  31 #include <exception_defines.h>
  32 #include <bits/c++config.h>
  33
  34 using std::new_handler;
  35 using std::bad_alloc;
  36
  37 extern "C" void *malloc (std::size_t);
  38 extern new_handler __new_handler;
  39
  40 _GLIBCXX_WEAK_DEFINITION void *
  41 operator new (std::size_t sz, const std::nothrow_t&) throw()
  42 {
  43   void *p;
  44
  45   /* malloc (0) is unpredictable; avoid it.  */
  46   if (sz == 0)
  47     sz = 1;
  48   p = (void *) malloc (sz);
  49   while (p == 0)
  50     {
  51       new_handler handler = __new_handler;
  52       if (! handler)
  53         return 0;
  54       try
  55         {
  56           handler ();
  57         }
  58       catch (bad_alloc &)
  59         {
  60           return 0;
  61         }
  62
  63       p = (void *) malloc (sz);
  64     }
  65
  66   return p;
  67 }