merge.c revision 130561
1/* SEC_MERGE support. 2 Copyright 2001, 2002, 2003 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 2 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ 20 21/* This file contains support for merging duplicate entities within sections, 22 as used in ELF SHF_MERGE. */ 23 24#include "bfd.h" 25#include "sysdep.h" 26#include "libbfd.h" 27#include "hashtab.h" 28#include "libiberty.h" 29 30struct sec_merge_sec_info; 31 32/* An entry in the section merge hash table. */ 33 34struct sec_merge_hash_entry 35{ 36 struct bfd_hash_entry root; 37 /* Length of this entry. This includes the zero terminator. */ 38 unsigned int len; 39 /* Start of this string needs to be aligned to 40 alignment octets (not 1 << align). */ 41 unsigned int alignment; 42 union 43 { 44 /* Index within the merged section. */ 45 bfd_size_type index; 46 /* Entry this is a suffix of (if alignment is 0). */ 47 struct sec_merge_hash_entry *suffix; 48 } u; 49 /* Which section is it in. */ 50 struct sec_merge_sec_info *secinfo; 51 /* Next entity in the hash table. */ 52 struct sec_merge_hash_entry *next; 53}; 54 55/* The section merge hash table. */ 56 57struct sec_merge_hash 58{ 59 struct bfd_hash_table table; 60 /* Next available index. */ 61 bfd_size_type size; 62 /* First entity in the SEC_MERGE sections of this type. */ 63 struct sec_merge_hash_entry *first; 64 /* Last entity in the SEC_MERGE sections of this type. */ 65 struct sec_merge_hash_entry *last; 66 /* Entity size. */ 67 unsigned int entsize; 68 /* Are entries fixed size or zero terminated strings? */ 69 bfd_boolean strings; 70}; 71 72struct sec_merge_info 73{ 74 /* Chain of sec_merge_infos. */ 75 struct sec_merge_info *next; 76 /* Chain of sec_merge_sec_infos. */ 77 struct sec_merge_sec_info *chain; 78 /* A hash table used to hold section content. */ 79 struct sec_merge_hash *htab; 80}; 81 82struct sec_merge_sec_info 83{ 84 /* Chain of sec_merge_sec_infos. */ 85 struct sec_merge_sec_info *next; 86 /* The corresponding section. */ 87 asection *sec; 88 /* Pointer to merge_info pointing to us. */ 89 void **psecinfo; 90 /* A hash table used to hold section content. */ 91 struct sec_merge_hash *htab; 92 /* First string in this section. */ 93 struct sec_merge_hash_entry *first; 94 /* Original section content. */ 95 unsigned char contents[1]; 96}; 97 98 99/* Routine to create an entry in a section merge hashtab. */ 100 101static struct bfd_hash_entry * 102sec_merge_hash_newfunc (struct bfd_hash_entry *entry, 103 struct bfd_hash_table *table, const char *string) 104{ 105 struct sec_merge_hash_entry *ret = (struct sec_merge_hash_entry *) entry; 106 107 /* Allocate the structure if it has not already been allocated by a 108 subclass. */ 109 if (ret == (struct sec_merge_hash_entry *) NULL) 110 ret = ((struct sec_merge_hash_entry *) 111 bfd_hash_allocate (table, sizeof (struct sec_merge_hash_entry))); 112 if (ret == (struct sec_merge_hash_entry *) NULL) 113 return NULL; 114 115 /* Call the allocation method of the superclass. */ 116 ret = ((struct sec_merge_hash_entry *) 117 bfd_hash_newfunc ((struct bfd_hash_entry *) ret, table, string)); 118 119 if (ret) 120 { 121 /* Initialize the local fields. */ 122 ret->u.suffix = NULL; 123 ret->alignment = 0; 124 ret->secinfo = NULL; 125 ret->next = NULL; 126 } 127 128 return (struct bfd_hash_entry *) ret; 129} 130 131/* Look up an entry in a section merge hash table. */ 132 133static struct