| 1 | /* SEC_MERGE support. |
| 2 | Copyright (C) 2001-2017 Free Software Foundation, Inc. |
| 3 | Written by Jakub Jelinek <jakub@redhat.com>. |
| 4 | |
| 5 | This file is part of BFD, the Binary File Descriptor library. |
| 6 | |
| 7 | This program is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 3 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | This program is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with this program; if not, write to the Free Software |
| 19 | Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, |
| 20 | MA 02110-1301, USA. */ |
| 21 | |
| 22 | |
| 23 | /* This file contains support for merging duplicate entities within sections, |
| 24 | as used in ELF SHF_MERGE. */ |
| 25 | |
| 26 | #include "sysdep.h" |
| 27 | #include "bfd.h" |
| 28 | #include "elf-bfd.h" |
| 29 | #include "libbfd.h" |
| 30 | #include "hashtab.h" |
| 31 | #include "libiberty.h" |
| 32 | |
| 33 | struct sec_merge_sec_info; |
| 34 | |
| 35 | /* An entry in the section merge hash table. */ |
| 36 | |
| 37 | struct sec_merge_hash_entry |
| 38 | { |
| 39 | struct bfd_hash_entry root; |
| 40 | /* Length of this entry. This includes the zero terminator. */ |
| 41 | unsigned int len; |
| 42 | /* Start of this string needs to be aligned to |
| 43 | alignment octets (not 1 << align). */ |
| 44 | unsigned int alignment; |
| 45 | union |
| 46 | { |
| 47 | /* Index within the merged section. */ |
| 48 | bfd_size_type index; |
| 49 | /* Entry this is a suffix of (if alignment is 0). */ |
| 50 | struct sec_merge_hash_entry *suffix; |
| 51 | } u; |
| 52 | /* Which section is it in. */ |
| 53 | struct sec_merge_sec_info *secinfo; |
| 54 | /* Next entity in the hash table. */ |
| 55 | struct sec_merge_hash_entry *next; |
| 56 | }; |
| 57 | |
| 58 | /* The section merge hash table. */ |
| 59 | |
| 60 | struct sec_merge_hash |
| 61 | { |
| 62 | struct bfd_hash_table table; |
| 63 | /* Next available index. */ |
| 64 | bfd_size_type size; |
| 65 | /* First entity in the SEC_MERGE sections of this type. */ |
| 66 | struct sec_merge_hash_entry *first; |
| 67 | /* Last entity in the SEC_MERGE sections of this type. */ |
| 68 | struct sec_merge_hash_entry *last; |
| 69 | /* Entity size. */ |
| 70 | unsigned int entsize; |
| 71 | /* Are entries fixed size or zero terminated strings? */ |
| 72 | bfd_boolean strings; |
| 73 | }; |
| 74 | |
| 75 | struct sec_merge_info |
| 76 | { |
| 77 | /* Chain of sec_merge_infos. */ |
| 78 | struct sec_merge_info *next; |
| 79 | /* Chain of sec_merge_sec_infos. */ |
| 80 | struct sec_merge_sec_info *chain; |
| 81 | /* A hash table used to hold section content. */ |
| 82 | struct sec_merge_hash *htab; |
| 83 | }; |
| 84 | |
| 85 | struct sec_merge_sec_info |
| 86 | { |
| 87 | /* Chain of sec_merge_sec_infos. */ |
| 88 | struct sec_merge_sec_info *next; |
| 89 | /* The corresponding section. */ |
| 90 | asection *sec; |
| 91 | /* Pointer to merge_info pointing to us. */ |
| 92 | void **psecinfo; |
| 93 | /* A hash table used to hold section content. */ |
| 94 | struct sec_merge_hash *htab; |
| 95 | /* First string in this section. */ |
| 96 | struct sec_merge_hash_entry *first_str; |
| 97 | /* Original section content. */ |
| 98 | unsigned char contents[1]; |
| 99 | }; |
| 100 | |
| 101 | |
| 102 | /* Routine to create an entry in a section merge hashtab. */ |
| 103 | |
| 104 | static struct bfd_hash_entry * |
| 105 | sec_merge_hash_newfunc (struct bfd_hash_entry *entry, |
| 106 | struct bfd_hash_table *table, const char *string) |
| 107 | { |
| 108 | /* Allocate the structure if it has not already been allocated by a |
| 109 | subclass. */ |
| 110 | if (entry == NULL) |
| 111 | entry = (struct bfd_hash_entry *) |
