aboutsummaryrefslogtreecommitdiff
path: root/gold/object.cc
blob: 8f1241ad879612b4d9d414449a15e2eb3c0f021e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
// object.cc -- support for an object file for linking in gold

#include "gold.h"

#include <cerrno>
#include <cstring>
#include <cassert>

#include "object.h"
#include "target-select.h"
#include "layout.h"
#include "output.h"

namespace gold
{

// Class Object.

const unsigned char*
Object::get_view(off_t start, off_t size)
{
  return this->input_file_->file().get_view(start + this->offset_, size);
}

void
Object::read(off_t start, off_t size, void* p)
{
  this->input_file_->file().read(start + this->offset_, size, p);
}

File_view*
Object::get_lasting_view(off_t start, off_t size)
{
  return this->input_file_->file().get_lasting_view(start + this->offset_,
						    size);
}

// Class Sized_object.

template<int size, bool big_endian>
Sized_object<size, big_endian>::Sized_object(
    const std::string& name,
    Input_file* input_file,
    off_t offset,
    const elfcpp::Ehdr<size, big_endian>& ehdr)
  : Object(name, input_file, false, offset),
    section_headers_(NULL),
    flags_(ehdr.get_e_flags()),
    shoff_(ehdr.get_e_shoff()),
    shstrndx_(0),
    symtab_shnum_(0),
    local_symbol_count_(0),
    output_local_symbol_count_(0),
    symbols_(NULL),
    local_symbol_offset_(0),
    values_(NULL)
{
  if (ehdr.get_e_ehsize() != This::ehdr_size)
    {
      fprintf(stderr, _("%s: %s: bad e_ehsize field (%d != %d)\n"),
	      program_name, this->name().c_str(), ehdr.get_e_ehsize(),
	      This::ehdr_size);
      gold_exit(false);
    }
  if (ehdr.get_e_shentsize() != This::shdr_size)
    {
      fprintf(stderr, _("%s: %s: bad e_shentsize field (%d != %d)\n"),
	      program_name, this->name().c_str(), ehdr.get_e_shentsize(),
	      This::shdr_size);
      gold_exit(false);
    }
}

template<int size, bool big_endian>
Sized_object<size, big_endian>::~Sized_object()
{
}

// Read the section header for section SHNUM.

template<int size, bool big_endian>
const unsigned char*
Sized_object<size, big_endian>::section_header(unsigned int shnum)
{
  assert(shnum < this->shnum());
  off_t symtabshdroff = this->shoff_ + shnum * This::shdr_size;
  return this->get_view(symtabshdroff, This::shdr_size);
}

// Set up an object file bsaed on the file header.  This sets up the
// target and reads the section information.

template<int size, bool big_endian>
void
Sized_object<size, big_endian>::setup(
    const elfcpp::Ehdr<size, big_endian>& ehdr)
{
  int machine = ehdr.get_e_machine();
  Target* target = select_target(machine, size, big_endian,
				 ehdr.get_e_ident()[elfcpp::EI_OSABI],
				 ehdr.get_e_ident()[elfcpp::EI_ABIVERSION]);
  if (target == NULL)
    {
      fprintf(stderr, _("%s: %s: unsupported ELF machine number %d\n"),
	      program_name, this->name().c_str(), machine);
      gold_exit(false);
    }
  this->set_target(target);

  unsigned int shnum = ehdr.get_e_shnum();
  unsigned int shstrndx = ehdr.get_e_shstrndx();
  if ((shnum == 0 || shstrndx == elfcpp::SHN_XINDEX)
      && this->shoff_ != 0)
    {
      typename This::Shdr shdr(this->section_header(0));
      if (shnum == 0)
	shnum = shdr.get_sh_size();
      if (shstrndx == elfcpp::SHN_XINDEX)
	shstrndx = shdr.get_sh_link();
    }
  this->set_shnum(shnum);
  this->shstrndx_ = shstrndx;

  if (shnum == 0)
    return;

  // We store the section headers in a File_view until do_read_symbols.
  this->section_headers_ = this->get_lasting_view(this->shoff_,
						  shnum * This::shdr_size);

  // Find the SHT_SYMTAB section.  The ELF standard says that maybe in
  // the future there can be more than one SHT_SYMTAB section.  Until
  // somebody figures out how that could work, we assume there is only
  // one.
  const unsigned char* p = this->section_headers_->data();

