bfd/merge.c

   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
  30 struct sec_merge_sec_info;
  31
  32 /* An entry in the section merge hash table.  */
  33
  34 struct sec_merge_hash_entry
  35 {
  36   struct bfd_hash_entry root;
  37   /* Length of this entry.  */
  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     /* Entity size (if present in suffix hash tables).  */
  47     unsigned int entsize;
  48     /* Entry this is a suffix of (if alignment is 0).  */
  49     struct sec_merge_hash_entry *suffix;
  50   } u;
  51   /* Which section is it in.  */
  52   struct sec_merge_sec_info *secinfo;
  53   /* Next entity in the hash table.  */
  54   struct sec_merge_hash_entry *next;
  55 };
  56
  57 /* The section merge hash table.  */
  58
  59 struct sec_merge_hash
  60 {
  61   struct bfd_hash_table table;
  62   /* Next available index.  */
  63   bfd_size_type size;
  64   /* First entity in the SEC_MERGE sections of this type.  */
  65   struct sec_merge_hash_entry *first;
  66   /* Last entity in the SEC_MERGE sections of this type.  */
  67   struct sec_merge_hash_entry *last;
  68   /* Entity size.  */
  69   unsigned int entsize;
  70   /* Are entries fixed size or zero terminated strings?  */
  71   bfd_boolean strings;
  72 };
  73
  74 struct sec_merge_info
  75 {
  76   /* Chain of sec_merge_infos.  */
  77   struct sec_merge_info *next;
  78   /* Chain of sec_merge_sec_infos.  */
  79   struct sec_merge_sec_info *chain;
  80   /* A hash table used to hold section content.  */
  81   struct sec_merge_hash *htab;
  82 };
  83
  84 struct sec_merge_sec_info
  85 {
  86   /* Chain of sec_merge_sec_infos.  */
  87   struct sec_merge_sec_info *next;
  88   /* The corresponding section.  */
  89   asection *sec;
  90   /* Pointer to merge_info pointing to us.  */
  91   void **psecinfo;
  92   /* A hash table used to hold section content.  */
  93   struct sec_merge_hash *htab;
  94   /* First string in this section.  */
  95   struct sec_merge_hash_entry *first;
  96   /* Original section content.  */
  97   unsigned char contents[1];
  98 };
  99
 100
 101 /* Routine to create an entry in a section merge hashtab.  */
 102
 103 static struct bfd_hash_entry *
 104 sec_merge_hash_newfunc (struct bfd_hash_entry *entry,
 105                         struct bfd_hash_table *table, const char *string)
 106 {
 107   struct sec_merge_hash_entry *ret = (struct sec_merge_hash_entry *) entry;
 108
 109   /* Allocate the structure if it has not already been allocated by a
 110      subclass.  */
 111   if (ret == (struct sec_merge_hash_entry *) NULL)
 112     ret = ((struct sec_merge_hash_entry *)
 113            bfd_hash_allocate (table, sizeof (struct sec_merge_hash_entry)));
 114   if (ret == (struct sec_merge_hash_entry *) NULL)
 115     return NULL;
 116
 117   /* Call the allocation method of the superclass.  */
 118   ret = ((struct sec_merge_hash_entry *)
 119          bfd_hash_newfunc ((struct bfd_hash_entry *) ret, table, string));
 120
 121   if (ret)
 122     {
 123       /* Initialize the local fields.  */
 124       ret->u.suffix = NULL;
 125       ret->alignment = 0;
 126       ret->secinfo = NULL;
 127       ret->next = NULL;
 128     }
 129
 130   return (struct bfd_hash_entry *) ret;
 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 != (struct sec_merge_hash_entry *) 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               /*  Mark the less aligned copy as deleted.  */
 209               hashp->len = 0;
 210               hashp->alignment = 0;
 211               break;
 212             }
 213           return hashp;
 214         }
 215     }
 216
 217   if (! create)
 218     return (struct sec_merge_hash_entry *) NULL;
