1/* Darwin host-specific hook definitions.
2   Copyright (C) 2003, 2004, 2005 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 2, 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 COPYING.  If not, write to the
18   Free Software Foundation, 51 Franklin Street, Fifth Floor, Boston,
19   MA 02110-1301, USA.  */
20
21#include "config.h"
22#include "system.h"
23#include "coretypes.h"
24#include <sys/mman.h>
25#include "toplev.h"
26#include "config/host-darwin.h"
27
28/* Yes, this is really supposed to work.  */
29static char pch_address_space[1024*1024*1024] __attribute__((aligned (4096)));
30
31/* Return the address of the PCH address space, if the PCH will fit in it.  */
32
33void *
34darwin_gt_pch_get_address (size_t sz, int fd ATTRIBUTE_UNUSED)
35{
36  if (sz <= sizeof (pch_address_space))
37    return pch_address_space;
38  else
39    return NULL;
40}
41
42/* Check ADDR and SZ for validity, and deallocate (using munmap) that part of
43   pch_address_space beyond SZ.  */
44
45int
46darwin_gt_pch_use_address (void *addr, size_t sz, int fd, size_t off)
47{
48  const size_t pagesize = getpagesize();
49  void *mmap_result;
50  int ret;
51
52  gcc_assert ((size_t)pch_address_space % pagesize == 0
53	      && sizeof (pch_address_space) % pagesize == 0);
54
55  ret = (addr == pch_address_space && sz <= sizeof (pch_address_space));
56  if (! ret)
57    sz = 0;
58
59  /* Round the size to a whole page size.  Normally this is a no-op.  */
60  sz = (sz + pagesize - 1) / pagesize * pagesize;
61
62  if (munmap (pch_address_space + sz, sizeof (pch_address_space) - sz) != 0)
63    fatal_error ("couldn't unmap pch_address_space: %m");
64
65  if (ret)
66    {
67      mmap_result = mmap (addr, sz,
68			  PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_FIXED,
69			  fd, off);
70
71      /* The file might not be mmap-able.  */
72      ret = mmap_result != (void *) MAP_FAILED;
73
74      /* Sanity check for broken MAP_FIXED.  */
75      gcc_assert (!ret || mmap_result == addr);
76    }
77
78  return ret;
79}
80