  // Skip the first section, which is always empty.
  p += This::shdr_size;
  for (unsigned int i = 1; i < shnum; ++i, p += This::shdr_size)
    {
      typename This::Shdr shdr(p);
      if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB)
	{
	  this->symtab_shnum_ = i;
	  break;
	}
    }
}

// Read the sections and symbols from an object file.

template<int size, bool big_endian>
void
Sized_object<size, big_endian>::do_read_symbols(Read_symbols_data* sd)
{
  // Transfer our view of the section headers to SD.
  sd->section_headers = this->section_headers_;
  this->section_headers_ = NULL;

  // Read the section names.
  const unsigned char* pshdrs = sd->section_headers->data();
  const unsigned char* pshdrnames = pshdrs + this->shstrndx_ * This::shdr_size;
  typename This::Shdr shdrnames(pshdrnames);
  sd->section_names_size = shdrnames.get_sh_size();
  sd->section_names = this->get_lasting_view(shdrnames.get_sh_offset(),
					     sd->section_names_size);

  if (this->symtab_shnum_ == 0)
    {
      // No symbol table.  Weird but legal.
      sd->symbols = NULL;
      sd->symbols_size = 0;
      sd->symbol_names = NULL;
      sd->symbol_names_size = 0;
      return;
    }

  // Get the symbol table section header.
  typename This::Shdr symtabshdr(pshdrs
				 + this->symtab_shnum_ * This::shdr_size);
  assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);

  // We only need the external symbols.
  const int sym_size = This::sym_size;
  off_t locsize = symtabshdr.get_sh_info() * sym_size;
  off_t extoff = symtabshdr.get_sh_offset() + locsize;
  off_t extsize = symtabshdr.get_sh_size() - locsize;

  // Read the symbol table.
  File_view* fvsymtab = this->get_lasting_view(extoff, extsize);

  // Read the section header for the symbol names.
  unsigned int strtab_shnum = symtabshdr.get_sh_link();
  if (strtab_shnum == 0 || strtab_shnum >= this->shnum())
    {
      fprintf(stderr, _("%s: %s: invalid symbol table name index: %u\n"),
	      program_name, this->name().c_str(), strtab_shnum);
      gold_exit(false);
    }
  typename This::Shdr strtabshdr(this->section_header(strtab_shnum));
  if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
    {
      fprintf(stderr,
	      _("%s: %s: symbol table name section has wrong type: %u\n"),
	      program_name, this->name().c_str(),
	      static_cast<unsigned int>(strtabshdr.get_sh_type()));
      gold_exit(false);
    }

  // Read the symbol names.
  File_view* fvstrtab = this->get_lasting_view(strtabshdr.get_sh_offset(),
					       strtabshdr.get_sh_size());

  sd->symbols = fvsymtab;
  sd->symbols_size = extsize;
  sd->symbol_names = fvstrtab;
  sd->symbol_names_size = strtabshdr.get_sh_size();
}

// Return whether to include a section group in the link.  LAYOUT is
// used to keep track of which section groups we have already seen.
// INDEX is the index of the section group and SHDR is the section
// header.  If we do not want to include this group, we set bits in
// OMIT for each section which should be discarded.

template<int size, bool big_endian>
bool
Sized_object<size, big_endian>::include_section_group(
    Layout* layout,
    unsigned int index,
    const elfcpp::Shdr<size, big_endian>& shdr,
    std::vector<bool>* omit)
{
  // Read the section contents.
  const unsigned char* pcon = this->get_view(shdr.get_sh_offset(),
					     shdr.get_sh_size());
  const elfcpp::Elf_Word* pword =
    reinterpret_cast<const elfcpp::Elf_Word*>(pcon);

  // The first word contains flags.  We only care about COMDAT section
  // groups.  Other section groups are always included in the link
  // just like ordinary sections.
  elfcpp::Elf_Word flags = elfcpp::read_elf_word<big_endian>(pword);
  if ((flags & elfcpp::GRP_COMDAT) == 0)
    return true;

  // Look up the group signature, which is the name of a symbol.  This
  // is a lot of effort to go to to read a string.  Why didn't they
  // just use the name of the SHT_GROUP section as the group
  // signature?