| 112 | bfd_hash_allocate (table, sizeof (struct sec_merge_hash_entry)); |
| 113 | if (entry == NULL) |
| 114 | return NULL; |
| 115 | |
| 116 | /* Call the allocation method of the superclass. */ |
| 117 | entry = bfd_hash_newfunc (entry, table, string); |
| 118 | |
| 119 | if (entry != NULL) |
| 120 | { |
| 121 | /* Initialize the local fields. */ |
| 122 | struct sec_merge_hash_entry *ret = (struct sec_merge_hash_entry *) entry; |
| 123 | |
| 124 | ret->u.suffix = NULL; |
| 125 | ret->alignment = 0; |
| 126 | ret->secinfo = NULL; |
| 127 | ret->next = NULL; |
| 128 | } |
| 129 | |
| 130 | return entry; |
| 131 | } |
| 132 | |
| 133 | /* Look up an entry in a section merge hash table. */ |
| 134 | |
| 135 | static struct sec_merge_hash_entry * |
| 136 | sec_merge_hash_lookup (struct sec_merge_hash *table, const char *string, |
| 137 | unsigned int alignment, bfd_boolean create) |
| 138 | { |
| 139 | const unsigned char *s; |
| 140 | unsigned long hash; |
| 141 | unsigned int c; |
| 142 | struct sec_merge_hash_entry *hashp; |
| 143 | unsigned int len, i; |
| 144 | unsigned int _index; |
| 145 | |
| 146 | hash = 0; |
| 147 | len = 0; |
| 148 | s = (const unsigned char *) string; |
| 149 | if (table->strings) |
| 150 | { |
| 151 | if (table->entsize == 1) |
| 152 | { |
| 153 | while ((c = *s++) != '\0') |
| 154 | { |
| 155 | hash += c + (c << 17); |
| 156 | hash ^= hash >> 2; |
| 157 | ++len; |
| 158 | } |
| 159 | hash += len + (len << 17); |
| 160 | } |
| 161 | else |
| 162 | { |
| 163 | for (;;) |
| 164 | { |
| 165 | for (i = 0; i < table->entsize; ++i) |
| 166 | if (s[i] != '\0') |
| 167 | break; |
| 168 | if (i == table->entsize) |
| 169 | break; |
| 170 | for (i = 0; i < table->entsize; ++i) |
| 171 | { |
| 172 | c = *s++; |
| 173 | hash += c + (c << 17); |
| 174 | hash ^= hash >> 2; |
| 175 | } |
| 176 | ++len; |
| 177 | } |
| 178 | hash += len + (len << 17); |
| 179 | len *= table->entsize; |
| 180 | } |
| 181 | hash ^= hash >> 2; |
| 182 | len += table->entsize; |
| 183 | } |
| 184 | else |
| 185 | { |
| 186 | for (i = 0; i < table->entsize; ++i) |
| 187 | { |
| 188 | c = *s++; |
| 189 | hash += c + (c << 17); |
| 190 | hash ^= hash >> 2; |
| 191 | } |
| 192 | len = table->entsize; |
| 193 | } |
| 194 | |
| 195 | _index = hash % table->table.size; |
| 196 | for (hashp = (struct sec_merge_hash_entry *) table->table.table[_index]; |
| 197 | hashp != NULL; |
| 198 | hashp = (struct sec_merge_hash_entry *) hashp->root.next) |
| 199 | { |
| 200 | if (hashp->root.hash == hash |
| 201 | && len == hashp->len |
| 202 | && memcmp (hashp->root.string, string, len) == 0) |
| 203 | { |
| 204 | /* If the string we found does not have at least the required |
| 205 | alignment, we need to insert another copy. */ |
| 206 | if (hashp->alignment < alignment) |
| 207 | { |
| 208 | if (create) |
| 209 | { |
| 210 | /* Mark the less aligned copy as deleted. */ |
| 211 | hashp->len = 0; |
| 212 | hashp->alignment = 0; |
| 213 | } |
| 214 | break; |
| 215 | } |
| 216 | return hashp; |
| 217 | } |
| 218 | } |
| 219 | |
| 220 | if (! create) |
| 221 | return NULL; |
| 222 | |
| 223 | hashp = ((struct sec_merge_hash_entry *) |
| 224 | bfd_hash_insert (&table->table, string, hash)); |
| 225 | if (hashp == NULL) |
| 226 | return NULL; |
| 227 | hashp->len = len; |
| 228 | hashp->alignment = alignment; |
| 229 | return hashp; |
| 230 | } |
| 231 | |
| 232 | /* Create a new hash table. */ |
| 233 | |
| 234 | static struct sec_merge_hash * |
| 235 | sec_merge_init (unsigned int entsize, bfd_boolean strings) |
| 236 | { |
| 237 | struct sec_merge_hash *table; |
| 238 | |
| 239 | table = (struct sec_merge_hash *) bfd_malloc (sizeof (struct sec_merge_hash)); |
