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[binutils.git] / bfd / merge.c
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1 /* SEC_MERGE support.
2 Copyright 2001, 2002, 2003 Free Software Foundation, Inc.
3 Written by Jakub Jelinek <jakub@redhat.com>.
5 This file is part of BFD, the Binary File Descriptor library.
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.
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.
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. */
21 /* This file contains support for merging duplicate entities within sections,
22 as used in ELF SHF_MERGE. */
24 #include "bfd.h"
25 #include "sysdep.h"
26 #include "libbfd.h"
27 #include "hashtab.h"
28 #include "libiberty.h"
30 struct sec_merge_sec_info;
32 /* An entry in the section merge hash table. */
34 struct sec_merge_hash_entry
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
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;
55 /* The section merge hash table. */
57 struct sec_merge_hash
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;
72 struct sec_merge_info
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;
82 struct sec_merge_sec_info
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];
99 /* Routine to create an entry in a section merge hashtab. */
101 static struct bfd_hash_entry *
102 sec_merge_hash_newfunc (struct bfd_hash_entry *entry,
103 struct bfd_hash_table *table, const char *string)
105 struct sec_merge_hash_entry *ret = (struct sec_merge_hash_entry *) entry;
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;
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));
119 if (ret)
121 /* Initialize the local fields. */
122 ret->u.suffix = NULL;
123 ret->alignment = 0;
124 ret->secinfo = NULL;
125 ret->next = NULL;
128 return (struct bfd_hash_entry *) ret;
131 /* Look up an entry in a section merge hash table. */
133 static struct sec_merge_hash_entry *
134 sec_merge_hash_lookup (struct sec_merge_hash *table, const char *string,
135 unsigned int alignment, bfd_boolean create)
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;
144 hash = 0;
145 len = 0;
146 s = (const unsigned char *) string;
147 if (table->strings)
149 if (table->entsize == 1)
151 while ((c = *s++) != '\0')
153 hash += c + (c << 17);
154 hash ^= hash >> 2;
155 ++len;
157 hash += len + (len << 17);
159 else
161 for (;;)
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)
170 c = *s++;
171 hash += c + (c << 17);
172 hash ^= hash >> 2;
174 ++len;
176 hash += len + (len << 17);
177 len *= table->entsize;
179 hash ^= hash >> 2;
180 len += table->entsize;
182 else
184 for (i = 0; i < table->entsize; ++i)
186 c = *s++;
187 hash += c + (c << 17);
188 hash ^= hash >> 2;
190 len = table->entsize;
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)
198 if (hashp->root.hash == hash
199 && len == hashp->len
200 && memcmp (hashp->root.string, string, len) == 0)
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)
206 if (create)
208 /* Mark the less aligned copy as deleted. */
209 hashp->len = 0;
210 hashp->alignment = 0;
212 break;
214 return hashp;
218 if (! create)
219 return (struct sec_merge_hash_entry *) NULL;
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;
233 return hashp;
236 /* Create a new hash table. */
238 static struct sec_merge_hash *
239 sec_merge_init (unsigned int entsize, bfd_boolean strings)
241 struct sec_merge_hash *table;
242 bfd_size_type amt = sizeof (struct sec_merge_hash);
244 table = (struct sec_merge_hash *) bfd_malloc (amt);
245 if (table == NULL)
246 return NULL;
248 if (! bfd_hash_table_init (&table->table, sec_merge_hash_newfunc))
250 free (table);
251 return NULL;
254 table->size = 0;
255 table->first = NULL;
256 table->last = NULL;
257 table->entsize = entsize;
258 table->strings = strings;
260 return table;
263 /* Get the index of an entity in a hash table, adding it if it is not
264 already present. */
266 static struct sec_merge_hash_entry *
267 sec_merge_add (struct sec_merge_hash *tab, const char *str,
268 unsigned int alignment, struct sec_merge_sec_info *secinfo)
270 register struct sec_merge_hash_entry *entry;
272 entry = sec_merge_hash_lookup (tab, str, alignment, TRUE);
273 if (entry == NULL)
274 return NULL;
276 if (entry->secinfo == NULL)
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;
287 return entry;
290 static bfd_boolean
291 sec_merge_emit (bfd *abfd, struct sec_merge_hash_entry *entry)
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);
299 if (alignment_power)