  // Get the appropriate symbol table header (this will normally be
  // the single SHT_SYMTAB section, but in principle it need not be).
  if (shdr.get_sh_link() >= this->shnum())
    {
      fprintf(stderr, _("%s: %s: section group %u link %u out of range\n"),
	      program_name, this->name().c_str(), index, shdr.get_sh_link());
      gold_exit(false);
    }

  typename This::Shdr symshdr(this->section_header(shdr.get_sh_link()));

  // Read the symbol table entry.
  if (shdr.get_sh_info() >= symshdr.get_sh_size() / This::sym_size)
    {
      fprintf(stderr, _("%s: %s: section group %u info %u out of range\n"),
	      program_name, this->name().c_str(), index, shdr.get_sh_info());
      gold_exit(false);
    }
  off_t symoff = symshdr.get_sh_offset() + shdr.get_sh_info() * This::sym_size;
  const unsigned char* psym = this->get_view(symoff, This::sym_size);
  elfcpp::Sym<size, big_endian> sym(psym);

  // Read the section header for the symbol table names.
  if (symshdr.get_sh_link() >= this->shnum())
    {
      fprintf(stderr, _("%s; %s: symtab section %u link %u out of range\n"),
	      program_name, this->name().c_str(), shdr.get_sh_link(),
	      symshdr.get_sh_link());
      gold_exit(false);
    }

  typename This::Shdr symnamehdr(this->section_header(symshdr.get_sh_link()));

  // Read the symbol table names.
  const unsigned char *psymnamesu = this->get_view(symnamehdr.get_sh_offset(),
						   symnamehdr.get_sh_size());
  const char* psymnames = reinterpret_cast<const char*>(psymnamesu);

  // Get the section group signature.
  if (sym.get_st_name() >= symnamehdr.get_sh_size())
    {
      fprintf(stderr, _("%s: %s: symbol %u name offset %u out of range\n"),
	      program_name, this->name().c_str(), shdr.get_sh_info(),
	      sym.get_st_name());
      gold_exit(false);
    }

  const char* signature = psymnames + sym.get_st_name();

  // Record this section group, and see whether we've already seen one
  // with the same signature.
  if (layout->add_comdat(signature, true))
    return true;

  // This is a duplicate.  We want to discard the sections in this
  // group.
  size_t count = shdr.get_sh_size() / sizeof(elfcpp::Elf_Word);
  for (size_t i = 1; i < count; ++i)
    {
      elfcpp::Elf_Word secnum = elfcpp::read_elf_word<big_endian>(pword + i);
      if (secnum >= this->shnum())
	{
	  fprintf(stderr,
		  _("%s: %s: section %u in section group %u out of range"),
		  program_name, this->name().c_str(), secnum,
		  index);
	  gold_exit(false);
	}
      (*omit)[secnum] = true;
    }

  return false;
}

// Whether to include a linkonce section in the link.  NAME is the
// name of the section and SHDR is the section header.

// Linkonce sections are a GNU extension implemented in the original
// GNU linker before section groups were defined.  The semantics are
// that we only include one linkonce section with a given name.  The
// name of a linkonce section is normally .gnu.linkonce.T.SYMNAME,
// where T is the type of section and SYMNAME is the name of a symbol.
// In an attempt to make linkonce sections interact well with section
// groups, we try to identify SYMNAME and use it like a section group
// signature.  We want to block section groups with that signature,
// but not other linkonce sections with that signature.  We also use
// the full name of the linkonce section as a normal section group
// signature.

template<int size, bool big_endian>
bool
Sized_object<size, big_endian>::include_linkonce_section(
    Layout* layout,
    const char* name,
    const elfcpp::Shdr<size, big_endian>&)
{
  const char* symname = strrchr(name, '.') + 1;
  bool include1 = layout->add_comdat(symname, false);
  bool include2 = layout->add_comdat(name, true);
  return include1 && include2;
}

// Lay out the input sections.  We walk through the sections and check
// whether they should be included in the link.  If they should, we
// pass them to the Layout object, which will return an output section
// and an offset.

template<int size, bool big_endian>
void
Sized_object<size, big_endian>::do_layout(Layout* layout,
					  Read_symbols_data* sd)
{
  unsigned int shnum = this->shnum();
  if (shnum == 0)
    return;

  // Get the section headers.
  const unsigned char* pshdrs = sd->section_headers->data();

  // Get the section names.
  const unsigned char* pnamesu = sd->section_names->data();
  const char* pnames = reinterpret_cast<const char*>(pnamesu);

  std::vector<Map_to_output>& map_sections(this->map_to_output());
  map_sections.resize(shnum);

