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[/] [openrisc/] [trunk/] [gnu-stable/] [binutils-2.20.1/] [gold/] [object.cc] - Blame information for rev 853

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1 205 julius
// object.cc -- support for an object file for linking in gold
2
 
3
// Copyright 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
4
// Written by Ian Lance Taylor <iant@google.com>.
5
 
6
// This file is part of gold.
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
#include "gold.h"
24
 
25
#include <cerrno>
26
#include <cstring>
27
#include <cstdarg>
28
#include "demangle.h"
29
#include "libiberty.h"
30
 
31
#include "gc.h"
32
#include "target-select.h"
33
#include "dwarf_reader.h"
34
#include "layout.h"
35
#include "output.h"
36
#include "symtab.h"
37
#include "cref.h"
38
#include "reloc.h"
39
#include "object.h"
40
#include "dynobj.h"
41
#include "plugin.h"
42
 
43
namespace gold
44
{
45
 
46
// Class Xindex.
47
 
48
// Initialize the symtab_xindex_ array.  Find the SHT_SYMTAB_SHNDX
49
// section and read it in.  SYMTAB_SHNDX is the index of the symbol
50
// table we care about.
51
 
52
template<int size, bool big_endian>
53
void
54
Xindex::initialize_symtab_xindex(Object* object, unsigned int symtab_shndx)
55
{
56
  if (!this->symtab_xindex_.empty())
57
    return;
58
 
59
  gold_assert(symtab_shndx != 0);
60
 
61
  // Look through the sections in reverse order, on the theory that it
62
  // is more likely to be near the end than the beginning.
63
  unsigned int i = object->shnum();
64
  while (i > 0)
65
    {
66
      --i;
67
      if (object->section_type(i) == elfcpp::SHT_SYMTAB_SHNDX
68
          && this->adjust_shndx(object->section_link(i)) == symtab_shndx)
69
        {
70
          this->read_symtab_xindex<size, big_endian>(object, i, NULL);
71
          return;
72
        }
73
    }
74
 
75
  object->error(_("missing SHT_SYMTAB_SHNDX section"));
76
}
77
 
78
// Read in the symtab_xindex_ array, given the section index of the
79
// SHT_SYMTAB_SHNDX section.  If PSHDRS is not NULL, it points at the
80
// section headers.
81
 
82
template<int size, bool big_endian>
83
void
84
Xindex::read_symtab_xindex(Object* object, unsigned int xindex_shndx,
85
                           const unsigned char* pshdrs)
86
{
87
  section_size_type bytecount;
88
  const unsigned char* contents;
89
  if (pshdrs == NULL)
90
    contents = object->section_contents(xindex_shndx, &bytecount, false);
91
  else
92
    {
93
      const unsigned char* p = (pshdrs
94
                                + (xindex_shndx
95
                                   * elfcpp::Elf_sizes<size>::shdr_size));
96
      typename elfcpp::Shdr<size, big_endian> shdr(p);
97
      bytecount = convert_to_section_size_type(shdr.get_sh_size());
98
      contents = object->get_view(shdr.get_sh_offset(), bytecount, true, false);
99
    }
100
 
101
  gold_assert(this->symtab_xindex_.empty());
102
  this->symtab_xindex_.reserve(bytecount / 4);
103
  for (section_size_type i = 0; i < bytecount; i += 4)
104
    {
105
      unsigned int shndx = elfcpp::Swap<32, big_endian>::readval(contents + i);
106
      // We preadjust the section indexes we save.
107
      this->symtab_xindex_.push_back(this->adjust_shndx(shndx));
108
    }
109
}
110
 
111
// Symbol symndx has a section of SHN_XINDEX; return the real section
112
// index.
113
 
114
unsigned int
115
Xindex::sym_xindex_to_shndx(Object* object, unsigned int symndx)
116
{
117
  if (symndx >= this->symtab_xindex_.size())
118
    {
119
      object->error(_("symbol %u out of range for SHT_SYMTAB_SHNDX section"),
120
                    symndx);
121
      return elfcpp::SHN_UNDEF;
122
    }
123
  unsigned int shndx = this->symtab_xindex_[symndx];
124
  if (shndx < elfcpp::SHN_LORESERVE || shndx >= object->shnum())
125
    {
126
      object->error(_("extended index for symbol %u out of range: %u"),
127
                    symndx, shndx);
128
      return elfcpp::SHN_UNDEF;
129
    }
130
  return shndx;
131
}
132
 
133
// Class Object.
134
 
135
// Report an error for this object file.  This is used by the
136
// elfcpp::Elf_file interface, and also called by the Object code
137
// itself.
138
 
139
void
140
Object::error(const char* format, ...) const
141
{
142
  va_list args;
143
  va_start(args, format);
144
  char* buf = NULL;
145
  if (vasprintf(&buf, format, args) < 0)
146
    gold_nomem();
147
  va_end(args);
148
  gold_error(_("%s: %s"), this->name().c_str(), buf);
149
  free(buf);
150
}
151
 
152
// Return a view of the contents of a section.
153
 
154
const unsigned char*
155
Object::section_contents(unsigned int shndx, section_size_type* plen,
156
                         bool cache)
157
{
158
  Location loc(this->do_section_contents(shndx));
159
  *plen = convert_to_section_size_type(loc.data_size);
160
  if (*plen == 0)
161
    {
162
      static const unsigned char empty[1] = { '\0' };
163
      return empty;
164
    }
165
  return this->get_view(loc.file_offset, *plen, true, cache);
166
}
167
 
168
// Read the section data into SD.  This is code common to Sized_relobj
169
// and Sized_dynobj, so we put it into Object.
170
 
171
template<int size, bool big_endian>
172
void
173
Object::read_section_data(elfcpp::Elf_file<size, big_endian, Object>* elf_file,
174
                          Read_symbols_data* sd)
175
{
176
  const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
177
 
178
  // Read the section headers.
179
  const off_t shoff = elf_file->shoff();
180
  const unsigned int shnum = this->shnum();
181
  sd->section_headers = this->get_lasting_view(shoff, shnum * shdr_size,
182
                                               true, true);
183
 
184
  // Read the section names.
185
  const unsigned char* pshdrs = sd->section_headers->data();
186
  const unsigned char* pshdrnames = pshdrs + elf_file->shstrndx() * shdr_size;
187
  typename elfcpp::Shdr<size, big_endian> shdrnames(pshdrnames);
188
 
189
  if (shdrnames.get_sh_type() != elfcpp::SHT_STRTAB)
190
    this->error(_("section name section has wrong type: %u"),
191
                static_cast<unsigned int>(shdrnames.get_sh_type()));
192
 
193
  sd->section_names_size =
194
    convert_to_section_size_type(shdrnames.get_sh_size());
195
  sd->section_names = this->get_lasting_view(shdrnames.get_sh_offset(),
196
                                             sd->section_names_size, false,
197
                                             false);
198
}
199
 
200
// If NAME is the name of a special .gnu.warning section, arrange for
201
// the warning to be issued.  SHNDX is the section index.  Return
202
// whether it is a warning section.
203
 
204
bool
205
Object::handle_gnu_warning_section(const char* name, unsigned int shndx,
206
                                   Symbol_table* symtab)
207
{
208
  const char warn_prefix[] = ".gnu.warning.";
209
  const int warn_prefix_len = sizeof warn_prefix - 1;
210
  if (strncmp(name, warn_prefix, warn_prefix_len) == 0)
211
    {
212
      // Read the section contents to get the warning text.  It would
213
      // be nicer if we only did this if we have to actually issue a
214
      // warning.  Unfortunately, warnings are issued as we relocate
215
      // sections.  That means that we can not lock the object then,
216
      // as we might try to issue the same warning multiple times
217
      // simultaneously.
218
      section_size_type len;
219
      const unsigned char* contents = this->section_contents(shndx, &len,
220
                                                             false);
221
      if (len == 0)
222
        {
223
          const char* warning = name + warn_prefix_len;
224
          contents = reinterpret_cast<const unsigned char*>(warning);
225
          len = strlen(warning);
226
        }
227
      std::string warning(reinterpret_cast<const char*>(contents), len);
228
      symtab->add_warning(name + warn_prefix_len, this, warning);
229
      return true;
230
    }
231
  return false;
232
}
233
 
234
// If NAME is the name of the special section which indicates that
235
// this object was compiled with -fstack-split, mark it accordingly.
236
 
237
bool
238
Object::handle_split_stack_section(const char* name)
239
{
240
  if (strcmp(name, ".note.GNU-split-stack") == 0)
241
    {
242
      this->uses_split_stack_ = true;
243
      return true;
244
    }
245
  if (strcmp(name, ".note.GNU-no-split-stack") == 0)
246
    {
247
      this->has_no_split_stack_ = true;
248
      return true;
249
    }
250
  return false;
251
}
252
 
253
// Class Relobj
254
 
255
// To copy the symbols data read from the file to a local data structure.
256
// This function is called from do_layout only while doing garbage 
257
// collection.
258
 
259
void
260
Relobj::copy_symbols_data(Symbols_data* gc_sd, Read_symbols_data* sd,
261
                          unsigned int section_header_size)
262
{
263
  gc_sd->section_headers_data =
264
         new unsigned char[(section_header_size)];
265
  memcpy(gc_sd->section_headers_data, sd->section_headers->data(),
266
         section_header_size);
267
  gc_sd->section_names_data =
268
         new unsigned char[sd->section_names_size];
269
  memcpy(gc_sd->section_names_data, sd->section_names->data(),
270
         sd->section_names_size);
271
  gc_sd->section_names_size = sd->section_names_size;
272
  if (sd->symbols != NULL)
273
    {
274
      gc_sd->symbols_data =
275
             new unsigned char[sd->symbols_size];
276
      memcpy(gc_sd->symbols_data, sd->symbols->data(),
277
            sd->symbols_size);
278
    }
279
  else
280
    {
281
      gc_sd->symbols_data = NULL;
282
    }
283
  gc_sd->symbols_size = sd->symbols_size;
284
  gc_sd->external_symbols_offset = sd->external_symbols_offset;
285
  if (sd->symbol_names != NULL)
286
    {
287
      gc_sd->symbol_names_data =
288
             new unsigned char[sd->symbol_names_size];
289
      memcpy(gc_sd->symbol_names_data, sd->symbol_names->data(),
290
            sd->symbol_names_size);
291
    }
292
  else
293
    {
294
      gc_sd->symbol_names_data = NULL;
295
    }
296
  gc_sd->symbol_names_size = sd->symbol_names_size;
297
}
298
 
299
// This function determines if a particular section name must be included
300
// in the link.  This is used during garbage collection to determine the
301
// roots of the worklist.
302
 
303
bool
304
Relobj::is_section_name_included(const char* name)
305
{
306
  if (is_prefix_of(".ctors", name)
307
      || is_prefix_of(".dtors", name)
308
      || is_prefix_of(".note", name)
309
      || is_prefix_of(".init", name)
310
      || is_prefix_of(".fini", name)
311
      || is_prefix_of(".gcc_except_table", name)
312
      || is_prefix_of(".jcr", name)
313
      || is_prefix_of(".preinit_array", name)
314
      || (is_prefix_of(".text", name)
315
          && strstr(name, "personality"))
316
      || (is_prefix_of(".data", name)
317
          &&  strstr(name, "personality"))
318
      || (is_prefix_of(".gnu.linkonce.d", name) &&
319
            strstr(name, "personality")))
320
    {
321
      return true;
322
    }
323
  return false;
324
}
325
 