sec_merge_hash_entry * 134sec_merge_hash_lookup (struct sec_merge_hash *table, const char *string, 135 unsigned int alignment, bfd_boolean create) 136{ 137 register const unsigned char *s; 138 register unsigned long hash; 139 register unsigned int c; 140 struct sec_merge_hash_entry *hashp; 141 unsigned int len, i; 142 unsigned int index; 143 144 hash = 0; 145 len = 0; 146 s = (const unsigned char *) string; 147 if (table->strings) 148 { 149 if (table->entsize == 1) 150 { 151 while ((c = *s++) != '\0') 152 { 153 hash += c + (c << 17); 154 hash ^= hash >> 2; 155 ++len; 156 } 157 hash += len + (len << 17); 158 } 159 else 160 { 161 for (;;) 162 { 163 for (i = 0; i < table->entsize; ++i) 164 if (s[i] != '\0') 165 break; 166 if (i == table->entsize) 167 break; 168 for (i = 0; i < table->entsize; ++i) 169 { 170 c = *s++; 171 hash += c + (c << 17); 172 hash ^= hash >> 2; 173 } 174 ++len; 175 } 176 hash += len + (len << 17); 177 len *= table->entsize; 178 } 179 hash ^= hash >> 2; 180 len += table->entsize; 181 } 182 else 183 { 184 for (i = 0; i < table->entsize; ++i) 185 { 186 c = *s++; 187 hash += c + (c << 17); 188 hash ^= hash >> 2; 189 } 190 len = table->entsize; 191 } 192 193 index = hash % table->table.size; 194 for (hashp = (struct sec_merge_hash_entry *) table->table.table[index]; 195 hashp != (struct sec_merge_hash_entry *) NULL; 196 hashp = (struct sec_merge_hash_entry *) hashp->root.next) 197 { 198 if (hashp->root.hash == hash 199 && len == hashp->len 200 && memcmp (hashp->root.string, string, len) == 0) 201 { 202 /* If the string we found does not have at least the required 203 alignment, we need to insert another copy. */ 204 if (hashp->alignment < alignment) 205 { 206 if (create) 207 { 208 /* Mark the less aligned copy as deleted. */ 209 hashp->len = 0; 210 hashp->alignment = 0; 211 } 212 break; 213 } 214 return hashp; 215 } 216 } 217 218 if (! create) 219 return (struct sec_merge_hash_entry *) NULL; 220 221 hashp = (struct sec_merge_hash_entry *) 222 sec_merge_hash_newfunc ((struct bfd_hash_entry *) NULL, 223 (struct bfd_hash_table *) table, string); 224 if (hashp == (struct sec_merge_hash_entry *) NULL) 225 return (struct sec_merge_hash_entry *) 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 bfd_size_type amt = sizeof (struct sec_merge_hash); 243 244 table = (struct sec_merge_hash *) bfd_malloc (amt); 245 if (table == NULL) 246 return NULL; 247 248 if (! bfd_hash_table_init (&table->table, sec_merge_hash_newfunc)) 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 = ""; 296 bfd_size_type off = 0; 297 int alignment_power = bfd_get_section_alignment (abfd, sec->output_section); 298 299 if (alignment_power) 300 pad = bfd_zmalloc ((bfd_size_type) 1 << alignment_power); 301 302 for (; entry != NULL && entry->secinfo == secinfo; entry = entry->next) 303 { 304 register const char *str; 305 register size_t len; 306 307 len = off & (entry->alignment - 1); 308 if (len) 309 { 310 len = entry->alignment - len; 311 if (bfd_bwrite (pad, (bfd_size_type) len, abfd) != len) 312 break; 313 off += len; 314 } 315 316 str = entry->root.string; 317 len = entry->len; 318 319 if (bfd_bwrite (str, (bfd_size_type) len, abfd) != len) 320 break; 321 322 off += len; 323 } 324 325 if (alignment_power) 326 free (pad); 327 328 return entry == NULL || entry->secinfo != secinfo; 329} 330 331/* This function is called for each input file from the add_symbols 332 pass of the linker. */ 