  // Keep track of which sections to omit.
  std::vector<bool> omit(shnum, false);

  for (unsigned int i = 0; i < shnum; ++i, pshdrs += This::shdr_size)
    {
      typename This::Shdr shdr(pshdrs);

      if (shdr.get_sh_name() >= sd->section_names_size)
	{
	  fprintf(stderr,
		  _("%s: %s: bad section name offset for section %u: %lu\n"),
		  program_name, this->name().c_str(), i,
		  static_cast<unsigned long>(shdr.get_sh_name()));
	  gold_exit(false);
	}

      const char* name = pnames + shdr.get_sh_name();

      bool discard = omit[i];
      if (!discard)
	{
	  if (shdr.get_sh_type() == elfcpp::SHT_GROUP)
	    {
	      if (!this->include_section_group(layout, i, shdr, &omit))
		discard = true;
	    }
	  else if (Layout::is_linkonce(name))
	    {
	      if (!this->include_linkonce_section(layout, name, shdr))
		discard = true;
	    }
	}

      if (discard)
	{
	  // Do not include this section in the link.
	  map_sections[i].output_section = NULL;
	  continue;
	}

      off_t offset;
      Output_section* os = layout->layout(this, name, shdr, &offset);

      map_sections[i].output_section = os;
      map_sections[i].offset = offset;
    }

  delete sd->section_headers;
  sd->section_headers = NULL;
  delete sd->section_names;
  sd->section_names = NULL;
}

// Add the symbols to the symbol table.

template<int size, bool big_endian>
void
Sized_object<size, big_endian>::do_add_symbols(Symbol_table* symtab,
					       Read_symbols_data* sd)
{
  if (sd->symbols == NULL)
    {
      assert(sd->symbol_names == NULL);
      return;
    }

  const int sym_size = This::sym_size;
  size_t symcount = sd->symbols_size / sym_size;
  if (symcount * sym_size != sd->symbols_size)
    {
      fprintf(stderr,
	      _("%s: %s: size of symbols is not multiple of symbol size\n"),
	      program_name, this->name().c_str());
      gold_exit(false);
    }

  this->symbols_ = new Symbol*[symcount];

  const unsigned char* psyms = sd->symbols->data();
  const elfcpp::Sym<size, big_endian>* syms =
    reinterpret_cast<const elfcpp::Sym<size, big_endian>*>(psyms);
  const char* sym_names =
    reinterpret_cast<const char*>(sd->symbol_names->data());
  symtab->add_from_object(this, syms, symcount, sym_names, 
			  sd->symbol_names_size,  this->symbols_);

  delete sd->symbols;
  sd->symbols = NULL;
  delete sd->symbol_names;
  sd->symbol_names = NULL;
}

// Finalize the local symbols.  Here we record the file offset at
// which they should be output, we add their names to *POOL, and we
// add their values to THIS->VALUES_.  Return the new file offset.
// This function is always called from the main thread.  The actual
// output of the local symbols will occur in a separate task.

template<int size, bool big_endian>
off_t
Sized_object<size, big_endian>::do_finalize_local_symbols(off_t off,
							  Stringpool* pool)
{
  if (this->symtab_shnum_ == 0)
    {
      // This object has no symbols.  Weird but legal.
      return off;
    }

  off = (off + (size >> 3) - 1) & ~ ((off_t) (size >> 3) - 1);

  this->local_symbol_offset_ = off;

  // Read the symbol table section header.
  typename This::Shdr symtabshdr(this->section_header(this->symtab_shnum_));
  assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);

  // Read the local symbols.
  unsigned int loccount = symtabshdr.get_sh_info();
  const int sym_size = This::sym_size;
  off_t locsize = loccount * sym_size;
  const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
					      locsize);

  this->local_symbol_count_ = loccount;

  this->values_ = new typename elfcpp::Elf_types<size>::Elf_Addr[loccount];

  // Read the section header for the symbol names.
  typename This::Shdr strtabshdr(
    this->section_header(symtabshdr.get_sh_link()));
  assert(strtabshdr.get_sh_type() == elfcpp::SHT_STRTAB);

  // Read the symbol names.
  const unsigned char* pnamesu = this->get_view(strtabshdr.get_sh_offset(),
						strtabshdr.get_sh_size());
  const char* pnames = reinterpret_cast<const char*>(pnamesu);

  // Loop over the local symbols.