326
// Class Sized_relobj.
327
 
328
template<int size, bool big_endian>
329
Sized_relobj<size, big_endian>::Sized_relobj(
330
    const std::string& name,
331
    Input_file* input_file,
332
    off_t offset,
333
    const elfcpp::Ehdr<size, big_endian>& ehdr)
334
  : Relobj(name, input_file, offset),
335
    elf_file_(this, ehdr),
336
    symtab_shndx_(-1U),
337
    local_symbol_count_(0),
338
    output_local_symbol_count_(0),
339
    output_local_dynsym_count_(0),
340
    symbols_(),
341
    defined_count_(0),
342
    local_symbol_offset_(0),
343
    local_dynsym_offset_(0),
344
    local_values_(),
345
    local_got_offsets_(),
346
    kept_comdat_sections_(),
347
    has_eh_frame_(false),
348
    discarded_eh_frame_shndx_(-1U)
349
{
350
}
351
 
352
template<int size, bool big_endian>
353
Sized_relobj<size, big_endian>::~Sized_relobj()
354
{
355
}
356
 
357
// Set up an object file based on the file header.  This sets up the
358
// section information.
359
 
360
template<int size, bool big_endian>
361
void
362
Sized_relobj<size, big_endian>::do_setup()
363
{
364
  const unsigned int shnum = this->elf_file_.shnum();
365
  this->set_shnum(shnum);
366
}
367
 
368
// Find the SHT_SYMTAB section, given the section headers.  The ELF
369
// standard says that maybe in the future there can be more than one
370
// SHT_SYMTAB section.  Until somebody figures out how that could
371
// work, we assume there is only one.
372
 
373
template<int size, bool big_endian>
374
void
375
Sized_relobj<size, big_endian>::find_symtab(const unsigned char* pshdrs)
376
{
377
  const unsigned int shnum = this->shnum();
378
  this->symtab_shndx_ = 0;
379
  if (shnum > 0)
380
    {
381
      // Look through the sections in reverse order, since gas tends
382
      // to put the symbol table at the end.
383
      const unsigned char* p = pshdrs + shnum * This::shdr_size;
384
      unsigned int i = shnum;
385
      unsigned int xindex_shndx = 0;
386
      unsigned int xindex_link = 0;
387
      while (i > 0)
388
        {
389
          --i;
390
          p -= This::shdr_size;
391
          typename This::Shdr shdr(p);
392
          if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB)
393
            {
394
              this->symtab_shndx_ = i;
395
              if (xindex_shndx > 0 && xindex_link == i)
396
                {
397
                  Xindex* xindex =
398
                    new Xindex(this->elf_file_.large_shndx_offset());
399
                  xindex->read_symtab_xindex<size, big_endian>(this,
400
                                                               xindex_shndx,
401
                                                               pshdrs);
402
                  this->set_xindex(xindex);
403
                }
404
              break;
405
            }
406
 
407
          // Try to pick up the SHT_SYMTAB_SHNDX section, if there is
408
          // one.  This will work if it follows the SHT_SYMTAB
409
          // section.
410
          if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB_SHNDX)
411
            {
412
              xindex_shndx = i;
413
              xindex_link = this->adjust_shndx(shdr.get_sh_link());
414
            }
415
        }
416
    }
417
}
418
 
419
// Return the Xindex structure to use for object with lots of
420
// sections.
421
 
422
template<int size, bool big_endian>
423
Xindex*
424
Sized_relobj<size, big_endian>::do_initialize_xindex()
425
{
426
  gold_assert(this->symtab_shndx_ != -1U);
427
  Xindex* xindex = new Xindex(this->elf_file_.large_shndx_offset());
428
  xindex->initialize_symtab_xindex<size, big_endian>(this, this->symtab_shndx_);
429
  return xindex;
430
}
431
 
432
// Return whether SHDR has the right type and flags to be a GNU
433
// .eh_frame section.
434
 
435
template<int size, bool big_endian>
436
bool
437
Sized_relobj<size, big_endian>::check_eh_frame_flags(
438
    const elfcpp::Shdr<size, big_endian>* shdr) const
439
{
440
  return (shdr->get_sh_type() == elfcpp::SHT_PROGBITS
441
          && (shdr->get_sh_flags() & elfcpp::SHF_ALLOC) != 0);
442
}
443
 
444
// Return whether there is a GNU .eh_frame section, given the section
445
// headers and the section names.
446
 
447
template<int size, bool big_endian>
448
bool
449
Sized_relobj<size, big_endian>::find_eh_frame(
450
    const unsigned char* pshdrs,
451
    const char* names,
452
    section_size_type names_size) const
453
{
454
  const unsigned int shnum = this->shnum();
455
  const unsigned char* p = pshdrs + This::shdr_size;
456
  for (unsigned int i = 1; i < shnum; ++i, p += This::shdr_size)
457
    {
458
      typename This::Shdr shdr(p);
459
      if (this->check_eh_frame_flags(&shdr))
460
        {
461
          if (shdr.get_sh_name() >= names_size)
462
            {
463
              this->error(_("bad section name offset for section %u: %lu"),
464
                          i, static_cast<unsigned long>(shdr.get_sh_name()));
465
              continue;
466
            }
467
 
468
          const char* name = names + shdr.get_sh_name();
469
          if (strcmp(name, ".eh_frame") == 0)
470
            return true;
471
        }
472
    }
473
  return false;
474
}
475
 
476
// Read the sections and symbols from an object file.
477
 
478
template<int size, bool big_endian>
479
void
480
Sized_relobj<size, big_endian>::do_read_symbols(Read_symbols_data* sd)
481
{
482
  this->read_section_data(&this->elf_file_, sd);
483
 
484
  const unsigned char* const pshdrs = sd->section_headers->data();
485
 
486
  this->find_symtab(pshdrs);
487
 
488
  const unsigned char* namesu = sd->section_names->data();
489
  const char* names = reinterpret_cast<const char*>(namesu);
490
  if (memmem(names, sd->section_names_size, ".eh_frame", 10) != NULL)
491
    {
492
      if (this->find_eh_frame(pshdrs, names, sd->section_names_size))
493
        this->has_eh_frame_ = true;
494
    }
495
 
496
  sd->symbols = NULL;
497
  sd->symbols_size = 0;
498
  sd->external_symbols_offset = 0;
499
  sd->symbol_names = NULL;
500
  sd->symbol_names_size = 0;
501
 
502
  if (this->symtab_shndx_ == 0)
503
    {
504
      // No symbol table.  Weird but legal.
505
      return;
506
    }
507
 
508
  // Get the symbol table section header.
509
  typename This::Shdr symtabshdr(pshdrs
510
                                 + this->symtab_shndx_ * This::shdr_size);
511
  gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
512
 
513
  // If this object has a .eh_frame section, we need all the symbols.
514
  // Otherwise we only need the external symbols.  While it would be
515
  // simpler to just always read all the symbols, I've seen object
516
  // files with well over 2000 local symbols, which for a 64-bit
517
  // object file format is over 5 pages that we don't need to read
518
  // now.
519
 
520
  const int sym_size = This::sym_size;
521
  const unsigned int loccount = symtabshdr.get_sh_info();
522
  this->local_symbol_count_ = loccount;
523
  this->local_values_.resize(loccount);
524
  section_offset_type locsize = loccount * sym_size;
525
  off_t dataoff = symtabshdr.get_sh_offset();
526
  section_size_type datasize =
527
    convert_to_section_size_type(symtabshdr.get_sh_size());
528
  off_t extoff = dataoff + locsize;
529
  section_size_type extsize = datasize - locsize;
530
 
531
  off_t readoff = this->has_eh_frame_ ? dataoff : extoff;
532
  section_size_type readsize = this->has_eh_frame_ ? datasize : extsize;
533
 
534
  if (readsize == 0)
535
    {
536
      // No external symbols.  Also weird but also legal.
537
      return;
538
    }
539
 
540
  File_view* fvsymtab = this->get_lasting_view(readoff, readsize, true, false);
541
 
542
  // Read the section header for the symbol names.
543
  unsigned int strtab_shndx = this->adjust_shndx(symtabshdr.get_sh_link());
544
  if (strtab_shndx >= this->shnum())
545
    {
546
      this->error(_("invalid symbol table name index: %u"), strtab_shndx);
547
      return;
548
    }
549
  typename This::Shdr strtabshdr(pshdrs + strtab_shndx * This::shdr_size);
550
  if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
551
    {
552
      this->error(_("symbol table name section has wrong type: %u"),
553
                  static_cast<unsigned int>(strtabshdr.get_sh_type()));
554
      return;
555
    }
556
 
557
  // Read the symbol names.
558
  File_view* fvstrtab = this->get_lasting_view(strtabshdr.get_sh_offset(),
559
                                               strtabshdr.get_sh_size(),
560
                                               false, true);
561
 
562
  sd->symbols = fvsymtab;
563
  sd->symbols_size = readsize;
564
  sd->external_symbols_offset = this->has_eh_frame_ ? locsize : 0;
565
  sd->symbol_names = fvstrtab;
566
  sd->symbol_names_size =
567
    convert_to_section_size_type(strtabshdr.get_sh_size());
568
}
569
 
570
// Return the section index of symbol SYM.  Set *VALUE to its value in
571
// the object file.  Set *IS_ORDINARY if this is an ordinary section
572
// index.  not a special cod between SHN_LORESERVE and SHN_HIRESERVE.
573
// Note that for a symbol which is not defined in this object file,
574
// this will set *VALUE to 0 and return SHN_UNDEF; it will not return
575
// the final value of the symbol in the link.
576
 
577
template<int size, bool big_endian>
578
unsigned int
579
Sized_relobj<size, big_endian>::symbol_section_and_value(unsigned int sym,
580
                                                         Address* value,
581
                                                         bool* is_ordinary)
582
{
583
  section_size_type symbols_size;
584
  const unsigned char* symbols = this->section_contents(this->symtab_shndx_,
585
                                                        &symbols_size,
586
                                                        false);
587
 
588
  const size_t count = symbols_size / This::sym_size;
589
  gold_assert(sym < count);
590
 
591
  elfcpp::Sym<size, big_endian> elfsym(symbols + sym * This::sym_size);
592
  *value = elfsym.get_st_value();
593
 
594
  return this->adjust_sym_shndx(sym, elfsym.get_st_shndx(), is_ordinary);
595
}
596
 
597
// Return whether to include a section group in the link.  LAYOUT is
598
// used to keep track of which section groups we have already seen.
599
// INDEX is the index of the section group and SHDR is the section
600
// header.  If we do not want to include this group, we set bits in
601
// OMIT for each section which should be discarded.
602
 
603
template<int size, bool big_endian>
604
bool
605
Sized_relobj<size, big_endian>::include_section_group(
606
    Symbol_table* symtab,
607
    Layout* layout,
608
    unsigned int index,
609
    const char* name,
610
    const unsigned char* shdrs,
611
    const char* section_names,
612
    section_size_type section_names_size,
613
    std::vector<bool>* omit)
614
{
615
  // Read the section contents.
616
  typename This::Shdr shdr(shdrs + index * This::shdr_size);
617
  const unsigned char* pcon = this->get_view(shdr.get_sh_offset(),
618
                                             shdr.get_sh_size(), true, false);
619
  const elfcpp::Elf_Word* pword =
620
    reinterpret_cast<const elfcpp::Elf_Word*>(pcon);
621
 
622
  // The first word contains flags.  We only care about COMDAT section
623
  // groups.  Other section groups are always included in the link
624
  // just like ordinary sections.
625
  elfcpp::Elf_Word flags = elfcpp::Swap<32, big_endian>::readval(pword);
626
 
627
  // Look up the group signature, which is the name of a symbol.  This
628
  // is a lot of effort to go to to read a string.  Why didn't they
629
  // just have the group signature point into the string table, rather
630
  // than indirect through a symbol?
631
 
632
  // Get the appropriate symbol table header (this will normally be
633
  // the single SHT_SYMTAB section, but in principle it need not be).
634
  const unsigned int link = this->adjust_shndx(shdr.get_sh_link());
635
  typename This::Shdr symshdr(this, this->elf_file_.section_header(link));
636
 