 219
 220   hashp = (struct sec_merge_hash_entry *)
 221           sec_merge_hash_newfunc ((struct bfd_hash_entry *) NULL,
 222                                   (struct bfd_hash_table *) table, string);
 223   if (hashp == (struct sec_merge_hash_entry *) NULL)
 224     return (struct sec_merge_hash_entry *) NULL;
 225   hashp->root.string = string;
 226   hashp->root.hash = hash;
 227   hashp->len = len;
 228   hashp->alignment = alignment;
 229   hashp->root.next = table->table.table[index];
 230   table->table.table[index] = (struct bfd_hash_entry *) hashp;
 231
 232   return hashp;
 233 }
 234
 235 /* Create a new hash table.  */
 236
 237 static struct sec_merge_hash *
 238 sec_merge_init (unsigned int entsize, bfd_boolean strings)
 239 {
 240   struct sec_merge_hash *table;
 241   bfd_size_type amt = sizeof (struct sec_merge_hash);
 242
 243   table = (struct sec_merge_hash *) bfd_malloc (amt);
 244   if (table == NULL)
 245     return NULL;
 246
 247   if (! bfd_hash_table_init (&table->table, sec_merge_hash_newfunc))
 248     {
 249       free (table);
 250       return NULL;
 251     }
 252
 253   table->size = 0;
 254   table->first = NULL;
 255   table->last = NULL;
 256   table->entsize = entsize;
 257   table->strings = strings;
 258
 259   return table;
 260 }
 261
 262 /* Get the index of an entity in a hash table, adding it if it is not
 263    already present.  */
 264
 265 static struct sec_merge_hash_entry *
 266 sec_merge_add (struct sec_merge_hash *tab, const char *str,
 267                unsigned int alignment, struct sec_merge_sec_info *secinfo)
 268 {
 269   register struct sec_merge_hash_entry *entry;
 270
 271   entry = sec_merge_hash_lookup (tab, str, alignment, TRUE);
 272   if (entry == NULL)
 273     return NULL;
 274
 275   if (entry->secinfo == NULL)
 276     {
 277       tab->size++;
 278       entry->secinfo = secinfo;
 279       if (tab->first == NULL)
 280         tab->first = entry;
 281       else
 282         tab->last->next = entry;
 283       tab->last = entry;
 284     }
 285
 286   return entry;
 287 }
 288
 289 static bfd_boolean
 290 sec_merge_emit (register bfd *abfd, struct sec_merge_hash_entry *entry)
 291 {
 292   struct sec_merge_sec_info *secinfo = entry->secinfo;
 293   asection *sec = secinfo->sec;
 294   char *pad = "";
 295   bfd_size_type off = 0;
 296   int alignment_power = bfd_get_section_alignment (abfd, sec->output_section);
 297
 298   if (alignment_power)
 299     pad = bfd_zmalloc ((bfd_size_type) 1 << alignment_power);
 300
 301   for (; entry != NULL && entry->secinfo == secinfo; entry = entry->next)
 302     {
 303       register const char *str;
 304       register size_t len;
 305
 306       len = off & (entry->alignment - 1);
 307       if (len)
 308         {
 309           len = entry->alignment - len;
 310           if (bfd_bwrite (pad, (bfd_size_type) len, abfd) != len)
 311             break;
 312           off += len;
 313         }
 314
 315       str = entry->root.string;
 316       len = entry->len;
 317
 318       if (bfd_bwrite (str, (bfd_size_type) len, abfd) != len)
 319         break;
 320
 321       off += len;
 322     }
 323
 324   if (alignment_power)
 325     free (pad);
 326
 327   return entry == NULL || entry->secinfo != secinfo;
 328 }
 329
 330 /* This function is called for each input file from the add_symbols
 331    pass of the linker.  */
 332
 333 bfd_boolean
 334 _bfd_merge_section (bfd *abfd, void **psinfo, asection *sec, void **psecinfo)
 335 {
 336   struct sec_merge_info *sinfo;
 337   struct sec_merge_sec_info *secinfo;
 338   unsigned int align;
 339   bfd_size_type amt;
 340
 341   if (sec->_raw_size == 0
 342       || (sec->flags & SEC_EXCLUDE)
