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/* ELF strtab with GC and suffix merging support.
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Copyright 2001, 2002 Free Software Foundation, Inc.
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Written by Jakub Jelinek <jakub@redhat.com>.
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This file is part of BFD, the Binary File Descriptor library.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
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#include "libiberty.h"
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/* An entry in the strtab hash table. */
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struct elf_strtab_hash_entry
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struct bfd_hash_entry root;
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/* Length of this entry. */
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unsigned int refcount;
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/* Index within the merged section. */
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/* Entry this is a suffix of (if len is 0). */
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struct elf_strtab_hash_entry *suffix;
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struct elf_strtab_hash_entry *next;
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/* The strtab hash table. */
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struct elf_strtab_hash
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struct bfd_hash_table table;
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/* Next available index. */
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/* Number of array entries alloced. */
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bfd_size_type alloced;
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/* Final strtab size. */
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bfd_size_type sec_size;
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/* Array of pointers to strtab entries. */
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struct elf_strtab_hash_entry **array;
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/* Routine to create an entry in a section merge hashtab. */
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static struct bfd_hash_entry *
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elf_strtab_hash_newfunc (struct bfd_hash_entry *entry,
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struct bfd_hash_table *table,
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/* Allocate the structure if it has not already been allocated by a
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entry = bfd_hash_allocate (table, sizeof (struct elf_strtab_hash_entry));
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/* Call the allocation method of the superclass. */
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entry = bfd_hash_newfunc (entry, table, string);
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/* Initialize the local fields. */
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struct elf_strtab_hash_entry *ret;
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ret = (struct elf_strtab_hash_entry *) entry;
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/* Create a new hash table. */
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struct elf_strtab_hash *
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_bfd_elf_strtab_init (void)
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struct elf_strtab_hash *table;
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bfd_size_type amt = sizeof (struct elf_strtab_hash);
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table = bfd_malloc (amt);
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if (! bfd_hash_table_init (&table->table, elf_strtab_hash_newfunc))
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amt = sizeof (struct elf_strtab_hasn_entry *);
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table->array = bfd_malloc (table->alloced * amt);
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if (table->array == NULL)
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table->array[0] = NULL;
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_bfd_elf_strtab_free (struct elf_strtab_hash *tab)
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bfd_hash_table_free (&tab->table);
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/* Get the index of an entity in a hash table, adding it if it is not
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_bfd_elf_strtab_add (struct elf_strtab_hash *tab,
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register struct elf_strtab_hash_entry *entry;
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/* We handle this specially, since we don't want to do refcounting
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BFD_ASSERT (tab->sec_size == 0);
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entry = (struct elf_strtab_hash_entry *)
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bfd_hash_lookup (&tab->table, str, TRUE, copy);
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return (bfd_size_type) -1;
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entry->len = strlen (str) + 1;
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if (tab->size == tab->alloced)
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bfd_size_type amt = sizeof (struct elf_strtab_hash_entry *);
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tab->array = bfd_realloc (tab->array, tab->alloced * amt);
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if (tab->array == NULL)
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return (bfd_size_type) -1;
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entry->u.index = tab->size++;
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tab->array[entry->u.index] = entry;
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return entry->u.index;
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_bfd_elf_strtab_addref (struct elf_strtab_hash *tab, bfd_size_type idx)
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if (idx == 0 || idx == (bfd_size_type) -1)
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BFD_ASSERT (tab->sec_size == 0);
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BFD_ASSERT (idx < tab->size);
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++tab->array[idx]->refcount;
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_bfd_elf_strtab_delref (struct elf_strtab_hash *tab, bfd_size_type idx)
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if (idx == 0 || idx == (bfd_size_type) -1)
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BFD_ASSERT (tab->sec_size == 0);
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BFD_ASSERT (idx < tab->size);
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BFD_ASSERT (tab->array[idx]->refcount > 0);
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--tab->array[idx]->refcount;
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_bfd_elf_strtab_clear_all_refs (struct elf_strtab_hash *tab)
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for (idx = 1; idx < tab->size; ++idx)
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tab->array[idx]->refcount = 0;
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_bfd_elf_strtab_size (struct elf_strtab_hash *tab)
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return tab->sec_size ? tab->sec_size : tab->size;
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_bfd_elf_strtab_offset (struct elf_strtab_hash *tab, bfd_size_type idx)
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struct elf_strtab_hash_entry *entry;