637
  // Read the symbol table entry.
638
  unsigned int symndx = shdr.get_sh_info();
639
  if (symndx >= symshdr.get_sh_size() / This::sym_size)
640
    {
641
      this->error(_("section group %u info %u out of range"),
642
                  index, symndx);
643
      return false;
644
    }
645
  off_t symoff = symshdr.get_sh_offset() + symndx * This::sym_size;
646
  const unsigned char* psym = this->get_view(symoff, This::sym_size, true,
647
                                             false);
648
  elfcpp::Sym<size, big_endian> sym(psym);
649
 
650
  // Read the symbol table names.
651
  section_size_type symnamelen;
652
  const unsigned char* psymnamesu;
653
  psymnamesu = this->section_contents(this->adjust_shndx(symshdr.get_sh_link()),
654
                                      &symnamelen, true);
655
  const char* psymnames = reinterpret_cast<const char*>(psymnamesu);
656
 
657
  // Get the section group signature.
658
  if (sym.get_st_name() >= symnamelen)
659
    {
660
      this->error(_("symbol %u name offset %u out of range"),
661
                  symndx, sym.get_st_name());
662
      return false;
663
    }
664
 
665
  std::string signature(psymnames + sym.get_st_name());
666
 
667
  // It seems that some versions of gas will create a section group
668
  // associated with a section symbol, and then fail to give a name to
669
  // the section symbol.  In such a case, use the name of the section.
670
  if (signature[0] == '\0' && sym.get_st_type() == elfcpp::STT_SECTION)
671
    {
672
      bool is_ordinary;
673
      unsigned int sym_shndx = this->adjust_sym_shndx(symndx,
674
                                                      sym.get_st_shndx(),
675
                                                      &is_ordinary);
676
      if (!is_ordinary || sym_shndx >= this->shnum())
677
        {
678
          this->error(_("symbol %u invalid section index %u"),
679
                      symndx, sym_shndx);
680
          return false;
681
        }
682
      typename This::Shdr member_shdr(shdrs + sym_shndx * This::shdr_size);
683
      if (member_shdr.get_sh_name() < section_names_size)
684
        signature = section_names + member_shdr.get_sh_name();
685
    }
686
 
687
  // Record this section group in the layout, and see whether we've already
688
  // seen one with the same signature.
689
  bool include_group;
690
  bool is_comdat;
691
  Kept_section* kept_section = NULL;
692
 
693
  if ((flags & elfcpp::GRP_COMDAT) == 0)
694
    {
695
      include_group = true;
696
      is_comdat = false;
697
    }
698
  else
699
    {
700
      include_group = layout->find_or_add_kept_section(signature,
701
                                                       this, index, true,
702
                                                       true, &kept_section);
703
      is_comdat = true;
704
    }
705
 
706
  size_t count = shdr.get_sh_size() / sizeof(elfcpp::Elf_Word);
707
 
708
  std::vector<unsigned int> shndxes;
709
  bool relocate_group = include_group && parameters->options().relocatable();
710
  if (relocate_group)
711
    shndxes.reserve(count - 1);
712
 
713
  for (size_t i = 1; i < count; ++i)
714
    {
715
      elfcpp::Elf_Word shndx =
716
        this->adjust_shndx(elfcpp::Swap<32, big_endian>::readval(pword + i));
717
 
718
      if (relocate_group)
719
        shndxes.push_back(shndx);
720
 
721
      if (shndx >= this->shnum())
722
        {
723
          this->error(_("section %u in section group %u out of range"),
724
                      shndx, index);
725
          continue;
726
        }
727
 
728
      // Check for an earlier section number, since we're going to get
729
      // it wrong--we may have already decided to include the section.
730
      if (shndx < index)
731
        this->error(_("invalid section group %u refers to earlier section %u"),
732
                    index, shndx);
733
 
734
      // Get the name of the member section.
735
      typename This::Shdr member_shdr(shdrs + shndx * This::shdr_size);
736
      if (member_shdr.get_sh_name() >= section_names_size)
737
        {
738
          // This is an error, but it will be diagnosed eventually
739
          // in do_layout, so we don't need to do anything here but
740
          // ignore it.
741
          continue;
742
        }
743
      std::string mname(section_names + member_shdr.get_sh_name());
744
 
745
      if (include_group)
746
        {
747
          if (is_comdat)
748
            kept_section->add_comdat_section(mname, shndx,
749
                                             member_shdr.get_sh_size());
750
        }
751
      else
752
        {
753
          (*omit)[shndx] = true;
754
 
755
          if (is_comdat)
756
            {
757
              Relobj* kept_object = kept_section->object();
758
              if (kept_section->is_comdat())
759
                {
760
                  // Find the corresponding kept section, and store
761
                  // that info in the discarded section table.
762
                  unsigned int kept_shndx;
763
                  uint64_t kept_size;
764
                  if (kept_section->find_comdat_section(mname, &kept_shndx,
765
                                                        &kept_size))
766
                    {
767
                      // We don't keep a mapping for this section if
768
                      // it has a different size.  The mapping is only
769
                      // used for relocation processing, and we don't
770
                      // want to treat the sections as similar if the
771
                      // sizes are different.  Checking the section
772
                      // size is the approach used by the GNU linker.
773
                      if (kept_size == member_shdr.get_sh_size())
774
                        this->set_kept_comdat_section(shndx, kept_object,
775
                                                      kept_shndx);
776
                    }
777
                }
778
              else
779
                {
780
                  // The existing section is a linkonce section.  Add
781
                  // a mapping if there is exactly one section in the
782
                  // group (which is true when COUNT == 2) and if it
783
                  // is the same size.
784
                  if (count == 2
785
                      && (kept_section->linkonce_size()
786
                          == member_shdr.get_sh_size()))
787
                    this->set_kept_comdat_section(shndx, kept_object,
788
                                                  kept_section->shndx());
789
                }
790
            }
791
        }
792
    }
793
 
794
  if (relocate_group)
795
    layout->layout_group(symtab, this, index, name, signature.c_str(),
796
                         shdr, flags, &shndxes);
797
 
798
  return include_group;
799
}
800
 
801
// Whether to include a linkonce section in the link.  NAME is the
802
// name of the section and SHDR is the section header.
803
 
804
// Linkonce sections are a GNU extension implemented in the original
805
// GNU linker before section groups were defined.  The semantics are
806
// that we only include one linkonce section with a given name.  The
807
// name of a linkonce section is normally .gnu.linkonce.T.SYMNAME,
808
// where T is the type of section and SYMNAME is the name of a symbol.
809
// In an attempt to make linkonce sections interact well with section
810
// groups, we try to identify SYMNAME and use it like a section group
811
// signature.  We want to block section groups with that signature,
812
// but not other linkonce sections with that signature.  We also use
813
// the full name of the linkonce section as a normal section group
814
// signature.
815
 
816
template<int size, bool big_endian>
817
bool
818
Sized_relobj<size, big_endian>::include_linkonce_section(
819
    Layout* layout,
820
    unsigned int index,
821
    const char* name,
822
    const elfcpp::Shdr<size, big_endian>& shdr)
823
{
824
  typename elfcpp::Elf_types<size>::Elf_WXword sh_size = shdr.get_sh_size();
825
  // In general the symbol name we want will be the string following
826
  // the last '.'.  However, we have to handle the case of
827
  // .gnu.linkonce.t.__i686.get_pc_thunk.bx, which was generated by
828
  // some versions of gcc.  So we use a heuristic: if the name starts
829
  // with ".gnu.linkonce.t.", we use everything after that.  Otherwise
830
  // we look for the last '.'.  We can't always simply skip
831
  // ".gnu.linkonce.X", because we have to deal with cases like
832
  // ".gnu.linkonce.d.rel.ro.local".
833
  const char* const linkonce_t = ".gnu.linkonce.t.";
834
  const char* symname;
835
  if (strncmp(name, linkonce_t, strlen(linkonce_t)) == 0)
836
    symname = name + strlen(linkonce_t);
837
  else
838
    symname = strrchr(name, '.') + 1;
839
  std::string sig1(symname);
840
  std::string sig2(name);
841
  Kept_section* kept1;
842
  Kept_section* kept2;
843
  bool include1 = layout->find_or_add_kept_section(sig1, this, index, false,
844
                                                   false, &kept1);
845
  bool include2 = layout->find_or_add_kept_section(sig2, this, index, false,
846
                                                   true, &kept2);
847
 
848
  if (!include2)
849
    {
850
      // We are not including this section because we already saw the
851
      // name of the section as a signature.  This normally implies
852
      // that the kept section is another linkonce section.  If it is
853
      // the same size, record it as the section which corresponds to
854
      // this one.
855
      if (kept2->object() != NULL
856
          && !kept2->is_comdat()
857
          && kept2->linkonce_size() == sh_size)
858
        this->set_kept_comdat_section(index, kept2->object(), kept2->shndx());
859
    }
860
  else if (!include1)
861
    {
862
      // The section is being discarded on the basis of its symbol
863
      // name.  This means that the corresponding kept section was
864
      // part of a comdat group, and it will be difficult to identify
865
      // the specific section within that group that corresponds to
866
      // this linkonce section.  We'll handle the simple case where
867
      // the group has only one member section.  Otherwise, it's not
868
      // worth the effort.
869
      unsigned int kept_shndx;
870
      uint64_t kept_size;
871
      if (kept1->object() != NULL
872
          && kept1->is_comdat()
873
          && kept1->find_single_comdat_section(&kept_shndx, &kept_size)
874
          && kept_size == sh_size)
875
        this->set_kept_comdat_section(index, kept1->object(), kept_shndx);
876
    }
877
  else
878
    {
879
      kept1->set_linkonce_size(sh_size);
880
      kept2->set_linkonce_size(sh_size);
881
    }
882
 
883
  return include1 && include2;
884
}
885
 
886
// Layout an input section.
887
 
888
template<int size, bool big_endian>
889
inline void
890
Sized_relobj<size, big_endian>::layout_section(Layout* layout,
891
                                               unsigned int shndx,
892
                                               const char* name,
893
                                               typename This::Shdr& shdr,
894
                                               unsigned int reloc_shndx,
895
                                               unsigned int reloc_type)
896
{
897
  off_t offset;
898
  Output_section* os = layout->layout(this, shndx, name, shdr,
899
                                          reloc_shndx, reloc_type, &offset);
900
 
901
  this->output_sections()[shndx] = os;
902
  if (offset == -1)
903
    this->section_offsets_[shndx] = invalid_address;
904
  else
905
    this->section_offsets_[shndx] = convert_types<Address, off_t>(offset);
906
 
907
  // If this section requires special handling, and if there are
908
  // relocs that apply to it, then we must do the special handling
909
  // before we apply the relocs.
910
  if (offset == -1 && reloc_shndx != 0)
911
    this->set_relocs_must_follow_section_writes();
912
}
913
 
914
// Lay out the input sections.  We walk through the sections and check
915
// whether they should be included in the link.  If they should, we
916
// pass them to the Layout object, which will return an output section
917
// and an offset.  
918
// During garbage collection (--gc-sections) and identical code folding 
919
// (--icf), this function is called twice.  When it is called the first 
920
// time, it is for setting up some sections as roots to a work-list for
921
// --gc-sections and to do comdat processing.  Actual layout happens the 
922
// second time around after all the relevant sections have been determined.  
923
// The first time, is_worklist_ready or is_icf_ready is false. It is then 
924
// set to true after the garbage collection worklist or identical code 
925
// folding is processed and the relevant sections to be kept are 
926
// determined.  Then, this function is called again to layout the sections.
927
 
928
template<int size, bool big_endian>
929
void
930
Sized_relobj<size, big_endian>::do_layout(Symbol_table* symtab,
931
                                          Layout* layout,
932
                                          Read_symbols_data* sd)
933
{
934
  const unsigned int shnum = this->shnum();
935
  bool is_gc_pass_one = ((parameters->options().gc_sections()
936
                          && !symtab->gc()->is_worklist_ready())
937
                         || (parameters->options().icf_enabled()
938
                             && !symtab->icf()->is_icf_ready()));
939
 