  std::vector<Map_to_output>& mo(this->map_to_output());
  unsigned int shnum = this->shnum();
  unsigned int count = 0;
  // Skip the first, dummy, symbol.
  psyms += sym_size;
  for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
    {
      elfcpp::Sym<size, big_endian> sym(psyms);

      unsigned int shndx = sym.get_st_shndx();

      if (shndx >= elfcpp::SHN_LORESERVE)
	{
	  if (shndx == elfcpp::SHN_ABS)
	    this->values_[i] = sym.get_st_value();
	  else
	    {
	      // FIXME: Handle SHN_XINDEX.
	      fprintf(stderr,
		      _("%s: %s: unknown section index %u "
			"for local symbol %u\n"),
		      program_name, this->name().c_str(), shndx, i);
	      gold_exit(false);
	    }
	}
      else
	{
	  if (shndx >= shnum)
	    {
	      fprintf(stderr,
		      _("%s: %s: local symbol %u section index %u "
			"out of range\n"),
		      program_name, this->name().c_str(), i, shndx);
	      gold_exit(false);
	    }

	  if (mo[shndx].output_section == NULL)
	    {
	      this->values_[i] = 0;
	      continue;
	    }

	  this->values_[i] = (mo[shndx].output_section->address()
			      + sym.get_st_value());
	}

      pool->add(pnames + sym.get_st_name());
      off += sym_size;
      ++count;
    }

  this->output_local_symbol_count_ = count;

  return off;
}

// Write out the local symbols.

template<int size, bool big_endian>
void
Sized_object<size, big_endian>::write_local_symbols(Output_file* of,
						    const Stringpool* sympool)
{
  if (this->symtab_shnum_ == 0)
    {
      // This object has no symbols.  Weird but legal.
      return;
    }

  // Read the symbol table section header.
  typename This::Shdr symtabshdr(this->section_header(this->symtab_shnum_));
  assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
  unsigned int local_symbol_count = this->local_symbol_count_;
  assert(local_symbol_count == symtabshdr.get_sh_info());

  // Read the local symbols.
  const int sym_size = This::sym_size;
  off_t locsize = local_symbol_count * sym_size;
  const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
					      locsize);

  // Read the section header for the symbol names.
  typename This::Shdr strtabshdr(
    this->section_header(symtabshdr.get_sh_link()));
  assert(strtabshdr.get_sh_type() == elfcpp::SHT_STRTAB);

  // Read the symbol names.
  const unsigned char* pnamesu = this->get_view(strtabshdr.get_sh_offset(),
						strtabshdr.get_sh_size());
  const char* pnames = reinterpret_cast<const char*>(pnamesu);

  // Get a view into the output file.
  off_t output_size = this->output_local_symbol_count_ * sym_size;
  unsigned char* oview = of->get_output_view(this->local_symbol_offset_,
					     output_size);

  std::vector<Map_to_output>& mo(this->map_to_output());

  psyms += sym_size;
  unsigned char* ov = oview;
  for (unsigned int i = 1; i < local_symbol_count; ++i, psyms += sym_size)
    {
      elfcpp::Sym<size, big_endian> isym(psyms);
      elfcpp::Sym_write<size, big_endian> osym(ov);

      unsigned int st_shndx = isym.get_st_shndx();
      if (st_shndx < elfcpp::SHN_LORESERVE)
	{
	  assert(st_shndx < mo.size());
	  if (mo[st_shndx].output_section == NULL)
	    continue;
	  st_shndx = mo[st_shndx].output_section->shndx();
	}

      osym.put_st_name(sympool->get_offset(pnames + isym.get_st_name()));
      osym.put_st_value(this->values_[i]);
      osym.put_st_size(isym.get_st_size());
      osym.put_st_info(isym.get_st_info());
      osym.put_st_other(isym.get_st_other());
      osym.put_st_shndx(st_shndx);

      ov += sym_size;
    }

  assert(ov - oview == output_size);

  of->write_output_view(this->local_symbol_offset_, output_size, oview);
}

// Input_objects methods.

void
Input_objects::add_object(Object* obj)
{
  this->object_list_.push_back(obj);

  Target* target = obj->target();
  if (this->target_ == NULL)
    this->target_ = target;
  else if (this->target_ != target)
    {
      fprintf(stderr, "%s: %s: incompatible target\n",
	      program_name, obj->name().c_str());
      gold_exit(false);
    }

  if (obj->is_dynamic())
    this->any_dynamic_ = true;
}

} // End namespace gold.

namespace
{

using namespace gold;

// Read an ELF file with the header and return the appropriate
// instance of Object.