 343       || (sec->flags & SEC_MERGE) == 0
 344       || sec->entsize == 0)
 345     return TRUE;
 346
 347   if ((sec->flags & SEC_RELOC) != 0)
 348     {
 349       /* We aren't prepared to handle relocations in merged sections.  */
 350       return TRUE;
 351     }
 352
 353   align = bfd_get_section_alignment (sec->owner, sec);
 354   if ((sec->entsize < (unsigned int)(1 << align)
 355        && ((sec->entsize & (sec->entsize - 1))
 356            || !(sec->flags & SEC_STRINGS)))
 357       || (sec->entsize > (unsigned int)(1 << align)
 358           && (sec->entsize & ((1 << align) - 1))))
 359     {
 360       /* Sanity check.  If string character size is smaller than
 361          alignment, then we require character size to be a power
 362          of 2, otherwise character size must be integer multiple
 363          of alignment.  For non-string constants, alignment must
 364          be smaller than or equal to entity size and entity size
 365          must be integer multiple of alignment.  */
 366       return TRUE;
 367     }
 368
 369   for (sinfo = (struct sec_merge_info *) *psinfo; sinfo; sinfo = sinfo->next)
 370     if ((secinfo = sinfo->chain)
 371         && ! ((secinfo->sec->flags ^ sec->flags) & (SEC_MERGE | SEC_STRINGS))
 372         && secinfo->sec->entsize == sec->entsize
 373         && ! strcmp (secinfo->sec->name, sec->name))
 374       break;
 375
 376   if (sinfo == NULL)
 377     {
 378       /* Initialize the information we need to keep track of.  */
 379       amt = sizeof (struct sec_merge_info);
 380       sinfo = (struct sec_merge_info *) bfd_alloc (abfd, amt);
 381       if (sinfo == NULL)
 382         goto error_return;
 383       sinfo->next = (struct sec_merge_info *) *psinfo;
 384       sinfo->chain = NULL;
 385       *psinfo = sinfo;
 386       sinfo->htab = sec_merge_init (sec->entsize, (sec->flags & SEC_STRINGS));
 387       if (sinfo->htab == NULL)
 388         goto error_return;
 389     }
 390
 391   /* Read the section from abfd.  */
 392
 393   amt = sizeof (struct sec_merge_sec_info) + sec->_raw_size - 1;
 394   *psecinfo = bfd_alloc (abfd, amt);
 395   if (*psecinfo == NULL)
 396     goto error_return;
 397
 398   secinfo = (struct sec_merge_sec_info *)*psecinfo;
 399   if (sinfo->chain)
 400     {
 401       secinfo->next = sinfo->chain->next;
 402       sinfo->chain->next = secinfo;
 403     }
 404   else
 405     secinfo->next = secinfo;
 406   sinfo->chain = secinfo;
 407   secinfo->sec = sec;
 408   secinfo->psecinfo = psecinfo;
 409   secinfo->htab = sinfo->htab;
 410   secinfo->first = NULL;
 411
 412   if (! bfd_get_section_contents (sec->owner, sec, secinfo->contents,
 413                                   (bfd_vma) 0, sec->_raw_size))
 414     goto error_return;
 415
 416   return TRUE;
 417
 418  error_return:
 419   *psecinfo = NULL;
 420   return FALSE;
 421 }
 422
 423 /* Compare two sec_merge_hash_entry structures.  This is called via qsort.  */
 424
 425 static int
 426 cmplengthentry (const void *a, const void *b)
 427 {
 428   struct sec_merge_hash_entry * A = *(struct sec_merge_hash_entry **) a;
 429   struct sec_merge_hash_entry * B = *(struct sec_merge_hash_entry **) b;
 430
 431   if (A->len < B->len)
 432     return 1;
 433   else if (A->len > B->len)
 434     return -1;
 435
 436   return memcmp (A->root.string, B->root.string, A->len);
 437 }
 438
 439 static int
 440 last4_eq (const void *a, const void *b)
 441 {
 442   struct sec_merge_hash_entry * A = (struct sec_merge_hash_entry *) a;
 443   struct sec_merge_hash_entry * B = (struct sec_merge_hash_entry *) b;
 444
 445   if (memcmp (A->root.string + A->len - 5 * A->u.entsize,
 446               B->root.string + B->len - 5 * A->u.entsize,
