1/* HP-UX host-specific hook definitions.
2   Copyright (C) 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 <unistd.h>
26#include "hosthooks.h"
27#include "hosthooks-def.h"
28
29#ifndef MAP_FAILED
30#define MAP_FAILED (void *)-1L
31#endif
32
33static void *hpux_gt_pch_get_address (size_t, int);
34static int hpux_gt_pch_use_address (void *, size_t, int, size_t);
35
36#undef HOST_HOOKS_GT_PCH_GET_ADDRESS
37#define HOST_HOOKS_GT_PCH_GET_ADDRESS hpux_gt_pch_get_address
38#undef HOST_HOOKS_GT_PCH_USE_ADDRESS
39#define HOST_HOOKS_GT_PCH_USE_ADDRESS hpux_gt_pch_use_address
40
41/* For various ports, try to guess a fixed spot in the vm space
42   that's probably free.  */
43#if (defined(__hppa__) || defined(__ia64__)) && defined(__LP64__)
44# define TRY_EMPTY_VM_SPACE	0x8000000000000000
45#elif defined(__hppa__) || defined(__ia64__)
46# define TRY_EMPTY_VM_SPACE	0x60000000
47#else
48# define TRY_EMPTY_VM_SPACE	0
49#endif
50
51/* Determine a location where we might be able to reliably allocate
52   SIZE bytes.  FD is the PCH file, though we should return with the
53   file unmapped.  */
54
55static void *
56hpux_gt_pch_get_address (size_t size, int fd)
57{
58  void *addr;
59
60  addr = mmap ((void *)TRY_EMPTY_VM_SPACE, size, PROT_READ | PROT_WRITE,
61	       MAP_PRIVATE, fd, 0);
62
63  /* If we failed the map, that means there's *no* free space.  */
64  if (addr == (void *) MAP_FAILED)
65    return NULL;
66  /* Unmap the area before returning.  */
67  munmap (addr, size);
68
69  return addr;
70}
71
72/* Map SIZE bytes of FD+OFFSET at BASE.  Return 1 if we succeeded at
73   mapping the data at BASE, -1 if we couldn't.
74
75   It's not possibly to reliably mmap a file using MAP_PRIVATE to
76   a specific START address on either hpux or linux.  First we see
77   if mmap with MAP_PRIVATE works.  If it does, we are off to the
78   races.  If it doesn't, we try an anonymous private mmap since the
79   kernel is more likely to honor the BASE address in anonymous maps.
80   We then copy the data to the anonymous private map.  This assumes
81   of course that we don't need to change the data in the PCH file
82   after it is created.
83
84   This approach obviously causes a performance penalty but there is
85   little else we can do given the current PCH implementation.  */
86
87static int
88hpux_gt_pch_use_address (void *base, size_t size, int fd, size_t offset)
89{
90  void *addr;
91
92  /* We're called with size == 0 if we're not planning to load a PCH
93     file at all.  This allows the hook to free any static space that
94     we might have allocated at link time.  */
95  if (size == 0)
96    return -1;
97
98  /* Try to map the file with MAP_PRIVATE.  */
99  addr = mmap (base, size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, offset);
100
101  if (addr == base)
102    return 1;
103
104  if (addr != (void *) MAP_FAILED)
105    munmap (addr, size);
106
107  /* Try to make an anonymous private mmap at the desired location.  */
108  addr = mmap (base, size, PROT_READ | PROT_WRITE,
109	       MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
110
111  if (addr != base)
112    {
113      if (addr != (void *) MAP_FAILED)
114        munmap (addr, size);
115      return -1;
116    }
117
118  if (lseek (fd, offset, SEEK_SET) == (off_t)-1)
119    return -1;
120
121  while (size)
122    {
123      ssize_t nbytes;
124
125      nbytes = read (fd, base, MIN (size, SSIZE_MAX));
126      if (nbytes <= 0)
127        return -1;
128      base = (char *) base + nbytes;
129      size -= nbytes;
130    }
131
132  return 1;
133}
134
135
136const struct host_hooks host_hooks = HOST_HOOKS_INITIALIZER;
137