940
  bool is_gc_pass_two = ((parameters->options().gc_sections()
941
                          && symtab->gc()->is_worklist_ready())
942
                         || (parameters->options().icf_enabled()
943
                             && symtab->icf()->is_icf_ready()));
944
 
945
  bool is_gc_or_icf = (parameters->options().gc_sections()
946
                       || parameters->options().icf_enabled());
947
 
948
  // Both is_gc_pass_one and is_gc_pass_two should not be true.
949
  gold_assert(!(is_gc_pass_one  && is_gc_pass_two));
950
 
951
  if (shnum == 0)
952
    return;
953
  Symbols_data* gc_sd = NULL;
954
  if (is_gc_pass_one)
955
    {
956
      // During garbage collection save the symbols data to use it when 
957
      // re-entering this function.   
958
      gc_sd = new Symbols_data;
959
      this->copy_symbols_data(gc_sd, sd, This::shdr_size * shnum);
960
      this->set_symbols_data(gc_sd);
961
    }
962
  else if (is_gc_pass_two)
963
    {
964
      gc_sd = this->get_symbols_data();
965
    }
966
 
967
  const unsigned char* section_headers_data = NULL;
968
  section_size_type section_names_size;
969
  const unsigned char* symbols_data = NULL;
970
  section_size_type symbols_size;
971
  section_offset_type external_symbols_offset;
972
  const unsigned char* symbol_names_data = NULL;
973
  section_size_type symbol_names_size;
974
 
975
  if (is_gc_or_icf)
976
    {
977
      section_headers_data = gc_sd->section_headers_data;
978
      section_names_size = gc_sd->section_names_size;
979
      symbols_data = gc_sd->symbols_data;
980
      symbols_size = gc_sd->symbols_size;
981
      external_symbols_offset = gc_sd->external_symbols_offset;
982
      symbol_names_data = gc_sd->symbol_names_data;
983
      symbol_names_size = gc_sd->symbol_names_size;
984
    }
985
  else
986
    {
987
      section_headers_data = sd->section_headers->data();
988
      section_names_size = sd->section_names_size;
989
      if (sd->symbols != NULL)
990
        symbols_data = sd->symbols->data();
991
      symbols_size = sd->symbols_size;
992
      external_symbols_offset = sd->external_symbols_offset;
993
      if (sd->symbol_names != NULL)
994
        symbol_names_data = sd->symbol_names->data();
995
      symbol_names_size = sd->symbol_names_size;
996
    }
997
 
998
  // Get the section headers.
999
  const unsigned char* shdrs = section_headers_data;
1000
  const unsigned char* pshdrs;
1001
 
1002
  // Get the section names.
1003
  const unsigned char* pnamesu = (is_gc_or_icf)
1004
                                 ? gc_sd->section_names_data
1005
                                 : sd->section_names->data();
1006
 
1007
  const char* pnames = reinterpret_cast<const char*>(pnamesu);
1008
 
1009
  // If any input files have been claimed by plugins, we need to defer
1010
  // actual layout until the replacement files have arrived.
1011
  const bool should_defer_layout =
1012
      (parameters->options().has_plugins()
1013
       && parameters->options().plugins()->should_defer_layout());
1014
  unsigned int num_sections_to_defer = 0;
1015
 
1016
  // For each section, record the index of the reloc section if any.
1017
  // Use 0 to mean that there is no reloc section, -1U to mean that
1018
  // there is more than one.
1019
  std::vector<unsigned int> reloc_shndx(shnum, 0);
1020
  std::vector<unsigned int> reloc_type(shnum, elfcpp::SHT_NULL);
1021
  // Skip the first, dummy, section.
1022
  pshdrs = shdrs + This::shdr_size;
1023
  for (unsigned int i = 1; i < shnum; ++i, pshdrs += This::shdr_size)
1024
    {
1025
      typename This::Shdr shdr(pshdrs);
1026
 
1027
      // Count the number of sections whose layout will be deferred.
1028
      if (should_defer_layout && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC))
1029
        ++num_sections_to_defer;
1030
 
1031
      unsigned int sh_type = shdr.get_sh_type();
1032
      if (sh_type == elfcpp::SHT_REL || sh_type == elfcpp::SHT_RELA)
1033
        {
1034
          unsigned int target_shndx = this->adjust_shndx(shdr.get_sh_info());
1035
          if (target_shndx == 0 || target_shndx >= shnum)
1036
            {
1037
              this->error(_("relocation section %u has bad info %u"),
1038
                          i, target_shndx);
1039
              continue;
1040
            }
1041
 
1042
          if (reloc_shndx[target_shndx] != 0)
1043
            reloc_shndx[target_shndx] = -1U;
1044
          else
1045
            {
1046
              reloc_shndx[target_shndx] = i;
1047
              reloc_type[target_shndx] = sh_type;
1048
            }
1049
        }
1050
    }
1051
 
1052
  Output_sections& out_sections(this->output_sections());
1053
  std::vector<Address>& out_section_offsets(this->section_offsets_);
1054
 
1055
  if (!is_gc_pass_two)
1056
    {
1057
      out_sections.resize(shnum);
1058
      out_section_offsets.resize(shnum);
1059
    }
1060
 
1061
  // If we are only linking for symbols, then there is nothing else to
1062
  // do here.
1063
  if (this->input_file()->just_symbols())
1064
    {
1065
      if (!is_gc_pass_two)
1066
        {
1067
          delete sd->section_headers;
1068
          sd->section_headers = NULL;
1069
          delete sd->section_names;
1070
          sd->section_names = NULL;
1071
        }
1072
      return;
1073
    }
1074
 
1075
  if (num_sections_to_defer > 0)
1076
    {
1077
      parameters->options().plugins()->add_deferred_layout_object(this);
1078
      this->deferred_layout_.reserve(num_sections_to_defer);
1079
    }
1080
 
1081
  // Whether we've seen a .note.GNU-stack section.
1082
  bool seen_gnu_stack = false;
1083
  // The flags of a .note.GNU-stack section.
1084
  uint64_t gnu_stack_flags = 0;
1085
 
1086
  // Keep track of which sections to omit.
1087
  std::vector<bool> omit(shnum, false);
1088
 
1089
  // Keep track of reloc sections when emitting relocations.
1090
  const bool relocatable = parameters->options().relocatable();
1091
  const bool emit_relocs = (relocatable
1092
                            || parameters->options().emit_relocs());
1093
  std::vector<unsigned int> reloc_sections;
1094
 
1095
  // Keep track of .eh_frame sections.
1096
  std::vector<unsigned int> eh_frame_sections;
1097
 
1098
  // Skip the first, dummy, section.
1099
  pshdrs = shdrs + This::shdr_size;
1100
  for (unsigned int i = 1; i < shnum; ++i, pshdrs += This::shdr_size)
1101
    {
1102
      typename This::Shdr shdr(pshdrs);
1103
 
1104
      if (shdr.get_sh_name() >= section_names_size)
1105
        {
1106
          this->error(_("bad section name offset for section %u: %lu"),
1107
                      i, static_cast<unsigned long>(shdr.get_sh_name()));
1108
          return;
1109
        }
1110
 
1111
      const char* name = pnames + shdr.get_sh_name();
1112
 
1113
      if (!is_gc_pass_two)
1114
        {
1115
          if (this->handle_gnu_warning_section(name, i, symtab))
1116
            {
1117
              if (!relocatable)
1118
                omit[i] = true;
1119
            }
1120
 
1121
          // The .note.GNU-stack section is special.  It gives the
1122
          // protection flags that this object file requires for the stack
1123
          // in memory.
1124
          if (strcmp(name, ".note.GNU-stack") == 0)
1125
            {
1126
              seen_gnu_stack = true;
1127
              gnu_stack_flags |= shdr.get_sh_flags();
1128
              omit[i] = true;
1129
            }
1130
 
1131
          // The .note.GNU-split-stack section is also special.  It
1132
          // indicates that the object was compiled with
1133
          // -fsplit-stack.
1134
          if (this->handle_split_stack_section(name))
1135
            {
1136
              if (!parameters->options().relocatable()
1137
                  && !parameters->options().shared())
1138
                omit[i] = true;
1139
            }
1140
 
1141
          bool discard = omit[i];
1142
          if (!discard)
1143
            {
1144
              if (shdr.get_sh_type() == elfcpp::SHT_GROUP)
1145
                {
1146
                  if (!this->include_section_group(symtab, layout, i, name,
1147
                                                   shdrs, pnames,
1148
                                                   section_names_size,
1149
                                                   &omit))
1150
                    discard = true;
1151
                }
1152
              else if ((shdr.get_sh_flags() & elfcpp::SHF_GROUP) == 0
1153
                       && Layout::is_linkonce(name))
1154
                {
1155
                  if (!this->include_linkonce_section(layout, i, name, shdr))
1156
                    discard = true;
1157
                }
1158
            }
1159
 
1160
          if (discard)
1161
            {
1162
              // Do not include this section in the link.
1163
              out_sections[i] = NULL;
1164
              out_section_offsets[i] = invalid_address;
1165
              continue;
1166
            }
1167
        }
1168
 
1169
      if (is_gc_pass_one && parameters->options().gc_sections())
1170
        {
1171
          if (is_section_name_included(name)
1172
              || shdr.get_sh_type() == elfcpp::SHT_INIT_ARRAY
1173
              || shdr.get_sh_type() == elfcpp::SHT_FINI_ARRAY)
1174
            {
1175
              symtab->gc()->worklist().push(Section_id(this, i));
1176
            }
1177
        }
1178
 
1179
      // When doing a relocatable link we are going to copy input
1180
      // reloc sections into the output.  We only want to copy the
1181
      // ones associated with sections which are not being discarded.
1182
      // However, we don't know that yet for all sections.  So save
1183
      // reloc sections and process them later. Garbage collection is
1184
      // not triggered when relocatable code is desired.
1185
      if (emit_relocs
1186
          && (shdr.get_sh_type() == elfcpp::SHT_REL
1187
              || shdr.get_sh_type() == elfcpp::SHT_RELA))
1188
        {
1189
          reloc_sections.push_back(i);
1190
          continue;
1191
        }
1192
 
1193
      if (relocatable && shdr.get_sh_type() == elfcpp::SHT_GROUP)
1194
        continue;
1195
 
1196
      // The .eh_frame section is special.  It holds exception frame
1197
      // information that we need to read in order to generate the
1198
      // exception frame header.  We process these after all the other
1199
      // sections so that the exception frame reader can reliably
1200
      // determine which sections are being discarded, and discard the
1201
      // corresponding information.
1202
      if (!relocatable
1203
          && strcmp(name, ".eh_frame") == 0
1204
          && this->check_eh_frame_flags(&shdr))
1205
        {
1206
          if (is_gc_pass_one)
1207
            {
1208
              out_sections[i] = reinterpret_cast<Output_section*>(1);
1209
              out_section_offsets[i] = invalid_address;
1210
            }
1211
          else
1212
            eh_frame_sections.push_back(i);
1213
          continue;
1214
        }
1215
 
1216
      if (is_gc_pass_two && parameters->options().gc_sections())
1217
        {
1218
          // This is executed during the second pass of garbage 
1219
          // collection. do_layout has been called before and some 
1220
          // sections have been already discarded. Simply ignore 
1221
          // such sections this time around.
1222
          if (out_sections[i] == NULL)
1223
            {
1224
              gold_assert(out_section_offsets[i] == invalid_address);
1225
              continue;
1226
            }
1227
          if (((shdr.get_sh_flags() & elfcpp::SHF_ALLOC) != 0)
1228
              && symtab->gc()->is_section_garbage(this, i))
1229
              {
1230
                if (parameters->options().print_gc_sections())
1231
                  gold_info(_("%s: removing unused section from '%s'"
1232
                              " in file '%s'"),
1233
                            program_name, this->section_name(i).c_str(),
1234
                            this->name().c_str());
1235
                out_sections[i] = NULL;
1236
                out_section_offsets[i] = invalid_address;
1237
                continue;
1238
              }
1239
        }
1240
 