 447               4 * A->u.entsize) != 0)
 448     /* This was a hashtable collision.  */
 449     return 0;
 450
 451   if (A->len <= B->len)
 452     /* B cannot be a suffix of A unless A is equal to B, which is guaranteed
 453        not to be equal by the hash table.  */
 454     return 0;
 455
 456   if (A->alignment < B->alignment
 457       || ((A->len - B->len) & (B->alignment - 1)))
 458     /* The suffix is not sufficiently aligned.  */
 459     return 0;
 460
 461   return memcmp (A->root.string + (A->len - B->len),
 462                  B->root.string, B->len - 5 * A->u.entsize) == 0;
 463 }
 464
 465 static int
 466 last_eq (const void *a, const void *b)
 467 {
 468   struct sec_merge_hash_entry * A = (struct sec_merge_hash_entry *) a;
 469   struct sec_merge_hash_entry * B = (struct sec_merge_hash_entry *) b;
 470
 471   if (B->len >= 5 * A->u.entsize)
 472     /* Longer strings are just pushed into the hash table,
 473        they'll be used when looking up for very short strings.  */
 474     return 0;
 475
 476   if (memcmp (A->root.string + A->len - 2 * A->u.entsize,
 477               B->root.string + B->len - 2 * A->u.entsize,
 478               A->u.entsize) != 0)
 479     /* This was a hashtable collision.  */
 480     return 0;
 481
 482   if (A->len <= B->len)
 483     /* B cannot be a suffix of A unless A is equal to B, which is guaranteed
 484        not to be equal by the hash table.  */
 485     return 0;
 486
 487   if (A->alignment < B->alignment
 488       || ((A->len - B->len) & (B->alignment - 1)))
 489     /* The suffix is not sufficiently aligned.  */
 490     return 0;
 491
 492   return memcmp (A->root.string + (A->len - B->len),
 493                  B->root.string, B->len - 2 * A->u.entsize) == 0;
 494 }
 495
 496 /* Record one section into the hash table.  */
 497 static bfd_boolean
 498 record_section (struct sec_merge_info *sinfo,
 499                 struct sec_merge_sec_info *secinfo)
 500 {
 501   asection *sec = secinfo->sec;
 502   struct sec_merge_hash_entry *entry;
 503   bfd_boolean nul;
 504   unsigned char *p, *end;
 505   bfd_vma mask, eltalign;
 506   unsigned int align, i;
 507
 508   align = bfd_get_section_alignment (sec->owner, sec);
 509   end = secinfo->contents + sec->_raw_size;
 510   nul = FALSE;
 511   mask = ((bfd_vma) 1 << align) - 1;
 512   if (sec->flags & SEC_STRINGS)
 513     {
 514       for (p = secinfo->contents; p < end; )
 515         {
 516           eltalign = p - secinfo->contents;
 517           eltalign = ((eltalign ^ (eltalign - 1)) + 1) >> 1;
 518           if (!eltalign || eltalign > mask)
 519             eltalign = mask + 1;
 520           entry = sec_merge_add (sinfo->htab, p, (unsigned) eltalign, secinfo);
 521           if (! entry)
 522             goto error_return;
 523           p += entry->len;
 524           if (sec->entsize == 1)
 525             {
 526               while (p < end && *p == 0)
 527                 {
 528                   if (!nul && !((p - secinfo->contents) & mask))
 529                     {
 530                       nul = TRUE;
 531                       entry = sec_merge_add (sinfo->htab, "",
 532                                              (unsigned) mask + 1, secinfo);
 533                       if (! entry)
 534                         goto error_return;
 535                     }
 536                   p++;
 537                 }
 538             }
 539           else
 540             {
 541               while (p < end)
 542                 {
 543                   for (i = 0; i < sec->entsize; i++)
 544                     if (p[i] != '\0')
 545                       break;
 546                   if (i != sec->entsize)