| 240 | if (table == NULL) |
| 241 | return NULL; |
| 242 | |
| 243 | if (! bfd_hash_table_init_n (&table->table, sec_merge_hash_newfunc, |
| 244 | sizeof (struct sec_merge_hash_entry), 16699)) |
| 245 | { |
| 246 | free (table); |
| 247 | return NULL; |
| 248 | } |
| 249 | |
| 250 | table->size = 0; |
| 251 | table->first = NULL; |
| 252 | table->last = NULL; |
| 253 | table->entsize = entsize; |
| 254 | table->strings = strings; |
| 255 | |
| 256 | return table; |
| 257 | } |
| 258 | |
| 259 | /* Get the index of an entity in a hash table, adding it if it is not |
| 260 | already present. */ |
| 261 | |
| 262 | static struct sec_merge_hash_entry * |
| 263 | sec_merge_add (struct sec_merge_hash *tab, const char *str, |
| 264 | unsigned int alignment, struct sec_merge_sec_info *secinfo) |
| 265 | { |
| 266 | struct sec_merge_hash_entry *entry; |
| 267 | |
| 268 | entry = sec_merge_hash_lookup (tab, str, alignment, TRUE); |
| 269 | if (entry == NULL) |
| 270 | return NULL; |
| 271 | |
| 272 | if (entry->secinfo == NULL) |
| 273 | { |
| 274 | tab->size++; |
| 275 | entry->secinfo = secinfo; |
| 276 | if (tab->first == NULL) |
| 277 | tab->first = entry; |
| 278 | else |
| 279 | tab->last->next = entry; |
| 280 | tab->last = entry; |
| 281 | } |
| 282 | |
| 283 | return entry; |
| 284 | } |
| 285 | |
| 286 | static bfd_boolean |
| 287 | sec_merge_emit (bfd *abfd, struct sec_merge_hash_entry *entry, |
| 288 | unsigned char *contents, file_ptr offset) |
| 289 | { |
| 290 | struct sec_merge_sec_info *secinfo = entry->secinfo; |
| 291 | asection *sec = secinfo->sec; |
| 292 | char *pad = NULL; |
| 293 | bfd_size_type off = 0; |
| 294 | int alignment_power = sec->output_section->alignment_power; |
| 295 | |
| 296 | if (alignment_power) |
| 297 | { |
| 298 | pad = (char *) bfd_zmalloc ((bfd_size_type) 1 << alignment_power); |
| 299 | if (pad == NULL) |
| 300 | return FALSE; |
| 301 | } |
| 302 | |
| 303 | for (; entry != NULL && entry->secinfo == secinfo; entry = entry->next) |
| 304 | { |
| 305 | const char *str; |
| 306 | bfd_size_type len; |
| 307 | |
| 308 | len = -off & (entry->alignment - 1); |
| 309 | if (len != 0) |
| 310 | { |
| 311 | if (contents) |
| 312 | { |
| 313 | memcpy (contents + offset, pad, len); |
| 314 | offset += len; |
| 315 | } |
| 316 | else if (bfd_bwrite (pad, len, abfd) != len) |
| 317 | goto err; |
| 318 | off += len; |
| 319 | } |
| 320 | |
| 321 | str = entry->root.string; |
| 322 | len = entry->len; |
| 323 | |
| 324 | if (contents) |
| 325 | { |
| 326 | memcpy (contents + offset, str, len); |
| 327 | offset += len; |
| 328 | } |
| 329 | else if (bfd_bwrite (str, len, abfd) != len) |
| 330 | goto err; |
| 331 | |
| 332 | off += len; |
| 333 | } |
| 334 | |
| 335 | /* Trailing alignment needed? */ |
| 336 | off = sec->size - off; |
| 337 | if (off != 0) |
| 338 | { |
| 339 | if (contents) |
| 340 | memcpy (contents + offset, pad, off); |
| 341 | else if (bfd_bwrite (pad, off, abfd) != off) |
| 342 | goto err; |
| 343 | } |
| 344 | |
| 345 | if (pad != NULL) |
| 346 | free (pad); |
| 347 | return TRUE; |
| 348 | |
| 349 | err: |
| 350 | if (pad != NULL) |
| 351 | free (pad); |
| 352 | return FALSE; |
| 353 | } |
| 354 | |
| 355 | /* Register a SEC_MERGE section as a candidate for merging. |
| 356 | This function is called for all non-dynamic SEC_MERGE input sections. */ |
| 357 | |
| 358 | bfd_boolean |
| 359 | _bfd_add_merge_section (bfd *abfd, void **psinfo, asection *sec, |
| 360 | void **psecinfo) |
| 361 | { |
| 362 | struct sec_merge_info *sinfo; |
| 363 | struct sec_merge_sec_info *secinfo; |
| 364 | unsigned int align; |
| 365 | bfd_size_type amt; |
| 366 | bfd_byte *contents; |