template<int size, bool big_endian>
Object*
make_elf_sized_object(const std::string& name, Input_file* input_file,
		      off_t offset, const elfcpp::Ehdr<size, big_endian>& ehdr)
{
  int et = ehdr.get_e_type();
  if (et != elfcpp::ET_REL && et != elfcpp::ET_DYN)
    {
      fprintf(stderr, "%s: %s: unsupported ELF type %d\n",
	      program_name, name.c_str(), static_cast<int>(et));
      gold_exit(false);
    }

  if (et == elfcpp::ET_REL)
    {
      Sized_object<size, big_endian>* obj =
	new Sized_object<size, big_endian>(name, input_file, offset, ehdr);
      obj->setup(ehdr);
      return obj;
    }
  else
    {
      // elfcpp::ET_DYN
      fprintf(stderr, _("%s: %s: dynamic objects are not yet supported\n"),
	      program_name, name.c_str());
      gold_exit(false);
//       Sized_dynobj<size, big_endian>* obj =
// 	new Sized_dynobj<size, big_endian>(this->input_.name(), input_file,
// 					   offset, ehdr);
//       obj->setup(ehdr);
//       return obj;
    }
}

} // End anonymous namespace.

namespace gold
{

// Read an ELF file and return the appropriate instance of Object.

Object*
make_elf_object(const std::string& name, Input_file* input_file, off_t offset,
		const unsigned char* p, off_t bytes)
{
  if (bytes < elfcpp::EI_NIDENT)
    {
      fprintf(stderr, _("%s: %s: ELF file too short\n"),
	      program_name, name.c_str());
      gold_exit(false);
    }

  int v = p[elfcpp::EI_VERSION];
  if (v != elfcpp::EV_CURRENT)
    {
      if (v == elfcpp::EV_NONE)
	fprintf(stderr, _("%s: %s: invalid ELF version 0\n"),
		program_name, name.c_str());
      else
	fprintf(stderr, _("%s: %s: unsupported ELF version %d\n"),
		program_name, name.c_str(), v);
      gold_exit(false);
    }

  int c = p[elfcpp::EI_CLASS];
  if (c == elfcpp::ELFCLASSNONE)
    {
      fprintf(stderr, _("%s: %s: invalid ELF class 0\n"),
	      program_name, name.c_str());
      gold_exit(false);
    }
  else if (c != elfcpp::ELFCLASS32
	   && c != elfcpp::ELFCLASS64)
    {
      fprintf(stderr, _("%s: %s: unsupported ELF class %d\n"),
	      program_name, name.c_str(), c);
      gold_exit(false);
    }

  int d = p[elfcpp::EI_DATA];
  if (d == elfcpp::ELFDATANONE)
    {
      fprintf(stderr, _("%s: %s: invalid ELF data encoding\n"),
	      program_name, name.c_str());
      gold_exit(false);
    }
  else if (d != elfcpp::ELFDATA2LSB
	   && d != elfcpp::ELFDATA2MSB)
    {
      fprintf(stderr, _("%s: %s: unsupported ELF data encoding %d\n"),
	      program_name, name.c_str(), d);
      gold_exit(false);
    }

  bool big_endian = d == elfcpp::ELFDATA2MSB;

  if (c == elfcpp::ELFCLASS32)
    {
      if (bytes < elfcpp::Elf_sizes<32>::ehdr_size)
	{
	  fprintf(stderr, _("%s: %s: ELF file too short\n"),
		  program_name, name.c_str());
	  gold_exit(false);
	}
      if (big_endian)
	{
	  elfcpp::Ehdr<32, true> ehdr(p);
	  return make_elf_sized_object<32, true>(name, input_file,
						 offset, ehdr);
	}
      else
	{
	  elfcpp::Ehdr<32, false> ehdr(p);
	  return make_elf_sized_object<32, false>(name, input_file,
						  offset, ehdr);
	}
    }
  else
    {
      if (bytes < elfcpp::Elf_sizes<32>::ehdr_size)
	{
	  fprintf(stderr, _("%s: %s: ELF file too short\n"),
		  program_name, name.c_str());
	  gold_exit(false);
	}
      if (big_endian)
	{
	  elfcpp::Ehdr<64, true> ehdr(p);
	  return make_elf_sized_object<64, true>(name, input_file,
						 offset, ehdr);
	}
      else
	{
	  elfcpp::Ehdr<64, false> ehdr(p);
	  return make_elf_sized_object<64, false>(name, input_file,
						  offset, ehdr);
	}
    }
}

// Instantiate the templates we need.  We could use the configure
// script to restrict this to only the ones for implemented targets.

template
class Sized_object<32, false>;

template
class Sized_object<32, true>;

template
class Sized_object<64, false>;

template
class Sized_object<64, true>;

} // End namespace gold.