1/* SEC_MERGE support. 2 Copyright 2001, 2002, 2003, 2004, 2005, 2006, 2007 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 33struct sec_merge_sec_info; 34 35/* An entry in the section merge hash table. */ 36 37struct 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 60struct 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 75struct 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 85struct 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 104static struct bfd_hash_entry * 105sec_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 = bfd_hash_allocate (table, sizeof (struct sec_merge_hash_entry)); 112 if (entry == NULL) 113 return NULL; 114 115 /* Call the allocation method of the superclass. */ 116 entry = bfd_hash_newfunc (entry, table, string); 117 118 if (entry != NULL) 119 { 120 /* Initialize the local fields. */ 121 struct sec_merge_hash_entry *ret = (struct sec_merge_hash_entry *) entry; 122 123 ret->u.suffix = NULL; 124 ret->alignment = 0; 125 ret->secinfo = NULL; 126 ret->next = NULL; 127 } 128 129 return entry; 130} 131 132/* Look up an entry in a section merge hash table. */ 133 134static struct sec_merge_hash_entry * 135sec_merge_hash_lookup (struct sec_merge_hash *table, const char *string, 136 unsigned int alignment, bfd_boolean create) 137{ 138 register const unsigned char *s; 139 register unsigned long hash; 140 register unsigned int c; 141 struct sec_merge_hash_entry *hashp; 142 unsigned int len, i; 143 unsigned int index; 144 145 hash = 0; 146 len = 0; 147 s = (const unsigned char *) string; 148 if (table->strings) 149 { 150 if (table->entsize == 1) 151 { 152 while ((c = *s++) != '\0') 153 { 154 hash += c + (c << 17); 155 hash ^= hash >> 2; 156 ++len; 157 } 158 hash += len + (len << 17); 159 } 160 else 161 { 162 for (;;) 163 { 164 for (i = 0; i < table->entsize; ++i) 165 if (s[i] != '\0') 166 break; 167 if (i == table->entsize) 168 break; 169 for (i = 0; i < table->entsize; ++i) 170 { 171 c = *s++; 172 hash += c + (c << 17); 173 hash ^= hash >> 2; 174 } 175 ++len; 176 } 177 hash += len + (len << 17); 178 len *= table->entsize; 179 } 180 hash ^= hash >> 2; 181 len += table->entsize; 182 } 183 else 184 { 185 for (i = 0; i < table->entsize; ++i) 186 { 187 c = *s++; 188 hash += c + (c << 17); 189 hash ^= hash >> 2; 190 } 191 len = table->entsize; 192 } 193 194 index = hash % table->table.size; 195 for (hashp = (struct sec_merge_hash_entry *) table->table.table[index]; 196 hashp != NULL; 197 hashp = (struct sec_merge_hash_entry *) hashp->root.next) 198 { 199 if (hashp->root.hash == hash 200 && len == hashp->len 201 && memcmp (hashp->root.string, string, len) == 0) 202 { 203 /* If the string we found does not have at least the required 204 alignment, we need to insert another copy. */ 205 if (hashp->alignment < alignment) 206 { 207 if (create) 208 { 209 /* Mark the less aligned copy as deleted. */ 210 hashp->len = 0; 211 hashp->alignment = 0; 212 } 213 break; 214 } 215 return hashp; 216 } 217 } 218 219 if (! create) 220 return NULL; 221 222 hashp = ((struct sec_merge_hash_entry *) 223 sec_merge_hash_newfunc (NULL, &table->table, string)); 224 if (hashp == NULL) 225 return NULL; 226 hashp->root.string = string; 227 hashp->root.hash = hash; 228 hashp->len = len; 229 hashp->alignment = alignment; 230 hashp->root.next = table->table.table[index]; 