333 334bfd_boolean 335_bfd_merge_section (bfd *abfd, void **psinfo, asection *sec, void **psecinfo) 336{ 337 struct sec_merge_info *sinfo; 338 struct sec_merge_sec_info *secinfo; 339 unsigned int align; 340 bfd_size_type amt; 341 342 if (sec->_raw_size == 0 343 || (sec->flags & SEC_EXCLUDE) 344 || (sec->flags & SEC_MERGE) == 0 345 || sec->entsize == 0) 346 return TRUE; 347 348 if ((sec->flags & SEC_RELOC) != 0) 349 { 350 /* We aren't prepared to handle relocations in merged sections. */ 351 return TRUE; 352 } 353 354 align = bfd_get_section_alignment (sec->owner, sec); 355 if ((sec->entsize < (unsigned int)(1 << align) 356 && ((sec->entsize & (sec->entsize - 1)) 357 || !(sec->flags & SEC_STRINGS))) 358 || (sec->entsize > (unsigned int)(1 << align) 359 && (sec->entsize & ((1 << align) - 1)))) 360 { 361 /* Sanity check. If string character size is smaller than 362 alignment, then we require character size to be a power 363 of 2, otherwise character size must be integer multiple 364 of alignment. For non-string constants, alignment must 365 be smaller than or equal to entity size and entity size 366 must be integer multiple of alignment. */ 367 return TRUE; 368 } 369 370 for (sinfo = (struct sec_merge_info *) *psinfo; sinfo; sinfo = sinfo->next) 371 if ((secinfo = sinfo->chain) 372 && ! ((secinfo->sec->flags ^ sec->flags) & (SEC_MERGE | SEC_STRINGS)) 373 && secinfo->sec->entsize == sec->entsize 374 && ! strcmp (secinfo->sec->name, sec->name)) 375 break; 376 377 if (sinfo == NULL) 378 { 379 /* Initialize the information we need to keep track of. */ 380 amt = sizeof (struct sec_merge_info); 381 sinfo = (struct sec_merge_info *) bfd_alloc (abfd, amt); 382 if (sinfo == NULL) 383 goto error_return; 384 sinfo->next = (struct sec_merge_info *) *psinfo; 385 sinfo->chain = NULL; 386 *psinfo = sinfo; 387 sinfo->htab = sec_merge_init (sec->entsize, (sec->flags & SEC_STRINGS)); 388 if (sinfo->htab == NULL) 389 goto error_return; 390 } 391 392 /* Read the section from abfd. */ 393 394 amt = sizeof (struct sec_merge_sec_info) + sec->_raw_size - 1; 395 *psecinfo = bfd_alloc (abfd, amt); 396 if (*psecinfo == NULL) 397 goto error_return; 398 399 secinfo = (struct sec_merge_sec_info *)*psecinfo; 400 if (sinfo->chain) 401 { 402 secinfo->next = sinfo->chain->next; 403 sinfo->chain->next = secinfo; 404 } 405 else 406 secinfo->next = secinfo; 407 sinfo->chain = secinfo; 408 secinfo->sec = sec; 409 secinfo->psecinfo = psecinfo; 410 secinfo->htab = sinfo->htab; 411 secinfo->first = NULL; 412 413 if (! bfd_get_section_contents (sec->owner, sec, secinfo->contents, 414 (bfd_vma) 0, sec->_raw_size)) 415 goto error_return; 416 417 return TRUE; 418 419 error_return: 420 *psecinfo = NULL; 421 return FALSE; 422} 423 424/* Record one section into the hash table. */ 425static bfd_boolean 426record_section (struct sec_merge_info *sinfo, 427 struct sec_merge_sec_info *secinfo) 428{ 429 asection *sec = secinfo->sec; 430 struct sec_merge_hash_entry *entry; 431 bfd_boolean nul; 432 unsigned char *p, *end; 433 bfd_vma mask, eltalign; 434 unsigned int align, i; 435 436 align = bfd_get_section_alignment (sec->owner, sec); 437 end = secinfo->contents + sec->_raw_size; 438 nul = FALSE; 439 mask = ((bfd_vma) 1 << align) - 1; 440 if (sec->flags & SEC_STRINGS) 441 { 442 for (p = secinfo->contents; p < end; ) 443 { 444 eltalign = p - secinfo->contents; 445 eltalign = ((eltalign ^ (eltalign - 1)) + 1) >> 1; 446 if (!eltalign || eltalign > mask) 447 eltalign = mask + 1; 448 entry = sec_merge_add (sinfo->htab, p, (unsigned) eltalign, secinfo); 449 if (! entry) 450 goto error_return; 451 p += entry->len; 452 if (sec->entsize == 1) 453 { 454 while (p < end && *p == 0) 455 { 456 if (!nul && !