300 pad = bfd_zmalloc ((bfd_size_type) 1 << alignment_power);
302 for (; entry != NULL && entry->secinfo == secinfo; entry = entry->next)
304 register const char *str;
305 register size_t len;
307 len = off & (entry->alignment - 1);
308 if (len)
310 len = entry->alignment - len;
311 if (bfd_bwrite (pad, (bfd_size_type) len, abfd) != len)
312 break;
313 off += len;
316 str = entry->root.string;
317 len = entry->len;
319 if (bfd_bwrite (str, (bfd_size_type) len, abfd) != len)
320 break;
322 off += len;
325 if (alignment_power)
326 free (pad);
328 return entry == NULL || entry->secinfo != secinfo;
331 /* This function is called for each input file from the add_symbols
332 pass of the linker. */
334 bfd_boolean
335 _bfd_merge_section (bfd *abfd, void **psinfo, asection *sec, void **psecinfo)
337 struct sec_merge_info *sinfo;
338 struct sec_merge_sec_info *secinfo;
339 unsigned int align;
340 bfd_size_type amt;
342 if (sec->_raw_size == 0
343 || (sec->flags & SEC_EXCLUDE)
344 || (sec->flags & SEC_MERGE) == 0
345 || sec->entsize == 0)
346 return TRUE;
348 if ((sec->flags & SEC_RELOC) != 0)
350 /* We aren't prepared to handle relocations in merged sections. */
351 return TRUE;
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))))
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;
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;
377 if (sinfo == NULL)
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;
392 /* Read the section from abfd. */
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;
399 secinfo = (struct sec_merge_sec_info *)*psecinfo;
400 if (sinfo->chain)
402 secinfo->next = sinfo->chain->next;
403 sinfo->chain->next = secinfo;
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;
413 if (! bfd_get_section_contents (sec->owner, sec, secinfo->contents,
414 (bfd_vma) 0, sec->_raw_size))
415 goto error_return;
417 return TRUE;
419 error_return:
420 *psecinfo = NULL;
421 return FALSE;
424 /* Record one section into the hash table. */
425 static bfd_boolean
426 record_section (struct sec_merge_info *sinfo,
427 struct sec_merge_sec_info *secinfo)
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;
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)
442 for (p = secinfo->contents; p < end; )
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)
454 while (p < end && *p == 0)
456 if (!nul && !((p - secinfo->contents) & mask))
458 nul = TRUE;
459 entry = sec_merge_add (sinfo->htab, "",
460 (unsigned) mask + 1, secinfo);
461 if (! entry)
462 goto error_return;
464 p++;
467 else
469 while (p < end)
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))
478 nul = TRUE;
479 entry = sec_merge_add (sinfo->htab, p,
480 (unsigned) mask + 1, secinfo);
481 if (! entry)
482 goto error_return;
484 p += sec->entsize;
489 else
491 for (p = secinfo->contents; p < end; p += sec->entsize)
493 entry = sec_merge_add (sinfo->htab, p, 1, secinfo);
494 if (! entry)
495 goto error_return;
499 return TRUE;
501 error_return:
502 for (secinfo = sinfo->chain; secinfo; secinfo = secinfo->next)
503 *secinfo->psecinfo = NULL;
504 return FALSE;
507 static int
508 strrevcmp (const void *a, const void *b)
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;
518 while (l)
520 if (*s != *t)
521 return (int) *s - (int) *t;
522 s--;
523 t--;
524 l--;
526 return lenA - lenB;
529 /* Like strrevcmp, but for the case where all strings have the same
530 alignment > entsize. */
532 static int
533 strrevcmp_align (const void *a, const void *b)
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));
544 if (tail_align != 0)
545 return tail_align;
547 while (l)
549 if (*s != *t)
550 return (int) *s - (int) *t;
551 s--;
552 t--;
553 l--;
555 return lenA - lenB;
558 static inline int
559 is_suffix (const struct sec_merge_hash_entry *A,
560 const struct sec_merge_hash_entry *B)
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;
567 return memcmp (A->root.string + (A->len - B->len),
568 B->root.string, B->len) == 0;
571 /* This is a helper function for _bfd_merge_sections. It attempts to
572 merge strings matching suffixes of longer strings. */
573 static void
574 merge_strings (struct sec_merge_info *sinfo)
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;
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;
587 for (e = sinfo->htab->first, a = array; e; e = e->next)
588 if (e->alignment)
590 *a++ = e;
591 /* Adjust the length to not include the zero terminator. */
592 e->len -= sinfo->htab->entsize;
593 if (alignment != e->alignment)
595 if (alignment == 0)
596 alignment = e->alignment;
