Ulrich Drepper | b08d5a8 | 2005-07-26 05:00:05 +0000 | [diff] [blame^] | 1 | /* Unaligned memory access functionality. |
| 2 | Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005 Red Hat, Inc. |
| 3 | Written by Ulrich Drepper <drepper@redhat.com>, 2001. |
| 4 | |
| 5 | This program is Open Source software; you can redistribute it and/or |
| 6 | modify it under the terms of the Open Software License version 1.0 as |
| 7 | published by the Open Source Initiative. |
| 8 | |
| 9 | You should have received a copy of the Open Software License along |
| 10 | with this program; if not, you may obtain a copy of the Open Software |
| 11 | License version 1.0 from http://www.opensource.org/licenses/osl.php or |
| 12 | by writing the Open Source Initiative c/o Lawrence Rosen, Esq., |
| 13 | 3001 King Ranch Road, Ukiah, CA 95482. */ |
| 14 | |
| 15 | #ifndef _MEMORY_ACCESS_H |
| 16 | #define _MEMORY_ACCESS_H 1 |
| 17 | |
| 18 | #include <byteswap.h> |
| 19 | #include <limits.h> |
| 20 | #include <stdint.h> |
| 21 | |
| 22 | |
| 23 | /* Number decoding macros. See 7.6 Variable Length Data. */ |
| 24 | |
| 25 | #define get_uleb128_step(var, addr, nth, break) \ |
| 26 | __b = *(addr)++; \ |
| 27 | var |= (uintmax_t) (__b & 0x7f) << (nth * 7); \ |
| 28 | if (likely ((__b & 0x80) == 0)) \ |
| 29 | break |
| 30 | |
| 31 | #define get_uleb128(var, addr) \ |
| 32 | do { \ |
| 33 | unsigned char __b; \ |
| 34 | var = 0; \ |
| 35 | get_uleb128_step (var, addr, 0, break); \ |
| 36 | var = __libdw_get_uleb128 (var, 1, &(addr)); \ |
| 37 | } while (0) |
| 38 | |
| 39 | #define get_uleb128_rest_return(var, i, addrp) \ |
| 40 | do { \ |
| 41 | for (; i < 10; ++i) \ |
| 42 | { \ |
| 43 | get_uleb128_step (var, *addrp, i, return var); \ |
| 44 | } \ |
| 45 | /* Other implementations set VALUE to UINT_MAX in this \ |
| 46 | case. So we better do this as well. */ \ |
| 47 | return UINT64_MAX; \ |
| 48 | } while (0) |
| 49 | |
| 50 | /* The signed case is similar, but we sign-extend the result. */ |
| 51 | |
| 52 | #define get_sleb128_step(var, addr, nth, break) \ |
| 53 | __b = *(addr)++; \ |
| 54 | _v |= (uint64_t) (__b & 0x7f) << (nth * 7); \ |
| 55 | if (likely ((__b & 0x80) == 0)) \ |
| 56 | { \ |
| 57 | var = (_v << (64 - (nth * 7) - 7) >> (64 - (nth * 7) - 7)); \ |
| 58 | break; \ |
| 59 | } \ |
| 60 | else do {} while (0) |
| 61 | |
| 62 | #define get_sleb128(var, addr) \ |
| 63 | do { \ |
| 64 | unsigned char __b; \ |
| 65 | int64_t _v = 0; \ |
| 66 | get_sleb128_step (var, addr, 0, break); \ |
| 67 | var = __libdw_get_sleb128 (_v, 1, &(addr)); \ |
| 68 | } while (0) |
| 69 | |
| 70 | #define get_sleb128_rest_return(var, i, addrp) \ |
| 71 | do { \ |
| 72 | for (; i < 9; ++i) \ |
| 73 | { \ |
| 74 | get_sleb128_step (var, *addrp, i, return var); \ |
| 75 | } \ |
| 76 | /* Other implementations set VALUE to INT_MAX in this \ |
| 77 | case. So we better do this as well. */ \ |
| 78 | return INT64_MAX; \ |
