1/* OpenBSD host-specific hook definitions.
2   Copyright (C) 2004-2020 Free Software Foundation, Inc.
3
4   This file is part of GCC.
5
6   GCC is free software; you can redistribute it and/or modify it
7   under the terms of the GNU General Public License as published
8   by the Free Software Foundation; either version 3, or (at your
9   option) any later version.
10
11   GCC is distributed in the hope that it will be useful, but WITHOUT
12   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
13   or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
14   License for more details.
15
16   You should have received a copy of the GNU General Public License
17   along with GCC; see the file COPYING3.  If not see
18   <http://www.gnu.org/licenses/>.  */
19
20#include "config.h"
21#include "system.h"
22#include "coretypes.h"
23#include "hosthooks.h"
24#include "hosthooks-def.h"
25
26
27#undef HOST_HOOKS_GT_PCH_GET_ADDRESS
28#define HOST_HOOKS_GT_PCH_GET_ADDRESS openbsd_gt_pch_get_address
29#undef HOST_HOOKS_GT_PCH_USE_ADDRESS
30#define HOST_HOOKS_GT_PCH_USE_ADDRESS openbsd_gt_pch_use_address
31
32/* For various ports, try to guess a fixed spot in the vm space
33   that's probably free.  */
34#if defined(__amd64__)
35# define TRY_EMPTY_VM_SPACE	0x400000000000
36#elif defined(__hppa__)
37# define TRY_EMPTY_VM_SPACE	0xb0000000
38#elif defined(__i386__)
39# define TRY_EMPTY_VM_SPACE	0xb0000000
40#else
41# define TRY_EMPTY_VM_SPACE	0
42#endif
43
44/* Determine a location where we might be able to reliably allocate
45   SIZE bytes.  FD is the PCH file, though we should return with the
46   file unmapped.  */
47
48static void *
49openbsd_gt_pch_get_address (size_t size, int fd)
50{
51  void *addr;
52
53  addr = mmap ((void *) TRY_EMPTY_VM_SPACE, size, PROT_READ | PROT_WRITE,
54	       MAP_PRIVATE, fd, 0);
55
56  /* If we failed the map, that means there's *no* free space.  */
57  if (addr == (void *) MAP_FAILED)
58    return NULL;
59  /* Unmap the area before returning.  */
60  munmap (addr, size);
61
62  return addr;
63}
64
65/* Map SIZE bytes of FD+OFFSET at BASE.  Return 1 if we succeeded at
66   mapping the data at BASE, -1 if we couldn't.  */
67
68static int
69openbsd_gt_pch_use_address (void *base, size_t size, int fd, size_t offset)
70{
71  void *addr;
72
73  /* We're called with size == 0 if we're not planning to load a PCH
74     file at all.  This allows the hook to free any static space that
75     we might have allocated at link time.  */
76  if (size == 0)
77    return -1;
78
79  addr = mmap (base, size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, offset);
80
81  return addr == base ? 1 : -1;
82}
83
84
85const struct host_hooks host_hooks = HOST_HOOKS_INITIALIZER;
86