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5197 serge 1
/* SEC_MERGE support.
2
   Copyright 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
3
   Free Software Foundation, Inc.
4
   Written by Jakub Jelinek .
5
 
6
   This file is part of BFD, the Binary File Descriptor library.
7
 
8
   This program is free software; you can redistribute it and/or modify
9
   it under the terms of the GNU General Public License as published by
10
   the Free Software Foundation; either version 3 of the License, or
11
   (at your option) any later version.
12
 
13
   This program is distributed in the hope that it will be useful,
14
   but WITHOUT ANY WARRANTY; without even the implied warranty of
15
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16
   GNU General Public License for more details.
17
 
18
   You should have received a copy of the GNU General Public License
19
   along with this program; if not, write to the Free Software
20
   Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21
   MA 02110-1301, USA.  */
22
 
23
 
24
/* This file contains support for merging duplicate entities within sections,
25
   as used in ELF SHF_MERGE.  */
26
 
27
#include "sysdep.h"
28
#include "bfd.h"
29
#include "libbfd.h"
30
#include "hashtab.h"
31
#include "libiberty.h"
32
 
33
struct sec_merge_sec_info;
34
 
35
/* An entry in the section merge hash table.  */
36
 
37
struct sec_merge_hash_entry
38
{
39
  struct bfd_hash_entry root;
40
  /* Length of this entry.  This includes the zero terminator.  */
41
  unsigned int len;
42
  /* Start of this string needs to be aligned to
43
     alignment octets (not 1 << align).  */
44
  unsigned int alignment;
45
  union
46
  {
47
    /* Index within the merged section.  */
48
    bfd_size_type index;
49
    /* Entry this is a suffix of (if alignment is 0).  */
50
    struct sec_merge_hash_entry *suffix;
51
  } u;
52
  /* Which section is it in.  */
53
  struct sec_merge_sec_info *secinfo;
54
  /* Next entity in the hash table.  */
55
  struct sec_merge_hash_entry *next;
56
};
57
 
58
/* The section merge hash table.  */
59
 
60
struct sec_merge_hash
61
{
62
  struct bfd_hash_table table;
63
  /* Next available index.  */
64
  bfd_size_type size;
65
  /* First entity in the SEC_MERGE sections of this type.  */
66
  struct sec_merge_hash_entry *first;
67
  /* Last entity in the SEC_MERGE sections of this type.  */
68
  struct sec_merge_hash_entry *last;
69
  /* Entity size.  */
70
  unsigned int entsize;
71
  /* Are entries fixed size or zero terminated strings?  */
72
  bfd_boolean strings;
73
};
74
 
75
struct sec_merge_info
76
{
77
  /* Chain of sec_merge_infos.  */
78
  struct sec_merge_info *next;
79
  /* Chain of sec_merge_sec_infos.  */
80
  struct sec_merge_sec_info *chain;
81
  /* A hash table used to hold section content.  */
82
  struct sec_merge_hash *htab;
83
};
84
 
85
struct sec_merge_sec_info
86
{
87
  /* Chain of sec_merge_sec_infos.  */
88
  struct sec_merge_sec_info *next;
89
  /* The corresponding section.  */
90
  asection *sec;
91
  /* Pointer to merge_info pointing to us.  */
92
  void **psecinfo;
93
  /* A hash table used to hold section content.  */
94
  struct sec_merge_hash *htab;
95
  /* First string in this section.  */
96
  struct sec_merge_hash_entry *first_str;
97
  /* Original section content.  */
98
  unsigned char contents[1];
99
};
100
 
101
 
102
/* Routine to create an entry in a section merge hashtab.  */
103
 
104
static struct bfd_hash_entry *
105
sec_merge_hash_newfunc (struct bfd_hash_entry *entry,
106
			struct bfd_hash_table *table, const char *string)
107
{
108
  /* Allocate the structure if it has not already been allocated by a
109
     subclass.  */
110
  if (entry == NULL)
111
    entry = (struct bfd_hash_entry *)
112
        bfd_hash_allocate (table, sizeof (struct sec_merge_hash_entry));
113
  if (entry == NULL)
114
    return NULL;
115
 
