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

   1 // Support routines for the -*- C++ -*- dynamic memory management.
   2
   3 // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2004
   4 // Free Software Foundation
   5 //
   6 // This file is part of GCC.
   7 //
   8 // GCC is free software; you can redistribute it and/or modify
   9 // it under the terms of the GNU General Public License as published by
  10 // the Free Software Foundation; either version 2, or (at your option)
  11 // any later version.
  12 //
  13 // GCC is distributed in the hope that it will be useful,
  14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 // GNU General Public License for more details.
  17 //
  18 // You should have received a copy of the GNU General Public License
  19 // along with GCC; see the file COPYING.  If not, write to
  20 // the Free Software Foundation, 51 Franklin Street, Fifth Floor,
  21 // Boston, MA 02110-1301, USA.
  22 //
  23 // As a special exception, you may use this file as part of a free software
  24 // library without restriction.  Specifically, if other files instantiate
  25 // templates or use macros or inline functions from this file, or you compile
  26 // this file and link it with other files to produce an executable, this
  27 // file does not by itself cause the resulting executable to be covered by
  28 // the GNU General Public License.  This exception does not however
  29 // invalidate any other reasons why the executable file might be covered by
  30 // the GNU General Public License.
  31
  32 #include "new"
  33 #include <cstdlib>
  34 #include <exception_defines.h>
  35 #include <bits/c++config.h>
  36
  37 using std::new_handler;
  38 using std::bad_alloc;
  39 #if _GLIBCXX_HOSTED
  40 using std::malloc;
  41 #else
  42 // A freestanding C runtime may not provide "malloc" -- but there is no
  43 // other reasonable way to implement "operator new".
  44 extern "C" void *malloc (std::size_t);
  45 #endif
  46
  47 extern new_handler __new_handler;
  48
  49 _GLIBCXX_WEAK_DEFINITION void *
  50 operator new (std::size_t sz) throw (std::bad_alloc)
  51 {
  52   void *p;
  53
  54   /* malloc (0) is unpredictable; avoid it.  */
  55   if (sz == 0)
  56     sz = 1;
  57   p = (void *) malloc (sz);
  58   while (p == 0)
  59     {
  60       new_handler handler = __new_handler;
  61       if (! handler)
  62 #ifdef __EXCEPTIONS
  63         throw bad_alloc();
  64 #else
  65         std::abort();
  66 #endif
  67       handler ();
  68       p = (void *) malloc (sz);
  69     }
  70
  71   return p;
  72 }