host-hpux.c revision 1.11
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