 547                     break;
 548                   if (!nul && !((p - secinfo->contents) & mask))
 549                     {
 550                       nul = TRUE;
 551                       entry = sec_merge_add (sinfo->htab, p,
 552                                              (unsigned) mask + 1, secinfo);
 553                       if (! entry)
 554                         goto error_return;
 555                     }
 556                   p += sec->entsize;
 557                 }
 558             }
 559         }
 560     }
 561   else
 562     {
 563       for (p = secinfo->contents; p < end; p += sec->entsize)
 564         {
 565           entry = sec_merge_add (sinfo->htab, p, 1, secinfo);
 566           if (! entry)
 567             goto error_return;
 568         }
 569     }
 570
 571   return TRUE;
 572
 573 error_return:
 574   for (secinfo = sinfo->chain; secinfo; secinfo = secinfo->next)
 575     *secinfo->psecinfo = NULL;
 576   return FALSE;
 577 }
 578
 579 /* This is a helper function for _bfd_merge_sections.  It attempts to
 580    merge strings matching suffixes of longer strings.  */
 581 static void
 582 merge_strings (struct sec_merge_info *sinfo)
 583 {
 584   struct sec_merge_hash_entry **array, **a, **end, *e;
 585   struct sec_merge_sec_info *secinfo;
 586   htab_t lasttab = NULL, last4tab = NULL;
 587   bfd_size_type size, amt;
 588
 589   /* Now sort the strings by length, longest first.  */
 590   array = NULL;
 591   amt = sinfo->htab->size * sizeof (struct sec_merge_hash_entry *);
 592   array = (struct sec_merge_hash_entry **) bfd_malloc (amt);
 593   if (array == NULL)
 594     goto alloc_failure;
 595
 596   for (e = sinfo->htab->first, a = array; e; e = e->next)
 597     if (e->alignment)
 598       *a++ = e;
 599
 600   sinfo->htab->size = a - array;
 601
 602   qsort (array, (size_t) sinfo->htab->size,
 603          sizeof (struct sec_merge_hash_entry *), cmplengthentry);
 604
 605   last4tab = htab_create_alloc ((size_t) sinfo->htab->size * 4,
 606                                 NULL, last4_eq, NULL, calloc, free);
 607   lasttab = htab_create_alloc ((size_t) sinfo->htab->size * 4,
 608                                NULL, last_eq, NULL, calloc, free);
 609   if (lasttab == NULL || last4tab == NULL)
 610     goto alloc_failure;
 611
 612   /* Now insert the strings into hash tables (strings with last 4 characters
 613      and strings with last character equal), look for longer strings which
 614      we're suffix of.  */
 615   for (a = array, end = array + sinfo->htab->size; a < end; a++)
 616     {
 617       register hashval_t hash;
 618       unsigned int c;
 619       unsigned int i;
 620       const unsigned char *s;
 621       void **p;
 622
 623       e = *a;
 624       e->u.entsize = sinfo->htab->entsize;
 625       if (e->len <= e->u.entsize)
 626         break;
 627       if (e->len > 4 * e->u.entsize)
 628         {
 629           s = (const unsigned char *) (e->root.string + e->len - e->u.entsize);
 630           hash = 0;
 631           for (i = 0; i < 4 * e->u.entsize; i++)
 632             {
 633               c = *--s;
 634               hash += c + (c << 17);
 635               hash ^= hash >> 2;
 636             }
 637           p = htab_find_slot_with_hash (last4tab, e, hash, INSERT);
 638           if (p == NULL)
 639             goto alloc_failure;
 640           if (*p)
 641             {
 642               struct sec_merge_hash_entry *ent;
 643
 644               ent = (struct sec_merge_hash_entry *) *p;
 645               e->u.suffix = ent;
 646               e->alignment = 0;
 647               continue;
 648             }
 649           else
 650             *p = e;
