1 /* PA host-specific hook definitions.
2 Copyright (C) 2004 Free Software Foundation, Inc.
4 This file is part of GCC.
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.
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.
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, 59 Temple Place - Suite 330, Boston,
19 MA 02111-1307, USA. */
23 #include "coretypes.h"
26 #include "hosthooks.h"
27 #include "hosthooks-def.h"
29 static void *pa_gt_pch_get_address (size_t, int);
30 static int pa_gt_pch_use_address (void *, size_t, int, size_t);
32 #undef HOST_HOOKS_GT_PCH_GET_ADDRESS
33 #define HOST_HOOKS_GT_PCH_GET_ADDRESS pa_gt_pch_get_address
34 #undef HOST_HOOKS_GT_PCH_USE_ADDRESS
35 #define HOST_HOOKS_GT_PCH_USE_ADDRESS pa_gt_pch_use_address
37 /* For various ports, try to guess a fixed spot in the vm space
38 that's probably free. */
39 #if defined(__hppa__) && defined(__LP64__)
40 # define TRY_EMPTY_VM_SPACE 0x8000000000000000
41 #elif defined(__hppa__)
42 # define TRY_EMPTY_VM_SPACE 0x60000000
44 # define TRY_EMPTY_VM_SPACE 0
47 /* Determine a location where we might be able to reliably allocate
48 SIZE bytes. FD is the PCH file, though we should return with the
52 pa_gt_pch_get_address (size_t size, int fd)
56 addr = mmap ((void *)TRY_EMPTY_VM_SPACE, size, PROT_READ | PROT_WRITE,
59 /* If we failed the map, that means there's *no* free space. */
60 if (addr == (void *) MAP_FAILED)
62 /* Unmap the area before returning. */
68 /* Map SIZE bytes of FD+OFFSET at BASE. Return 1 if we succeeded at
69 mapping the data at BASE, -1 if we couldn't.
71 It's not possibly to reliably mmap a file using MAP_PRIVATE to
72 a specific START address on either hpux or linux. First we see
73 if mmap with MAP_PRIVATE works. If it does, we are off to the
74 races. If it doesn't, we try an anonymous private mmap since the
75 kernel is more likely to honor the BASE address in anonymous maps.
76 We then copy the data to the anonymous private map. This assumes
77 of course that we don't need to change the data in the PCH file
80 This approach obviously causes a performance penalty but there is
81 little else we can do given the current PCH implementation. */
84 pa_gt_pch_use_address (void *base, size_t size, int fd, size_t offset)
88 /* We're called with size == 0 if we're not planning to load a PCH
89 file at all. This allows the hook to free any static space that
90 we might have allocated at link time. */
94 /* Try to map the file with MAP_PRIVATE. */
95 addr = mmap (base, size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, offset);
100 if (addr != (void *) MAP_FAILED)
103 /* Try to make an anonymous private mmap at the desired location. */
104 addr = mmap (base, size, PROT_READ | PROT_WRITE,
105 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
109 if (addr != (void *) MAP_FAILED)
114 if (lseek (fd, offset, SEEK_SET) == (off_t)-1)
117 if (read (fd, base, size) == -1)
124 const struct host_hooks host_hooks = HOST_HOOKS_INITIALIZER;