1/* Darwin host-specific hook definitions.
2   Copyright (C) 2003, 2004, 2005, 2007 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 <sys/mman.h>
24#include "toplev.h"
25#include "config/host-darwin.h"
26
27/* Yes, this is really supposed to work.  */
28static char pch_address_space[1024*1024*1024] __attribute__((aligned (4096)));
29
30/* Return the address of the PCH address space, if the PCH will fit in it.  */
31
32void *
33darwin_gt_pch_get_address (size_t sz, int fd ATTRIBUTE_UNUSED)
34{
35  if (sz <= sizeof (pch_address_space))
36    return pch_address_space;
37  else
38    return NULL;
39}
40
41/* Check ADDR and SZ for validity, and deallocate (using munmap) that part of
42   pch_address_space beyond SZ.  */
43
44int
45darwin_gt_pch_use_address (void *addr, size_t sz, int fd, size_t off)
46{
47  const size_t pagesize = getpagesize();
48  void *mmap_result;
49  int ret;
50
51  gcc_assert ((size_t)pch_address_space % pagesize == 0
52	      && sizeof (pch_address_space) % pagesize == 0);
53
54  ret = (addr == pch_address_space && sz <= sizeof (pch_address_space));
55  if (! ret)
56    sz = 0;
57
58  /* Round the size to a whole page size.  Normally this is a no-op.  */
59  sz = (sz + pagesize - 1) / pagesize * pagesize;
60
61  if (munmap (pch_address_space + sz, sizeof (pch_address_space) - sz) != 0)
62    fatal_error ("couldn't unmap pch_address_space: %m");
63
64  if (ret)
65    {
66      mmap_result = mmap (addr, sz,
67			  PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_FIXED,
68			  fd, off);
69
70      /* The file might not be mmap-able.  */
71      ret = mmap_result != (void *) MAP_FAILED;
72
73      /* Sanity check for broken MAP_FIXED.  */
74      gcc_assert (!ret || mmap_result == addr);
75    }
76
77  return ret;
78}
79