1241
      if (is_gc_pass_two && parameters->options().icf_enabled())
1242
        {
1243
          if (out_sections[i] == NULL)
1244
            {
1245
              gold_assert(out_section_offsets[i] == invalid_address);
1246
              continue;
1247
            }
1248
          if (((shdr.get_sh_flags() & elfcpp::SHF_ALLOC) != 0)
1249
              && symtab->icf()->is_section_folded(this, i))
1250
              {
1251
                if (parameters->options().print_icf_sections())
1252
                  {
1253
                    Section_id folded =
1254
                                symtab->icf()->get_folded_section(this, i);
1255
                    Relobj* folded_obj =
1256
                                reinterpret_cast<Relobj*>(folded.first);
1257
                    gold_info(_("%s: ICF folding section '%s' in file '%s'"
1258
                                "into '%s' in file '%s'"),
1259
                              program_name, this->section_name(i).c_str(),
1260
                              this->name().c_str(),
1261
                              folded_obj->section_name(folded.second).c_str(),
1262
                              folded_obj->name().c_str());
1263
                  }
1264
                out_sections[i] = NULL;
1265
                out_section_offsets[i] = invalid_address;
1266
                continue;
1267
              }
1268
        }
1269
 
1270
      // Defer layout here if input files are claimed by plugins.  When gc
1271
      // is turned on this function is called twice.  For the second call
1272
      // should_defer_layout should be false.
1273
      if (should_defer_layout && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC))
1274
        {
1275
          gold_assert(!is_gc_pass_two);
1276
          this->deferred_layout_.push_back(Deferred_layout(i, name,
1277
                                                           pshdrs,
1278
                                                           reloc_shndx[i],
1279
                                                           reloc_type[i]));
1280
          // Put dummy values here; real values will be supplied by
1281
          // do_layout_deferred_sections.
1282
          out_sections[i] = reinterpret_cast<Output_section*>(2);
1283
          out_section_offsets[i] = invalid_address;
1284
          continue;
1285
        }
1286
 
1287
      // During gc_pass_two if a section that was previously deferred is
1288
      // found, do not layout the section as layout_deferred_sections will
1289
      // do it later from gold.cc.
1290
      if (is_gc_pass_two
1291
          && (out_sections[i] == reinterpret_cast<Output_section*>(2)))
1292
        continue;
1293
 
1294
      if (is_gc_pass_one)
1295
        {
1296
          // This is during garbage collection. The out_sections are 
1297
          // assigned in the second call to this function. 
1298
          out_sections[i] = reinterpret_cast<Output_section*>(1);
1299
          out_section_offsets[i] = invalid_address;
1300
        }
1301
      else
1302
        {
1303
          // When garbage collection is switched on the actual layout
1304
          // only happens in the second call.
1305
          this->layout_section(layout, i, name, shdr, reloc_shndx[i],
1306
                               reloc_type[i]);
1307
        }
1308
    }
1309
 
1310
  if (!is_gc_pass_one)
1311
    layout->layout_gnu_stack(seen_gnu_stack, gnu_stack_flags);
1312
 
1313
  // When doing a relocatable link handle the reloc sections at the
1314
  // end.  Garbage collection  and Identical Code Folding is not 
1315
  // turned on for relocatable code. 
1316
  if (emit_relocs)
1317
    this->size_relocatable_relocs();
1318
 
1319
  gold_assert(!(is_gc_or_icf) || reloc_sections.empty());
1320
 
1321
  for (std::vector<unsigned int>::const_iterator p = reloc_sections.begin();
1322
       p != reloc_sections.end();
1323
       ++p)
1324
    {
1325
      unsigned int i = *p;
1326
      const unsigned char* pshdr;
1327
      pshdr = section_headers_data + i * This::shdr_size;
1328
      typename This::Shdr shdr(pshdr);
1329
 
1330
      unsigned int data_shndx = this->adjust_shndx(shdr.get_sh_info());
1331
      if (data_shndx >= shnum)
1332
        {
1333
          // We already warned about this above.
1334
          continue;
1335
        }
1336
 
1337
      Output_section* data_section = out_sections[data_shndx];
1338
      if (data_section == NULL)
1339
        {
1340
          out_sections[i] = NULL;
1341
          out_section_offsets[i] = invalid_address;
1342
          continue;
1343
        }
1344
 
1345
      Relocatable_relocs* rr = new Relocatable_relocs();
1346
      this->set_relocatable_relocs(i, rr);
1347
 
1348
      Output_section* os = layout->layout_reloc(this, i, shdr, data_section,
1349
                                                rr);
1350
      out_sections[i] = os;
1351
      out_section_offsets[i] = invalid_address;
1352
    }
1353
 
1354
  // Handle the .eh_frame sections at the end.
1355
  gold_assert(!is_gc_pass_one || eh_frame_sections.empty());
1356
  for (std::vector<unsigned int>::const_iterator p = eh_frame_sections.begin();
1357
       p != eh_frame_sections.end();
1358
       ++p)
1359
    {
1360
      gold_assert(this->has_eh_frame_);
1361
      gold_assert(external_symbols_offset != 0);
1362
 
1363
      unsigned int i = *p;
1364
      const unsigned char *pshdr;
1365
      pshdr = section_headers_data + i * This::shdr_size;
1366
      typename This::Shdr shdr(pshdr);
1367
 
1368
      off_t offset;
1369
      Output_section* os = layout->layout_eh_frame(this,
1370
                                                   symbols_data,
1371
                                                   symbols_size,
1372
                                                   symbol_names_data,
1373
                                                   symbol_names_size,
1374
                                                   i, shdr,
1375
                                                   reloc_shndx[i],
1376
                                                   reloc_type[i],
1377
                                                   &offset);
1378
      out_sections[i] = os;
1379
      if (offset == -1)
1380
        {
1381
          // An object can contain at most one section holding exception
1382
          // frame information.
1383
          gold_assert(this->discarded_eh_frame_shndx_ == -1U);
1384
          this->discarded_eh_frame_shndx_ = i;
1385
          out_section_offsets[i] = invalid_address;
1386
        }
1387
      else
1388
        out_section_offsets[i] = convert_types<Address, off_t>(offset);
1389
 
1390
      // If this section requires special handling, and if there are
1391
      // relocs that apply to it, then we must do the special handling
1392
      // before we apply the relocs.
1393
      if (offset == -1 && reloc_shndx[i] != 0)
1394
        this->set_relocs_must_follow_section_writes();
1395
    }
1396
 
1397
  if (is_gc_pass_two)
1398
    {
1399
      delete[] gc_sd->section_headers_data;
1400
      delete[] gc_sd->section_names_data;
1401
      delete[] gc_sd->symbols_data;
1402
      delete[] gc_sd->symbol_names_data;
1403
      this->set_symbols_data(NULL);
1404
    }
1405
  else
1406
    {
1407
      delete sd->section_headers;
1408
      sd->section_headers = NULL;
1409
      delete sd->section_names;
1410
      sd->section_names = NULL;
1411
    }
1412
}
1413
 
1414
// Layout sections whose layout was deferred while waiting for
1415
// input files from a plugin.
1416
 
1417
template<int size, bool big_endian>
1418
void
1419
Sized_relobj<size, big_endian>::do_layout_deferred_sections(Layout* layout)
1420
{
1421
  typename std::vector<Deferred_layout>::iterator deferred;
1422
 
1423
  for (deferred = this->deferred_layout_.begin();
1424
       deferred != this->deferred_layout_.end();
1425
       ++deferred)
1426
    {
1427
      typename This::Shdr shdr(deferred->shdr_data_);
1428
      this->layout_section(layout, deferred->shndx_, deferred->name_.c_str(),
1429
                           shdr, deferred->reloc_shndx_, deferred->reloc_type_);
1430
    }
1431
 
1432
  this->deferred_layout_.clear();
1433
}
1434
 
1435
// Add the symbols to the symbol table.
1436
 
1437
template<int size, bool big_endian>
1438
void
1439
Sized_relobj<size, big_endian>::do_add_symbols(Symbol_table* symtab,
1440
                                               Read_symbols_data* sd,
1441
                                               Layout*)
1442
{
1443
  if (sd->symbols == NULL)
1444
    {
1445
      gold_assert(sd->symbol_names == NULL);
1446
      return;
1447
    }
1448
 
1449
  const int sym_size = This::sym_size;
1450
  size_t symcount = ((sd->symbols_size - sd->external_symbols_offset)
1451
                     / sym_size);
1452
  if (symcount * sym_size != sd->symbols_size - sd->external_symbols_offset)
1453
    {
1454
      this->error(_("size of symbols is not multiple of symbol size"));
1455
      return;
1456
    }
1457
 
1458
  this->symbols_.resize(symcount);
1459
 
1460
  const char* sym_names =
1461
    reinterpret_cast<const char*>(sd->symbol_names->data());
1462
  symtab->add_from_relobj(this,
1463
                          sd->symbols->data() + sd->external_symbols_offset,
1464
                          symcount, this->local_symbol_count_,
1465
                          sym_names, sd->symbol_names_size,
1466
                          &this->symbols_,
1467
                          &this->defined_count_);
1468
 
1469
  delete sd->symbols;
1470
  sd->symbols = NULL;
1471
  delete sd->symbol_names;
1472
  sd->symbol_names = NULL;
1473
}
1474
 
1475
// First pass over the local symbols.  Here we add their names to
1476
// *POOL and *DYNPOOL, and we store the symbol value in
1477
// THIS->LOCAL_VALUES_.  This function is always called from a
1478
// singleton thread.  This is followed by a call to
1479
// finalize_local_symbols.
1480
 
1481
template<int size, bool big_endian>
1482
void
1483
Sized_relobj<size, big_endian>::do_count_local_symbols(Stringpool* pool,
1484
                                                       Stringpool* dynpool)
1485
{
1486
  gold_assert(this->symtab_shndx_ != -1U);
1487
  if (this->symtab_shndx_ == 0)
1488
    {
1489
      // This object has no symbols.  Weird but legal.
1490
      return;
1491
    }
1492
 
1493
  // Read the symbol table section header.
1494
  const unsigned int symtab_shndx = this->symtab_shndx_;
1495
  typename This::Shdr symtabshdr(this,
1496
                                 this->elf_file_.section_header(symtab_shndx));
1497
  gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
1498
 
1499
  // Read the local symbols.
1500
  const int sym_size = This::sym_size;
1501
  const unsigned int loccount = this->local_symbol_count_;
1502
  gold_assert(loccount == symtabshdr.get_sh_info());
1503
  off_t locsize = loccount * sym_size;
1504
  const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
1505
                                              locsize, true, true);
1506
 
1507
  // Read the symbol names.
1508
  const unsigned int strtab_shndx =
1509
    this->adjust_shndx(symtabshdr.get_sh_link());
1510
  section_size_type strtab_size;
1511
  const unsigned char* pnamesu = this->section_contents(strtab_shndx,
1512
                                                        &strtab_size,
1513
                                                        true);
1514
  const char* pnames = reinterpret_cast<const char*>(pnamesu);
1515
 
1516
  // Loop over the local symbols.
1517
 
1518
  const Output_sections& out_sections(this->output_sections());
1519
  unsigned int shnum = this->shnum();
1520
  unsigned int count = 0;
1521
  unsigned int dyncount = 0;
1522
  // Skip the first, dummy, symbol.
1523
  psyms += sym_size;
1524
  bool discard_locals = parameters->options().discard_locals();
1525
  for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
1526
    {
1527
      elfcpp::Sym<size, big_endian> sym(psyms);
1528
 
1529
      Symbol_value<size>& lv(this->local_values_[i]);
1530
 
1531
      bool is_ordinary;
1532
      unsigned int shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(),
1533
                                                  &is_ordinary);
1534
      lv.set_input_shndx(shndx, is_ordinary);
1535
 
