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[binutils.git] / bfd / merge.c
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1 /* SEC_MERGE support.
2 Copyright 2001, 2002, 2003, 2004, 2005 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., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, 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_str;
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 /* Allocate the structure if it has not already been allocated by a
106 subclass. */
107 if (entry == NULL)
108 entry = bfd_hash_allocate (table, sizeof (struct sec_merge_hash_entry));
109 if (entry == NULL)
110 return NULL;
112 /* Call the allocation method of the superclass. */
113 entry = bfd_hash_newfunc (entry, table, string);
115 if (entry != NULL)
117 /* Initialize the local fields. */
118 struct sec_merge_hash_entry *ret = (struct sec_merge_hash_entry *) entry;
120 ret->u.suffix = NULL;
121 ret->alignment = 0;
122 ret->secinfo = NULL;
123 ret->next = NULL;
126 return entry;
129 /* Look up an entry in a section merge hash table. */
131 static struct sec_merge_hash_entry *
132 sec_merge_hash_lookup (struct sec_merge_hash *table, const char *string,
133 unsigned int alignment, bfd_boolean create)
135 register const unsigned char *s;
136 register unsigned long hash;
137 register unsigned int c;
138 struct sec_merge_hash_entry *hashp;
139 unsigned int len, i;
140 unsigned int index;
142 hash = 0;
143 len = 0;
144 s = (const unsigned char *) string;
145 if (table->strings)
147 if (table->entsize == 1)
149 while ((c = *s++) != '\0')
151 hash += c + (c << 17);
152 hash ^= hash >> 2;
153 ++len;
155 hash += len + (len << 17);
157 else
159 for (;;)
161 for (i = 0; i < table->entsize; ++i)
162 if (s[i] != '\0')
163 break;
164 if (i == table->entsize)
165 break;
166 for (i = 0; i < table->entsize; ++i)
168 c = *s++;
169 hash += c + (c << 17);
170 hash ^= hash >> 2;
172 ++len;
174 hash += len + (len << 17);
175 len *= table->entsize;
177 hash ^= hash >> 2;
178 len += table->entsize;
180 else
182 for (i = 0; i < table->entsize; ++i)
184 c = *s++;
185 hash += c + (c << 17);
186 hash ^= hash >> 2;
188 len = table->entsize;
191 index = hash % table->table.size;
192 for (hashp = (struct sec_merge_hash_entry *) table->table.table[index];
193 hashp != NULL;
194 hashp = (struct sec_merge_hash_entry *) hashp->root.next)
196 if (hashp->root.hash == hash
197 && len == hashp->len
198 && memcmp (hashp->root.string, string, len) == 0)
200 /* If the string we found does not have at least the required
201 alignment, we need to insert another copy. */
202 if (hashp->alignment < alignment)
204 if (create)
206 /* Mark the less aligned copy as deleted. */
207 hashp->len = 0;
208 hashp->alignment = 0;
210 break;
212 return hashp;
216 if (! create)
217 return NULL;
219 hashp = ((struct sec_merge_hash_entry *)
220 sec_merge_hash_newfunc (NULL, &table->table, string));
221 if (hashp == NULL)
222 return NULL;
223 hashp->root.string = string;
224 hashp->root.hash = hash;
225 hashp->len = len;
226 hashp->alignment = alignment;
227 hashp->root.next = table->table.table[index];
228 table->table.table[index] = (struct bfd_hash_entry *) hashp;
230 return hashp;
233 /* Create a new hash table. */
235 static struct sec_merge_hash *
236 sec_merge_init (unsigned int entsize, bfd_boolean strings)
238 struct sec_merge_hash *table;
240 table = bfd_malloc (sizeof (struct sec_merge_hash));
241 if (table == NULL)
242 return NULL;
244 if (! bfd_hash_table_init_n (&table->table, sec_merge_hash_newfunc,
245 16699))
247 free (table);
248 return NULL;
251 table->size = 0;
252 table->first = NULL;
253 table->last = NULL;