| 367 | |
| 368 | if ((abfd->flags & DYNAMIC) != 0 |
| 369 | || (sec->flags & SEC_MERGE) == 0) |
| 370 | abort (); |
| 371 | |
| 372 | if (sec->size == 0 |
| 373 | || (sec->flags & SEC_EXCLUDE) != 0 |
| 374 | || sec->entsize == 0) |
| 375 | return TRUE; |
| 376 | |
| 377 | if ((sec->flags & SEC_RELOC) != 0) |
| 378 | { |
| 379 | /* We aren't prepared to handle relocations in merged sections. */ |
| 380 | return TRUE; |
| 381 | } |
| 382 | |
| 383 | align = sec->alignment_power; |
| 384 | if ((sec->entsize < (unsigned) 1 << align |
| 385 | && ((sec->entsize & (sec->entsize - 1)) |
| 386 | || !(sec->flags & SEC_STRINGS))) |
| 387 | || (sec->entsize > (unsigned) 1 << align |
| 388 | && (sec->entsize & (((unsigned) 1 << align) - 1)))) |
| 389 | { |
| 390 | /* Sanity check. If string character size is smaller than |
| 391 | alignment, then we require character size to be a power |
| 392 | of 2, otherwise character size must be integer multiple |
| 393 | of alignment. For non-string constants, alignment must |
| 394 | be smaller than or equal to entity size and entity size |
| 395 | must be integer multiple of alignment. */ |
| 396 | return TRUE; |
| 397 | } |
| 398 | |
| 399 | for (sinfo = (struct sec_merge_info *) *psinfo; sinfo; sinfo = sinfo->next) |
| 400 | if ((secinfo = sinfo->chain) |
| 401 | && ! ((secinfo->sec->flags ^ sec->flags) & (SEC_MERGE | SEC_STRINGS)) |
| 402 | && secinfo->sec->entsize == sec->entsize |
| 403 | && secinfo->sec->alignment_power == sec->alignment_power |
| 404 | && secinfo->sec->output_section == sec->output_section) |
| 405 | break; |
| 406 | |
| 407 | if (sinfo == NULL) |
| 408 | { |
| 409 | /* Initialize the information we need to keep track of. */ |
| 410 | sinfo = (struct sec_merge_info *) |
| 411 | bfd_alloc (abfd, sizeof (struct sec_merge_info)); |
| 412 | if (sinfo == NULL) |
| 413 | goto error_return; |
| 414 | sinfo->next = (struct sec_merge_info *) *psinfo; |
| 415 | sinfo->chain = NULL; |
| 416 | *psinfo = sinfo; |
| 417 | sinfo->htab = sec_merge_init (sec->entsize, (sec->flags & SEC_STRINGS)); |
| 418 | if (sinfo->htab == NULL) |
| 419 | goto error_return; |
| 420 | } |
| 421 | |
| 422 | /* Read the section from abfd. */ |
| 423 | |
| 424 | amt = sizeof (struct sec_merge_sec_info) - 1 + sec->size; |
| 425 | if (sec->flags & SEC_STRINGS) |
| 426 | /* Some versions of gcc may emit a string without a zero terminator. |
| 427 | See http://gcc.gnu.org/ml/gcc-patches/2006-06/msg01004.html |
| 428 | Allocate space for an extra zero. */ |
| 429 | amt += sec->entsize; |
| 430 | *psecinfo = bfd_alloc (abfd, amt); |
| 431 | if (*psecinfo == NULL) |
| 432 | goto error_return; |
| 433 | |
| 434 | secinfo = (struct sec_merge_sec_info *) *psecinfo; |
| 435 | if (sinfo->chain) |
| 436 | { |
| 437 | secinfo->next = sinfo->chain->next; |
| 438 | sinfo->chain->next = secinfo; |
| 439 | } |
| 440 | else |
| 441 | secinfo->next = secinfo; |
| 442 | sinfo->chain = secinfo; |
| 443 | secinfo->sec = sec; |
| 444 | secinfo->psecinfo = psecinfo; |
| 445 | secinfo->htab = sinfo->htab; |
| 446 | secinfo->first_str = NULL; |
| 447 | |
| 448 | sec->rawsize = sec->size; |
| 449 | if (sec->flags & SEC_STRINGS) |
| 450 | memset (secinfo->contents + sec->size, 0, sec->entsize); |
| 451 | contents = secinfo->contents; |
| 452 | if (! bfd_get_full_section_contents (sec->owner, sec, &contents)) |
| 453 | goto error_return; |
| 454 | |
| 455 | return TRUE; |
| 456 | |
| 457 | error_return: |
| 458 | *psecinfo = NULL; |
| 459 | return FALSE; |
| 460 | } |
| 461 | |
| 462 | /* Record one section into the hash table. */ |
| 463 | static bfd_boolean |
| 464 | record_section (struct sec_merge_info *sinfo, |