1536
      if (sym.get_st_type() == elfcpp::STT_SECTION)
1537
        lv.set_is_section_symbol();
1538
      else if (sym.get_st_type() == elfcpp::STT_TLS)
1539
        lv.set_is_tls_symbol();
1540
 
1541
      // Save the input symbol value for use in do_finalize_local_symbols().
1542
      lv.set_input_value(sym.get_st_value());
1543
 
1544
      // Decide whether this symbol should go into the output file.
1545
 
1546
      if ((shndx < shnum && out_sections[shndx] == NULL)
1547
          || (shndx == this->discarded_eh_frame_shndx_))
1548
        {
1549
          lv.set_no_output_symtab_entry();
1550
          gold_assert(!lv.needs_output_dynsym_entry());
1551
          continue;
1552
        }
1553
 
1554
      if (sym.get_st_type() == elfcpp::STT_SECTION)
1555
        {
1556
          lv.set_no_output_symtab_entry();
1557
          gold_assert(!lv.needs_output_dynsym_entry());
1558
          continue;
1559
        }
1560
 
1561
      if (sym.get_st_name() >= strtab_size)
1562
        {
1563
          this->error(_("local symbol %u section name out of range: %u >= %u"),
1564
                      i, sym.get_st_name(),
1565
                      static_cast<unsigned int>(strtab_size));
1566
          lv.set_no_output_symtab_entry();
1567
          continue;
1568
        }
1569
 
1570
      // If --discard-locals option is used, discard all temporary local
1571
      // symbols.  These symbols start with system-specific local label
1572
      // prefixes, typically .L for ELF system.  We want to be compatible
1573
      // with GNU ld so here we essentially use the same check in
1574
      // bfd_is_local_label().  The code is different because we already
1575
      // know that:
1576
      //
1577
      //   - the symbol is local and thus cannot have global or weak binding.
1578
      //   - the symbol is not a section symbol.
1579
      //   - the symbol has a name.
1580
      //
1581
      // We do not discard a symbol if it needs a dynamic symbol entry.
1582
      const char* name = pnames + sym.get_st_name();
1583
      if (discard_locals
1584
          && sym.get_st_type() != elfcpp::STT_FILE
1585
          && !lv.needs_output_dynsym_entry()
1586
          && parameters->target().is_local_label_name(name))
1587
        {
1588
          lv.set_no_output_symtab_entry();
1589
          continue;
1590
        }
1591
 
1592
      // Discard the local symbol if -retain_symbols_file is specified
1593
      // and the local symbol is not in that file.
1594
      if (!parameters->options().should_retain_symbol(name))
1595
        {
1596
          lv.set_no_output_symtab_entry();
1597
          continue;
1598
        }
1599
 
1600
      // Add the symbol to the symbol table string pool.
1601
      pool->add(name, true, NULL);
1602
      ++count;
1603
 
1604
      // If needed, add the symbol to the dynamic symbol table string pool.
1605
      if (lv.needs_output_dynsym_entry())
1606
        {
1607
          dynpool->add(name, true, NULL);
1608
          ++dyncount;
1609
        }
1610
    }
1611
 
1612
  this->output_local_symbol_count_ = count;
1613
  this->output_local_dynsym_count_ = dyncount;
1614
}
1615
 
1616
// Finalize the local symbols.  Here we set the final value in
1617
// THIS->LOCAL_VALUES_ and set their output symbol table indexes.
1618
// This function is always called from a singleton thread.  The actual
1619
// output of the local symbols will occur in a separate task.
1620
 
1621
template<int size, bool big_endian>
1622
unsigned int
1623
Sized_relobj<size, big_endian>::do_finalize_local_symbols(unsigned int index,
1624
                                                          off_t off,
1625
                                                          Symbol_table* symtab)
1626
{
1627
  gold_assert(off == static_cast<off_t>(align_address(off, size >> 3)));
1628
 
1629
  const unsigned int loccount = this->local_symbol_count_;
1630
  this->local_symbol_offset_ = off;
1631
 
1632
  const bool relocatable = parameters->options().relocatable();
1633
  const Output_sections& out_sections(this->output_sections());
1634
  const std::vector<Address>& out_offsets(this->section_offsets_);
1635
  unsigned int shnum = this->shnum();
1636
 
1637
  for (unsigned int i = 1; i < loccount; ++i)
1638
    {
1639
      Symbol_value<size>& lv(this->local_values_[i]);
1640
 
1641
      bool is_ordinary;
1642
      unsigned int shndx = lv.input_shndx(&is_ordinary);
1643
 
1644
      // Set the output symbol value.
1645
 
1646
      if (!is_ordinary)
1647
        {
1648
          if (shndx == elfcpp::SHN_ABS || Symbol::is_common_shndx(shndx))
1649
            lv.set_output_value(lv.input_value());
1650
          else
1651
            {
1652
              this->error(_("unknown section index %u for local symbol %u"),
1653
                          shndx, i);
1654
              lv.set_output_value(0);
1655
            }
1656
        }
1657
      else
1658
        {
1659
          if (shndx >= shnum)
1660
            {
1661
              this->error(_("local symbol %u section index %u out of range"),
1662
                          i, shndx);
1663
              shndx = 0;
1664
            }
1665
 
1666
          Output_section* os = out_sections[shndx];
1667
          Address secoffset = out_offsets[shndx];
1668
          if (symtab->is_section_folded(this, shndx))
1669
            {
1670
              gold_assert (os == NULL && secoffset == invalid_address);
1671
              // Get the os of the section it is folded onto.
1672
              Section_id folded = symtab->icf()->get_folded_section(this,
1673
                                                                    shndx);
1674
              gold_assert(folded.first != NULL);
1675
              Sized_relobj<size, big_endian>* folded_obj = reinterpret_cast
1676
                <Sized_relobj<size, big_endian>*>(folded.first);
1677
              os = folded_obj->output_section(folded.second);
1678
              gold_assert(os != NULL);
1679
              secoffset = folded_obj->get_output_section_offset(folded.second);
1680
              gold_assert(secoffset != invalid_address);
1681
            }
1682
 
1683
          if (os == NULL)
1684
            {
1685
              // This local symbol belongs to a section we are discarding.
1686
              // In some cases when applying relocations later, we will
1687
              // attempt to match it to the corresponding kept section,
1688
              // so we leave the input value unchanged here.
1689
              continue;
1690
            }
1691
          else if (secoffset == invalid_address)
1692
            {
1693
              uint64_t start;
1694
 
1695
              // This is a SHF_MERGE section or one which otherwise
1696
              // requires special handling.
1697
              if (shndx == this->discarded_eh_frame_shndx_)
1698
                {
1699
                  // This local symbol belongs to a discarded .eh_frame
1700
                  // section.  Just treat it like the case in which
1701
                  // os == NULL above.
1702
                  gold_assert(this->has_eh_frame_);
1703
                  continue;
1704
                }
1705
              else if (!lv.is_section_symbol())
1706
                {
1707
                  // This is not a section symbol.  We can determine
1708
                  // the final value now.
1709
                  lv.set_output_value(os->output_address(this, shndx,
1710
                                                         lv.input_value()));
1711
                }
1712
              else if (!os->find_starting_output_address(this, shndx, &start))
1713
                {
1714
                  // This is a section symbol, but apparently not one
1715
                  // in a merged section.  Just use the start of the
1716
                  // output section.  This happens with relocatable
1717
                  // links when the input object has section symbols
1718
                  // for arbitrary non-merge sections.
1719
                  lv.set_output_value(os->address());
1720
                }
1721
              else
1722
                {
1723
                  // We have to consider the addend to determine the
1724
                  // value to use in a relocation.  START is the start
1725
                  // of this input section.
1726
                  Merged_symbol_value<size>* msv =
1727
                    new Merged_symbol_value<size>(lv.input_value(), start);
1728
                  lv.set_merged_symbol_value(msv);
1729
                }
1730
            }
1731
          else if (lv.is_tls_symbol())
1732
            lv.set_output_value(os->tls_offset()
1733
                                + secoffset
1734
                                + lv.input_value());
1735
          else
1736
            lv.set_output_value((relocatable ? 0 : os->address())
1737
                                + secoffset
1738
                                + lv.input_value());
1739
        }
1740
 
1741
      if (lv.needs_output_symtab_entry())
1742
        {
1743
          lv.set_output_symtab_index(index);
1744
          ++index;
1745
        }
1746
    }
1747
  return index;
1748
}
1749
 
1750
// Set the output dynamic symbol table indexes for the local variables.
1751
 
1752
template<int size, bool big_endian>
1753
unsigned int
1754
Sized_relobj<size, big_endian>::do_set_local_dynsym_indexes(unsigned int index)
1755
{
1756
  const unsigned int loccount = this->local_symbol_count_;
1757
  for (unsigned int i = 1; i < loccount; ++i)
1758
    {
1759
      Symbol_value<size>& lv(this->local_values_[i]);
1760
      if (lv.needs_output_dynsym_entry())
1761
        {
1762
          lv.set_output_dynsym_index(index);
1763
          ++index;
1764
        }
1765
    }
1766
  return index;
1767
}
1768
 
1769
// Set the offset where local dynamic symbol information will be stored.
1770
// Returns the count of local symbols contributed to the symbol table by
1771
// this object.
1772
 
1773
template<int size, bool big_endian>
1774
unsigned int
1775
Sized_relobj<size, big_endian>::do_set_local_dynsym_offset(off_t off)
1776
{
1777
  gold_assert(off == static_cast<off_t>(align_address(off, size >> 3)));
1778
  this->local_dynsym_offset_ = off;
1779
  return this->output_local_dynsym_count_;
1780
}
1781
 
1782
// If Symbols_data is not NULL get the section flags from here otherwise
1783
// get it from the file.
1784
 
1785
template<int size, bool big_endian>
1786
uint64_t
1787
Sized_relobj<size, big_endian>::do_section_flags(unsigned int shndx)
1788
{
1789
  Symbols_data* sd = this->get_symbols_data();
1790
  if (sd != NULL)
1791
    {
1792
      const unsigned char* pshdrs = sd->section_headers_data
1793
                                    + This::shdr_size * shndx;
1794
      typename This::Shdr shdr(pshdrs);
1795
      return shdr.get_sh_flags();
1796
    }
1797
  // If sd is NULL, read the section header from the file.
1798
  return this->elf_file_.section_flags(shndx);
1799
}
1800
 
1801
// Get the section's ent size from Symbols_data.  Called by get_section_contents
1802
// in icf.cc
1803
 
1804
template<int size, bool big_endian>
1805
uint64_t
1806
Sized_relobj<size, big_endian>::do_section_entsize(unsigned int shndx)
1807
{
1808
  Symbols_data* sd = this->get_symbols_data();
1809
  gold_assert (sd != NULL);
1810
 
1811
  const unsigned char* pshdrs = sd->section_headers_data
1812
                                + This::shdr_size * shndx;
1813
  typename This::Shdr shdr(pshdrs);
1814
  return shdr.get_sh_entsize();
1815
}
1816
 
1817
 
1818
// Write out the local symbols.
1819
 
1820
template<int size, bool big_endian>
1821
void
1822
Sized_relobj<size, big_endian>::write_local_symbols(
1823
    Output_file* of,
1824
    const Stringpool* sympool,
1825
    const Stringpool* dynpool,
1826
    Output_symtab_xindex* symtab_xindex,
1827
    Output_symtab_xindex* dynsym_xindex)
1828
{
1829
  const bool strip_all = parameters->options().strip_all();
1830
  if (strip_all)
1831
    {
1832
      if (this->output_local_dynsym_count_ == 0)
1833
        return;
1834
      this->output_local_symbol_count_ = 0;
1835
    }
1836
 