254 table->entsize = entsize;
255 table->strings = strings;
257 return table;
260 /* Get the index of an entity in a hash table, adding it if it is not
261 already present. */
263 static struct sec_merge_hash_entry *
264 sec_merge_add (struct sec_merge_hash *tab, const char *str,
265 unsigned int alignment, struct sec_merge_sec_info *secinfo)
267 register struct sec_merge_hash_entry *entry;
269 entry = sec_merge_hash_lookup (tab, str, alignment, TRUE);
270 if (entry == NULL)
271 return NULL;
273 if (entry->secinfo == NULL)
275 tab->size++;
276 entry->secinfo = secinfo;
277 if (tab->first == NULL)
278 tab->first = entry;
279 else
280 tab->last->next = entry;
281 tab->last = entry;
284 return entry;
287 static bfd_boolean
288 sec_merge_emit (bfd *abfd, struct sec_merge_hash_entry *entry)
290 struct sec_merge_sec_info *secinfo = entry->secinfo;
291 asection *sec = secinfo->sec;
292 char *pad = NULL;
293 bfd_size_type off = 0;
294 int alignment_power = sec->output_section->alignment_power;
296 if (alignment_power)
298 pad = bfd_zmalloc ((bfd_size_type) 1 << alignment_power);
299 if (pad == NULL)
300 return FALSE;
303 for (; entry != NULL && entry->secinfo == secinfo; entry = entry->next)
305 const char *str;
306 bfd_size_type len;
308 len = -off & (entry->alignment - 1);
309 if (len != 0)
311 if (bfd_bwrite (pad, len, abfd) != len)
312 goto err;
313 off += len;
316 str = entry->root.string;
317 len = entry->len;
319 if (bfd_bwrite (str, len, abfd) != len)
320 goto err;
322 off += len;
325 /* Trailing alignment needed? */
326 off = sec->size - off;
327 if (off != 0
328 && bfd_bwrite (pad, off, abfd) != off)
329 goto err;
331 if (pad != NULL)
332 free (pad);
333 return TRUE;
335 err:
336 if (pad != NULL)
337 free (pad);
338 return FALSE;
341 /* Register a SEC_MERGE section as a candidate for merging.
342 This function is called for all non-dynamic SEC_MERGE input sections. */
344 bfd_boolean
345 _bfd_add_merge_section (bfd *abfd, void **psinfo, asection *sec,
346 void **psecinfo)
348 struct sec_merge_info *sinfo;
349 struct sec_merge_sec_info *secinfo;
350 unsigned int align;
351 bfd_size_type amt;
353 if ((abfd->flags & DYNAMIC) != 0
354 || (sec->flags & SEC_MERGE) == 0)
355 abort ();
357 if (sec->size == 0
358 || (sec->flags & SEC_EXCLUDE) != 0
359 || sec->entsize == 0)
360 return TRUE;
362 if ((sec->flags & SEC_RELOC) != 0)
364 /* We aren't prepared to handle relocations in merged sections. */
365 return TRUE;
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))))
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;
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;
392 if (sinfo == NULL)
394 /* Initialize the information we need to keep track of. */
395 sinfo = 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;
406 /* Read the section from abfd. */
408 amt = sizeof (struct sec_merge_sec_info) + sec->size - 1;
409 *psecinfo = bfd_alloc (abfd, amt);
410 if (*psecinfo == NULL)
411 goto error_return;
413 secinfo = (struct sec_merge_sec_info *) *psecinfo;
414 if (sinfo->chain)
416 secinfo->next = sinfo->chain->next;
417 sinfo->chain->next = secinfo;
419 else
420 secinfo->next = secinfo;
421 sinfo->chain = secinfo;
422 secinfo->sec = sec;
423 secinfo->psecinfo = psecinfo;
424 secinfo->htab = sinfo->htab;
425 secinfo->first_str = NULL;
427 sec->rawsize = sec->size;
428 if (! bfd_get_section_contents (sec->owner, sec, secinfo->contents,
429 0, sec->size))
430 goto error_return;
432 return TRUE;
434 error_return:
435 *psecinfo = NULL;
436 return FALSE;
439 /* Record one section into the hash table. */
440 static bfd_boolean
441 record_section (struct sec_merge_info *sinfo,