231 table->table.table[index] = (struct bfd_hash_entry *) hashp; 232 233 return hashp; 234} 235 236/* Create a new hash table. */ 237 238static struct sec_merge_hash * 239sec_merge_init (unsigned int entsize, bfd_boolean strings) 240{ 241 struct sec_merge_hash *table; 242 243 table = bfd_malloc (sizeof (struct sec_merge_hash)); 244 if (table == NULL) 245 return NULL; 246 247 if (! bfd_hash_table_init_n (&table->table, sec_merge_hash_newfunc, 248 sizeof (struct sec_merge_hash_entry), 16699)) 249 { 250 free (table); 251 return NULL; 252 } 253 254 table->size = 0; 255 table->first = NULL; 256 table->last = NULL; 257 table->entsize = entsize; 258 table->strings = strings; 259 260 return table; 261} 262 263/* Get the index of an entity in a hash table, adding it if it is not 264 already present. */ 265 266static struct sec_merge_hash_entry * 267sec_merge_add (struct sec_merge_hash *tab, const char *str, 268 unsigned int alignment, struct sec_merge_sec_info *secinfo) 269{ 270 register struct sec_merge_hash_entry *entry; 271 272 entry = sec_merge_hash_lookup (tab, str, alignment, TRUE); 273 if (entry == NULL) 274 return NULL; 275 276 if (entry->secinfo == NULL) 277 { 278 tab->size++; 279 entry->secinfo = secinfo; 280 if (tab->first == NULL) 281 tab->first = entry; 282 else 283 tab->last->next = entry; 284 tab->last = entry; 285 } 286 287 return entry; 288} 289 290static bfd_boolean 291sec_merge_emit (bfd *abfd, struct sec_merge_hash_entry *entry) 292{ 293 struct sec_merge_sec_info *secinfo = entry->secinfo; 294 asection *sec = secinfo->sec; 295 char *pad = NULL; 296 bfd_size_type off = 0; 297 int alignment_power = sec->output_section->alignment_power; 298 299 if (alignment_power) 300 { 301 pad = bfd_zmalloc ((bfd_size_type) 1 << alignment_power); 302 if (pad == NULL) 303 return FALSE; 304 } 305 306 for (; entry != NULL && entry->secinfo == secinfo; entry = entry->next) 307 { 308 const char *str; 309 bfd_size_type len; 310 311 len = -off & (entry->alignment - 1); 312 if (len != 0) 313 { 314 if (bfd_bwrite (pad, len, abfd) != len) 315 goto err; 316 off += len; 317 } 318 319 str = entry->root.string; 320 len = entry->len; 321 322 if (bfd_bwrite (str, len, abfd) != len) 323 goto err; 324 325 off += len; 326 } 327 328 /* Trailing alignment needed? */ 329 off = sec->size - off; 330 if (off != 0 331 && bfd_bwrite (pad, off, abfd) != off) 332 goto err; 333 334 if (pad != NULL) 335 free (pad); 336 return TRUE; 337 338 err: 339 if (pad != NULL) 340 free (pad); 341 return FALSE; 342} 343 344/* Register a SEC_MERGE section as a candidate for merging. 345 This function is called for all non-dynamic SEC_MERGE input sections. */ 346 347bfd_boolean 348_bfd_add_merge_section (bfd *abfd, void **psinfo, asection *sec, 349 void **psecinfo) 350{ 351 struct sec_merge_info *sinfo; 352 struct sec_merge_sec_info *secinfo; 353 unsigned int align; 354 bfd_size_type amt; 355 356 if ((abfd->flags & DYNAMIC) != 0 357 || (sec->flags & SEC_MERGE) == 0) 358 abort (); 359 360 if (sec->size == 0 361 || (sec->flags & SEC_EXCLUDE) != 0 362 || sec->entsize == 0) 363 return TRUE; 364 365 if ((sec->flags & SEC_RELOC) != 0) 366 { 367 /* We aren't prepared to handle relocations in merged sections. */ 368 return TRUE; 369 } 370 371 align = sec->alignment_power; 372 if ((sec->entsize < (unsigned) 1 << align 373 && ((sec->entsize & (sec->entsize - 1)) 374 || !