116
  /* Call the allocation method of the superclass.  */
117
  entry = bfd_hash_newfunc (entry, table, string);
118
 
119
  if (entry != NULL)
120
    {
121
      /* Initialize the local fields.  */
122
      struct sec_merge_hash_entry *ret = (struct sec_merge_hash_entry *) entry;
123
 
124
      ret->u.suffix = NULL;
125
      ret->alignment = 0;
126
      ret->secinfo = NULL;
127
      ret->next = NULL;
128
    }
129
 
130
  return entry;
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
  const unsigned char *s;
140
  unsigned long hash;
141
  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 != 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
	      if (create)
209
		{
210
		  /*  Mark the less aligned copy as deleted.  */
211
		  hashp->len = 0;
212
		  hashp->alignment = 0;
213
		}
214
	      break;
215
	    }
216
	  return hashp;
217
	}
218
    }
219
 
220
  if (! create)
221
    return NULL;
222
 
223
  hashp = ((struct sec_merge_hash_entry *)
224
	   bfd_hash_insert (&table->table, string, hash));
225
  if (hashp == NULL)
226
    return NULL;
227
  hashp->len = len;
228
  hashp->alignment = alignment;
229
  return hashp;
230
}
231
 
232
/* Create a new hash table.  */
233
 
234
static struct sec_merge_hash *
235
sec_merge_init (unsigned int entsize, bfd_boolean strings)
236
{
237
  struct sec_merge_hash *table;
238
 
239
  table = (struct sec_merge_hash *) bfd_malloc (sizeof (struct sec_merge_hash));
240
  if (table == NULL)
241
    return NULL;
242
 
243
  if (! bfd_hash_table_init_n (&table->table, sec_merge_hash_newfunc,
244
			       sizeof (struct sec_merge_hash_entry), 16699))
245
    {
246
      free (table);
247
      return NULL;
248
    }
249
 
250
  table->size = 0;
251
  table->first = NULL;
252
  table->last = NULL;
253
  table->entsize = entsize;
254
  table->strings = strings;
255
 
256
  return table;
257
}
258
 
259
/* Get the index of an entity in a hash table, adding it if it is not
260
   already present.  */
261
 
262
static struct sec_merge_hash_entry *
263
sec_merge_add (struct sec_merge_hash *tab, const char *str,
264
	       unsigned int alignment, struct sec_merge_sec_info *secinfo)
265
{
266
  struct sec_merge_hash_entry *entry;
267
 
268
  entry = sec_merge_hash_lookup (tab, str, alignment, TRUE);
269
  if (entry == NULL)
270
    return NULL;
271
 
272
  if (entry->secinfo == NULL)
273
    {
274
      tab->size++;
275
      entry->secinfo = secinfo;
276
      if (tab->first == NULL)
277
	tab->first = entry;
278
      else
279
	tab->last->next = entry;
280
      tab->last = entry;
281
    }
282
 
283
  return entry;
284
}
285
 
286
static bfd_boolean
287
sec_merge_emit (bfd *abfd, struct sec_merge_hash_entry *entry)
288
{
289
  struct sec_merge_sec_info *secinfo = entry->secinfo;
290
  asection *sec = secinfo->sec;
291
  char *pad = NULL;
292
  bfd_size_type off = 0;
293
  int alignment_power = sec->output_section->alignment_power;
294
 
295
  if (alignment_power)
296
    {
297
      pad = (char *) bfd_zmalloc ((bfd_size_type) 1 << alignment_power);
298
      if (pad == NULL)
299
	return FALSE;
300
    }
301
 
302
  for (; entry != NULL && entry->secinfo == secinfo; entry = entry->next)
303
    {
304
      const char *str;
305
      bfd_size_type len;
306
 
307
      len = -off & (entry->alignment - 1);
308
      if (len != 0)
309
	{
310
	  if (bfd_bwrite (pad, len, abfd) != len)
311
	    goto err;
312
	  off += len;
313
	}
314
 
