Use CSTD and remove local CSTD settings which are no longer needed.
[dragonfly.git] / lib / libstand / sbrk.c
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1/*-
2 * Copyright (c) 1998 Michael Smith
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD: src/lib/libstand/sbrk.c,v 1.2.2.1 2000/05/18 08:00:57 ps Exp $
1de703da 27 * $DragonFly: src/lib/libstand/sbrk.c,v 1.2 2003/06/17 04:26:51 dillon Exp $
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28 */
29
30/*
31 * Minimal sbrk() emulation required for malloc support.
32 */
33
34#include <string.h>
35#include "stand.h"
36
37static size_t maxheap, heapsize = 0;
38static void *heapbase;
39
40void
41setheap(void *base, void *top)
42{
43 /* Align start address to 16 bytes for the malloc code. Sigh. */
44 heapbase = (void *)(((uintptr_t)base + 15) & ~15);
45 maxheap = top - heapbase;
46}
47
48char *
49sbrk(int incr)
50{
51 char *ret;
52
53 if ((heapsize + incr) <= maxheap) {
54 ret = heapbase + heapsize;
55 bzero(ret, incr);
56 heapsize += incr;
57 return(ret);
58 }
59 errno = ENOMEM;
60 return((char *)-1);
61}
62