| 465 | struct sec_merge_sec_info *secinfo) |
| 466 | { |
| 467 | asection *sec = secinfo->sec; |
| 468 | struct sec_merge_hash_entry *entry; |
| 469 | bfd_boolean nul; |
| 470 | unsigned char *p, *end; |
| 471 | bfd_vma mask, eltalign; |
| 472 | unsigned int align, i; |
| 473 | |
| 474 | align = sec->alignment_power; |
| 475 | end = secinfo->contents + sec->size; |
| 476 | nul = FALSE; |
| 477 | mask = ((bfd_vma) 1 << align) - 1; |
| 478 | if (sec->flags & SEC_STRINGS) |
| 479 | { |
| 480 | for (p = secinfo->contents; p < end; ) |
| 481 | { |
| 482 | eltalign = p - secinfo->contents; |
| 483 | eltalign = ((eltalign ^ (eltalign - 1)) + 1) >> 1; |
| 484 | if (!eltalign || eltalign > mask) |
| 485 | eltalign = mask + 1; |
| 486 | entry = sec_merge_add (sinfo->htab, (char *) p, (unsigned) eltalign, |
| 487 | secinfo); |
| 488 | if (! entry) |
| 489 | goto error_return; |
| 490 | p += entry->len; |
| 491 | if (sec->entsize == 1) |
| 492 | { |
| 493 | while (p < end && *p == 0) |
| 494 | { |
| 495 | if (!nul && !((p - secinfo->contents) & mask)) |
| 496 | { |
| 497 | nul = TRUE; |
| 498 | entry = sec_merge_add (sinfo->htab, "", |
| 499 | (unsigned) mask + 1, secinfo); |
| 500 | if (! entry) |
| 501 | goto error_return; |
| 502 | } |
| 503 | p++; |
| 504 | } |
| 505 | } |
| 506 | else |
| 507 | { |
| 508 | while (p < end) |
| 509 | { |
| 510 | for (i = 0; i < sec->entsize; i++) |
| 511 | if (p[i] != '\0') |
| 512 | break; |
| 513 | if (i != sec->entsize) |
| 514 | break; |
| 515 | if (!nul && !((p - secinfo->contents) & mask)) |
| 516 | { |
| 517 | nul = TRUE; |
| 518 | entry = sec_merge_add (sinfo->htab, (char *) p, |
| 519 | (unsigned) mask + 1, secinfo); |
| 520 | if (! entry) |
| 521 | goto error_return; |
| 522 | } |
| 523 | p += sec->entsize; |
| 524 | } |
| 525 | } |
| 526 | } |
| 527 | } |
| 528 | else |
| 529 | { |
| 530 | for (p = secinfo->contents; p < end; p += sec->entsize) |
| 531 | { |
| 532 | entry = sec_merge_add (sinfo->htab, (char *) p, 1, secinfo); |
| 533 | if (! entry) |
| 534 | goto error_return; |
| 535 | } |
| 536 | } |
| 537 | |
| 538 | return TRUE; |
| 539 | |
| 540 | error_return: |
| 541 | for (secinfo = sinfo->chain; secinfo; secinfo = secinfo->next) |
| 542 | *secinfo->psecinfo = NULL; |
| 543 | return FALSE; |
| 544 | } |
| 545 | |
| 546 | static int |
| 547 | strrevcmp (const void *a, const void *b) |
| 548 | { |
| 549 | struct sec_merge_hash_entry *A = *(struct sec_merge_hash_entry **) a; |
| 550 | struct sec_merge_hash_entry *B = *(struct sec_merge_hash_entry **) b; |
| 551 | unsigned int lenA = A->len; |
| 552 | unsigned int lenB = B->len; |
| 553 | const unsigned char *s = (const unsigned char *) A->root.string + lenA - 1; |
| 554 | const unsigned char *t = (const unsigned char *) B->root.string + lenB - 1; |
| 555 | int l = lenA < lenB ? lenA : lenB; |
| 556 | |
| 557 | while (l) |
| 558 | { |
| 559 | if (*s != *t) |
| 560 | return (int) *s - (int) *t; |
| 561 | s--; |
| 562 | t--; |
| 563 | l--; |
| 564 | } |
| 565 | return lenA - lenB; |
| 566 | } |
| 567 | |
| 568 | /* Like strrevcmp, but for the case where all strings have the same |
| 569 | alignment > entsize. */ |
| 570 | |
| 571 | static int |
| 572 | strrevcmp_align (const void *a, const void *b) |
| 573 | { |
| 574 | struct sec_merge_hash_entry *A = *(struct sec_merge_hash_entry **) a; |
| 575 | struct sec_merge_hash_entry *B = *(struct sec_merge_hash_entry **) b; |
| 576 | unsigned int lenA = A->len; |
| 577 | unsigned int lenB = B->len; |
| 578 | const unsigned char *s = (const unsigned char *) A->root.string + lenA - 1; |
| 579 | const unsigned char *t = (const unsigned char *) B->root.string + lenB - 1; |
| 580 | int l = lenA < lenB ? lenA : lenB; |