315
      str = entry->root.string;
316
      len = entry->len;
317
 
318
      if (bfd_bwrite (str, len, abfd) != len)
319
	goto err;
320
 
321
      off += len;
322
    }
323
 
324
  /* Trailing alignment needed?  */
325
  off = sec->size - off;
326
  if (off != 0
327
      && bfd_bwrite (pad, off, abfd) != off)
328
    goto err;
329
 
330
  if (pad != NULL)
331
    free (pad);
332
  return TRUE;
333
 
334
 err:
335
  if (pad != NULL)
336
    free (pad);
337
  return FALSE;
338
}
339
 
340
/* Register a SEC_MERGE section as a candidate for merging.
341
   This function is called for all non-dynamic SEC_MERGE input sections.  */
342
 
343
bfd_boolean
344
_bfd_add_merge_section (bfd *abfd, void **psinfo, asection *sec,
345
			void **psecinfo)
346
{
347
  struct sec_merge_info *sinfo;
348
  struct sec_merge_sec_info *secinfo;
349
  unsigned int align;
350
  bfd_size_type amt;
351
  bfd_byte *contents;
352
 
353
  if ((abfd->flags & DYNAMIC) != 0
354
      || (sec->flags & SEC_MERGE) == 0)
355
    abort ();
356
 
357
  if (sec->size == 0
358
      || (sec->flags & SEC_EXCLUDE) != 0
359
      || sec->entsize == 0)
360
    return TRUE;
361
 
362
  if ((sec->flags & SEC_RELOC) != 0)
363
    {
364
      /* We aren't prepared to handle relocations in merged sections.  */
365
      return TRUE;
366
    }
367
 
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))))
374
    {
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;
382
    }
383
 
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;
391
 
392
  if (sinfo == NULL)
393
    {
394
      /* Initialize the information we need to keep track of.  */
395
      sinfo = (struct sec_merge_info *)
396
          bfd_alloc (abfd, sizeof (struct sec_merge_info));
397
      if (sinfo == NULL)
398
	goto error_return;
399
      sinfo->next = (struct sec_merge_info *) *psinfo;
400
      sinfo->chain = NULL;
401
      *psinfo = sinfo;
402
      sinfo->htab = sec_merge_init (sec->entsize, (sec->flags & SEC_STRINGS));
403
      if (sinfo->htab == NULL)
404
	goto error_return;
405
    }
406
 
407
  /* Read the section from abfd.  */
408
 
409
  amt = sizeof (struct sec_merge_sec_info) - 1 + sec->size;
410
  if (sec->flags & SEC_STRINGS)
411
    /* Some versions of gcc may emit a string without a zero terminator.
412
       See http://gcc.gnu.org/ml/gcc-patches/2006-06/msg01004.html
413
       Allocate space for an extra zero.  */
414
    amt += sec->entsize;
415
  *psecinfo = bfd_alloc (abfd, amt);
416
  if (*psecinfo == NULL)
417
    goto error_return;
418
 
419
  secinfo = (struct sec_merge_sec_info *) *psecinfo;
420
  if (sinfo->chain)
421
    {
422
      secinfo->next = sinfo->chain->next;
423
      sinfo->chain->next = secinfo;
424
    }
425
  else
426
    secinfo->next = secinfo;
427
  sinfo->chain = secinfo;
428
  secinfo->sec = sec;
429
  secinfo->psecinfo = psecinfo;
430
  secinfo->htab = sinfo->htab;
431
  secinfo->first_str = NULL;
432
 
433
  sec->rawsize = sec->size;
434
  if (sec->flags & SEC_STRINGS)
435
    memset (secinfo->contents + sec->size, 0, sec->entsize);
436
  contents = secinfo->contents;
437
  if (! bfd_get_full_section_contents (sec->owner, sec, &contents))
438
    goto error_return;
439
 