(sec->flags & SEC_STRINGS))) 375 || (sec->entsize > (unsigned) 1 << align 376 && (sec->entsize & (((unsigned) 1 << align) - 1)))) 377 { 378 /* Sanity check. If string character size is smaller than 379 alignment, then we require character size to be a power 380 of 2, otherwise character size must be integer multiple 381 of alignment. For non-string constants, alignment must 382 be smaller than or equal to entity size and entity size 383 must be integer multiple of alignment. */ 384 return TRUE; 385 } 386 387 for (sinfo = (struct sec_merge_info *) *psinfo; sinfo; sinfo = sinfo->next) 388 if ((secinfo = sinfo->chain) 389 && ! ((secinfo->sec->flags ^ sec->flags) & (SEC_MERGE | SEC_STRINGS)) 390 && secinfo->sec->entsize == sec->entsize 391 && secinfo->sec->alignment_power == sec->alignment_power 392 && secinfo->sec->output_section == sec->output_section) 393 break; 394 395 if (sinfo == NULL) 396 { 397 /* Initialize the information we need to keep track of. */ 398 sinfo = bfd_alloc (abfd, sizeof (struct sec_merge_info)); 399 if (sinfo == NULL) 400 goto error_return; 401 sinfo->next = (struct sec_merge_info *) *psinfo; 402 sinfo->chain = NULL; 403 *psinfo = sinfo; 404 sinfo->htab = sec_merge_init (sec->entsize, (sec->flags & SEC_STRINGS)); 405 if (sinfo->htab == NULL) 406 goto error_return; 407 } 408 409 /* Read the section from abfd. */ 410 411 amt = sizeof (struct sec_merge_sec_info) + sec->size - 1; 412 *psecinfo = bfd_alloc (abfd, amt); 413 if (*psecinfo == NULL) 414 goto error_return; 415 416 secinfo = (struct sec_merge_sec_info *) *psecinfo; 417 if (sinfo->chain) 418 { 419 secinfo->next = sinfo->chain->next; 420 sinfo->chain->next = secinfo; 421 } 422 else 423 secinfo->next = secinfo; 424 sinfo->chain = secinfo; 425 secinfo->sec = sec; 426 secinfo->psecinfo = psecinfo; 427 secinfo->htab = sinfo->htab; 428 secinfo->first_str = NULL; 429 430 sec->rawsize = sec->size; 431 if (! bfd_get_section_contents (sec->owner, sec, secinfo->contents, 432 0, sec->size)) 433 goto error_return; 434 435 return TRUE; 436 437 error_return: 438 *psecinfo = NULL; 439 return FALSE; 440} 441 442/* Record one section into the hash table. */ 443static bfd_boolean 444record_section (struct sec_merge_info *sinfo, 445 struct sec_merge_sec_info *secinfo) 446{ 447 asection *sec = secinfo->sec; 448 struct sec_merge_hash_entry *entry; 449 bfd_boolean nul; 450 unsigned char *p, *end; 451 bfd_vma mask, eltalign; 452 unsigned int align, i; 453 454 align = sec->alignment_power; 455 end = secinfo->contents + sec->size; 456 nul = FALSE; 457 mask = ((bfd_vma) 1 << align) - 1; 458 if (sec->flags & SEC_STRINGS) 459 { 460 for (p = secinfo->contents; p < end; ) 461 { 462 eltalign = p - secinfo->contents; 463 eltalign = ((eltalign ^ (eltalign - 1)) + 1) >> 1; 464 if (!eltalign || eltalign > mask) 465 eltalign = mask + 1; 466 entry = sec_merge_add (sinfo->htab, (char *) p, (unsigned) eltalign, 467 secinfo); 468 if (! entry) 469 goto error_return; 470 p += entry->len; 471 if (sec->entsize == 1) 472 { 473 while (p < end && *p == 0) 474 { 475 if (!nul && !((p - secinfo->contents) & mask)) 476 { 477 nul = TRUE; 478 entry = sec_merge_add (sinfo->htab, "", 479 (unsigned) mask + 1, secinfo); 480 if (! entry) 481 goto error_return; 482 } 483 p++; 484 } 485 } 486 else 487 { 488 while (p < end) 489 { 490 for (i = 0; i < sec->entsize; i++) 491 if (p[i] != '\0') 492 break; 493 if (i != sec->entsize) 494 break; 495 if (!nul && !