1 /* SEC_MERGE support. 2 Copyright 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 3 Free Software Foundation, Inc. 4 Written by Jakub Jelinek <jakub@redhat.com>. 5 6 This file is part of BFD, the Binary File Descriptor library. 7 8 This program is free software; you can redistribute it and/or modify 9 it under the terms of the GNU General Public License as published by 10 the Free Software Foundation; either version 3 of the License, or 11 (at your option) any later version. 12 13 This program is distributed in the hope that it will be useful, 14 but WITHOUT ANY WARRANTY; without even the implied warranty of 15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 GNU General Public License for more details. 17 18 You should have received a copy of the GNU General Public License 19 along with this program; if not, write to the Free Software 20 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, 21 MA 02110-1301, USA. */ 22 23 24 /* This file contains support for merging duplicate entities within sections, 25 as used in ELF SHF_MERGE. */ 26 27 #include "sysdep.h" 28 #include "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 { 289 struct sec_merge_sec_info *secinfo = entry->secinfo; 290 asection *sec = secinfo->sec; 291 char *pad = NULL; 292 bfd_size_type off = 0; 293 int alignment_power = sec->output_section->alignment_power; 294 295 if (alignment_power) 296 { 297 pad = (char *) bfd_zmalloc ((bfd_size_type) 1 << alignment_power); 298 if (pad == NULL) 299 return FALSE; 300 } 301 302 for (; entry != NULL && entry->secinfo == secinfo; entry = entry->next) 303 { 304 const char *str; 305 bfd_size_type len; 306 307 len = -off & (entry->alignment - 1); 308 if (len != 0) 309 { 310 if (bfd_bwrite (pad, len, abfd) != len) 311 goto err; 312 off += len; 313 } 314 315 str = entry->root.string; 316 len = entry->len; 317 318 if (bfd_bwrite (str, len, abfd) != len) 319 goto err; 320 321 off += len; 322 } 323 324 /* Trailing alignment needed? */ 325 off = sec->size - off; 326 if (off != 0 327 && bfd_bwrite (pad, off, abfd) != off) 328 goto err; 329 330 if (pad != NULL) 331 free (pad); 332 return TRUE; 333 334 err: 335 if (pad != NULL) 336 free (pad); 337 return FALSE; 338 } 339 340 /* Register a SEC_MERGE section as a candidate for merging. 341 This function is called for all non-dynamic SEC_MERGE input sections. */ 342 343 bfd_boolean 344 _bfd_add_merge_section (bfd *abfd, void **psinfo, asection *sec, 345 void **psecinfo) 346 { 347 struct sec_merge_info *sinfo; 348 struct sec_merge_sec_info *secinfo; 349 unsigned int align; 350 bfd_size_type amt; 351 bfd_byte *contents; 352 353 if ((abfd->flags & DYNAMIC) != 0 354 || (sec->flags & SEC_MERGE) == 0) 355 abort (); 356 357 if (sec->size == 0 358 || (sec->flags & SEC_EXCLUDE) != 0 359 || sec->entsize == 0) 360 return TRUE; 361 362 if ((sec->flags & SEC_RELOC) != 0) 363 { 364 /* We aren't prepared to handle relocations in merged sections. */ 365 return TRUE; 366 } 367 368 align = sec->alignment_power; 369 if ((sec->entsize < (unsigned) 1 << align 370 && ((sec->entsize & (sec->entsize - 1)) 371 || !