| 1 | /* simple-object.c -- simple routines to read and write object files. |
| 2 | Copyright 2010 Free Software Foundation, Inc. |
| 3 | Written by Ian Lance Taylor, Google. |
| 4 | |
| 5 | This program is free software; you can redistribute it and/or modify it |
| 6 | under the terms of the GNU General Public License as published by the |
| 7 | Free Software Foundation; either version 2, or (at your option) any |
| 8 | later version. |
| 9 | |
| 10 | This program is distributed in the hope that it will be useful, |
| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | GNU General Public License for more details. |
| 14 | |
| 15 | You should have received a copy of the GNU General Public License |
| 16 | along with this program; if not, write to the Free Software |
| 17 | Foundation, 51 Franklin Street - Fifth Floor, |
| 18 | Boston, MA 02110-1301, USA. */ |
| 19 | |
| 20 | #include "config.h" |
| 21 | #include "libiberty.h" |
| 22 | #include "simple-object.h" |
| 23 | |
| 24 | #include <errno.h> |
| 25 | |
| 26 | #ifdef HAVE_STDLIB_H |
| 27 | #include <stdlib.h> |
| 28 | #endif |
| 29 | |
| 30 | #ifdef HAVE_STDINT_H |
| 31 | #include <stdint.h> |
| 32 | #endif |
| 33 | |
| 34 | #ifdef HAVE_STRING_H |
| 35 | #include <string.h> |
| 36 | #endif |
| 37 | |
| 38 | #ifdef HAVE_INTTYPES_H |
| 39 | #include <inttypes.h> |
| 40 | #endif |
| 41 | |
| 42 | #ifndef SEEK_SET |
| 43 | #define SEEK_SET 0 |
| 44 | #endif |
| 45 | |
| 46 | #include "simple-object-common.h" |
| 47 | |
| 48 | /* The known object file formats. */ |
| 49 | |
| 50 | static const struct simple_object_functions * const format_functions[] = |
| 51 | { |
| 52 | &simple_object_elf_functions, |
| 53 | &simple_object_mach_o_functions, |
| 54 | &simple_object_coff_functions, |
| 55 | &simple_object_xcoff_functions |
| 56 | }; |
| 57 | |
| 58 | /* Read data from a file using the simple_object error reporting |
| 59 | conventions. */ |
| 60 | |
| 61 | int |
| 62 | simple_object_internal_read (int descriptor, off_t offset, |
| 63 | unsigned char *buffer, size_t size, |
| 64 | const char **errmsg, int *err) |
| 65 | { |
| 66 | if (lseek (descriptor, offset, SEEK_SET) < 0) |
| 67 | { |
| 68 | *errmsg = "lseek"; |
| 69 | *err = errno; |
| 70 | return 0; |
| 71 | } |
| 72 | |
| 73 | do |
| 74 | { |
| 75 | ssize_t got = read (descriptor, buffer, size); |
| 76 | if (got == 0) |
| 77 | break; |
| 78 | else if (got > 0) |
| 79 | { |
| 80 | buffer += got; |
| 81 | size -= got; |
| 82 | } |
| 83 | else if (errno != EINTR) |
| 84 | { |
| 85 | *errmsg = "read"; |
| 86 | *err = errno; |
| 87 | return 0; |
| 88 | } |
| 89 | } |
| 90 | while (size > 0); |
| 91 | |
| 92 | if (size > 0) |
| 93 | { |
| 94 | *errmsg = "file too short"; |
| 95 | *err = 0; |
| 96 | return 0; |
| 97 | } |
| 98 | |
| 99 | return 1; |
| 100 | } |
| 101 | |
| 102 | /* Write data to a file using the simple_object error reporting |
| 103 | conventions. */ |
| 104 | |
| 105 | int |
| 106 | simple_object_internal_write (int descriptor, off_t offset, |
| 107 | const unsigned char *buffer, size_t size, |
| 108 | const char **errmsg, int *err) |
| 109 | { |
| 110 | if (lseek (descriptor, offset, SEEK_SET) < 0) |
