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 register const unsigned char *s; 140 register unsigned long hash; 141 register 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 register 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; 351 352 if ((abfd->flags & DYNAMIC) != 0 353 || (sec->flags & SEC_MERGE) == 0) 354 abort (); 355 356 if (sec->size == 0 357 || (sec->flags & SEC_EXCLUDE) != 0 358 || sec->entsize == 0) 359 return TRUE; 360 361 if ((sec->flags & SEC_RELOC) != 0) 362 { 363 /* We aren't prepared to handle relocations in merged sections. */ 364 return TRUE; 365 } 366 367 align = sec->alignment_power; 368 if ((sec->entsize < (unsigned) 1 << align 369 && ((sec->entsize & (sec->entsize - 1)) 370 || !(sec->flags & SEC_STRINGS))) 371 || (sec->entsize > (unsigned) 1 << align 372 && (sec->entsize & (((unsigned) 1 << align) - 1)))) 373 { 374 /* Sanity check. If string character size is smaller than 375 alignment, then we require character size to be a power 376 of 2, otherwise character size must be integer multiple 377 of alignment. For non-string constants, alignment must 378 be smaller than or equal to entity size and entity size 379 must be integer multiple of alignment. */ 380 return TRUE; 381 } 382 383 for (sinfo = (struct sec_merge_info *) *psinfo; sinfo; sinfo = sinfo->next) 384 if ((secinfo = sinfo->chain) 385 && ! ((secinfo->sec->flags ^ sec->flags) & (SEC_MERGE | SEC_STRINGS)) 386 && secinfo->sec->entsize == sec->entsize 387 && secinfo->sec->alignment_power == sec->alignment_power 388 && secinfo->sec->output_section == sec->output_section) 389 break; 390 391 if (sinfo == NULL) 392 { 393 /* Initialize the information we need to keep track of. */ 394 sinfo = (struct sec_merge_info *) 395 bfd_alloc (abfd, sizeof (struct sec_merge_info)); 396 if (sinfo == NULL) 397 goto error_return; 398 sinfo->next = (struct sec_merge_info *) *psinfo; 399 sinfo->chain = NULL; 400 *psinfo = sinfo; 401 sinfo->htab = sec_merge_init (sec->entsize, (sec->flags & SEC_STRINGS)); 402 if (sinfo->htab == NULL) 403 goto error_return; 404 } 405 406 /* Read the section from abfd. */ 407 408 amt = sizeof (struct sec_merge_sec_info) - 1 + sec->size; 409 if (sec->flags & SEC_STRINGS) 410 /* Some versions of gcc may emit a string without a zero terminator. 411 See http://gcc.gnu.org/ml/gcc-patches/2006-06/msg01004.html 412 Allocate space for an extra zero. */ 413 amt += sec->entsize; 414 *psecinfo = bfd_alloc (abfd, amt); 415 if (*psecinfo == NULL) 416 goto error_return; 417 418 secinfo = (struct sec_merge_sec_info *) *psecinfo; 419 if (sinfo->chain) 420 { 421 secinfo->next = sinfo->chain->next; 422 sinfo->chain->next = secinfo; 423 } 424 else 425 secinfo->next = secinfo; 426 sinfo->chain = secinfo; 427 secinfo->sec = sec; 428 secinfo->psecinfo = psecinfo; 429 secinfo->htab = sinfo->htab; 430 secinfo->first_str = NULL; 431 432 sec->rawsize = sec->size; 433 if (sec->flags & SEC_STRINGS) 434 memset (secinfo->contents + sec->size, 0, sec->entsize); 435 if (! bfd_get_section_contents (sec->owner, sec, secinfo->contents, 436 0, sec->size)) 437 goto error_return; 438 439 return TRUE; 440 441 error_return: 442 *psecinfo = NULL; 443 return FALSE; 444 } 445 446 /* Record one section into the hash table. */ 447 static bfd_boolean 448 record_section (struct sec_merge_info *sinfo, 449 struct sec_merge_sec_info *secinfo) 450 { 451 asection *sec = secinfo->sec; 452 struct sec_merge_hash_entry *entry; 453 bfd_boolean nul; 454 unsigned char *p, *end; 455 bfd_vma mask, eltalign; 456 unsigned int align, i; 457 458 align = sec->alignment_power; 459 end = secinfo->contents + sec->size; 460 nul = FALSE; 461 mask = ((bfd_vma) 1 << align) - 1; 462 if (sec->flags & SEC_STRINGS) 463 { 464 for (p = secinfo->contents; p < end; ) 465 { 466 eltalign = p - secinfo->contents; 467 eltalign = ((eltalign ^ (eltalign - 1)) + 1) >> 1; 468 if (!eltalign || eltalign > mask) 469 eltalign = mask + 1; 470 entry = sec_merge_add (sinfo->htab, (char *) p, (unsigned) eltalign, 471 secinfo); 472 if (! entry) 473 goto error_return; 474 p += entry->len; 475 if (sec->entsize == 1) 476 { 477 while (p < end && *p == 0) 478 { 479 if (!nul && !