1837
  gold_assert(this->symtab_shndx_ != -1U);
1838
  if (this->symtab_shndx_ == 0)
1839
    {
1840
      // This object has no symbols.  Weird but legal.
1841
      return;
1842
    }
1843
 
1844
  // Read the symbol table section header.
1845
  const unsigned int symtab_shndx = this->symtab_shndx_;
1846
  typename This::Shdr symtabshdr(this,
1847
                                 this->elf_file_.section_header(symtab_shndx));
1848
  gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
1849
  const unsigned int loccount = this->local_symbol_count_;
1850
  gold_assert(loccount == symtabshdr.get_sh_info());
1851
 
1852
  // Read the local symbols.
1853
  const int sym_size = This::sym_size;
1854
  off_t locsize = loccount * sym_size;
1855
  const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
1856
                                              locsize, true, false);
1857
 
1858
  // Read the symbol names.
1859
  const unsigned int strtab_shndx =
1860
    this->adjust_shndx(symtabshdr.get_sh_link());
1861
  section_size_type strtab_size;
1862
  const unsigned char* pnamesu = this->section_contents(strtab_shndx,
1863
                                                        &strtab_size,
1864
                                                        false);
1865
  const char* pnames = reinterpret_cast<const char*>(pnamesu);
1866
 
1867
  // Get views into the output file for the portions of the symbol table
1868
  // and the dynamic symbol table that we will be writing.
1869
  off_t output_size = this->output_local_symbol_count_ * sym_size;
1870
  unsigned char* oview = NULL;
1871
  if (output_size > 0)
1872
    oview = of->get_output_view(this->local_symbol_offset_, output_size);
1873
 
1874
  off_t dyn_output_size = this->output_local_dynsym_count_ * sym_size;
1875
  unsigned char* dyn_oview = NULL;
1876
  if (dyn_output_size > 0)
1877
    dyn_oview = of->get_output_view(this->local_dynsym_offset_,
1878
                                    dyn_output_size);
1879
 
1880
  const Output_sections out_sections(this->output_sections());
1881
 
1882
  gold_assert(this->local_values_.size() == loccount);
1883
 
1884
  unsigned char* ov = oview;
1885
  unsigned char* dyn_ov = dyn_oview;
1886
  psyms += sym_size;
1887
  for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
1888
    {
1889
      elfcpp::Sym<size, big_endian> isym(psyms);
1890
 
1891
      Symbol_value<size>& lv(this->local_values_[i]);
1892
 
1893
      bool is_ordinary;
1894
      unsigned int st_shndx = this->adjust_sym_shndx(i, isym.get_st_shndx(),
1895
                                                     &is_ordinary);
1896
      if (is_ordinary)
1897
        {
1898
          gold_assert(st_shndx < out_sections.size());
1899
          if (out_sections[st_shndx] == NULL)
1900
            continue;
1901
          st_shndx = out_sections[st_shndx]->out_shndx();
1902
          if (st_shndx >= elfcpp::SHN_LORESERVE)
1903
            {
1904
              if (lv.needs_output_symtab_entry() && !strip_all)
1905
                symtab_xindex->add(lv.output_symtab_index(), st_shndx);
1906
              if (lv.needs_output_dynsym_entry())
1907
                dynsym_xindex->add(lv.output_dynsym_index(), st_shndx);
1908
              st_shndx = elfcpp::SHN_XINDEX;
1909
            }
1910
        }
1911
 
1912
      // Write the symbol to the output symbol table.
1913
      if (!strip_all && lv.needs_output_symtab_entry())
1914
        {
1915
          elfcpp::Sym_write<size, big_endian> osym(ov);
1916
 
1917
          gold_assert(isym.get_st_name() < strtab_size);
1918
          const char* name = pnames + isym.get_st_name();
1919
          osym.put_st_name(sympool->get_offset(name));
1920
          osym.put_st_value(this->local_values_[i].value(this, 0));
1921
          osym.put_st_size(isym.get_st_size());
1922
          osym.put_st_info(isym.get_st_info());
1923
          osym.put_st_other(isym.get_st_other());
1924
          osym.put_st_shndx(st_shndx);
1925
 
1926
          ov += sym_size;
1927
        }
1928
 
1929
      // Write the symbol to the output dynamic symbol table.
1930
      if (lv.needs_output_dynsym_entry())
1931
        {
1932
          gold_assert(dyn_ov < dyn_oview + dyn_output_size);
1933
          elfcpp::Sym_write<size, big_endian> osym(dyn_ov);
1934
 
1935
          gold_assert(isym.get_st_name() < strtab_size);
1936
          const char* name = pnames + isym.get_st_name();
1937
          osym.put_st_name(dynpool->get_offset(name));
1938
          osym.put_st_value(this->local_values_[i].value(this, 0));
1939
          osym.put_st_size(isym.get_st_size());
1940
          osym.put_st_info(isym.get_st_info());
1941
          osym.put_st_other(isym.get_st_other());
1942
          osym.put_st_shndx(st_shndx);
1943
 
1944
          dyn_ov += sym_size;
1945
        }
1946
    }
1947
 
1948
 
1949
  if (output_size > 0)
1950
    {
1951
      gold_assert(ov - oview == output_size);
1952
      of->write_output_view(this->local_symbol_offset_, output_size, oview);
1953
    }
1954
 
1955
  if (dyn_output_size > 0)
1956
    {
1957
      gold_assert(dyn_ov - dyn_oview == dyn_output_size);
1958
      of->write_output_view(this->local_dynsym_offset_, dyn_output_size,
1959
                            dyn_oview);
1960
    }
1961
}
1962
 
1963
// Set *INFO to symbolic information about the offset OFFSET in the
1964
// section SHNDX.  Return true if we found something, false if we
1965
// found nothing.
1966
 
1967
template<int size, bool big_endian>
1968
bool
1969
Sized_relobj<size, big_endian>::get_symbol_location_info(
1970
    unsigned int shndx,
1971
    off_t offset,
1972
    Symbol_location_info* info)
1973
{
1974
  if (this->symtab_shndx_ == 0)
1975
    return false;
1976
 
1977
  section_size_type symbols_size;
1978
  const unsigned char* symbols = this->section_contents(this->symtab_shndx_,
1979
                                                        &symbols_size,
1980
                                                        false);
1981
 
1982
  unsigned int symbol_names_shndx =
1983
    this->adjust_shndx(this->section_link(this->symtab_shndx_));
1984
  section_size_type names_size;
1985
  const unsigned char* symbol_names_u =
1986
    this->section_contents(symbol_names_shndx, &names_size, false);
1987
  const char* symbol_names = reinterpret_cast<const char*>(symbol_names_u);
1988
 
1989
  const int sym_size = This::sym_size;
1990
  const size_t count = symbols_size / sym_size;
1991
 
1992
  const unsigned char* p = symbols;
1993
  for (size_t i = 0; i < count; ++i, p += sym_size)
1994
    {
1995
      elfcpp::Sym<size, big_endian> sym(p);
1996
 
1997
      if (sym.get_st_type() == elfcpp::STT_FILE)
1998
        {
1999
          if (sym.get_st_name() >= names_size)
2000
            info->source_file = "(invalid)";
2001
          else
2002
            info->source_file = symbol_names + sym.get_st_name();
2003
          continue;
2004
        }
2005
 
2006
      bool is_ordinary;
2007
      unsigned int st_shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(),
2008
                                                     &is_ordinary);
2009
      if (is_ordinary
2010
          && st_shndx == shndx
2011
          && static_cast<off_t>(sym.get_st_value()) <= offset
2012
          && (static_cast<off_t>(sym.get_st_value() + sym.get_st_size())
2013
              > offset))
2014
        {
2015
          if (sym.get_st_name() > names_size)
2016
            info->enclosing_symbol_name = "(invalid)";
2017
          else
2018
            {
2019
              info->enclosing_symbol_name = symbol_names + sym.get_st_name();
2020
              if (parameters->options().do_demangle())
2021
                {
2022
                  char* demangled_name = cplus_demangle(
2023
                      info->enclosing_symbol_name.c_str(),
2024
                      DMGL_ANSI | DMGL_PARAMS);
2025
                  if (demangled_name != NULL)
2026
                    {
2027
                      info->enclosing_symbol_name.assign(demangled_name);
2028
                      free(demangled_name);
2029
                    }
2030
                }
2031
            }
2032
          return true;
2033
        }
2034
    }
2035
 
2036
  return false;
2037
}
2038
 
2039
// Look for a kept section corresponding to the given discarded section,
2040
// and return its output address.  This is used only for relocations in
2041
// debugging sections.  If we can't find the kept section, return 0.
2042
 
2043
template<int size, bool big_endian>
2044
typename Sized_relobj<size, big_endian>::Address
2045
Sized_relobj<size, big_endian>::map_to_kept_section(
2046
    unsigned int shndx,
2047
    bool* found) const
2048
{
2049
  Relobj* kept_object;
2050
  unsigned int kept_shndx;
2051
  if (this->get_kept_comdat_section(shndx, &kept_object, &kept_shndx))
2052
    {
2053
      Sized_relobj<size, big_endian>* kept_relobj =
2054
        static_cast<Sized_relobj<size, big_endian>*>(kept_object);
2055
      Output_section* os = kept_relobj->output_section(kept_shndx);
2056
      Address offset = kept_relobj->get_output_section_offset(kept_shndx);
2057
      if (os != NULL && offset != invalid_address)
2058
        {
2059
          *found = true;
2060
          return os->address() + offset;
2061
        }
2062
    }
2063
  *found = false;
2064
  return 0;
2065
}
2066
 
2067
// Get symbol counts.
2068
 
2069
template<int size, bool big_endian>
2070
void
2071
Sized_relobj<size, big_endian>::do_get_global_symbol_counts(
2072
    const Symbol_table*,
2073
    size_t* defined,
2074
    size_t* used) const
2075
{
2076
  *defined = this->defined_count_;
2077
  size_t count = 0;
2078
  for (Symbols::const_iterator p = this->symbols_.begin();
2079
       p != this->symbols_.end();
2080
       ++p)
2081
    if (*p != NULL
2082
        && (*p)->source() == Symbol::FROM_OBJECT
2083
        && (*p)->object() == this
2084
        && (*p)->is_defined())
2085
      ++count;
2086
  *used = count;
2087
}
2088
 
2089
// Input_objects methods.
2090
 
2091
// Add a regular relocatable object to the list.  Return false if this
2092
// object should be ignored.
2093
 
2094
bool
2095
Input_objects::add_object(Object* obj)
2096
{
2097
  // Print the filename if the -t/--trace option is selected.
2098
  if (parameters->options().trace())
2099
    gold_info("%s", obj->name().c_str());
2100
 
2101
  if (!obj->is_dynamic())
2102
    this->relobj_list_.push_back(static_cast<Relobj*>(obj));
2103
  else
2104
    {
2105
      // See if this is a duplicate SONAME.
2106
      Dynobj* dynobj = static_cast<Dynobj*>(obj);
2107
      const char* soname = dynobj->soname();
2108
 
2109
      std::pair<Unordered_set<std::string>::iterator, bool> ins =
2110
        this->sonames_.insert(soname);
2111
      if (!ins.second)
2112
        {
2113
          // We have already seen a dynamic object with this soname.
2114
          return false;
2115
        }
2116
 
2117
      this->dynobj_list_.push_back(dynobj);
2118
    }
2119
 
2120
  // Add this object to the cross-referencer if requested.
2121
  if (parameters->options().user_set_print_symbol_counts())
2122
    {
2123
      if (this->cref_ == NULL)
2124
        this->cref_ = new Cref();
2125
      this->cref_->add_object(obj);
2126
    }
2127
 
2128
  return true;
2129
}
2130
 
2131
// For each dynamic object, record whether we've seen all of its
2132
// explicit dependencies.
2133
 