442 struct sec_merge_sec_info *secinfo)
444 asection *sec = secinfo->sec;
445 struct sec_merge_hash_entry *entry;
446 bfd_boolean nul;
447 unsigned char *p, *end;
448 bfd_vma mask, eltalign;
449 unsigned int align, i;
451 align = sec->alignment_power;
452 end = secinfo->contents + sec->size;
453 nul = FALSE;
454 mask = ((bfd_vma) 1 << align) - 1;
455 if (sec->flags & SEC_STRINGS)
457 for (p = secinfo->contents; p < end; )
459 eltalign = p - secinfo->contents;
460 eltalign = ((eltalign ^ (eltalign - 1)) + 1) >> 1;
461 if (!eltalign || eltalign > mask)
462 eltalign = mask + 1;
463 entry = sec_merge_add (sinfo->htab, (char *) p, (unsigned) eltalign,
464 secinfo);
465 if (! entry)
466 goto error_return;
467 p += entry->len;
468 if (sec->entsize == 1)
470 while (p < end && *p == 0)
472 if (!nul && !((p - secinfo->contents) & mask))
474 nul = TRUE;
475 entry = sec_merge_add (sinfo->htab, "",
476 (unsigned) mask + 1, secinfo);
477 if (! entry)
478 goto error_return;
480 p++;
483 else
485 while (p < end)
487 for (i = 0; i < sec->entsize; i++)
488 if (p[i] != '\0')
489 break;
490 if (i != sec->entsize)
491 break;
492 if (!nul && !((p - secinfo->contents) & mask))
494 nul = TRUE;
495 entry = sec_merge_add (sinfo->htab, (char *) p,
496 (unsigned) mask + 1, secinfo);
497 if (! entry)
498 goto error_return;
500 p += sec->entsize;
505 else
507 for (p = secinfo->contents; p < end; p += sec->entsize)
509 entry = sec_merge_add (sinfo->htab, (char *) p, 1, secinfo);
510 if (! entry)
511 goto error_return;
515 return TRUE;
517 error_return:
518 for (secinfo = sinfo->chain; secinfo; secinfo = secinfo->next)
519 *secinfo->psecinfo = NULL;
520 return FALSE;
523 static int
524 strrevcmp (const void *a, const void *b)
526 struct sec_merge_hash_entry *A = *(struct sec_merge_hash_entry **) a;
527 struct sec_merge_hash_entry *B = *(struct sec_merge_hash_entry **) b;
528 unsigned int lenA = A->len;
529 unsigned int lenB = B->len;
530 const unsigned char *s = (const unsigned char *) A->root.string + lenA - 1;
531 const unsigned char *t = (const unsigned char *) B->root.string + lenB - 1;
532 int l = lenA < lenB ? lenA : lenB;
534 while (l)
536 if (*s != *t)
537 return (int) *s - (int) *t;
538 s--;
539 t--;
540 l--;
542 return lenA - lenB;
545 /* Like strrevcmp, but for the case where all strings have the same
546 alignment > entsize. */
548 static int
549 strrevcmp_align (const void *a, const void *b)
551 struct sec_merge_hash_entry *A = *(struct sec_merge_hash_entry **) a;
552 struct sec_merge_hash_entry *B = *(struct sec_merge_hash_entry **) b;
553 unsigned int lenA = A->len;
554 unsigned int lenB = B->len;
555 const unsigned char *s = (const unsigned char *) A->root.string + lenA - 1;
556 const unsigned char *t = (const unsigned char *) B->root.string + lenB - 1;
557 int l = lenA < lenB ? lenA : lenB;
558 int tail_align = (lenA & (A->alignment - 1)) - (lenB & (A->alignment - 1));
560 if (tail_align != 0)
561 return tail_align;
563 while (l)
565 if (*s != *t)
566 return (int) *s - (int) *t;
567 s--;
568 t--;
569 l--;
571 return lenA - lenB;
574 static inline int
575 is_suffix (const struct sec_merge_hash_entry *A,
576 const struct sec_merge_hash_entry *B)
578 if (A->len <= B->len)
579 /* B cannot be a suffix of A unless A is equal to B, which is guaranteed
580 not to be equal by the hash table. */
581 return 0;
583 return memcmp (A->root.string + (A->len - B->len),
584 B->root.string, B->len) == 0;
587 /* This is a helper function for _bfd_merge_sections. It attempts to
588 merge strings matching suffixes of longer strings. */
589 static void
590 merge_strings (struct sec_merge_info *sinfo)