440
  return TRUE;
441
 
442
 error_return:
443
  *psecinfo = NULL;
444
  return FALSE;
445
}
446
 
447
/* Record one section into the hash table.  */
448
static bfd_boolean
449
record_section (struct sec_merge_info *sinfo,
450
		struct sec_merge_sec_info *secinfo)
451
{
452
  asection *sec = secinfo->sec;
453
  struct sec_merge_hash_entry *entry;
454
  bfd_boolean nul;
455
  unsigned char *p, *end;
456
  bfd_vma mask, eltalign;
457
  unsigned int align, i;
458
 
459
  align = sec->alignment_power;
460
  end = secinfo->contents + sec->size;
461
  nul = FALSE;
462
  mask = ((bfd_vma) 1 << align) - 1;
463
  if (sec->flags & SEC_STRINGS)
464
    {
465
      for (p = secinfo->contents; p < end; )
466
	{
467
	  eltalign = p - secinfo->contents;
468
	  eltalign = ((eltalign ^ (eltalign - 1)) + 1) >> 1;
469
	  if (!eltalign || eltalign > mask)
470
	    eltalign = mask + 1;
471
	  entry = sec_merge_add (sinfo->htab, (char *) p, (unsigned) eltalign,
472
				 secinfo);
473
	  if (! entry)
474
	    goto error_return;
475
	  p += entry->len;
476
	  if (sec->entsize == 1)
477
	    {
478
	      while (p < end && *p == 0)
479
		{
480
		  if (!nul && !((p - secinfo->contents) & mask))
481
		    {
482
		      nul = TRUE;
483
		      entry = sec_merge_add (sinfo->htab, "",
484
					     (unsigned) mask + 1, secinfo);
485
		      if (! entry)
486
			goto error_return;
487
		    }
488
		  p++;
489
		}
490
	    }
491
	  else
492
	    {
493
	      while (p < end)
494
		{
495
		  for (i = 0; i < sec->entsize; i++)
496
		    if (p[i] != '\0')
497
		      break;
498
		  if (i != sec->entsize)
499
		    break;
500
		  if (!nul && !((p - secinfo->contents) & mask))
501
		    {
502
		      nul = TRUE;
503
		      entry = sec_merge_add (sinfo->htab, (char *) p,
504
					     (unsigned) mask + 1, secinfo);
505
		      if (! entry)
506
			goto error_return;
507
		    }
508
		  p += sec->entsize;
509
		}
510
	    }
511
	}
512
    }
513
  else
514
    {
515
      for (p = secinfo->contents; p < end; p += sec->entsize)
516
	{
517
	  entry = sec_merge_add (sinfo->htab, (char *) p, 1, secinfo);
518
	  if (! entry)
519
	    goto error_return;
520
	}
521
    }
522
 
523
  return TRUE;
524
 
525
error_return:
526
  for (secinfo = sinfo->chain; secinfo; secinfo = secinfo->next)
527
    *secinfo->psecinfo = NULL;
528
  return FALSE;
529
}
530
 
531
static int
532
strrevcmp (const void *a, const void *b)
533
{
534
  struct sec_merge_hash_entry *A = *(struct sec_merge_hash_entry **) a;
535
  struct sec_merge_hash_entry *B = *(struct sec_merge_hash_entry **) b;
536
  unsigned int lenA = A->len;
537
  unsigned int lenB = B->len;
538
  const unsigned char *s = (const unsigned char *) A->root.string + lenA - 1;
539
  const unsigned char *t = (const unsigned char *) B->root.string + lenB - 1;
540
  int l = lenA < lenB ? lenA : lenB;
541
 
542
  while (l)
543
    {
544
      if (*s != *t)
545
	return (int) *s - (int) *t;
546
      s--;
547
      t--;
548
      l--;
549
    }
550
  return lenA - lenB;
551
}
552
 
553
/* Like strrevcmp, but for the case where all strings have the same
554
   alignment > entsize.  */
555
 