((p - secinfo->contents) & mask)) 457 { 458 nul = TRUE; 459 entry = sec_merge_add (sinfo->htab, "", 460 (unsigned) mask + 1, secinfo); 461 if (! entry) 462 goto error_return; 463 } 464 p++; 465 } 466 } 467 else 468 { 469 while (p < end) 470 { 471 for (i = 0; i < sec->entsize; i++) 472 if (p[i] != '\0') 473 break; 474 if (i != sec->entsize) 475 break; 476 if (!nul && !((p - secinfo->contents) & mask)) 477 { 478 nul = TRUE; 479 entry = sec_merge_add (sinfo->htab, p, 480 (unsigned) mask + 1, secinfo); 481 if (! entry) 482 goto error_return; 483 } 484 p += sec->entsize; 485 } 486 } 487 } 488 } 489 else 490 { 491 for (p = secinfo->contents; p < end; p += sec->entsize) 492 { 493 entry = sec_merge_add (sinfo->htab, p, 1, secinfo); 494 if (! entry) 495 goto error_return; 496 } 497 } 498 499 return TRUE; 500 501error_return: 502 for (secinfo = sinfo->chain; secinfo; secinfo = secinfo->next) 503 *secinfo->psecinfo = NULL; 504 return FALSE; 505} 506 507static int 508strrevcmp (const void *a, const void *b) 509{ 510 struct sec_merge_hash_entry *A = *(struct sec_merge_hash_entry **) a; 511 struct sec_merge_hash_entry *B = *(struct sec_merge_hash_entry **) b; 512 unsigned int lenA = A->len; 513 unsigned int lenB = B->len; 514 const unsigned char *s = A->root.string + lenA - 1; 515 const unsigned char *t = B->root.string + lenB - 1; 516 int l = lenA < lenB ? lenA : lenB; 517 518 while (l) 519 { 520 if (*s != *t) 521 return (int) *s - (int) *t; 522 s--; 523 t--; 524 l--; 525 } 526 return lenA - lenB; 527} 528 529/* Like strrevcmp, but for the case where all strings have the same 530 alignment > entsize. */ 531 532static int 533strrevcmp_align (const void *a, const void *b) 534{ 535 struct sec_merge_hash_entry *A = *(struct sec_merge_hash_entry **) a; 536 struct sec_merge_hash_entry *B = *(struct sec_merge_hash_entry **) b; 537 unsigned int lenA = A->len; 538 unsigned int lenB = B->len; 539 const unsigned char *s = A->root.string + lenA - 1; 540 const unsigned char *t = B->root.string + lenB - 1; 541 int l = lenA < lenB ? lenA : lenB; 542 int tail_align = (lenA & (A->alignment - 1)) - (lenB & (A->alignment - 1)); 543 544 if (tail_align != 0) 545 return tail_align; 546 547 while (l) 548 { 549 if (*s != *t) 550 return (int) *s - (int) *t; 551 s--; 552 t--; 553 l--; 554 } 555 return lenA - lenB; 556} 557 558static inline int 559is_suffix (const struct sec_merge_hash_entry *A, 560 const struct sec_merge_hash_entry *B) 561{ 562 if (A->len <= B->len) 563 /* B cannot be a suffix of A unless A is equal to B, which is guaranteed 564 not to be equal by the hash table. */ 565 return 0; 566 567 return memcmp (A->root.string + (A->len - B->len), 568 B->root.string, B->len) == 0; 569} 570 571/* This is a helper function for _bfd_merge_sections. It attempts to 572 merge strings matching suffixes of longer strings. */ 573static void 574merge_strings (struct sec_merge_info *sinfo) 575{ 576 struct sec_merge_hash_entry **array, **a, *e; 577 struct sec_merge_sec_info *secinfo; 578 bfd_size_type size, amt; 579 unsigned int alignment = 0; 580 581 /* Now sort the strings */ 582 amt = sinfo->htab->size * sizeof (struct sec_merge_hash_entry *); 