1 /* $NetBSD: morecore.c,v 1.2 2016/01/13 21:56:38 christos Exp $ */
2
3 /* Copyright (C) 1991, 1992, 1993, 1994 Free Software Foundation, Inc.
4 This file is part of the GNU C Library.
5
6 The GNU C Library 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 The GNU C Library 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 the GNU C Library; see the file COPYING. If not, write to
18 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
19
20 #ifndef _MALLOC_INTERNAL
21 #define _MALLOC_INTERNAL
22 #include <malloc.h>
23 #include <unistd.h>
24 #endif
25
26 #ifndef __GNU_LIBRARY__
27 #define __sbrk sbrk
28 #endif
29
30 #ifdef __GNU_LIBRARY__
31 /* It is best not to declare this and cast its result on foreign operating
32 systems with potentially hostile include files. */
33 extern __ptr_t __sbrk __P ((int increment));
34 #endif
35
36 #ifndef NULL
37 #define NULL 0
38 #endif
39
40 /* Allocate INCREMENT more bytes of data space,
41 and return the start of data space, or NULL on errors.
42 If INCREMENT is negative, shrink data space. */
43 __ptr_t
__default_morecore(increment)44 __default_morecore (increment)
45 #ifdef __STDC__
46 ptrdiff_t increment;
47 #else
48 int increment;
49 #endif
50 {
51 __ptr_t result = (__ptr_t) __sbrk ((int) increment);
52 if (result == (__ptr_t) -1)
53 return NULL;
54 return result;
55 }
56