556
static int
557
strrevcmp_align (const void *a, const void *b)
558
{
559
  struct sec_merge_hash_entry *A = *(struct sec_merge_hash_entry **) a;
560
  struct sec_merge_hash_entry *B = *(struct sec_merge_hash_entry **) b;
561
  unsigned int lenA = A->len;
562
  unsigned int lenB = B->len;
563
  const unsigned char *s = (const unsigned char *) A->root.string + lenA - 1;
564
  const unsigned char *t = (const unsigned char *) B->root.string + lenB - 1;
565
  int l = lenA < lenB ? lenA : lenB;
566
  int tail_align = (lenA & (A->alignment - 1)) - (lenB & (A->alignment - 1));
567
 
568
  if (tail_align != 0)
569
    return tail_align;
570
 
571
  while (l)
572
    {
573
      if (*s != *t)
574
	return (int) *s - (int) *t;
575
      s--;
576
      t--;
577
      l--;
578
    }
579
  return lenA - lenB;
580
}
581
 
582
static inline int
583
is_suffix (const struct sec_merge_hash_entry *A,
584
	   const struct sec_merge_hash_entry *B)
585
{
586
  if (A->len <= B->len)
587
    /* B cannot be a suffix of A unless A is equal to B, which is guaranteed
588
       not to be equal by the hash table.  */
589
    return 0;
590
 
591
  return memcmp (A->root.string + (A->len - B->len),
592
		 B->root.string, B->len) == 0;
593
}
594
 
595
/* This is a helper function for _bfd_merge_sections.  It attempts to
596
   merge strings matching suffixes of longer strings.  */
597
static void
598
merge_strings (struct sec_merge_info *sinfo)
599
{
600
  struct sec_merge_hash_entry **array, **a, *e;
601
  struct sec_merge_sec_info *secinfo;
602
  bfd_size_type size, amt;
603
  unsigned int alignment = 0;
604
 
605
  /* Now sort the strings */
606
  amt = sinfo->htab->size * sizeof (struct sec_merge_hash_entry *);
607
  array = (struct sec_merge_hash_entry **) bfd_malloc (amt);
608
  if (array == NULL)
609
    goto alloc_failure;
610
 
611
  for (e = sinfo->htab->first, a = array; e; e = e->next)
612
    if (e->alignment)
613
      {
614
	*a++ = e;
615
	/* Adjust the length to not include the zero terminator.  */
616
	e->len -= sinfo->htab->entsize;
617
	if (alignment != e->alignment)
618
	  {
619
	    if (alignment == 0)
620
	      alignment = e->alignment;
621
	    else
622
	      alignment = (unsigned) -1;
623
	  }
624
      }
625
 
626
  sinfo->htab->size = a - array;
627
  if (sinfo->htab->size != 0)
628
    {
629
      qsort (array, (size_t) sinfo->htab->size,
630
	     sizeof (struct sec_merge_hash_entry *),
631
	     (alignment != (unsigned) -1 && alignment > sinfo->htab->entsize
632
	      ? strrevcmp_align : strrevcmp));
633
 
634
      /* Loop over the sorted array and merge suffixes */
635
      e = *--a;
636
      e->len += sinfo->htab->entsize;
637
      while (--a >= array)
638
	{
639
	  struct sec_merge_hash_entry *cmp = *a;
640
 
641
	  cmp->len += sinfo->htab->entsize;
642
	  if (e->alignment >= cmp->alignment
643
	      && !((e->len - cmp->len) & (cmp->alignment - 1))
644
	      && is_suffix (e, cmp))
645
	    {
646
	      cmp->u.suffix = e;
647
	      cmp->alignment = 0;
648
	    }
649
	  else
650
	    e = cmp;
651
	}
652
    }
653
 
654
alloc_failure:
655
  if (array)
656
    free (array);
657
 
658
  /* Now assign positions to the strings we want to keep.  */
659
  size = 0;
660
  secinfo = sinfo->htab->first->secinfo;
661
  for (e = sinfo->htab->first; e; e = e->next)
662
    {
663
      if (e->secinfo != secinfo)
664
	{
665
	  secinfo->sec->size = size;
666
	  secinfo = e->secinfo;
667
	}
668
      if (e->alignment)
669
	{
670
	  if (e->secinfo->first_str == NULL)
671
	    {
672
	      e->secinfo->first_str = e;
673
	      size = 0;
674
	    }
675
	  size = (size + e->alignment - 1) & ~((bfd_vma) e->alignment - 1);
676
	  e->u.index = size;
677
	  size += e->len;
678
	}
679
    }
680
  secinfo->sec->size = size;
681
  if (secinfo->sec->alignment_power != 0)
682
    {
683
      bfd_size_type align = (bfd_size_type) 1 << secinfo->sec->alignment_power;
684
      secinfo->sec->size = (secinfo->sec->size + align - 1) & -align;
685
    }
686
 