((p - secinfo->contents) & mask)) 480 { 481 nul = TRUE; 482 entry = sec_merge_add (sinfo->htab, "", 483 (unsigned) mask + 1, secinfo); 484 if (! entry) 485 goto error_return; 486 } 487 p++; 488 } 489 } 490 else 491 { 492 while (p < end) 493 { 494 for (i = 0; i < sec->entsize; i++) 495 if (p[i] != '\0') 496 break; 497 if (i != sec->entsize) 498 break; 499 if (!nul && !((p - secinfo->contents) & mask)) 500 { 501 nul = TRUE; 502 entry = sec_merge_add (sinfo->htab, (char *) p, 503 (unsigned) mask + 1, secinfo); 504 if (! entry) 505 goto error_return; 506 } 507 p += sec->entsize; 508 } 509 } 510 } 511 } 512 else 513 { 514 for (p = secinfo->contents; p < end; p += sec->entsize) 515 { 516 entry = sec_merge_add (sinfo->htab, (char *) p, 1, secinfo); 517 if (! entry) 518 goto error_return; 519 } 520 } 521 522 return TRUE; 523 524 error_return: 525 for (secinfo = sinfo->chain; secinfo; secinfo = secinfo->next) 526 *secinfo->psecinfo = NULL; 527 return FALSE; 528 } 529 530 static int 531 strrevcmp (const void *a, const void *b) 532 { 533 struct sec_merge_hash_entry *A = *(struct sec_merge_hash_entry **) a; 534 struct sec_merge_hash_entry *B = *(struct sec_merge_hash_entry **) b; 535 unsigned int lenA = A->len; 536 unsigned int lenB = B->len; 537 const unsigned char *s = (const unsigned char *) A->root.string + lenA - 1; 538 const unsigned char *t = (const unsigned char *) B->root.string + lenB - 1; 539 int l = lenA < lenB ? lenA : lenB; 540 541 while (l) 542 { 543 if (*s != *t) 544 return (int) *s - (int) *t; 545 s--; 546 t--; 547 l--; 548 } 549 return lenA - lenB; 550 } 551 552 /* Like strrevcmp, but for the case where all strings have the same 553 alignment > entsize. */ 554 555 static int 556 strrevcmp_align (const void *a, const void *b) 557 { 558 struct sec_merge_hash_entry *A = *(struct sec_merge_hash_entry **) a; 559 struct sec_merge_hash_entry *B = *(struct sec_merge_hash_entry **) b; 560 unsigned int lenA = A->len; 561 unsigned int lenB = B->len; 562 const unsigned char *s = (const unsigned char *) A->root.string + lenA - 1; 563 const unsigned char *t = (const unsigned char *) B->root.string + lenB - 1; 564 int l = lenA < lenB ? lenA : lenB; 565 int tail_align = (lenA & (A->alignment - 1)) - (lenB & (A->alignment - 1)); 566 567 if (tail_align != 0) 568 return tail_align; 569 570 while (l) 571 { 572 if (*s != *t) 573 return (int) *s - (int) *t; 574 s--; 575 t--; 576 l--; 577 } 578 return lenA - lenB; 579 } 580 581 static inline int 582 is_suffix (const struct sec_merge_hash_entry *A, 583 const struct sec_merge_hash_entry *B) 584 { 585 if (A->len <= B->len) 586 /* B cannot be a suffix of A unless A is equal to B, which is guaranteed 587 not to be equal by the hash table. */ 588 return 0; 589 590 return memcmp (A->root.string + (A->len - B->len), 591 B->root.string, B->len) == 0; 592 } 593 594 /* This is a helper function for _bfd_merge_sections. It attempts to 595 merge strings matching suffixes of longer strings. */ 596 static void 597 merge_strings (struct sec_merge_info *sinfo) 598 { 599 struct sec_merge_hash_entry **array, **a, *e; 600 struct sec_merge_sec_info *secinfo; 601 bfd_size_type size, amt; 602 unsigned int alignment = 0; 603 604 /* Now sort the strings */ 605 amt = sinfo->htab->size * sizeof (struct sec_merge_hash_entry *); 606 array = (struct sec_merge_hash_entry **) bfd_malloc (amt); 607 if (array == NULL) 608 goto alloc_failure; 609 610 for (e = sinfo->htab->first, a = array; e; e = e->next) 611 if (e->alignment) 612 { 613 *a++ = e; 614 /* Adjust the length to not include the zero terminator. */ 615 e->len -= sinfo->htab->entsize; 616 if (alignment != e->alignment) 617 { 618 if (alignment == 0) 619 alignment = e->alignment; 620 else 621 alignment = (unsigned) -1; 622 } 623 } 624 625 sinfo->htab->size = a - array; 626 if (sinfo->htab->size != 0) 627 { 628 qsort (array, (size_t) sinfo->htab->size, 629 sizeof (struct sec_merge_hash_entry *), 630 (alignment != (unsigned) -1 && alignment > sinfo->htab->entsize 631 ? strrevcmp_align : strrevcmp)); 632 633 /* Loop over the sorted array and merge suffixes */ 634 e = *--a; 635 e->len += sinfo->htab->entsize; 636 while (--a >= array) 637 { 638 struct sec_merge_hash_entry *cmp = *a; 639 640 cmp->len += sinfo->htab->entsize; 641 if (e->alignment >= cmp->alignment 642 && !((e->len - cmp->len) & (cmp->alignment - 1)) 643 && is_suffix (e, cmp)) 644 { 645 cmp->u.suffix = e; 646 cmp->alignment = 0; 647 } 648 else 649 e = cmp; 650 } 651 } 652 653 alloc_failure: 654 if (array) 655 free (array); 656 657 /* Now assign positions to the strings we want to keep. */ 658 size = 0; 659 secinfo = sinfo->htab->first->secinfo; 660 for (e = sinfo->htab->first; e; e = e->next) 661 { 662 if (e->secinfo != secinfo) 663 { 664 secinfo->sec->size = size; 665 secinfo = e->secinfo; 666 } 667 if (e->alignment) 668 { 669 if (e->secinfo->first_str == NULL) 670 { 671 e->secinfo->first_str = e; 672 size = 0; 673 } 674 size = (size + e->alignment - 1) & ~((bfd_vma) e->alignment - 1); 675 e->u.index = size; 676 size += e->len; 677 } 678 } 679 secinfo->sec->size = size; 680 if (secinfo->sec->alignment_power != 0) 681 { 682 bfd_size_type align = (bfd_size_type) 1 << secinfo->sec->alignment_power; 683 secinfo->sec->size = (secinfo->sec->size + align - 1) & -align; 684 } 685 686 /* And now adjust the rest, removing them from the chain (but not hashtable) 687 at the same time. */ 688 for (a = &sinfo->htab->first, e = *a; e; e = e->next) 689 if (e->alignment) 690 a = &e->next; 691 else 692 { 693 *a = e->next; 694 if (e->len) 695 { 696 e->secinfo = e->u.suffix->secinfo; 697 e->alignment = e->u.suffix->alignment; 698 e->u.index = e->u.suffix->u.index + (e->u.suffix->len - e->len); 699 } 700 } 701 } 702 703 /* This function is called once after all SEC_MERGE sections are registered 704 with _bfd_merge_section. */ 705 706 bfd_boolean 707 _bfd_merge_sections (bfd *abfd, 708 struct bfd_link_info *info ATTRIBUTE_UNUSED, 709 void *xsinfo, 710 void (*remove_hook) (bfd *, asection *)) 711 { 712 struct sec_merge_info *sinfo; 713 714 for (sinfo = (struct sec_merge_info *) xsinfo; sinfo; sinfo = sinfo->next) 715 { 716 struct sec_merge_sec_info * secinfo; 717 718 if (! sinfo->chain) 719 continue; 720 721 /* Move sinfo->chain to head of the chain, terminate it. */ 722 secinfo = sinfo->chain; 723 sinfo->chain = secinfo->next; 724 secinfo->next = NULL; 725 726 /* Record the sections into the hash table. */ 727 for (secinfo = sinfo->chain; secinfo; secinfo = secinfo->next) 728 if (secinfo->sec->flags & SEC_EXCLUDE) 729 { 730 *secinfo->psecinfo = NULL; 731 if (remove_hook) 732 (*remove_hook) (abfd, secinfo->sec); 733 } 734 else if (! record_section (sinfo, secinfo)) 735 break; 736 737 if (secinfo) 738 continue; 739 740 if (sinfo->htab->first == NULL) 741 continue; 742 743 if (sinfo->htab->strings) 744 merge_strings (sinfo); 745 else 746 { 747 struct sec_merge_hash_entry *e; 748 bfd_size_type size = 0; 749 750 /* Things are much simpler for non-strings. 