| 111 | { |
| 112 | *errmsg = "lseek"; |
| 113 | *err = errno; |
| 114 | return 0; |
| 115 | } |
| 116 | |
| 117 | do |
| 118 | { |
| 119 | ssize_t wrote = write (descriptor, buffer, size); |
| 120 | if (wrote == 0) |
| 121 | break; |
| 122 | else if (wrote > 0) |
| 123 | { |
| 124 | buffer += wrote; |
| 125 | size -= wrote; |
| 126 | } |
| 127 | else if (errno != EINTR) |
| 128 | { |
| 129 | *errmsg = "write"; |
| 130 | *err = errno; |
| 131 | return 0; |
| 132 | } |
| 133 | } |
| 134 | while (size > 0); |
| 135 | |
| 136 | if (size > 0) |
| 137 | { |
| 138 | *errmsg = "short write"; |
| 139 | *err = 0; |
| 140 | return 0; |
| 141 | } |
| 142 | |
| 143 | return 1; |
| 144 | } |
| 145 | |
| 146 | /* Open for read. */ |
| 147 | |
| 148 | simple_object_read * |
| 149 | simple_object_start_read (int descriptor, off_t offset, |
| 150 | const char *segment_name, const char **errmsg, |
| 151 | int *err) |
| 152 | { |
| 153 | unsigned char header[SIMPLE_OBJECT_MATCH_HEADER_LEN]; |
| 154 | size_t len, i; |
| 155 | |
| 156 | if (!simple_object_internal_read (descriptor, offset, header, |
| 157 | SIMPLE_OBJECT_MATCH_HEADER_LEN, |
| 158 | errmsg, err)) |
| 159 | return NULL; |
| 160 | |
| 161 | len = sizeof (format_functions) / sizeof (format_functions[0]); |
| 162 | for (i = 0; i < len; ++i) |
| 163 | { |
| 164 | void *data; |
| 165 | |
| 166 | data = format_functions[i]->match (header, descriptor, offset, |
| 167 | segment_name, errmsg, err); |
| 168 | if (data != NULL) |
| 169 | { |
| 170 | simple_object_read *ret; |
| 171 | |
| 172 | ret = XNEW (simple_object_read); |
| 173 | ret->descriptor = descriptor; |
| 174 | ret->offset = offset; |
| 175 | ret->functions = format_functions[i]; |
| 176 | ret->data = data; |
| 177 | return ret; |
| 178 | } |
| 179 | } |
| 180 | |
| 181 | *errmsg = "file not recognized"; |
| 182 | *err = 0; |
| 183 | return NULL; |
| 184 | } |
| 185 | |
| 186 | /* Find all sections. */ |
| 187 | |
| 188 | const char * |
| 189 | simple_object_find_sections (simple_object_read *sobj, |
| 190 | int (*pfn) (void *, const char *, off_t, off_t), |
| 191 | void *data, |
| 192 | int *err) |
| 193 | { |
| 194 | return sobj->functions->find_sections (sobj, pfn, data, err); |
| 195 | } |
| 196 | |
| 197 | /* Internal data passed to find_one_section. */ |
| 198 | |
| 199 | struct find_one_section_data |
| 200 | { |
| 201 | /* The section we are looking for. */ |
| 202 | const char *name; |
| 203 | /* Where to store the section offset. */ |
| 204 | off_t *offset; |
| 205 | /* Where to store the section length. */ |
| 206 | off_t *length; |
| 207 | /* Set if the name is found. */ |
| 208 | int found; |
| 209 | }; |
| 210 | |
| 211 | /* Internal function passed to find_sections. */ |
| 212 | |
| 213 | static int |
| 214 | find_one_section (void *data, const char *name, off_t offset, off_t length) |
| 215 | { |
| 216 | struct find_one_section_data *fosd = (struct find_one_section_data *) data; |
| 217 | |
| 218 | if (strcmp (name, fosd->name) != 0) |
| 219 | return 1; |
| 220 | |
| 221 | *fosd->offset = offset; |
| 222 | *fosd->length = length; |
| 223 | fosd->found = 1; |
| 224 | |
| 225 | /* Stop iteration. */ |
| 226 | return 0; |