((p - secinfo->contents) & mask)) 496 { 497 nul = TRUE; 498 entry = sec_merge_add (sinfo->htab, (char *) p, 499 (unsigned) mask + 1, secinfo); 500 if (! entry) 501 goto error_return; 502 } 503 p += sec->entsize; 504 } 505 } 506 } 507 } 508 else 509 { 510 for (p = secinfo->contents; p < end; p += sec->entsize) 511 { 512 entry = sec_merge_add (sinfo->htab, (char *) p, 1, secinfo); 513 if (! entry) 514 goto error_return; 515 } 516 } 517 518 return TRUE; 519 520error_return: 521 for (secinfo = sinfo->chain; secinfo; secinfo = secinfo->next) 522 *secinfo->psecinfo = NULL; 523 return FALSE; 524} 525 526static int 527strrevcmp (const void *a, const void *b) 528{ 529 struct sec_merge_hash_entry *A = *(struct sec_merge_hash_entry **) a; 530 struct sec_merge_hash_entry *B = *(struct sec_merge_hash_entry **) b; 531 unsigned int lenA = A->len; 532 unsigned int lenB = B->len; 533 const unsigned char *s = (const unsigned char *) A->root.string + lenA - 1; 534 const unsigned char *t = (const unsigned char *) B->root.string + lenB - 1; 535 int l = lenA < lenB ? lenA : lenB; 536 537 while (l) 538 { 539 if (*s != *t) 540 return (int) *s - (int) *t; 541 s--; 542 t--; 543 l--; 544 } 545 return lenA - lenB; 546} 547 548/* Like strrevcmp, but for the case where all strings have the same 549 alignment > entsize. */ 550 551static int 552strrevcmp_align (const void *a, const void *b) 553{ 554 struct sec_merge_hash_entry *A = *(struct sec_merge_hash_entry **) a; 555 struct sec_merge_hash_entry *B = *(struct sec_merge_hash_entry **) b; 556 unsigned int lenA = A->len; 557 unsigned int lenB = B->len; 558 const unsigned char *s = (const unsigned char *) A->root.string + lenA - 1; 559 const unsigned char *t = (const unsigned char *) B->root.string + lenB - 1; 560 int l = lenA < lenB ? lenA : lenB; 561 int tail_align = (lenA & (A->alignment - 1)) - (lenB & (A->alignment - 1)); 562 563 if (tail_align != 0) 564 return tail_align; 565 566 while (l) 567 { 568 if (*s != *t) 569 return (int) *s - (int) *t; 570 s--; 571 t--; 572 l--; 573 } 574 return lenA - lenB; 575} 576 577static inline int 578is_suffix (const struct sec_merge_hash_entry *A, 579 const struct sec_merge_hash_entry *B) 580{ 581 if (A->len <= B->len) 582 /* B cannot be a suffix of A unless A is equal to B, which is guaranteed 583 not to be equal by the hash table. */ 584 return 0; 585 586 return memcmp (A->root.string + (A->len - B->len), 587 B->root.string, B->len) == 0; 588} 589 590/* This is a helper function for _bfd_merge_sections. It attempts to 591 merge strings matching suffixes of longer strings. */ 592static void 593merge_strings (struct sec_merge_info *sinfo) 594{ 595 struct sec_merge_hash_entry **array, **a, *e; 596 struct sec_merge_sec_info *secinfo; 597 bfd_size_type size, amt; 598 unsigned int alignment = 0; 599 600 /* Now sort the strings */ 601 amt = sinfo->htab->size * sizeof (struct sec_merge_hash_entry *); 602 array = bfd_malloc (amt); 603 if (array == NULL) 604 goto alloc_failure; 605 606 for (e = sinfo->htab->first, a = array; e; e = e->next) 607 if (e->alignment) 608 { 609 *a++ = e; 610 /* Adjust the length to not include the zero terminator. */ 611 e->len -= sinfo->htab->entsize; 