1/* HP-UX 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
26static void *hpux_gt_pch_get_address (size_t, int);
27static int hpux_gt_pch_use_address (void *, size_t, int, size_t);
28
29#undef HOST_HOOKS_GT_PCH_GET_ADDRESS
30#define HOST_HOOKS_GT_PCH_GET_ADDRESS hpux_gt_pch_get_address
31#undef HOST_HOOKS_GT_PCH_USE_ADDRESS
32#define HOST_HOOKS_GT_PCH_USE_ADDRESS hpux_gt_pch_use_address
33
34/* For various ports, try to guess a fixed spot in the vm space
35   that's probably free.  */
36#if (defined(__hppa__) || defined(__ia64__)) && defined(__LP64__)
37# define TRY_EMPTY_VM_SPACE	0x8000000000000000
38#elif defined(__hppa__) || defined(__ia64__)
39# define TRY_EMPTY_VM_SPACE	0x60000000
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 *
49hpux_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
68   It's not possibly to reliably mmap a file using MAP_PRIVATE to
69   a specific START address on either hpux or linux.  First we see
70   if mmap with MAP_PRIVATE works.  If it does, we are off to the
71   races.  If it doesn't, we try an anonymous private mmap since the
72   kernel is more likely to honor the BASE address in anonymous maps.
73   We then copy the data to the anonymous private map.  This assumes
74   of course that we don't need to change the data in the PCH file
75   after it is created.
76
77   This approach obviously causes a performance penalty but there is
78   little else we can do given the current PCH implementation.  */
79
80static int
81hpux_gt_pch_use_address (void *base, size_t size, int fd, size_t offset)
82{
83  void *addr;
84
85  /* We're called with size == 0 if we're not planning to load a PCH
86     file at all.  This allows the hook to free any static space that
87     we might have allocated at link time.  */
88  if (size == 0)
89    return -1;
90
91  /* Try to map the file with MAP_PRIVATE.  */
92  addr = mmap (base, size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, offset);
93
94  if (addr == base)
95    return 1;
96
97  if (addr != (void *) MAP_FAILED)
98    munmap (addr, size);
99
100  /* Try to make an anonymous private mmap at the desired location.  */
101  addr = mmap (base, size, PROT_READ | PROT_WRITE,
102	       MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
103
104  if (addr != base)
105    {
106      if (addr != (void *) MAP_FAILED)
107        munmap (addr, size);
108      return -1;
109    }
110
111  if (lseek (fd, offset, SEEK_SET) == (off_t)-1)
112    return -1;
113
114  while (size)
115    {
116      ssize_t nbytes;
117
118      nbytes = read (fd, base, MIN (size, SSIZE_MAX));
119      if (nbytes <= 0)
120        return -1;
121      base = (char *) base + nbytes;
122      size -= nbytes;
123    }
124
125  return 1;
126}
127
128
129const struct host_hooks host_hooks = HOST_HOOKS_INITIALIZER;
130