 651         }
 652       s = (const unsigned char *) (e->root.string + e->len - e->u.entsize);
 653       hash = 0;
 654       for (i = 0; i < e->u.entsize; i++)
 655         {
 656           c = *--s;
 657           hash += c + (c << 17);
 658           hash ^= hash >> 2;
 659         }
 660       p = htab_find_slot_with_hash (lasttab, e, hash, INSERT);
 661       if (p == NULL)
 662         goto alloc_failure;
 663       if (*p)
 664         {
 665           struct sec_merge_hash_entry *ent;
 666
 667           ent = (struct sec_merge_hash_entry *) *p;
 668           e->u.suffix = ent;
 669           e->alignment = 0;
 670         }
 671       else
 672         *p = e;
 673     }
 674
 675 alloc_failure:
 676   if (array)
 677     free (array);
 678   if (lasttab)
 679     htab_delete (lasttab);
 680   if (last4tab)
 681     htab_delete (last4tab);
 682
 683   /* Now assign positions to the strings we want to keep.  */
 684   size = 0;
 685   secinfo = sinfo->htab->first->secinfo;
 686   for (e = sinfo->htab->first; e; e = e->next)
 687     {
 688       if (e->secinfo != secinfo)
 689         {
 690           secinfo->sec->_cooked_size = size;
 691           secinfo = e->secinfo;
 692         }
 693       if (e->alignment)
 694         {
 695           if (e->secinfo->first == NULL)
 696             {
 697               e->secinfo->first = e;
 698               size = 0;
 699             }
 700           size = (size + e->alignment - 1) & ~((bfd_vma) e->alignment - 1);
 701           e->u.index = size;
 702           size += e->len;
 703         }
 704     }
 705   secinfo->sec->_cooked_size = size;
 706
 707   /* And now adjust the rest, removing them from the chain (but not hashtable)
 708      at the same time.  */
 709   for (a = &sinfo->htab->first, e = *a; e; e = e->next)
 710     if (e->alignment)
 711       a = &e->next;
 712     else
 713       {
 714         *a = e->next;
 715         if (e->len)
 716           {
 717             e->secinfo = e->u.suffix->secinfo;
 718             e->alignment = e->u.suffix->alignment;
 719             e->u.index = e->u.suffix->u.index + (e->u.suffix->len - e->len);
 720           }
 721       }
 722 }
 723
 724 /* This function is called once after all SEC_MERGE sections are registered
 725    with _bfd_merge_section.  */
 726
 727 bfd_boolean
 728 _bfd_merge_sections (bfd *abfd ATTRIBUTE_UNUSED, void *xsinfo,
 729                      void (*remove_hook) (bfd *, asection *))
 730 {
 731   struct sec_merge_info *sinfo;
 732
 733   for (sinfo = (struct sec_merge_info *) xsinfo; sinfo; sinfo = sinfo->next)
 734     {
 735       struct sec_merge_sec_info * secinfo;
 736
 737       if (! sinfo->chain)
 738         continue;
 739
 740       /* Move sinfo->chain to head of the chain, terminate it.  */
 741       secinfo = sinfo->chain;
 742       sinfo->chain = secinfo->next;
 743       secinfo->next = NULL;
 744
 745       /* Record the sections into the hash table.  */
 746       for (secinfo = sinfo->chain; secinfo; secinfo = secinfo->next)
 747         if (secinfo->sec->flags & SEC_EXCLUDE)
 748           {
 749             *secinfo->psecinfo = NULL;
 750             if (remove_hook)
 751               (*remove_hook) (abfd, secinfo->sec);
 752           }
 753         else if (! record_section (sinfo, secinfo))
 754           break;
 755
 756       if (secinfo)
 757         continue;
 758
 759       if (sinfo->htab->first == NULL)
 760         continue;
 761
 762       if (sinfo->htab->strings)
 763         merge_strings (sinfo);
 764       else
 765         {
 766           struct sec_merge_hash_entry *e;
 767           bfd_size_type size = 0;
 768
 769           /* Things are much simpler for non-strings.