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BFD_ASSERT (idx < tab->size);
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BFD_ASSERT (tab->sec_size);
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entry = tab->array[idx];
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BFD_ASSERT (entry->refcount > 0);
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return tab->array[idx]->u.index;
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_bfd_elf_strtab_emit (register bfd *abfd, struct elf_strtab_hash *tab)
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bfd_size_type off = 1, i;
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if (bfd_bwrite ("", 1, abfd) != 1)
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for (i = 1; i < tab->size; ++i)
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register const char *str;
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str = tab->array[i]->root.string;
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len = tab->array[i]->len;
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BFD_ASSERT (tab->array[i]->refcount == 0);
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if (bfd_bwrite (str, len, abfd) != len)
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BFD_ASSERT (off == tab->sec_size);
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/* Compare two elf_strtab_hash_entry structures. This is called via qsort. */
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cmplengthentry (const void *a, const void *b)
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struct elf_strtab_hash_entry *A = *(struct elf_strtab_hash_entry **) a;
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struct elf_strtab_hash_entry *B = *(struct elf_strtab_hash_entry **) b;
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else if (A->len > B->len)
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return memcmp (A->root.string, B->root.string, A->len);
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last4_eq (const void *a, const void *b)
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const struct elf_strtab_hash_entry *A = a;
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const struct elf_strtab_hash_entry *B = b;
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if (memcmp (A->root.string + A->len - 5, B->root.string + B->len - 5, 4)
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/* This was a hashtable collision. */
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if (A->len <= B->len)
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/* B cannot be a suffix of A unless A is equal to B, which is guaranteed
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not to be equal by the hash table. */
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return memcmp (A->root.string + (A->len - B->len),
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B->root.string, B->len - 5) == 0;
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/* This function assigns final string table offsets for used strings,
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merging strings matching suffixes of longer strings if possible. */
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_bfd_elf_strtab_finalize (struct elf_strtab_hash *tab)
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struct elf_strtab_hash_entry **array, **a, **end, *e;
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htab_t last4tab = NULL;
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bfd_size_type size, amt;
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struct elf_strtab_hash_entry *last[256], **last_ptr[256];
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/* GCC 2.91.66 (egcs-1.1.2) on i386 miscompiles this function when i is
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a 64-bit bfd_size_type: a 64-bit target or --enable-64-bit-bfd.
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Besides, indexing with a long long wouldn't give anything but extra
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/* Now sort the strings by length, longest first. */
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amt = tab->size * sizeof (struct elf_strtab_hash_entry *);
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array = bfd_malloc (amt);
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memset (last, 0, sizeof (last));
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for (i = 0; i < 256; ++i)
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last_ptr[i] = &last[i];
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for (i = 1, a = array; i < tab->size; ++i)
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if (tab->array[i]->refcount)
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*a++ = tab->array[i];
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tab->array[i]->len = 0;
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qsort (array, size, sizeof (struct elf_strtab_hash_entry *), cmplengthentry);
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last4tab = htab_create_alloc (size * 4, NULL, last4_eq, NULL, calloc, free);
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if (last4tab == NULL)
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/* Now insert the strings into hash tables (strings with last 4 characters
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and strings with last character equal), look for longer strings which
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for (a = array, end = array + size; a < end; a++)
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register hashval_t hash;
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const unsigned char *s;
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s = e->root.string + e->len - 1;
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for (j = 0; j < 4; j++)
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hash += c + (c << 17);
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p = htab_find_slot_with_hash (last4tab, e, hash, INSERT);
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struct elf_strtab_hash_entry *ent;
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struct elf_strtab_hash_entry *tem;
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c = e->root.string[e->len - 2] & 0xff;
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for (tem = last[c]; tem; tem = tem->u.next)
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if (tem->len > e->len
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&& memcmp (tem->root.string + (tem->len - e->len),
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e->root.string, e->len - 1) == 0)
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c = e->root.string[e->len - 2] & 0xff;
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/* Put longest strings first. */
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last_ptr[c] = &e->u.next;
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htab_delete (last4tab);
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/* Now assign positions to the strings we want to keep. */
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for (i = 1; i < tab->size; ++i)
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if (e->refcount && e->len)
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tab->sec_size = size;
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/* And now adjust the rest. */
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for (i = 1; i < tab->size; ++i)
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if (e->refcount && ! e->len)
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e->u.index = e->u.suffix->u.index
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+ (e->u.suffix->len - strlen (e->root.string) - 1);