| 581 | int tail_align = (lenA & (A->alignment - 1)) - (lenB & (A->alignment - 1)); |
| 582 | |
| 583 | if (tail_align != 0) |
| 584 | return tail_align; |
| 585 | |
| 586 | while (l) |
| 587 | { |
| 588 | if (*s != *t) |
| 589 | return (int) *s - (int) *t; |
| 590 | s--; |
| 591 | t--; |
| 592 | l--; |
| 593 | } |
| 594 | return lenA - lenB; |
| 595 | } |
| 596 | |
| 597 | static inline int |
| 598 | is_suffix (const struct sec_merge_hash_entry *A, |
| 599 | const struct sec_merge_hash_entry *B) |
| 600 | { |
| 601 | if (A->len <= B->len) |
| 602 | /* B cannot be a suffix of A unless A is equal to B, which is guaranteed |
| 603 | not to be equal by the hash table. */ |
| 604 | return 0; |
| 605 | |
| 606 | return memcmp (A->root.string + (A->len - B->len), |
| 607 | B->root.string, B->len) == 0; |
| 608 | } |
| 609 | |
| 610 | /* This is a helper function for _bfd_merge_sections. It attempts to |
| 611 | merge strings matching suffixes of longer strings. */ |
| 612 | static void |
| 613 | merge_strings (struct sec_merge_info *sinfo) |
| 614 | { |
| 615 | struct sec_merge_hash_entry **array, **a, *e; |
| 616 | struct sec_merge_sec_info *secinfo; |
| 617 | bfd_size_type size, amt; |
| 618 | unsigned int alignment = 0; |
| 619 | |
| 620 | /* Now sort the strings */ |
| 621 | amt = sinfo->htab->size * sizeof (struct sec_merge_hash_entry *); |
| 622 | array = (struct sec_merge_hash_entry **) bfd_malloc (amt); |
| 623 | if (array == NULL) |
| 624 | goto alloc_failure; |
| 625 | |
| 626 | for (e = sinfo->htab->first, a = array; e; e = e->next) |
| 627 | if (e->alignment) |
| 628 | { |
| 629 | *a++ = e; |
| 630 | /* Adjust the length to not include the zero terminator. */ |
| 631 | e->len -= sinfo->htab->entsize; |
| 632 | if (alignment != e->alignment) |
| 633 | { |
| 634 | if (alignment == 0) |
| 635 | alignment = e->alignment; |
| 636 | else |
| 637 | alignment = (unsigned) -1; |
| 638 | } |
| 639 | } |
| 640 | |
| 641 | sinfo->htab->size = a - array; |
| 642 | if (sinfo->htab->size != 0) |
| 643 | { |
| 644 | qsort (array, (size_t) sinfo->htab->size, |
| 645 | sizeof (struct sec_merge_hash_entry *), |
| 646 | (alignment != (unsigned) -1 && alignment > sinfo->htab->entsize |
| 647 | ? strrevcmp_align : strrevcmp)); |
| 648 | |
| 649 | /* Loop over the sorted array and merge suffixes */ |
| 650 | e = *--a; |
| 651 | e->len += sinfo->htab->entsize; |
| 652 | while (--a >= array) |
| 653 | { |
| 654 | struct sec_merge_hash_entry *cmp = *a; |
| 655 | |
| 656 | cmp->len += sinfo->htab->entsize; |
| 657 | if (e->alignment >= cmp->alignment |
| 658 | && !((e->len - cmp->len) & (cmp->alignment - 1)) |
| 659 | && is_suffix (e, cmp)) |
| 660 | { |
| 661 | cmp->u.suffix = e; |
| 662 | cmp->alignment = 0; |
| 663 | } |
| 664 | else |
| 665 | e = cmp; |
| 666 | } |
| 667 | } |
| 668 | |
| 669 | alloc_failure: |
| 670 | if (array) |
| 671 | free (array); |
| 672 | |
| 673 | /* Now assign positions to the strings we want to keep. */ |
| 674 | size = 0; |
| 675 | secinfo = sinfo->htab->first->secinfo; |
| 676 | for (e = sinfo->htab->first; e; e = e->next) |
| 677 | { |
| 678 | if (e->secinfo != secinfo) |
| 679 | { |
| 680 | secinfo->sec->size = size; |
| 681 | secinfo = e->secinfo; |
| 682 | } |
| 683 | if (e->alignment) |
| 684 | { |
| 685 | if (e->secinfo->first_str == NULL) |
| 686 | { |
| 687 | e->secinfo->first_str = e; |
| 688 | size = 0; |
| 689 | } |
| 690 | size = (size + e->alignment - 1) & ~((bfd_vma) e->alignment - 1); |
| 691 | e->u.index = size; |
| 692 | size += e->len; |
| 693 | } |
| 694 | } |
| 695 | secinfo->sec->size = size; |
| 696 | if (secinfo->sec->alignment_power != 0) |
| 697 | { |