 770              Just assign them slots in the section.  */
 771           secinfo = NULL;
 772           for (e = sinfo->htab->first; e; e = e->next)
 773             {
 774               if (e->secinfo->first == NULL)
 775                 {
 776                   if (secinfo)
 777                     secinfo->sec->_cooked_size = size;
 778                   e->secinfo->first = e;
 779                   size = 0;
 780                 }
 781               size = (size + e->alignment - 1)
 782                      & ~((bfd_vma) e->alignment - 1);
 783               e->u.index = size;
 784               size += e->len;
 785               secinfo = e->secinfo;
 786             }
 787           secinfo->sec->_cooked_size = size;
 788         }
 789
 790         /* Finally shrink all input sections which have not made it into
 791            the hash table at all.  */
 792         for (secinfo = sinfo->chain; secinfo; secinfo = secinfo->next)
 793           if (secinfo->first == NULL)
 794             secinfo->sec->_cooked_size = 0;
 795     }
 796
 797   return TRUE;
 798 }
 799
 800 /* Write out the merged section.  */
 801
 802 bfd_boolean
 803 _bfd_write_merged_section (bfd *output_bfd, asection *sec, void *psecinfo)
 804 {
 805   struct sec_merge_sec_info *secinfo;
 806   file_ptr pos;
 807
 808   secinfo = (struct sec_merge_sec_info *) psecinfo;
 809
 810   if (!secinfo->first)
 811     return TRUE;
 812
 813   pos = sec->output_section->filepos + sec->output_offset;
 814   if (bfd_seek (output_bfd, pos, SEEK_SET) != 0)
 815     return FALSE;
 816
 817   if (! sec_merge_emit (output_bfd, secinfo->first))
 818     return FALSE;
 819
 820   return TRUE;
 821 }
 822
 823 /* Adjust an address in the SEC_MERGE section.  Given OFFSET within
 824    *PSEC, this returns the new offset in the adjusted SEC_MERGE
 825    section and writes the new section back into *PSEC.  */
 826
 827 bfd_vma
 828 _bfd_merged_section_offset (bfd *output_bfd ATTRIBUTE_UNUSED, asection **psec,
 829                             void *psecinfo, bfd_vma offset, bfd_vma addend)
 830 {
 831   struct sec_merge_sec_info *secinfo;
 832   struct sec_merge_hash_entry *entry;
 833   unsigned char *p;
 834   asection *sec = *psec;
 835
 836   secinfo = (struct sec_merge_sec_info *) psecinfo;
 837
 838   if (offset + addend >= sec->_raw_size)
 839     {
 840       if (offset + addend > sec->_raw_size)
 841         {
 842           (*_bfd_error_handler)
 843             (_("%s: access beyond end of merged section (%ld + %ld)"),
 844              bfd_get_filename (sec->owner), (long) offset, (long) addend);
 845         }
 846       return (secinfo->first ? sec->_cooked_size : 0);
 847     }
 848
 849   if (secinfo->htab->strings)
 850     {
 851       if (sec->entsize == 1)
 852         {
 853           p = secinfo->contents + offset + addend - 1;
 854           while (p >= secinfo->contents && *p)
 855             --p;
 856           ++p;
 857         }
 858       else
 859         {
 860           p = secinfo->contents
 861               + ((offset + addend) / sec->entsize) * sec->entsize;
 862           p -= sec->entsize;
 863           while (p >= secinfo->contents)
 864             {
 865               unsigned int i;
 866
 867               for (i = 0; i < sec->entsize; ++i)
 868                 if (p[i] != '\0')
 869                   break;
 870               if (i == sec->entsize)
 871                 break;
 872               p -= sec->entsize;
 873             }
 874           p += sec->entsize;
 875         }
 876     }
 877   else
 878     {
 879       p = secinfo->contents
 880           + ((offset + addend) / sec->entsize) * sec->entsize;
 881     }
 882   entry = sec_merge_hash_lookup (secinfo->htab, p, 0, FALSE);
 883   if (!entry)
 884     {
 885       if (! secinfo->htab->strings)
 886         abort ();
 887       /* This should only happen if somebody points into the padding
 888          after a NUL character but before next entity.  */
 889       if (*p)
 890         abort ();
 891       if (! secinfo->htab->first)
 892         abort ();
 893       entry = secinfo->htab->first;
 894       p = secinfo->contents
 895           + ((offset + addend) / sec->entsize + 1) * sec->entsize
 896           - entry->len;
 897     }
 898
 899   *psec = entry->secinfo->sec;
 900   return entry->u.index + (secinfo->contents + offset - p);
 901 }