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

// Support routines for the -*- C++ -*- dynamic memory management.
// Copyright (C) 1997-2015 Free Software Foundation, Inc.
//
// This file is part of GCC.
//
// GCC is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 3, or (at your option)
// any later version.
//
// GCC is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.

// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
// <http://www.gnu.org/licenses/>.

#include <bits/c++config.h>
#include <bits/exception_defines.h>
#include "new"

using std::new_handler;
using std::bad_alloc;

extern "C" void *malloc (std::size_t);

_GLIBCXX_WEAK_DEFINITION void *
operator new (std::size_t sz, const std::nothrow_t&) _GLIBCXX_USE_NOEXCEPT
{
  void *p;

  /* malloc (0) is unpredictable; avoid it.  */
  if (sz == 0)
    sz = 1;

  while (__builtin_expect ((p = malloc (sz)) == 0, false))
    {
      new_handler handler = std::get_new_handler ();
      if (! handler)
	return 0;
      __try
	{
	  handler ();
	}
      __catch(const bad_alloc&)
	{
	  return 0;
	}
    }

  return p;
}