| 79 | } while (0) |
| 80 | |
| 81 | #ifdef IS_LIBDW |
| 82 | extern uint64_t __libdw_get_uleb128 (uint64_t acc, unsigned int i, |
| 83 | const unsigned char **addrp) |
| 84 | internal_function attribute_hidden; |
| 85 | extern int64_t __libdw_get_sleb128 (int64_t acc, unsigned int i, |
| 86 | const unsigned char **addrp) |
| 87 | internal_function attribute_hidden; |
| 88 | #else |
| 89 | static uint64_t |
| 90 | __attribute__ ((unused)) |
| 91 | __libdw_get_uleb128 (uint64_t acc, unsigned int i, const unsigned char **addrp) |
| 92 | { |
| 93 | unsigned char __b; |
| 94 | get_uleb128_rest_return (acc, i, addrp); |
| 95 | } |
| 96 | static int64_t |
| 97 | __attribute__ ((unused)) |
| 98 | __libdw_get_sleb128 (int64_t acc, unsigned int i, const unsigned char **addrp) |
| 99 | { |
| 100 | unsigned char __b; |
| 101 | int64_t _v = acc; |
| 102 | get_sleb128_rest_return (acc, i, addrp); |
| 103 | } |
| 104 | #endif |
| 105 | |
| 106 | |
| 107 | /* We use simple memory access functions in case the hardware allows it. |
| 108 | The caller has to make sure we don't have alias problems. */ |
| 109 | #if ALLOW_UNALIGNED |
| 110 | |
| 111 | # define read_2ubyte_unaligned(Dbg, Addr) \ |
| 112 | (unlikely ((Dbg)->other_byte_order) \ |
| 113 | ? bswap_16 (*((const uint16_t *) (Addr))) \ |
| 114 | : *((const uint16_t *) (Addr))) |
| 115 | # define read_2sbyte_unaligned(Dbg, Addr) \ |
| 116 | (unlikely ((Dbg)->other_byte_order) \ |
| 117 | ? (int16_t) bswap_16 (*((const int16_t *) (Addr))) \ |
| 118 | : *((const int16_t *) (Addr))) |
| 119 | |
| 120 | # define read_4ubyte_unaligned_noncvt(Addr) \ |
| 121 | *((const uint32_t *) (Addr)) |
| 122 | # define read_4ubyte_unaligned(Dbg, Addr) \ |
| 123 | (unlikely ((Dbg)->other_byte_order) \ |
| 124 | ? bswap_32 (*((const uint32_t *) (Addr))) \ |
| 125 | : *((const uint32_t *) (Addr))) |
| 126 | # define read_4sbyte_unaligned(Dbg, Addr) \ |
| 127 | (unlikely ((Dbg)->other_byte_order) \ |
| 128 | ? (int32_t) bswap_32 (*((const int32_t *) (Addr))) \ |
| 129 | : *((const int32_t *) (Addr))) |
| 130 | |
| 131 | # define read_8ubyte_unaligned(Dbg, Addr) \ |
| 132 | (unlikely ((Dbg)->other_byte_order) \ |
| 133 | ? bswap_64 (*((const uint64_t *) (Addr))) \ |
| 134 | : *((const uint64_t *) (Addr))) |
| 135 | # define read_8sbyte_unaligned(Dbg, Addr) \ |
| 136 | (unlikely ((Dbg)->other_byte_order) \ |
| 137 | ? (int64_t) bswap_64 (*((const int64_t *) (Addr))) \ |
| 138 | : *((const int64_t *) (Addr))) |
| 139 | |
| 140 | #else |
| 141 | |
| 142 | union unaligned |
| 143 | { |
| 144 | void *p; |
| 145 | uint16_t u2; |
| 146 | uint32_t u4; |
| 147 | uint64_t u8; |
| 148 | int16_t s2; |
| 149 | int32_t s4; |
| 150 | int64_t s8; |
| 151 | } __attribute__ ((packed)); |
| 152 | |
| 153 | static inline uint16_t |
| 154 | read_2ubyte_unaligned (Dwarf *dbg, const void *p) |
| 155 | { |
| 156 | const union unaligned *up = p; |
| 157 | if (dbg->other_byte_order) |