(sec->flags & SEC_STRINGS))) 372 || (sec->entsize > (unsigned) 1 << align 373 && (sec->entsize & (((unsigned) 1 << align) - 1)))) 374 { 375 /* Sanity check. If string character size is smaller than 376 alignment, then we require character size to be a power 377 of 2, otherwise character size must be integer multiple 378 of alignment. For non-string constants, alignment must 379 be smaller than or equal to entity size and entity size 380 must be integer multiple of alignment. */ 381 return TRUE; 382 } 383 384 for (sinfo = (struct sec_merge_info *) *psinfo; sinfo; sinfo = sinfo->next) 385 if ((secinfo = sinfo->chain) 386 && ! ((secinfo->sec->flags ^ sec->flags) & (SEC_MERGE | SEC_STRINGS)) 387 && secinfo->sec->entsize == sec->entsize 388 && secinfo->sec->alignment_power == sec->alignment_power 389 && secinfo->sec->output_section == sec->output_section) 390 break; 391 392 if (sinfo == NULL) 393 { 394 /* Initialize the information we need to keep track of. */ 395 sinfo = (struct sec_merge_info *) 396 bfd_alloc (abfd, sizeof (struct sec_merge_info)); 397 if (sinfo == NULL) 398 goto error_return; 399 sinfo->next = (struct sec_merge_info *) *psinfo; 400 sinfo->chain = NULL; 401 *psinfo = sinfo; 402 sinfo->htab = sec_merge_init (sec->entsize, (sec->flags & SEC_STRINGS)); 403 if (sinfo->htab == NULL) 404 goto error_return; 405 } 406 407 /* Read the section from abfd. */ 408 409 amt = sizeof (struct sec_merge_sec_info) - 1 + sec->size; 410 if (sec->flags & SEC_STRINGS) 411 /* Some versions of gcc may emit a string without a zero terminator. 412 See http://gcc.gnu.org/ml/gcc-patches/2006-06/msg01004.html 413 Allocate space for an extra zero. */ 414 amt += sec->entsize; 415 *psecinfo = bfd_alloc (abfd, amt); 416 if (*psecinfo == NULL) 417 goto error_return; 418 419 secinfo = (struct sec_merge_sec_info *) *psecinfo; 420 if (sinfo->chain) 421 { 422 secinfo->next = sinfo->chain->next; 423 sinfo->chain->next = secinfo; 424 } 425 else 426 secinfo->next = secinfo; 427 sinfo->chain = secinfo; 428 secinfo->sec = sec; 429 secinfo->psecinfo = psecinfo; 430 secinfo->htab = sinfo->htab; 431 secinfo->first_str = NULL; 432 433 sec->rawsize = sec->size; 434 if (sec->flags & SEC_STRINGS) 435 memset (secinfo->contents + sec->size, 0, sec->entsize); 436 contents = secinfo->contents; 437 if (! bfd_get_full_section_contents (sec->owner, sec, &contents)) 438 goto error_return; 439 440 return TRUE; 441 442 error_return: 443 *psecinfo = NULL; 444 return FALSE; 445 } 446 447 /* Record one section into the hash table. */ 448 static bfd_boolean 449 record_section (struct sec_merge_info *sinfo, 450 struct sec_merge_sec_info *secinfo) 451 { 452 asection *sec = secinfo->sec; 453 struct sec_merge_hash_entry *entry; 454 bfd_boolean nul; 455 unsigned char *p, *end; 456 bfd_vma mask, eltalign; 457 unsigned int align, i; 458 459 align = sec->alignment_power; 460 end = secinfo->contents + sec->size; 461 nul = FALSE; 462 mask = ((bfd_vma) 1 << align) - 1; 463 if (sec->flags & SEC_STRINGS) 464 { 465 for (p = secinfo->contents; p < end; ) 466 { 467 eltalign = p - secinfo->contents; 468 eltalign = ((eltalign ^ (eltalign - 1)) + 1) >> 1; 469 if (!eltalign || eltalign > mask) 470 eltalign = mask + 1; 471 entry = sec_merge_add (sinfo->htab, (char *) p, (unsigned) eltalign, 472 secinfo); 473 if (! entry) 474 goto error_return; 475 p += entry->len; 476 if (sec->entsize == 1) 477 { 478 while (p < end && *p == 0) 479 { 480 if (!nul && !((p - secinfo->contents) & mask)) 481 { 482 nul = TRUE; 483 entry = sec_merge_add (sinfo->htab, "", 484 (unsigned) mask + 1, secinfo); 485 if (! entry) 486 goto error_return; 487 } 488 p++; 489 } 490 } 491 else 492 { 493 while (p < end) 494 { 495 for (i = 0; i < sec->entsize; i++) 496 if (p[i] != '\0') 497 break; 498 if (i != sec->entsize) 499 break; 500 if (!nul && !