583 array = (struct sec_merge_hash_entry **) bfd_malloc (amt); 584 if (array == NULL) 585 goto alloc_failure; 586 587 for (e = sinfo->htab->first, a = array; e; e = e->next) 588 if (e->alignment) 589 { 590 *a++ = e; 591 /* Adjust the length to not include the zero terminator. */ 592 e->len -= sinfo->htab->entsize; 593 if (alignment != e->alignment) 594 { 595 if (alignment == 0) 596 alignment = e->alignment; 597 else 598 alignment = (unsigned) -1; 599 } 600 } 601 602 sinfo->htab->size = a - array; 603 if (sinfo->htab->size != 0) 604 { 605 qsort (array, (size_t) sinfo->htab->size, 606 sizeof (struct sec_merge_hash_entry *), 607 (alignment != (unsigned) -1 && alignment > sinfo->htab->entsize 608 ? strrevcmp_align : strrevcmp)); 609 610 /* Loop over the sorted array and merge suffixes */ 611 e = *--a; 612 e->len += sinfo->htab->entsize; 613 while (--a >= array) 614 { 615 struct sec_merge_hash_entry *cmp = *a; 616 617 cmp->len += sinfo->htab->entsize; 618 if (e->alignment >= cmp->alignment 619 && !((e->len - cmp->len) & (cmp->alignment - 1)) 620 && is_suffix (e, cmp)) 621 { 622 cmp->u.suffix = e; 623 cmp->alignment = 0; 624 } 625 else 626 e = cmp; 627 } 628 } 629 630alloc_failure: 631 if (array) 632 free (array); 633 634 /* Now assign positions to the strings we want to keep. */ 635 size = 0; 636 secinfo = sinfo->htab->first->secinfo; 637 for (e = sinfo->htab->first; e; e = e->next) 638 { 639 if (e->secinfo != secinfo) 640 { 641 secinfo->sec->_cooked_size = size; 642 secinfo = e->secinfo; 643 } 644 if (e->alignment) 645 { 646 if (e->secinfo->first == NULL) 647 { 648 e->secinfo->first = e; 649 size = 0; 650 } 651 size = (size + e->alignment - 1) & ~((bfd_vma) e->alignment - 1); 652 e->u.index = size; 653 size += e->len; 654 } 655 } 656 secinfo->sec->_cooked_size = size; 657 658 /* And now adjust the rest, removing them from the chain (but not hashtable) 659 at the same time. */ 660 for (a = &sinfo->htab->first, e = *a; e; e = e->next) 661 if (e->alignment) 662 a = &e->next; 663 else 664 { 665 *a = e->next; 666 if (e->len) 667 { 668 e->secinfo = e->u.suffix->secinfo; 669 e->alignment = e->u.suffix->alignment; 670 e->u.index = e->u.suffix->u.index + (e->u.suffix->len - e->len); 671 } 672 } 673} 674 675/* This function is called once after all SEC_MERGE sections are registered 676 with _bfd_merge_section. */ 677 678bfd_boolean 679_bfd_merge_sections (bfd *abfd ATTRIBUTE_UNUSED, void *xsinfo, 680 void (*remove_hook) (bfd *, asection *)) 681{ 682 struct sec_merge_info *sinfo; 683 684 for (sinfo = (struct sec_merge_info *) xsinfo; sinfo; sinfo = sinfo->next) 685 { 686 struct sec_merge_sec_info * secinfo; 687 688 if (! sinfo->chain) 689 continue; 690 691 /* Move sinfo->chain to head of the chain, terminate it. */ 692 secinfo = sinfo->chain; 693 sinfo->chain = secinfo->next; 694 secinfo->next = NULL; 695 696 /* Record the sections into the hash table. */ 697 for (secinfo = sinfo->chain; secinfo; secinfo = secinfo->next) 698 if (secinfo->sec->flags & SEC_EXCLUDE) 699 { 700 *secinfo->psecinfo = NULL; 701 if (remove_hook) 702 (*remove_hook) (abfd, secinfo->sec); 703 } 704 else if (! record_section (sinfo, secinfo)) 705 break; 706 707 if (secinfo) 708 continue; 709 710 if (sinfo->htab->first == NULL) 711 continue; 712 713 if (sinfo->htab->strings) 714 merge_strings (sinfo); 715 else 716 { 717 struct sec_merge_hash_entry *e; 718 bfd_size_type size = 0; 719 720 /* Things are much simpler for non-strings. 