687
  /* And now adjust the rest, removing them from the chain (but not hashtable)
688
     at the same time.  */
689
  for (a = &sinfo->htab->first, e = *a; e; e = e->next)
690
    if (e->alignment)
691
      a = &e->next;
692
    else
693
      {
694
	*a = e->next;
695
	if (e->len)
696
	  {
697
	    e->secinfo = e->u.suffix->secinfo;
698
	    e->alignment = e->u.suffix->alignment;
699
	    e->u.index = e->u.suffix->u.index + (e->u.suffix->len - e->len);
700
	  }
701
      }
702
}
703
 
704
/* This function is called once after all SEC_MERGE sections are registered
705
   with _bfd_merge_section.  */
706
 
707
bfd_boolean
708
_bfd_merge_sections (bfd *abfd,
709
		     struct bfd_link_info *info ATTRIBUTE_UNUSED,
710
		     void *xsinfo,
711
		     void (*remove_hook) (bfd *, asection *))
712
{
713
  struct sec_merge_info *sinfo;
714
 
715
  for (sinfo = (struct sec_merge_info *) xsinfo; sinfo; sinfo = sinfo->next)
716
    {
717
      struct sec_merge_sec_info * secinfo;
718
 
719
      if (! sinfo->chain)
720
	continue;
721
 
722
      /* Move sinfo->chain to head of the chain, terminate it.  */
723
      secinfo = sinfo->chain;
724
      sinfo->chain = secinfo->next;
725
      secinfo->next = NULL;
726
 
727
      /* Record the sections into the hash table.  */
728
      for (secinfo = sinfo->chain; secinfo; secinfo = secinfo->next)
729
	if (secinfo->sec->flags & SEC_EXCLUDE)
730
	  {
731
	    *secinfo->psecinfo = NULL;
732
	    if (remove_hook)
733
	      (*remove_hook) (abfd, secinfo->sec);
734
	  }
735
	else if (! record_section (sinfo, secinfo))
736
	  break;
737
 
738
      if (secinfo)
739
	continue;
740
 
741
      if (sinfo->htab->first == NULL)
742
	continue;
743
 
744
      if (sinfo->htab->strings)
745
	merge_strings (sinfo);
746
      else
747
	{
748
	  struct sec_merge_hash_entry *e;
749
	  bfd_size_type size = 0;
750
 
751
	  /* Things are much simpler for non-strings.
752
	     Just assign them slots in the section.  */
753
	  secinfo = NULL;
754
	  for (e = sinfo->htab->first; e; e = e->next)
755
	    {
756
	      if (e->secinfo->first_str == NULL)
757
		{
758
		  if (secinfo)
759
		    secinfo->sec->size = size;
760
		  e->secinfo->first_str = e;
761
		  size = 0;
762
		}
763
	      size = (size + e->alignment - 1)
764
		     & ~((bfd_vma) e->alignment - 1);
765
	      e->u.index = size;
766
	      size += e->len;
767
	      secinfo = e->secinfo;
768
	    }
769
	  secinfo->sec->size = size;
770
	}
771
 
772
	/* Finally remove all input sections which have not made it into
773
	   the hash table at all.  */
774
	for (secinfo = sinfo->chain; secinfo; secinfo = secinfo->next)
775
	  if (secinfo->first_str == NULL)
776
	    secinfo->sec->flags |= SEC_EXCLUDE | SEC_KEEP;
777
    }
778
 