| 158 | return bswap_16 (up->u2); |
| 159 | return up->u2; |
| 160 | } |
| 161 | static inline int16_t |
| 162 | read_2sbyte_unaligned (Dwarf *dbg, const void *p) |
| 163 | { |
| 164 | const union unaligned *up = p; |
| 165 | if (dbg->other_byte_order) |
| 166 | return (int16_t) bswap_16 (up->u2); |
| 167 | return up->s2; |
| 168 | } |
| 169 | |
| 170 | static inline uint32_t |
| 171 | read_4ubyte_unaligned_noncvt (const void *p) |
| 172 | { |
| 173 | const union unaligned *up = p; |
| 174 | return up->u4; |
| 175 | } |
| 176 | static inline uint32_t |
| 177 | read_4ubyte_unaligned (Dwarf *dbg, const void *p) |
| 178 | { |
| 179 | const union unaligned *up = p; |
| 180 | if (dbg->other_byte_order) |
| 181 | return bswap_32 (up->u4); |
| 182 | return up->u4; |
| 183 | } |
| 184 | static inline int32_t |
| 185 | read_4sbyte_unaligned (Dwarf *dbg, const void *p) |
| 186 | { |
| 187 | const union unaligned *up = p; |
| 188 | if (dbg->other_byte_order) |
| 189 | return (int32_t) bswap_32 (up->u4); |
| 190 | return up->s4; |
| 191 | } |
| 192 | |
| 193 | static inline uint64_t |
| 194 | read_8ubyte_unaligned (Dwarf *dbg, const void *p) |
| 195 | { |
| 196 | const union unaligned *up = p; |
| 197 | if (dbg->other_byte_order) |
| 198 | return bswap_64 (up->u8); |
| 199 | return up->u8; |
| 200 | } |
| 201 | static inline int64_t |
| 202 | read_8sbyte_unaligned (Dwarf *dbg, const void *p) |
| 203 | { |
| 204 | const union unaligned *up = p; |
| 205 | if (dbg->other_byte_order) |
| 206 | return (int64_t) bswap_64 (up->u8); |
| 207 | return up->s8; |
| 208 | } |
| 209 | |
| 210 | #endif /* allow unaligned */ |
| 211 | |
| 212 | |
| 213 | #define read_2ubyte_unaligned_inc(Dbg, Addr) \ |
| 214 | ({ uint16_t t_ = read_2ubyte_unaligned (Dbg, Addr); \ |
| 215 | Addr = (__typeof (Addr)) (((uintptr_t) (Addr)) + 2); \ |
| 216 | t_; }) |
| 217 | #define read_2sbyte_unaligned_inc(Dbg, Addr) \ |
| 218 | ({ int16_t t_ = read_2sbyte_unaligned (Dbg, Addr); \ |
| 219 | Addr = (__typeof (Addr)) (((uintptr_t) (Addr)) + 2); \ |
| 220 | t_; }) |
| 221 | |
| 222 | #define read_4ubyte_unaligned_inc(Dbg, Addr) \ |
| 223 | ({ uint32_t t_ = read_4ubyte_unaligned (Dbg, Addr); \ |
| 224 | Addr = (__typeof (Addr)) (((uintptr_t) (Addr)) + 4); \ |
| 225 | t_; }) |
| 226 | #define read_4sbyte_unaligned_inc(Dbg, Addr) \ |
| 227 | ({ int32_t t_ = read_4sbyte_unaligned (Dbg, Addr); \ |
| 228 | Addr = (__typeof (Addr)) (((uintptr_t) (Addr)) + 4); \ |
| 229 | t_; }) |
| 230 | |
| 231 | #define read_8ubyte_unaligned_inc(Dbg, Addr) \ |
| 232 | ({ uint64_t t_ = read_8ubyte_unaligned (Dbg, Addr); \ |
| 233 | Addr = (__typeof (Addr)) (((uintptr_t) (Addr)) + 8); \ |
| 234 | t_; }) |
| 235 | #define read_8sbyte_unaligned_inc(Dbg, Addr) \ |
| 236 | ({ int64_t t_ = read_8sbyte_unaligned (Dbg, Addr); \ |
| 237 | Addr = (__typeof (Addr)) (((uintptr_t) (Addr)) + 8); \ |
| 238 | t_; }) |
| 239 | |
| 240 | #endif /* memory-access.h */ |