612 if (alignment != e->alignment) 613 { 614 if (alignment == 0) 615 alignment = e->alignment; 616 else 617 alignment = (unsigned) -1; 618 } 619 } 620 621 sinfo->htab->size = a - array; 622 if (sinfo->htab->size != 0) 623 { 624 qsort (array, (size_t) sinfo->htab->size, 625 sizeof (struct sec_merge_hash_entry *), 626 (alignment != (unsigned) -1 && alignment > sinfo->htab->entsize 627 ? strrevcmp_align : strrevcmp)); 628 629 /* Loop over the sorted array and merge suffixes */ 630 e = *--a; 631 e->len += sinfo->htab->entsize; 632 while (--a >= array) 633 { 634 struct sec_merge_hash_entry *cmp = *a; 635 636 cmp->len += sinfo->htab->entsize; 637 if (e->alignment >= cmp->alignment 638 && !((e->len - cmp->len) & (cmp->alignment - 1)) 639 && is_suffix (e, cmp)) 640 { 641 cmp->u.suffix = e; 642 cmp->alignment = 0; 643 } 644 else 645 e = cmp; 646 } 647 } 648 649alloc_failure: 650 if (array) 651 free (array); 652 653 /* Now assign positions to the strings we want to keep. */ 654 size = 0; 655 secinfo = sinfo->htab->first->secinfo; 656 for (e = sinfo->htab->first; e; e = e->next) 657 { 658 if (e->secinfo != secinfo) 659 { 660 secinfo->sec->size = size; 661 secinfo = e->secinfo; 662 } 663 if (e->alignment) 664 { 665 if (e->secinfo->first_str == NULL) 666 { 667 e->secinfo->first_str = e; 668 size = 0; 669 } 670 size = (size + e->alignment - 1) & ~((bfd_vma) e->alignment - 1); 671 e->u.index = size; 672 size += e->len; 673 } 674 } 675 secinfo->sec->size = size; 676 if (secinfo->sec->alignment_power != 0) 677 { 678 bfd_size_type align = (bfd_size_type) 1 << secinfo->sec->alignment_power; 679 secinfo->sec->size = (secinfo->sec->size + align - 1) & -align; 680 } 681 682 /* And now adjust the rest, removing them from the chain (but not hashtable) 683 at the same time. */ 684 for (a = &sinfo->htab->first, e = *a; e; e = e->next) 685 if (e->alignment) 686 a = &e->next; 687 else 688 { 689 *a = e->next; 690 if (e->len) 691 { 692 e->secinfo = e->u.suffix->secinfo; 693 e->alignment = e->u.suffix->alignment; 694 e->u.index = e->u.suffix->u.index + (e->u.suffix->len - e->len); 695 } 696 } 697} 698 699/* This function is called once after all SEC_MERGE sections are registered 700 with _bfd_merge_section. */ 701 702bfd_boolean 703_bfd_merge_sections (bfd *abfd ATTRIBUTE_UNUSED, 704 struct bfd_link_info *info ATTRIBUTE_UNUSED, 705 void *xsinfo, 706 void (*remove_hook) (bfd *, asection *)) 707{ 708 struct sec_merge_info *sinfo; 709 710 for (sinfo = (struct sec_merge_info *) xsinfo; sinfo; sinfo = sinfo->next) 711 { 712 struct sec_merge_sec_info * secinfo; 713 714 if (! sinfo->chain) 715 continue; 716 717 /* Move sinfo->chain to head of the chain, terminate it. */ 718 secinfo = sinfo->chain; 719 sinfo->chain = secinfo->next; 720 secinfo->next = NULL; 721 722 /* Record the sections into the hash table. */ 723 for (secinfo = sinfo->chain; secinfo; secinfo = secinfo->next) 724 if (secinfo->sec->flags & SEC_EXCLUDE) 725 { 726 *secinfo->psecinfo = NULL; 727 if (remove_hook) 728 (*remove_hook) (abfd, secinfo->sec); 729 } 730 else if (! record_section (sinfo, secinfo)) 731 break; 732 733 if (secinfo) 734 continue; 735 736 if (sinfo->htab->first == NULL) 737 continue; 738 739 if (sinfo->htab->strings) 740 merge_strings (sinfo); 741 else 742 { 743 struct sec_merge_hash_entry *e; 744 bfd_size_type size = 0; 745 746 /* Things are much simpler for non-strings. 