721 Just assign them slots in the section. */ 722 secinfo = NULL; 723 for (e = sinfo->htab->first; e; e = e->next) 724 { 725 if (e->secinfo->first == NULL) 726 { 727 if (secinfo) 728 secinfo->sec->_cooked_size = size; 729 e->secinfo->first = e; 730 size = 0; 731 } 732 size = (size + e->alignment - 1) 733 & ~((bfd_vma) e->alignment - 1); 734 e->u.index = size; 735 size += e->len; 736 secinfo = e->secinfo; 737 } 738 secinfo->sec->_cooked_size = size; 739 } 740 741 /* Finally remove all input sections which have not made it into 742 the hash table at all. */ 743 for (secinfo = sinfo->chain; secinfo; secinfo = secinfo->next) 744 if (secinfo->first == NULL) 745 { 746 secinfo->sec->_cooked_size = 0; 747 secinfo->sec->flags |= SEC_EXCLUDE; 748 } 749 } 750 751 return TRUE; 752} 753 754/* Write out the merged section. */ 755 756bfd_boolean 757_bfd_write_merged_section (bfd *output_bfd, asection *sec, void *psecinfo) 758{ 759 struct sec_merge_sec_info *secinfo; 760 file_ptr pos; 761 762 secinfo = (struct sec_merge_sec_info *) psecinfo; 763 764 if (!secinfo->first) 765 return TRUE; 766 767 pos = sec->output_section->filepos + sec->output_offset; 768 if (bfd_seek (output_bfd, pos, SEEK_SET) != 0) 769 return FALSE; 770 771 if (! sec_merge_emit (output_bfd, secinfo->first)) 772 return FALSE; 773 774 return TRUE; 775} 776 777/* Adjust an address in the SEC_MERGE section. Given OFFSET within 778 *PSEC, this returns the new offset in the adjusted SEC_MERGE 779 section and writes the new section back into *PSEC. */ 780 781bfd_vma 782_bfd_merged_section_offset (bfd *output_bfd ATTRIBUTE_UNUSED, asection **psec, 783 void *psecinfo, bfd_vma offset, bfd_vma addend) 784{ 785 struct sec_merge_sec_info *secinfo; 786 struct sec_merge_hash_entry *entry; 787 unsigned char *p; 788 asection *sec = *psec; 789 790 secinfo = (struct sec_merge_sec_info *) psecinfo; 791 792 if (offset + addend >= sec->_raw_size) 793 { 794 if (offset + addend > sec->_raw_size) 795 { 796 (*_bfd_error_handler) 797 (_("%s: access beyond end of merged section (%ld + %ld)"), 798 bfd_get_filename (sec->owner), (long) offset, (long) addend); 799 } 800 return (secinfo->first ? sec->_cooked_size : 0); 801 } 802 803 if (secinfo->htab->strings) 804 { 805 if (sec->entsize == 1) 806 { 807 p = secinfo->contents + offset + addend - 1; 808 while (p >= secinfo->contents && *p) 809 --p; 810 ++p; 811 } 812 else 813 { 814 p = secinfo->contents 815 + ((offset + addend) / sec->entsize) * sec->entsize; 816 p -= sec->entsize; 817 while (p >= secinfo->contents) 818 { 819 unsigned int i; 820 821 for (i = 0; i < sec->entsize; ++i) 822 if (p[i] != '\0') 823 break; 824 if (i == sec->entsize) 825 break; 826 p -= sec->entsize; 827 } 828 p += sec->entsize; 829 } 830 } 831 else 832 { 833 p = secinfo->contents 834 + ((offset + addend) / sec->entsize) * sec->entsize; 835 } 836 entry = sec_merge_hash_lookup (secinfo->htab, p, 0, FALSE); 837 if (!entry) 838 { 839 if (! secinfo->htab->strings) 840 abort (); 841 /* This should only happen if somebody points into the padding 842 after a NUL character but before next entity. */ 843 if (*p) 844 abort (); 845 if (! secinfo->htab->first) 846 abort (); 847 entry = secinfo->htab->first; 848 p = secinfo->contents 849 + ((offset + addend) / sec->entsize + 1) * sec->entsize 850 - entry->len; 851 } 852 853 *psec = entry->secinfo->sec; 854 return entry->u.index + (secinfo->contents + offset - p); 855} 856