((p - secinfo->contents) & mask)) 501 { 502 nul = TRUE; 503 entry = sec_merge_add (sinfo->htab, (char *) p, 504 (unsigned) mask + 1, secinfo); 505 if (! entry) 506 goto error_return; 507 } 508 p += sec->entsize; 509 } 510 } 511 } 512 } 513 else 514 { 515 for (p = secinfo->contents; p < end; p += sec->entsize) 516 { 517 entry = sec_merge_add (sinfo->htab, (char *) p, 1, secinfo); 518 if (! entry) 519 goto error_return; 520 } 521 } 522 523 return TRUE; 524 525 error_return: 526 for (secinfo = sinfo->chain; secinfo; secinfo = secinfo->next) 527 *secinfo->psecinfo = NULL; 528 return FALSE; 529 } 530 531 static int 532 strrevcmp (const void *a, const void *b) 533 { 534 struct sec_merge_hash_entry *A = *(struct sec_merge_hash_entry **) a; 535 struct sec_merge_hash_entry *B = *(struct sec_merge_hash_entry **) b; 536 unsigned int lenA = A->len; 537 unsigned int lenB = B->len; 538 const unsigned char *s = (const unsigned char *) A->root.string + lenA - 1; 539 const unsigned char *t = (const unsigned char *) B->root.string + lenB - 1; 540 int l = lenA < lenB ? lenA : lenB; 541 542 while (l) 543 { 544 if (*s != *t) 545 return (int) *s - (int) *t; 546 s--; 547 t--; 548 l--; 549 } 550 return lenA - lenB; 551 } 552 553 /* Like strrevcmp, but for the case where all strings have the same 554 alignment > entsize. */ 555 556 static int 557 strrevcmp_align (const void *a, const void *b) 558 { 559 struct sec_merge_hash_entry *A = *(struct sec_merge_hash_entry **) a; 560 struct sec_merge_hash_entry *B = *(struct sec_merge_hash_entry **) b; 561 unsigned int lenA = A->len; 562 unsigned int lenB = B->len; 563 const unsigned char *s = (const unsigned char *) A->root.string + lenA - 1; 564 const unsigned char *t = (const unsigned char *) B->root.string + lenB - 1; 565 int l = lenA < lenB ? lenA : lenB; 566 int tail_align = (lenA & (A->alignment - 1)) - (lenB & (A->alignment - 1)); 567 568 if (tail_align != 0) 569 return tail_align; 570 571 while (l) 572 { 573 if (*s != *t) 574 return (int) *s - (int) *t; 575 s--; 576 t--; 577 l--; 578 } 579 return lenA - lenB; 580 } 581 582 static inline int 583 is_suffix (const struct sec_merge_hash_entry *A, 584 const struct sec_merge_hash_entry *B) 585 { 586 if (A->len <= B->len) 587 /* B cannot be a suffix of A unless A is equal to B, which is guaranteed 588 not to be equal by the hash table. */ 589 return 0; 590 591 return memcmp (A->root.string + (A->len - B->len), 592 B->root.string, B->len) == 0; 593 } 594 595 /* This is a helper function for _bfd_merge_sections. It attempts to 596 merge strings matching suffixes of longer strings. */ 597 static void 598 merge_strings (struct sec_merge_info *sinfo) 599 { 600 struct sec_merge_hash_entry **array, **a, *e; 601 struct sec_merge_sec_info *secinfo; 602 bfd_size_type size, amt; 603 unsigned int alignment = 0; 604 605 /* Now sort the strings */ 606 amt = sinfo->htab->size * sizeof (struct sec_merge_hash_entry *); 607 array = (struct sec_merge_hash_entry **) bfd_malloc (amt); 608 if (array == NULL) 609 goto alloc_failure; 610 611 for (e = sinfo->htab->first, a = array; e; e = e->next) 612 if (e->alignment) 613 { 614 *a++ = e; 615 /* Adjust the length to not include the zero terminator. */ 616 e->len -= sinfo->htab->entsize; 617 if (alignment != e->alignment) 618 { 619 if (alignment == 0) 620 alignment = e->alignment; 621 else 622 alignment = (unsigned) -1; 623 } 624 } 625 626 sinfo->htab->size = a - array; 627 if (sinfo->htab->size != 0) 628 { 629 qsort (array, (size_t) sinfo->htab->size, 630 sizeof (struct sec_merge_hash_entry *), 631 (alignment != (unsigned) -1 && alignment > sinfo->htab->entsize 632 ? strrevcmp_align : strrevcmp)); 633 634 /* Loop over the sorted array and merge suffixes */ 635 e = *--a; 636 e->len += sinfo->htab->entsize; 637 while (--a >= array) 638 { 639 struct sec_merge_hash_entry *cmp = *a; 640 641 cmp->len += sinfo->htab->entsize; 642 if (e->alignment >= cmp->alignment 643 && !