779
  return TRUE;
780
}
781
 
782
/* Write out the merged section.  */
783
 
784
bfd_boolean
785
_bfd_write_merged_section (bfd *output_bfd, asection *sec, void *psecinfo)
786
{
787
  struct sec_merge_sec_info *secinfo;
788
  file_ptr pos;
789
 
790
  secinfo = (struct sec_merge_sec_info *) psecinfo;
791
 
792
  if (!secinfo)
793
    return FALSE;
794
 
795
  if (secinfo->first_str == NULL)
796
    return TRUE;
797
 
798
  /* FIXME: octets_per_byte.  */
799
  pos = sec->output_section->filepos + sec->output_offset;
800
  if (bfd_seek (output_bfd, pos, SEEK_SET) != 0)
801
    return FALSE;
802
 
803
  if (! sec_merge_emit (output_bfd, secinfo->first_str))
804
    return FALSE;
805
 
806
  return TRUE;
807
}
808
 
809
/* Adjust an address in the SEC_MERGE section.  Given OFFSET within
810
   *PSEC, this returns the new offset in the adjusted SEC_MERGE
811
   section and writes the new section back into *PSEC.  */
812
 
813
bfd_vma
814
_bfd_merged_section_offset (bfd *output_bfd ATTRIBUTE_UNUSED, asection **psec,
815
			    void *psecinfo, bfd_vma offset)
816
{
817
  struct sec_merge_sec_info *secinfo;
818
  struct sec_merge_hash_entry *entry;
819
  unsigned char *p;
820
  asection *sec = *psec;
821
 
822
  secinfo = (struct sec_merge_sec_info *) psecinfo;
823
 
824
  if (!secinfo)
825
    return offset;
826
 
827
  if (offset >= sec->rawsize)
828
    {
829
      if (offset > sec->rawsize)
830
	{
831
	  (*_bfd_error_handler)
832
	    (_("%s: access beyond end of merged section (%ld)"),
833
	     bfd_get_filename (sec->owner), (long) offset);
834
	}
835
      return secinfo->first_str ? sec->size : 0;
836
    }
837
 
838
  if (secinfo->htab->strings)
839
    {
840
      if (sec->entsize == 1)
841
	{
842
	  p = secinfo->contents + offset - 1;
843
	  while (p >= secinfo->contents && *p)
844
	    --p;
845
	  ++p;
846
	}
847
      else
848
	{
849
	  p = secinfo->contents + (offset / sec->entsize) * sec->entsize;
850
	  p -= sec->entsize;
851
	  while (p >= secinfo->contents)
852
	    {
853
	      unsigned int i;
854
 
855
	      for (i = 0; i < sec->entsize; ++i)
856
		if (p[i] != '\0')
857
		  break;
858
	      if (i == sec->entsize)
859
		break;
860
	      p -= sec->entsize;
861
	    }
862
	  p += sec->entsize;
863
	}
864
    }
865
  else
866
    {
867
      p = secinfo->contents + (offset / sec->entsize) * sec->entsize;
868
    }
869
  entry = sec_merge_hash_lookup (secinfo->htab, (char *) p, 0, FALSE);
870
  if (!entry)
871
    {
872
      if (! secinfo->htab->strings)
873
	abort ();
874
      /* This should only happen if somebody points into the padding
875
	 after a NUL character but before next entity.  */
876
      if (*p)
877
	abort ();
878
      if (! secinfo->htab->first)
879
	abort ();
880
      entry = secinfo->htab->first;
881
      p = (secinfo->contents + (offset / sec->entsize + 1) * sec->entsize
882
	   - entry->len);
883
    }
884
 
885
  *psec = entry->secinfo->sec;
886
  return entry->u.index + (secinfo->contents + offset - p);
887
}
888
 
889
/* Tidy up when done.  */
890
 
891
void
892
_bfd_merge_sections_free (void *xsinfo)
893
{
894
  struct sec_merge_info *sinfo;
895
 
896
  for (sinfo = (struct sec_merge_info *) xsinfo; sinfo; sinfo = sinfo->next)
897
    {
898
      bfd_hash_table_free (&sinfo->htab->table);
899
      free (sinfo->htab);
900
    }
901
}