| 698 | bfd_size_type align = (bfd_size_type) 1 << secinfo->sec->alignment_power; |
| 699 | secinfo->sec->size = (secinfo->sec->size + align - 1) & -align; |
| 700 | } |
| 701 | |
| 702 | /* And now adjust the rest, removing them from the chain (but not hashtable) |
| 703 | at the same time. */ |
| 704 | for (a = &sinfo->htab->first, e = *a; e; e = e->next) |
| 705 | if (e->alignment) |
| 706 | a = &e->next; |
| 707 | else |
| 708 | { |
| 709 | *a = e->next; |
| 710 | if (e->len) |
| 711 | { |
| 712 | e->secinfo = e->u.suffix->secinfo; |
| 713 | e->alignment = e->u.suffix->alignment; |
| 714 | e->u.index = e->u.suffix->u.index + (e->u.suffix->len - e->len); |
| 715 | } |
| 716 | } |
| 717 | } |
| 718 | |
| 719 | /* This function is called once after all SEC_MERGE sections are registered |
| 720 | with _bfd_merge_section. */ |
| 721 | |
| 722 | bfd_boolean |
| 723 | _bfd_merge_sections (bfd *abfd, |
| 724 | struct bfd_link_info *info ATTRIBUTE_UNUSED, |
| 725 | void *xsinfo, |
| 726 | void (*remove_hook) (bfd *, asection *)) |
| 727 | { |
| 728 | struct sec_merge_info *sinfo; |
| 729 | |
| 730 | for (sinfo = (struct sec_merge_info *) xsinfo; sinfo; sinfo = sinfo->next) |
| 731 | { |
| 732 | struct sec_merge_sec_info * secinfo; |
| 733 | |
| 734 | if (! sinfo->chain) |
| 735 | continue; |
| 736 | |
| 737 | /* Move sinfo->chain to head of the chain, terminate it. */ |
| 738 | secinfo = sinfo->chain; |
| 739 | sinfo->chain = secinfo->next; |
| 740 | secinfo->next = NULL; |
| 741 | |
| 742 | /* Record the sections into the hash table. */ |
| 743 | for (secinfo = sinfo->chain; secinfo; secinfo = secinfo->next) |
| 744 | if (secinfo->sec->flags & SEC_EXCLUDE) |
| 745 | { |
| 746 | *secinfo->psecinfo = NULL; |
| 747 | if (remove_hook) |
| 748 | (*remove_hook) (abfd, secinfo->sec); |
| 749 | } |
| 750 | else if (! record_section (sinfo, secinfo)) |
| 751 | break; |
| 752 | |
| 753 | if (secinfo) |
| 754 | continue; |
| 755 | |
| 756 | if (sinfo->htab->first == NULL) |
| 757 | continue; |
| 758 | |
| 759 | if (sinfo->htab->strings) |
| 760 | merge_strings (sinfo); |
| 761 | else |
| 762 | { |
| 763 | struct sec_merge_hash_entry *e; |
| 764 | bfd_size_type size = 0; |
| 765 | |
| 766 | /* Things are much simpler for non-strings. |
| 767 | Just assign them slots in the section. */ |
| 768 | secinfo = NULL; |
| 769 | for (e = sinfo->htab->first; e; e = e->next) |
| 770 | { |
| 771 | if (e->secinfo->first_str == NULL) |
| 772 | { |
| 773 | if (secinfo) |
| 774 | secinfo->sec->size = size; |
| 775 | e->secinfo->first_str = e; |
| 776 | size = 0; |
| 777 | } |
| 778 | size = (size + e->alignment - 1) |
| 779 | & ~((bfd_vma) e->alignment - 1); |
| 780 | e->u.index = size; |
| 781 | size += e->len; |
| 782 | secinfo = e->secinfo; |
| 783 | } |
| 784 | secinfo->sec->size = size; |
| 785 | } |
| 786 | |
| 787 | /* Finally remove all input sections which have not made it into |
| 788 | the hash table at all. */ |
| 789 | for (secinfo = sinfo->chain; secinfo; secinfo = secinfo->next) |
| 790 | if (secinfo->first_str == NULL) |
| 791 | secinfo->sec->flags |= SEC_EXCLUDE | SEC_KEEP; |
| 792 | } |
| 793 | |
| 794 | return TRUE; |
| 795 | } |
| 796 | |
| 797 | /* Write out the merged section. */ |
| 798 | |
| 799 | bfd_boolean |
| 800 | _bfd_write_merged_section (bfd *output_bfd, asection *sec, void *psecinfo) |
| 801 | { |
| 802 | struct sec_merge_sec_info *secinfo; |
| 803 | file_ptr pos; |
| 804 | unsigned char *contents; |
| 805 | Elf_Internal_Shdr *hdr; |
| 806 | |
| 807 | secinfo = (struct sec_merge_sec_info *) psecinfo; |
| 808 | |
| 809 | if (!secinfo) |
| 810 | return FALSE; |
| 811 | |
| 812 | if (secinfo->first_str == NULL) |
| 813 | return TRUE; |
| 814 | |