((e->len - cmp->len) & (cmp->alignment - 1)) 644 && is_suffix (e, cmp)) 645 { 646 cmp->u.suffix = e; 647 cmp->alignment = 0; 648 } 649 else 650 e = cmp; 651 } 652 } 653 654 alloc_failure: 655 if (array) 656 free (array); 657 658 /* Now assign positions to the strings we want to keep. */ 659 size = 0; 660 secinfo = sinfo->htab->first->secinfo; 661 for (e = sinfo->htab->first; e; e = e->next) 662 { 663 if (e->secinfo != secinfo) 664 { 665 secinfo->sec->size = size; 666 secinfo = e->secinfo; 667 } 668 if (e->alignment) 669 { 670 if (e->secinfo->first_str == NULL) 671 { 672 e->secinfo->first_str = e; 673 size = 0; 674 } 675 size = (size + e->alignment - 1) & ~((bfd_vma) e->alignment - 1); 676 e->u.index = size; 677 size += e->len; 678 } 679 } 680 secinfo->sec->size = size; 681 if (secinfo->sec->alignment_power != 0) 682 { 683 bfd_size_type align = (bfd_size_type) 1 << secinfo->sec->alignment_power; 684 secinfo->sec->size = (secinfo->sec->size + align - 1) & -align; 685 } 686 687 /* And now adjust the rest, removing them from the chain (but not hashtable) 688 at the same time. */ 689 for (a = &sinfo->htab->first, e = *a; e; e = e->next) 690 if (e->alignment) 691 a = &e->next; 692 else 693 { 694 *a = e->next; 695 if (e->len) 696 { 697 e->secinfo = e->u.suffix->secinfo; 698 e->alignment = e->u.suffix->alignment; 699 e->u.index = e->u.suffix->u.index + (e->u.suffix->len - e->len); 700 } 701 } 702 } 703 704 /* This function is called once after all SEC_MERGE sections are registered 705 with _bfd_merge_section. */ 706 707 bfd_boolean 708 _bfd_merge_sections (bfd *abfd, 709 struct bfd_link_info *info ATTRIBUTE_UNUSED, 710 void *xsinfo, 711 void (*remove_hook) (bfd *, asection *)) 712 { 713 struct sec_merge_info *sinfo; 714 715 for (sinfo = (struct sec_merge_info *) xsinfo; sinfo; sinfo = sinfo->next) 716 { 717 struct sec_merge_sec_info * secinfo; 718 719 if (! sinfo->chain) 720 continue; 721 722 /* Move sinfo->chain to head of the chain, terminate it. */ 723 secinfo = sinfo->chain; 724 sinfo->chain = secinfo->next; 725 secinfo->next = NULL; 726 727 /* Record the sections into the hash table. */ 728 for (secinfo = sinfo->chain; secinfo; secinfo = secinfo->next) 729 if (secinfo->sec->flags & SEC_EXCLUDE) 730 { 731 *secinfo->psecinfo = NULL; 732 if (remove_hook) 733 (*remove_hook) (abfd, secinfo->sec); 734 } 735 else if (! record_section (sinfo, secinfo)) 736 break; 737 738 if (secinfo) 739 continue; 740 741 if (sinfo->htab->first == NULL) 742 continue; 743 744 if (sinfo->htab->strings) 745 merge_strings (sinfo); 746 else 747 { 748 struct sec_merge_hash_entry *e; 749 bfd_size_type size = 0; 750 751 /* Things are much simpler for non-strings. 