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