| 227 | } |
| 228 | |
| 229 | /* Find a section. */ |
| 230 | |
| 231 | int |
| 232 | simple_object_find_section (simple_object_read *sobj, const char *name, |
| 233 | off_t *offset, off_t *length, |
| 234 | const char **errmsg, int *err) |
| 235 | { |
| 236 | struct find_one_section_data fosd; |
| 237 | |
| 238 | fosd.name = name; |
| 239 | fosd.offset = offset; |
| 240 | fosd.length = length; |
| 241 | fosd.found = 0; |
| 242 | |
| 243 | *errmsg = simple_object_find_sections (sobj, find_one_section, |
| 244 | (void *) &fosd, err); |
| 245 | if (*errmsg != NULL) |
| 246 | return 0; |
| 247 | if (!fosd.found) |
| 248 | return 0; |
| 249 | return 1; |
| 250 | } |
| 251 | |
| 252 | /* Fetch attributes. */ |
| 253 | |
| 254 | simple_object_attributes * |
| 255 | simple_object_fetch_attributes (simple_object_read *sobj, const char **errmsg, |
| 256 | int *err) |
| 257 | { |
| 258 | void *data; |
| 259 | simple_object_attributes *ret; |
| 260 | |
| 261 | data = sobj->functions->fetch_attributes (sobj, errmsg, err); |
| 262 | if (data == NULL) |
| 263 | return NULL; |
| 264 | ret = XNEW (simple_object_attributes); |
| 265 | ret->functions = sobj->functions; |
| 266 | ret->data = data; |
| 267 | return ret; |
| 268 | } |
| 269 | |
| 270 | /* Release an simple_object_read. */ |
| 271 | |
| 272 | void |
| 273 | simple_object_release_read (simple_object_read *sobj) |
| 274 | { |
| 275 | sobj->functions->release_read (sobj->data); |
| 276 | XDELETE (sobj); |
| 277 | } |
| 278 | |
| 279 | /* Merge attributes. */ |
| 280 | |
| 281 | const char * |
| 282 | simple_object_attributes_merge (simple_object_attributes *to, |
| 283 | simple_object_attributes *from, |
| 284 | int *err) |
| 285 | { |
| 286 | if (to->functions != from->functions) |
| 287 | { |
| 288 | *err = 0; |
| 289 | return "different object file format"; |
| 290 | } |
| 291 | return to->functions->attributes_merge (to->data, from->data, err); |
| 292 | } |
| 293 | |
| 294 | /* Release an attributes structure. */ |
| 295 | |
| 296 | void |
| 297 | simple_object_release_attributes (simple_object_attributes *attrs) |
| 298 | { |
| 299 | attrs->functions->release_attributes (attrs->data); |
| 300 | XDELETE (attrs); |
| 301 | } |
| 302 | |
| 303 | /* Start creating an object file. */ |
| 304 | |
| 305 | simple_object_write * |
| 306 | simple_object_start_write (simple_object_attributes *attrs, |
| 307 | const char *segment_name, const char **errmsg, |
| 308 | int *err) |
| 309 | { |
| 310 | void *data; |
| 311 | simple_object_write *ret; |
| 312 | |
| 313 | data = attrs->functions->start_write (attrs->data, errmsg, err); |
| 314 | if (data == NULL) |
| 315 | return NULL; |
| 316 | ret = XNEW (simple_object_write); |
| 317 | ret->functions = attrs->functions; |
| 318 | ret->segment_name = xstrdup (segment_name); |
| 319 | ret->sections = NULL; |
| 320 | ret->last_section = NULL; |
| 321 | ret->data = data; |
| 322 | return ret; |
| 323 | } |
| 324 | |
| 325 | /* Start creating a section. */ |
| 326 | |
| 327 | simple_object_write_section * |
| 328 | simple_object_write_create_section (simple_object_write *sobj, const char *name, |
| 329 | unsigned int align, |