592 struct sec_merge_hash_entry **array, **a, *e;
593 struct sec_merge_sec_info *secinfo;
594 bfd_size_type size, amt;
595 unsigned int alignment = 0;
597 /* Now sort the strings */
598 amt = sinfo->htab->size * sizeof (struct sec_merge_hash_entry *);
599 array = bfd_malloc (amt);
600 if (array == NULL)
601 goto alloc_failure;
603 for (e = sinfo->htab->first, a = array; e; e = e->next)
604 if (e->alignment)
606 *a++ = e;
607 /* Adjust the length to not include the zero terminator. */
608 e->len -= sinfo->htab->entsize;
609 if (alignment != e->alignment)
611 if (alignment == 0)
612 alignment = e->alignment;
613 else
614 alignment = (unsigned) -1;
618 sinfo->htab->size = a - array;
619 if (sinfo->htab->size != 0)
621 qsort (array, (size_t) sinfo->htab->size,
622 sizeof (struct sec_merge_hash_entry *),
623 (alignment != (unsigned) -1 && alignment > sinfo->htab->entsize
624 ? strrevcmp_align : strrevcmp));
626 /* Loop over the sorted array and merge suffixes */
627 e = *--a;
628 e->len += sinfo->htab->entsize;
629 while (--a >= array)
631 struct sec_merge_hash_entry *cmp = *a;
633 cmp->len += sinfo->htab->entsize;
634 if (e->alignment >= cmp->alignment
635 && !((e->len - cmp->len) & (cmp->alignment - 1))
636 && is_suffix (e, cmp))
638 cmp->u.suffix = e;
639 cmp->alignment = 0;
641 else
642 e = cmp;
646 alloc_failure:
647 if (array)
648 free (array);
650 /* Now assign positions to the strings we want to keep. */
651 size = 0;
652 secinfo = sinfo->htab->first->secinfo;
653 for (e = sinfo->htab->first; e; e = e->next)
655 if (e->secinfo != secinfo)
657 secinfo->sec->size = size;
658 secinfo = e->secinfo;
660 if (e->alignment)
662 if (e->secinfo->first_str == NULL)
664 e->secinfo->first_str = e;
665 size = 0;
667 size = (size + e->alignment - 1) & ~((bfd_vma) e->alignment - 1);
668 e->u.index = size;
669 size += e->len;
672 secinfo->sec->size = size;
673 if (secinfo->sec->alignment_power != 0)
675 bfd_size_type align = (bfd_size_type) 1 << secinfo->sec->alignment_power;
676 secinfo->sec->size = (secinfo->sec->size + align - 1) & -align;
679 /* And now adjust the rest, removing them from the chain (but not hashtable)
680 at the same time. */
681 for (a = &sinfo->htab->first, e = *a; e; e = e->next)
682 if (e->alignment)
683 a = &e->next;
684 else
686 *a = e->next;
687 if (e->len)
689 e->secinfo = e->u.suffix->secinfo;
690 e->alignment = e->u.suffix->alignment;
691 e->u.index = e->u.suffix->u.index + (e->u.suffix->len - e->len);
696 /* This function is called once after all SEC_MERGE sections are registered
697 with _bfd_merge_section. */
699 bfd_boolean
700 _bfd_merge_sections (bfd *abfd ATTRIBUTE_UNUSED,
701 struct bfd_link_info *info ATTRIBUTE_UNUSED,
702 void *xsinfo,
703 void (*remove_hook) (bfd *, asection *))
705 struct sec_merge_info *sinfo;
707 for (sinfo = (struct sec_merge_info *) xsinfo; sinfo; sinfo = sinfo->next)
709 struct sec_merge_sec_info * secinfo;
711 if (! sinfo->chain)
712 continue;
714 /* Move sinfo->chain to head of the chain, terminate it. */
715 secinfo = sinfo->chain;
716 sinfo->chain = secinfo->next;
717 secinfo->next = NULL;
719 /* Record the sections into the hash table. */
720 for (secinfo = sinfo->chain; secinfo; secinfo = secinfo->next)
721 if (secinfo->sec->flags & SEC_EXCLUDE)
723 *secinfo->psecinfo = NULL;
724 if (remove_hook)
725 (*remove_hook) (abfd, secinfo->sec);
727 else if (! record_section (sinfo, secinfo))
728 break;
730 if (secinfo)
731 continue;
733 if (sinfo->htab->first == NULL)
734 continue;
736 if (sinfo->htab->strings)
737 merge_strings (sinfo);
738 else
740 struct sec_merge_hash_entry *e;
741 bfd_size_type size = 0;
743 /* Things are much simpler for non-strings.