597 else
598 alignment = (unsigned) -1;
602 sinfo->htab->size = a - array;
603 if (sinfo->htab->size != 0)
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));
610 /* Loop over the sorted array and merge suffixes */
611 e = *--a;
612 e->len += sinfo->htab->entsize;
613 while (--a >= array)
615 struct sec_merge_hash_entry *cmp = *a;
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))
622 cmp->u.suffix = e;
623 cmp->alignment = 0;
625 else
626 e = cmp;
630 alloc_failure:
631 if (array)
632 free (array);
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)
639 if (e->secinfo != secinfo)
641 secinfo->sec->_cooked_size = size;
642 secinfo = e->secinfo;
644 if (e->alignment)
646 if (e->secinfo->first == NULL)
648 e->secinfo->first = e;
649 size = 0;
651 size = (size + e->alignment - 1) & ~((bfd_vma) e->alignment - 1);
652 e->u.index = size;
653 size += e->len;
656 secinfo->sec->_cooked_size = size;
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
665 *a = e->next;
666 if (e->len)
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);
675 /* This function is called once after all SEC_MERGE sections are registered
676 with _bfd_merge_section. */
678 bfd_boolean
679 _bfd_merge_sections (bfd *abfd ATTRIBUTE_UNUSED, void *xsinfo,
680 void (*remove_hook) (bfd *, asection *))
682 struct sec_merge_info *sinfo;
684 for (sinfo = (struct sec_merge_info *) xsinfo; sinfo; sinfo = sinfo->next)
686 struct sec_merge_sec_info * secinfo;
688 if (! sinfo->chain)
689 continue;
691 /* Move sinfo->chain to head of the chain, terminate it. */
692 secinfo = sinfo->chain;
693 sinfo->chain = secinfo->next;
694 secinfo->next = NULL;
696 /* Record the sections into the hash table. */
697 for (secinfo = sinfo->chain; secinfo; secinfo = secinfo->next)
698 if (secinfo->sec->flags & SEC_EXCLUDE)
700 *secinfo->psecinfo = NULL;
701 if (remove_hook)
702 (*remove_hook) (abfd, secinfo->sec);
704 else if (! record_section (sinfo, secinfo))
705 break;
707 if (secinfo)
708 continue;
710 if (sinfo->htab->first == NULL)
711 continue;
713 if (sinfo->htab->strings)
714 merge_strings (sinfo);
715 else
717 struct sec_merge_hash_entry *e;
718 bfd_size_type size = 0;
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)
725 if (e->secinfo->first == NULL)
727 if (secinfo)
728 secinfo->sec->_cooked_size = size;
729 e->secinfo->first = e;
730 size = 0;
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;
738 secinfo->sec->_cooked_size = size;
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)
746 secinfo->sec->_cooked_size = 0;
747 secinfo->sec->flags |= SEC_EXCLUDE;
751 return TRUE;
754 /* Write out the merged section. */
756 bfd_boolean
757 _bfd_write_merged_section (bfd *output_bfd, asection *sec, void *psecinfo)
759 struct sec_merge_sec_info *secinfo;
760 file_ptr pos;
762 secinfo = (struct sec_merge_sec_info *) psecinfo;
764 if (!secinfo->first)
765 return TRUE;
767 pos = sec->output_section->filepos + sec->output_offset;
768 if (bfd_seek (output_bfd, pos, SEEK_SET) != 0)
769 return FALSE;
771 if (! sec_merge_emit (output_bfd, secinfo->first))
772 return FALSE;
774 return TRUE;
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. */
781 bfd_vma
782 _bfd_merged_section_offset (bfd *output_bfd ATTRIBUTE_UNUSED, asection **psec,
783 void *psecinfo, bfd_vma offset, bfd_vma addend)
785 struct sec_merge_sec_info *secinfo;
786 struct sec_merge_hash_entry *entry;
787 unsigned char *p;
788 asection *sec = *psec;
790 secinfo = (struct sec_merge_sec_info *) psecinfo;
792 if (offset + addend >= sec->_raw_size)
794 if (offset + addend > sec->_raw_size)
796 (*_bfd_error_handler)
797 (_("%s: access beyond end of merged section (%ld + %ld)"),
798 bfd_get_filename (sec->owner), (long) offset, (long) addend);
800 return (secinfo->first ? sec->_cooked_size : 0);
803 if (secinfo->htab->strings)
805 if (sec->entsize == 1)
807 p = secinfo->contents + offset + addend - 1;
808 while (p >= secinfo->contents && *p)
809 --p;
810 ++p;
812 else
814 p = secinfo->contents
815 + ((offset + addend) / sec->entsize) * sec->entsize;
816 p -= sec->entsize;
817 while (p >= secinfo->contents)
819 unsigned int i;
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;
828 p += sec->entsize;
831 else
833 p = secinfo->contents
834 + ((offset + addend) / sec->entsize) * sec->entsize;
836 entry = sec_merge_hash_lookup (secinfo->htab, p, 0, FALSE);
837 if (!entry)
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;
853 *psec = entry->secinfo->sec;
854 return entry->u.index + (secinfo->contents + offset - p);