| 330 | const char **errmsg ATTRIBUTE_UNUSED, |
| 331 | int *err ATTRIBUTE_UNUSED) |
| 332 | { |
| 333 | simple_object_write_section *ret; |
| 334 | |
| 335 | ret = XNEW (simple_object_write_section); |
| 336 | ret->next = NULL; |
| 337 | ret->name = xstrdup (name); |
| 338 | ret->align = align; |
| 339 | ret->buffers = NULL; |
| 340 | ret->last_buffer = NULL; |
| 341 | |
| 342 | if (sobj->last_section == NULL) |
| 343 | { |
| 344 | sobj->sections = ret; |
| 345 | sobj->last_section = ret; |
| 346 | } |
| 347 | else |
| 348 | { |
| 349 | sobj->last_section->next = ret; |
| 350 | sobj->last_section = ret; |
| 351 | } |
| 352 | |
| 353 | return ret; |
| 354 | } |
| 355 | |
| 356 | /* Add data to a section. */ |
| 357 | |
| 358 | const char * |
| 359 | simple_object_write_add_data (simple_object_write *sobj ATTRIBUTE_UNUSED, |
| 360 | simple_object_write_section *section, |
| 361 | const void *buffer, |
| 362 | size_t size, int copy, |
| 363 | int *err ATTRIBUTE_UNUSED) |
| 364 | { |
| 365 | struct simple_object_write_section_buffer *wsb; |
| 366 | |
| 367 | wsb = XNEW (struct simple_object_write_section_buffer); |
| 368 | wsb->next = NULL; |
| 369 | wsb->size = size; |
| 370 | |
| 371 | if (!copy) |
| 372 | { |
| 373 | wsb->buffer = buffer; |
| 374 | wsb->free_buffer = NULL; |
| 375 | } |
| 376 | else |
| 377 | { |
| 378 | wsb->free_buffer = (void *) XNEWVEC (char, size); |
| 379 | memcpy (wsb->free_buffer, buffer, size); |
| 380 | wsb->buffer = wsb->free_buffer; |
| 381 | } |
| 382 | |
| 383 | if (section->last_buffer == NULL) |
| 384 | { |
| 385 | section->buffers = wsb; |
| 386 | section->last_buffer = wsb; |
| 387 | } |
| 388 | else |
| 389 | { |
| 390 | section->last_buffer->next = wsb; |
| 391 | section->last_buffer = wsb; |
| 392 | } |
| 393 | |
| 394 | return NULL; |
| 395 | } |
| 396 | |
| 397 | /* Write the complete object file. */ |
| 398 | |
| 399 | const char * |
| 400 | simple_object_write_to_file (simple_object_write *sobj, int descriptor, |
| 401 | int *err) |
| 402 | { |
| 403 | return sobj->functions->write_to_file (sobj, descriptor, err); |
| 404 | } |
| 405 | |
| 406 | /* Release an simple_object_write. */ |
| 407 | |
| 408 | void |
| 409 | simple_object_release_write (simple_object_write *sobj) |
| 410 | { |
| 411 | simple_object_write_section *section; |
| 412 | |
| 413 | free (sobj->segment_name); |
| 414 | |
| 415 | section = sobj->sections; |
| 416 | while (section != NULL) |
| 417 | { |
| 418 | struct simple_object_write_section_buffer *buffer; |
| 419 | simple_object_write_section *next_section; |
| 420 | |
| 421 | buffer = section->buffers; |
| 422 | while (buffer != NULL) |
| 423 | { |
| 424 | struct simple_object_write_section_buffer *next_buffer; |
| 425 | |
| 426 | if (buffer->free_buffer != NULL) |
| 427 | XDELETEVEC (buffer->free_buffer); |
| 428 | next_buffer = buffer->next; |
| 429 | XDELETE (buffer); |
| 430 | buffer = next_buffer; |
| 431 | } |
| 432 | |
| 433 | next_section = section->next; |
| 434 | free (section->name); |
| 435 | XDELETE (section); |
| 436 | section = next_section; |
| 437 | } |
| 438 | |
| 439 | sobj->functions->release_write (sobj->data); |
| 440 | XDELETE (sobj); |
| 441 | } |