747 Just assign them slots in the section. */ 748 secinfo = NULL; 749 for (e = sinfo->htab->first; e; e = e->next) 750 { 751 if (e->secinfo->first_str == NULL) 752 { 753 if (secinfo) 754 secinfo->sec->size = size; 755 e->secinfo->first_str = e; 756 size = 0; 757 } 758 size = (size + e->alignment - 1) 759 & ~((bfd_vma) e->alignment - 1); 760 e->u.index = size; 761 size += e->len; 762 secinfo = e->secinfo; 763 } 764 secinfo->sec->size = size; 765 } 766 767 /* Finally remove all input sections which have not made it into 768 the hash table at all. */ 769 for (secinfo = sinfo->chain; secinfo; secinfo = secinfo->next) 770 if (secinfo->first_str == NULL) 771 secinfo->sec->flags |= SEC_EXCLUDE | SEC_KEEP; 772 } 773 774 return TRUE; 775} 776 777/* Write out the merged section. */ 778 779bfd_boolean 780_bfd_write_merged_section (bfd *output_bfd, asection *sec, void *psecinfo) 781{ 782 struct sec_merge_sec_info *secinfo; 783 file_ptr pos; 784 785 secinfo = (struct sec_merge_sec_info *) psecinfo; 786 787 if (secinfo->first_str == NULL) 788 return TRUE; 789 790 pos = sec->output_section->filepos + sec->output_offset; 791 if (bfd_seek (output_bfd, pos, SEEK_SET) != 0) 792 return FALSE; 793 794 if (! sec_merge_emit (output_bfd, secinfo->first_str)) 795 return FALSE; 796 797 return TRUE; 798} 799 800/* Adjust an address in the SEC_MERGE section. Given OFFSET within 801 *PSEC, this returns the new offset in the adjusted SEC_MERGE 802 section and writes the new section back into *PSEC. */ 803 804bfd_vma 805_bfd_merged_section_offset (bfd *output_bfd ATTRIBUTE_UNUSED, asection **psec, 806 void *psecinfo, bfd_vma offset) 807{ 808 struct sec_merge_sec_info *secinfo; 809 struct sec_merge_hash_entry *entry; 810 unsigned char *p; 811 asection *sec = *psec; 812 813 secinfo = (struct sec_merge_sec_info *) psecinfo; 814 815 if (offset >= sec->rawsize) 816 { 817 if (offset > sec->rawsize) 818 { 819 (*_bfd_error_handler) 820 (_("%s: access beyond end of merged section (%ld)"), 821 bfd_get_filename (sec->owner), (long) offset); 822 } 823 return secinfo->first_str ? sec->size : 0; 824 } 825 826 if (secinfo->htab->strings) 827 { 828 if (sec->entsize == 1) 829 { 830 p = secinfo->contents + offset - 1; 831 while (p >= secinfo->contents && *p) 832 --p; 833 ++p; 834 } 835 else 836 { 837 p = secinfo->contents + (offset / sec->entsize) * sec->entsize; 838 p -= sec->entsize; 839 while (p >= secinfo->contents) 840 { 841 unsigned int i; 842 843 for (i = 0; i < sec->entsize; ++i) 844 if (p[i] != '\0') 845 break; 846 if (i == sec->entsize) 847 break; 848 p -= sec->entsize; 849 } 850 p += sec->entsize; 851 } 852 } 853 else 854 { 855 p = secinfo->contents + (offset / sec->entsize) * sec->entsize; 856 } 857 entry = sec_merge_hash_lookup (secinfo->htab, (char *) p, 0, FALSE); 858 if (!entry) 859 { 860 if (! secinfo->htab->strings) 861 abort (); 862 /* This should only happen if somebody points into the padding 863 after a NUL character but before next entity. */ 864 if (*p) 865 abort (); 866 if (! secinfo->htab->first) 867 abort (); 868 entry = secinfo->htab->first; 869 p = (secinfo->contents + (offset / sec->entsize + 1) * sec->entsize 870 - entry->len); 871 } 872 873 *psec = entry->secinfo->sec; 874 return entry->u.index + (secinfo->contents + offset - p); 875} 876