744 Just assign them slots in the section. */
745 secinfo = NULL;
746 for (e = sinfo->htab->first; e; e = e->next)
748 if (e->secinfo->first_str == NULL)
750 if (secinfo)
751 secinfo->sec->size = size;
752 e->secinfo->first_str = e;
753 size = 0;
755 size = (size + e->alignment - 1)
756 & ~((bfd_vma) e->alignment - 1);
757 e->u.index = size;
758 size += e->len;
759 secinfo = e->secinfo;
761 secinfo->sec->size = size;
764 /* Finally remove all input sections which have not made it into
765 the hash table at all. */
766 for (secinfo = sinfo->chain; secinfo; secinfo = secinfo->next)
767 if (secinfo->first_str == NULL)
768 secinfo->sec->flags |= SEC_EXCLUDE;
771 return TRUE;
774 /* Write out the merged section. */
776 bfd_boolean
777 _bfd_write_merged_section (bfd *output_bfd, asection *sec, void *psecinfo)
779 struct sec_merge_sec_info *secinfo;
780 file_ptr pos;
782 secinfo = (struct sec_merge_sec_info *) psecinfo;
784 if (secinfo->first_str == NULL)
785 return TRUE;
787 pos = sec->output_section->filepos + sec->output_offset;
788 if (bfd_seek (output_bfd, pos, SEEK_SET) != 0)
789 return FALSE;
791 if (! sec_merge_emit (output_bfd, secinfo->first_str))
792 return FALSE;
794 return TRUE;
797 /* Adjust an address in the SEC_MERGE section. Given OFFSET within
798 *PSEC, this returns the new offset in the adjusted SEC_MERGE
799 section and writes the new section back into *PSEC. */
801 bfd_vma
802 _bfd_merged_section_offset (bfd *output_bfd ATTRIBUTE_UNUSED, asection **psec,
803 void *psecinfo, bfd_vma offset)
805 struct sec_merge_sec_info *secinfo;
806 struct sec_merge_hash_entry *entry;
807 unsigned char *p;
808 asection *sec = *psec;
810 secinfo = (struct sec_merge_sec_info *) psecinfo;
812 if (offset >= sec->rawsize)
814 if (offset > sec->rawsize)
816 (*_bfd_error_handler)
817 (_("%s: access beyond end of merged section (%ld)"),
818 bfd_get_filename (sec->owner), (long) offset);
820 return secinfo->first_str ? sec->size : 0;
823 if (secinfo->htab->strings)
825 if (sec->entsize == 1)
827 p = secinfo->contents + offset - 1;
828 while (p >= secinfo->contents && *p)
829 --p;
830 ++p;
832 else
834 p = secinfo->contents + (offset / sec->entsize) * sec->entsize;
835 p -= sec->entsize;
836 while (p >= secinfo->contents)
838 unsigned int i;
840 for (i = 0; i < sec->entsize; ++i)
841 if (p[i] != '\0')
842 break;
843 if (i == sec->entsize)
844 break;
845 p -= sec->entsize;
847 p += sec->entsize;
850 else
852 p = secinfo->contents + (offset / sec->entsize) * sec->entsize;
854 entry = sec_merge_hash_lookup (secinfo->htab, (char *) p, 0, FALSE);
855 if (!entry)
857 if (! secinfo->htab->strings)
858 abort ();
859 /* This should only happen if somebody points into the padding
860 after a NUL character but before next entity. */
861 if (*p)
862 abort ();
863 if (! secinfo->htab->first)
864 abort ();
865 entry = secinfo->htab->first;
866 p = (secinfo->contents + (offset / sec->entsize + 1) * sec->entsize
867 - entry->len);
870 *psec = entry->secinfo->sec;
871 return entry->u.index + (secinfo->contents + offset - p);