2134
void
2135
Input_objects::check_dynamic_dependencies() const
2136
{
2137
  bool issued_copy_dt_needed_error = false;
2138
  for (Dynobj_list::const_iterator p = this->dynobj_list_.begin();
2139
       p != this->dynobj_list_.end();
2140
       ++p)
2141
    {
2142
      const Dynobj::Needed& needed((*p)->needed());
2143
      bool found_all = true;
2144
      Dynobj::Needed::const_iterator pneeded;
2145
      for (pneeded = needed.begin(); pneeded != needed.end(); ++pneeded)
2146
        {
2147
          if (this->sonames_.find(*pneeded) == this->sonames_.end())
2148
            {
2149
              found_all = false;
2150
              break;
2151
            }
2152
        }
2153
      (*p)->set_has_unknown_needed_entries(!found_all);
2154
 
2155
      // --copy-dt-needed-entries aka --add-needed is a GNU ld option
2156
      // --that gold does not support.  However, they cause no trouble
2157
      // --unless there is a DT_NEEDED entry that we don't know about;
2158
      // --warn only in that case.
2159
      if (!found_all
2160
          && !issued_copy_dt_needed_error
2161
          && (parameters->options().copy_dt_needed_entries()
2162
              || parameters->options().add_needed()))
2163
        {
2164
          const char* optname;
2165
          if (parameters->options().copy_dt_needed_entries())
2166
            optname = "--copy-dt-needed-entries";
2167
          else
2168
            optname = "--add-needed";
2169
          gold_error(_("%s is not supported but is required for %s in %s"),
2170
                     optname, (*pneeded).c_str(), (*p)->name().c_str());
2171
          issued_copy_dt_needed_error = true;
2172
        }
2173
    }
2174
}
2175
 
2176
// Start processing an archive.
2177
 
2178
void
2179
Input_objects::archive_start(Archive* archive)
2180
{
2181
  if (parameters->options().user_set_print_symbol_counts())
2182
    {
2183
      if (this->cref_ == NULL)
2184
        this->cref_ = new Cref();
2185
      this->cref_->add_archive_start(archive);
2186
    }
2187
}
2188
 
2189
// Stop processing an archive.
2190
 
2191
void
2192
Input_objects::archive_stop(Archive* archive)
2193
{
2194
  if (parameters->options().user_set_print_symbol_counts())
2195
    this->cref_->add_archive_stop(archive);
2196
}
2197
 
2198
// Print symbol counts
2199
 
2200
void
2201
Input_objects::print_symbol_counts(const Symbol_table* symtab) const
2202
{
2203
  if (parameters->options().user_set_print_symbol_counts()
2204
      && this->cref_ != NULL)
2205
    this->cref_->print_symbol_counts(symtab);
2206
}
2207
 
2208
// Relocate_info methods.
2209
 
2210
// Return a string describing the location of a relocation.  This is
2211
// only used in error messages.
2212
 
2213
template<int size, bool big_endian>
2214
std::string
2215
Relocate_info<size, big_endian>::location(size_t, off_t offset) const
2216
{
2217
  // See if we can get line-number information from debugging sections.
2218
  std::string filename;
2219
  std::string file_and_lineno;   // Better than filename-only, if available.
2220
 
2221
  Sized_dwarf_line_info<size, big_endian> line_info(this->object);
2222
  // This will be "" if we failed to parse the debug info for any reason.
2223
  file_and_lineno = line_info.addr2line(this->data_shndx, offset);
2224
 
2225
  std::string ret(this->object->name());
2226
  ret += ':';
2227
  Symbol_location_info info;
2228
  if (this->object->get_symbol_location_info(this->data_shndx, offset, &info))
2229
    {
2230
      ret += " in function ";
2231
      ret += info.enclosing_symbol_name;
2232
      ret += ":";
2233
      filename = info.source_file;
2234
    }
2235
 
2236
  if (!file_and_lineno.empty())
2237
    ret += file_and_lineno;
2238
  else
2239
    {
2240
      if (!filename.empty())
2241
        ret += filename;
2242
      ret += "(";
2243
      ret += this->object->section_name(this->data_shndx);
2244
      char buf[100];
2245
      // Offsets into sections have to be positive.
2246
      snprintf(buf, sizeof(buf), "+0x%lx", static_cast<long>(offset));
2247
      ret += buf;
2248
      ret += ")";
2249
    }
2250
  return ret;
2251
}
2252
 
2253
} // End namespace gold.
2254
 
2255
namespace
2256
{
2257
 
2258
using namespace gold;
2259
 
2260
// Read an ELF file with the header and return the appropriate
2261
// instance of Object.
2262
 
2263
template<int size, bool big_endian>
2264
Object*
2265
make_elf_sized_object(const std::string& name, Input_file* input_file,
2266
                      off_t offset, const elfcpp::Ehdr<size, big_endian>& ehdr,
2267
                      bool* punconfigured)
2268
{
2269
  Target* target = select_target(ehdr.get_e_machine(), size, big_endian,
2270
                                 ehdr.get_e_ident()[elfcpp::EI_OSABI],
2271
                                 ehdr.get_e_ident()[elfcpp::EI_ABIVERSION]);
2272
  if (target == NULL)
2273
    gold_fatal(_("%s: unsupported ELF machine number %d"),
2274
               name.c_str(), ehdr.get_e_machine());
2275
 
2276
  if (!parameters->target_valid())
2277
    set_parameters_target(target);
2278
  else if (target != &parameters->target())
2279
    {
2280
      if (punconfigured != NULL)
2281
        *punconfigured = true;
2282
      else
2283
        gold_error(_("%s: incompatible target"), name.c_str());
2284
      return NULL;
2285
    }
2286
 
2287
  return target->make_elf_object<size, big_endian>(name, input_file, offset,
2288
                                                   ehdr);
2289
}
2290
 
2291
} // End anonymous namespace.
2292
 
2293
namespace gold
2294
{
2295
 
2296
// Return whether INPUT_FILE is an ELF object.
2297
 
2298
bool
2299
is_elf_object(Input_file* input_file, off_t offset,
2300
              const unsigned char** start, int *read_size)
2301
{
2302
  off_t filesize = input_file->file().filesize();
2303
  int want = elfcpp::Elf_recognizer::max_header_size;
2304
  if (filesize - offset < want)
2305
    want = filesize - offset;
2306
 
2307
  const unsigned char* p = input_file->file().get_view(offset, 0, want,
2308
                                                       true, false);
2309
  *start = p;
2310
  *read_size = want;
2311
 
2312
  return elfcpp::Elf_recognizer::is_elf_file(p, want);
2313
}
2314
 
2315
// Read an ELF file and return the appropriate instance of Object.
2316
 
2317
Object*
2318
make_elf_object(const std::string& name, Input_file* input_file, off_t offset,
2319
                const unsigned char* p, section_offset_type bytes,
2320
                bool* punconfigured)
2321
{
2322
  if (punconfigured != NULL)
2323
    *punconfigured = false;
2324
 
2325
  std::string error;
2326
  bool big_endian;
2327
  int size;
2328
  if (!elfcpp::Elf_recognizer::is_valid_header(p, bytes, &size,
2329
                                               &big_endian, &error))
2330
    {
2331
      gold_error(_("%s: %s"), name.c_str(), error.c_str());
2332
      return NULL;
2333
    }
2334
 
2335
  if (size == 32)
2336
    {
2337
      if (big_endian)
2338
        {
2339
#ifdef HAVE_TARGET_32_BIG
2340
          elfcpp::Ehdr<32, true> ehdr(p);
2341
          return make_elf_sized_object<32, true>(name, input_file,
2342
                                                 offset, ehdr, punconfigured);
2343
#else
2344
          if (punconfigured != NULL)
2345
            *punconfigured = true;
2346
          else
2347
            gold_error(_("%s: not configured to support "
2348
                         "32-bit big-endian object"),
2349
                       name.c_str());
2350
          return NULL;
2351
#endif
2352
        }
2353
      else
2354
        {
2355
#ifdef HAVE_TARGET_32_LITTLE
2356
          elfcpp::Ehdr<32, false> ehdr(p);
2357
          return make_elf_sized_object<32, false>(name, input_file,
2358
                                                  offset, ehdr, punconfigured);
2359
#else
2360
          if (punconfigured != NULL)
2361
            *punconfigured = true;
2362
          else
2363
            gold_error(_("%s: not configured to support "
2364
                         "32-bit little-endian object"),
2365
                       name.c_str());
2366
          return NULL;
2367
#endif
2368
        }
2369
    }
2370
  else if (size == 64)
2371
    {
2372
      if (big_endian)
2373
        {
2374
#ifdef HAVE_TARGET_64_BIG
2375
          elfcpp::Ehdr<64, true> ehdr(p);
2376
          return make_elf_sized_object<64, true>(name, input_file,
2377
                                                 offset, ehdr, punconfigured);
2378
#else
2379
          if (punconfigured != NULL)
2380
            *punconfigured = true;
2381
          else
2382
            gold_error(_("%s: not configured to support "
2383
                         "64-bit big-endian object"),
2384
                       name.c_str());
2385
          return NULL;
2386
#endif
2387
        }
2388
      else
2389
        {
2390
#ifdef HAVE_TARGET_64_LITTLE
2391
          elfcpp::Ehdr<64, false> ehdr(p);
2392
          return make_elf_sized_object<64, false>(name, input_file,
2393
                                                  offset, ehdr, punconfigured);
2394
#else
2395
          if (punconfigured != NULL)
2396
            *punconfigured = true;
2397
          else
2398
            gold_error(_("%s: not configured to support "
2399
                         "64-bit little-endian object"),
2400
                       name.c_str());
2401
          return NULL;
2402
#endif
2403
        }
2404
    }
2405
  else
2406
    gold_unreachable();
2407
}
2408
 
2409
// Instantiate the templates we need.
2410
 
2411
#ifdef HAVE_TARGET_32_LITTLE
2412
template
2413
void
2414
Object::read_section_data<32, false>(elfcpp::Elf_file<32, false, Object>*,
2415
                                     Read_symbols_data*);
2416
#endif
2417
 
2418
#ifdef HAVE_TARGET_32_BIG
2419
template
2420
void
2421
Object::read_section_data<32, true>(elfcpp::Elf_file<32, true, Object>*,
2422
                                    Read_symbols_data*);
2423
#endif
2424
 
2425
#ifdef HAVE_TARGET_64_LITTLE
2426
template
2427
void
2428
Object::read_section_data<64, false>(elfcpp::Elf_file<64, false, Object>*,
2429
                                     Read_symbols_data*);
2430
#endif
2431
 
2432
#ifdef HAVE_TARGET_64_BIG
2433
template
2434
void
2435
Object::read_section_data<64, true>(elfcpp::Elf_file<64, true, Object>*,
2436
                                    Read_symbols_data*);
2437
#endif
2438
 
2439
#ifdef HAVE_TARGET_32_LITTLE
2440
template
2441
class Sized_relobj<32, false>;
2442
#endif
2443
 
2444
#ifdef HAVE_TARGET_32_BIG
2445
template
2446
class Sized_relobj<32, true>;
2447
#endif
2448
 
2449
#ifdef HAVE_TARGET_64_LITTLE
2450
template
2451
class Sized_relobj<64, false>;
2452
#endif
2453
 
2454
#ifdef HAVE_TARGET_64_BIG
2455
template
2456
class Sized_relobj<64, true>;
2457
#endif
2458
 
2459
#ifdef HAVE_TARGET_32_LITTLE
2460
template
2461
struct Relocate_info<32, false>;
2462
#endif
2463
 
2464
#ifdef HAVE_TARGET_32_BIG
2465
template
2466
struct Relocate_info<32, true>;
2467
#endif
2468
 
2469
#ifdef HAVE_TARGET_64_LITTLE
2470
template
2471
struct Relocate_info<64, false>;
2472
#endif
2473
 
2474
#ifdef HAVE_TARGET_64_BIG
2475
template
2476
struct Relocate_info<64, true>;
2477
#endif
2478
 
2479
} // End namespace gold.

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