| 815 | /* FIXME: octets_per_byte. */ |
| 816 | hdr = &elf_section_data (sec->output_section)->this_hdr; |
| 817 | if (hdr->sh_offset == (file_ptr) -1) |
| 818 | { |
| 819 | /* We must compress this section. Write output to the |
| 820 | buffer. */ |
| 821 | contents = hdr->contents; |
| 822 | if ((sec->output_section->flags & SEC_ELF_COMPRESS) == 0 |
| 823 | || contents == NULL) |
| 824 | abort (); |
| 825 | } |
| 826 | else |
| 827 | { |
| 828 | contents = NULL; |
| 829 | pos = sec->output_section->filepos + sec->output_offset; |
| 830 | if (bfd_seek (output_bfd, pos, SEEK_SET) != 0) |
| 831 | return FALSE; |
| 832 | } |
| 833 | |
| 834 | if (! sec_merge_emit (output_bfd, secinfo->first_str, contents, |
| 835 | sec->output_offset)) |
| 836 | return FALSE; |
| 837 | |
| 838 | return TRUE; |
| 839 | } |
| 840 | |
| 841 | /* Adjust an address in the SEC_MERGE section. Given OFFSET within |
| 842 | *PSEC, this returns the new offset in the adjusted SEC_MERGE |
| 843 | section and writes the new section back into *PSEC. */ |
| 844 | |
| 845 | bfd_vma |
| 846 | _bfd_merged_section_offset (bfd *output_bfd ATTRIBUTE_UNUSED, asection **psec, |
| 847 | void *psecinfo, bfd_vma offset) |
| 848 | { |
| 849 | struct sec_merge_sec_info *secinfo; |
| 850 | struct sec_merge_hash_entry *entry; |
| 851 | unsigned char *p; |
| 852 | asection *sec = *psec; |
| 853 | |
| 854 | secinfo = (struct sec_merge_sec_info *) psecinfo; |
| 855 | |
| 856 | if (!secinfo) |
| 857 | return offset; |
| 858 | |
| 859 | if (offset >= sec->rawsize) |
| 860 | { |
| 861 | if (offset > sec->rawsize) |
| 862 | _bfd_error_handler |
| 863 | /* xgettext:c-format */ |
| 864 | (_("%B: access beyond end of merged section (%Ld)"), |
| 865 | sec->owner, offset); |
| 866 | return secinfo->first_str ? sec->size : 0; |
| 867 | } |
| 868 | |
| 869 | if (secinfo->htab->strings) |
| 870 | { |
| 871 | if (sec->entsize == 1) |
| 872 | { |
| 873 | p = secinfo->contents + offset - 1; |
| 874 | while (p >= secinfo->contents && *p) |
| 875 | --p; |
| 876 | ++p; |
| 877 | } |
| 878 | else |
| 879 | { |
| 880 | p = secinfo->contents + (offset / sec->entsize) * sec->entsize; |
| 881 | p -= sec->entsize; |
| 882 | while (p >= secinfo->contents) |
| 883 | { |
| 884 | unsigned int i; |
| 885 | |
| 886 | for (i = 0; i < sec->entsize; ++i) |
| 887 | if (p[i] != '\0') |
| 888 | break; |
| 889 | if (i == sec->entsize) |
| 890 | break; |
| 891 | p -= sec->entsize; |
| 892 | } |
| 893 | p += sec->entsize; |
| 894 | } |
| 895 | } |
| 896 | else |
| 897 | { |
| 898 | p = secinfo->contents + (offset / sec->entsize) * sec->entsize; |
| 899 | } |
| 900 | entry = sec_merge_hash_lookup (secinfo->htab, (char *) p, 0, FALSE); |
| 901 | if (!entry) |
| 902 | { |
| 903 | if (! secinfo->htab->strings) |
| 904 | abort (); |
| 905 | /* This should only happen if somebody points into the padding |
| 906 | after a NUL character but before next entity. */ |
| 907 | if (*p) |
| 908 | abort (); |
| 909 | if (! secinfo->htab->first) |
| 910 | abort (); |
| 911 | entry = secinfo->htab->first; |
| 912 | p = (secinfo->contents + (offset / sec->entsize + 1) * sec->entsize |
| 913 | - entry->len); |
| 914 | } |
| 915 | |
| 916 | *psec = entry->secinfo->sec; |
| 917 | return entry->u.index + (secinfo->contents + offset - p); |
| 918 | } |
| 919 | |
| 920 | /* Tidy up when done. */ |
| 921 | |
| 922 | void |
| 923 | _bfd_merge_sections_free (void *xsinfo) |
| 924 | { |
| 925 | struct sec_merge_info *sinfo; |
| 926 | |
| 927 | for (sinfo = (struct sec_merge_info *) xsinfo; sinfo; sinfo = sinfo->next) |
| 928 | { |
| 929 | bfd_hash_table_free (&sinfo->htab->table); |
| 930 | free (sinfo->htab); |
| 931 | } |
| 932 | } |