glibc/sysdeps/generic/morecore.c

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1995-02-18 09:27:10 +08:00
/* Copyright (C) 1991, 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library 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 2, or (at your option)
any later version.
The GNU C Library 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.
You should have received a copy of the GNU General Public License
along with the GNU C Library; see the file COPYING. If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
#ifndef _MALLOC_INTERNAL
#define _MALLOC_INTERNAL
#include <malloc.h>
#endif
#ifndef __GNU_LIBRARY__
#define __sbrk sbrk
#endif
#ifdef __GNU_LIBRARY__
/* It is best not to declare this and cast its result on foreign operating
systems with potentially hostile include files. */
extern __ptr_t __sbrk __P ((int increment));
#endif
#ifndef NULL
#define NULL 0
#endif
/* Allocate INCREMENT more bytes of data space,
and return the start of data space, or NULL on errors.
If INCREMENT is negative, shrink data space. */
__ptr_t
__default_morecore (increment)
__malloc_ptrdiff_t increment;
{
__ptr_t result = (__ptr_t) __sbrk (increment);
if (result == (__ptr_t) -1)
return NULL;
return result;
}