751 Just assign them slots in the section. */ 752 secinfo = NULL; 753 for (e = sinfo->htab->first; e; e = e->next) 754 { 755 if (e->secinfo->first_str == NULL) 756 { 757 if (secinfo) 758 secinfo->sec->size = size; 759 e->secinfo->first_str = e; 760 size = 0; 761 } 762 size = (size + e->alignment - 1) 763 & ~((bfd_vma) e->alignment - 1); 764 e->u.index = size; 765 size += e->len; 766 secinfo = e->secinfo; 767 } 768 secinfo->sec->size = size; 769 } 770 771 /* Finally remove all input sections which have not made it into 772 the hash table at all. */ 773 for (secinfo = sinfo->chain; secinfo; secinfo = secinfo->next) 774 if (secinfo->first_str == NULL) 775 secinfo->sec->flags |= SEC_EXCLUDE | SEC_KEEP; 776 } 777 778 return TRUE; 779 } 780 781 /* Write out the merged section. */ 782 783 bfd_boolean 784 _bfd_write_merged_section (bfd *output_bfd, asection *sec, void *psecinfo) 785 { 786 struct sec_merge_sec_info *secinfo; 787 file_ptr pos; 788 789 secinfo = (struct sec_merge_sec_info *) psecinfo; 790 791 if (!secinfo) 792 return FALSE; 793 794 if (secinfo->first_str == NULL) 795 return TRUE; 796 797 /* FIXME: octets_per_byte. */ 798 pos = sec->output_section->filepos + sec->output_offset; 799 if (bfd_seek (output_bfd, pos, SEEK_SET) != 0) 800 return FALSE; 801 802 if (! sec_merge_emit (output_bfd, secinfo->first_str)) 803 return FALSE; 804 805 return TRUE; 806 } 807 808 /* Adjust an address in the SEC_MERGE section. Given OFFSET within 809 *PSEC, this returns the new offset in the adjusted SEC_MERGE 810 section and writes the new section back into *PSEC. */ 811 812 bfd_vma 813 _bfd_merged_section_offset (bfd *output_bfd ATTRIBUTE_UNUSED, asection **psec, 814 void *psecinfo, bfd_vma offset) 815 { 816 struct sec_merge_sec_info *secinfo; 817 struct sec_merge_hash_entry *entry; 818 unsigned char *p; 819 asection *sec = *psec; 820 821 secinfo = (struct sec_merge_sec_info *) psecinfo; 822 823 if (!secinfo) 824 return offset; 825 826 if (offset >= sec->rawsize) 827 { 828 if (offset > sec->rawsize) 829 { 830 (*_bfd_error_handler) 831 (_("%s: access beyond end of merged section (%ld)"), 832 bfd_get_filename (sec->owner), (long) offset); 833 } 834 return secinfo->first_str ? sec->size : 0; 835 } 836 837 if (secinfo->htab->strings) 838 { 839 if (sec->entsize == 1) 840 { 841 p = secinfo->contents + offset - 1; 842 while (p >= secinfo->contents && *p) 843 --p; 844 ++p; 845 } 846 else 847 { 848 p = secinfo->contents + (offset / sec->entsize) * sec->entsize; 849 p -= sec->entsize; 850 while (p >= secinfo->contents) 851 { 852 unsigned int i; 853 854 for (i = 0; i < sec->entsize; ++i) 855 if (p[i] != '\0') 856 break; 857 if (i == sec->entsize) 858 break; 859 p -= sec->entsize; 860 } 861 p += sec->entsize; 862 } 863 } 864 else 865 { 866 p = secinfo->contents + (offset / sec->entsize) * sec->entsize; 867 } 868 entry = sec_merge_hash_lookup (secinfo->htab, (char *) p, 0, FALSE); 869 if (!entry) 870 { 871 if (! secinfo->htab->strings) 872 abort (); 873 /* This should only happen if somebody points into the padding 874 after a NUL character but before next entity. */ 875 if (*p) 876 abort (); 877 if (! secinfo->htab->first) 878 abort (); 879 entry = secinfo->htab->first; 880 p = (secinfo->contents + (offset / sec->entsize + 1) * sec->entsize 881 - entry->len); 882 } 883 884 *psec = entry->secinfo->sec; 885 return entry->u.index + (secinfo->contents + offset - p); 886 } 887