752 Just assign them slots in the section. */ 753 secinfo = NULL; 754 for (e = sinfo->htab->first; e; e = e->next) 755 { 756 if (e->secinfo->first_str == NULL) 757 { 758 if (secinfo) 759 secinfo->sec->size = size; 760 e->secinfo->first_str = e; 761 size = 0; 762 } 763 size = (size + e->alignment - 1) 764 & ~((bfd_vma) e->alignment - 1); 765 e->u.index = size; 766 size += e->len; 767 secinfo = e->secinfo; 768 } 769 secinfo->sec->size = size; 770 } 771 772 /* Finally remove all input sections which have not made it into 773 the hash table at all. */ 774 for (secinfo = sinfo->chain; secinfo; secinfo = secinfo->next) 775 if (secinfo->first_str == NULL) 776 secinfo->sec->flags |= SEC_EXCLUDE | SEC_KEEP; 777 } 778 779 return TRUE; 780 } 781 782 /* Write out the merged section. */ 783 784 bfd_boolean 785 _bfd_write_merged_section (bfd *output_bfd, asection *sec, void *psecinfo) 786 { 787 struct sec_merge_sec_info *secinfo; 788 file_ptr pos; 789 790 secinfo = (struct sec_merge_sec_info *) psecinfo; 791 792 if (!secinfo) 793 return FALSE; 794 795 if (secinfo->first_str == NULL) 796 return TRUE; 797 798 /* FIXME: octets_per_byte. */ 799 pos = sec->output_section->filepos + sec->output_offset; 800 if (bfd_seek (output_bfd, pos, SEEK_SET) != 0) 801 return FALSE; 802 803 if (! sec_merge_emit (output_bfd, secinfo->first_str)) 804 return FALSE; 805 806 return TRUE; 807 } 808 809 /* Adjust an address in the SEC_MERGE section. Given OFFSET within 810 *PSEC, this returns the new offset in the adjusted SEC_MERGE 811 section and writes the new section back into *PSEC. */ 812 813 bfd_vma 814 _bfd_merged_section_offset (bfd *output_bfd ATTRIBUTE_UNUSED, asection **psec, 815 void *psecinfo, bfd_vma offset) 816 { 817 struct sec_merge_sec_info *secinfo; 818 struct sec_merge_hash_entry *entry; 819 unsigned char *p; 820 asection *sec = *psec; 821 822 secinfo = (struct sec_merge_sec_info *) psecinfo; 823 824 if (!secinfo) 825 return offset; 826 827 if (offset >= sec->rawsize) 828 { 829 if (offset > sec->rawsize) 830 { 831 (*_bfd_error_handler) 832 (_("%s: access beyond end of merged section (%ld)"), 833 bfd_get_filename (sec->owner), (long) offset); 834 } 835 return secinfo->first_str ? sec->size : 0; 836 } 837 838 if (secinfo->htab->strings) 839 { 840 if (sec->entsize == 1) 841 { 842 p = secinfo->contents + offset - 1; 843 while (p >= secinfo->contents && *p) 844 --p; 845 ++p; 846 } 847 else 848 { 849 p = secinfo->contents + (offset / sec->entsize) * sec->entsize; 850 p -= sec->entsize; 851 while (p >= secinfo->contents) 852 { 853 unsigned int i; 854 855 for (i = 0; i < sec->entsize; ++i) 856 if (p[i] != '\0') 857 break; 858 if (i == sec->entsize) 859 break; 860 p -= sec->entsize; 861 } 862 p += sec->entsize; 863 } 864 } 865 else 866 { 867 p = secinfo->contents + (offset / sec->entsize) * sec->entsize; 868 } 869 entry = sec_merge_hash_lookup (secinfo->htab, (char *) p, 0, FALSE); 870 if (!entry) 871 { 872 if (! secinfo->htab->strings) 873 abort (); 874 /* This should only happen if somebody points into the padding 875 after a NUL character but before next entity. */ 876 if (*p) 877 abort (); 878 if (! secinfo->htab->first) 879 abort (); 880 entry = secinfo->htab->first; 881 p = (secinfo->contents + (offset / sec->entsize + 1) * sec->entsize 882 - entry->len); 883 } 884 885 *psec = entry->secinfo->sec; 886 return entry->u.index + (secinfo->contents + offset - p); 887 } 888 889 /* Tidy up when done. */ 890 891 void 892 _bfd_merge_sections_free (void *xsinfo) 893 { 894 struct sec_merge_info *sinfo; 895 896 for (sinfo = (struct sec_merge_info *) xsinfo; sinfo; sinfo = sinfo->next) 897 { 898 bfd_hash_table_free (&sinfo->htab->table); 899 free (sinfo->htab); 900 } 901 } 902