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[/] [open8_urisc/] [trunk/] [gnu/] [binutils/] [gold/] [object.cc] - Blame information for rev 163

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1 27 khays
// object.cc -- support for an object file for linking in gold
2
 
3
// Copyright 2006, 2007, 2008, 2009, 2010, 2011 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
#include "compressed_output.h"
43
#include "incremental.h"
44
 
45
namespace gold
46
{
47
 
48
// Struct Read_symbols_data.
49
 
50
// Destroy any remaining File_view objects.
51
 
52
Read_symbols_data::~Read_symbols_data()
53
{
54
  if (this->section_headers != NULL)
55
    delete this->section_headers;
56
  if (this->section_names != NULL)
57
    delete this->section_names;
58
  if (this->symbols != NULL)
59
    delete this->symbols;
60
  if (this->symbol_names != NULL)
61
    delete this->symbol_names;
62
  if (this->versym != NULL)
63
    delete this->versym;
64
  if (this->verdef != NULL)
65
    delete this->verdef;
66
  if (this->verneed != NULL)
67
    delete this->verneed;
68
}
69
 
70
// Class Xindex.
71
 
72
// Initialize the symtab_xindex_ array.  Find the SHT_SYMTAB_SHNDX
73
// section and read it in.  SYMTAB_SHNDX is the index of the symbol
74
// table we care about.
75
 
76
template<int size, bool big_endian>
77
void
78
Xindex::initialize_symtab_xindex(Object* object, unsigned int symtab_shndx)
79
{
80
  if (!this->symtab_xindex_.empty())
81
    return;
82
 
83
  gold_assert(symtab_shndx != 0);
84
 
85
  // Look through the sections in reverse order, on the theory that it
86
  // is more likely to be near the end than the beginning.
87
  unsigned int i = object->shnum();
88
  while (i > 0)
89
    {
90
      --i;
91
      if (object->section_type(i) == elfcpp::SHT_SYMTAB_SHNDX
92
          && this->adjust_shndx(object->section_link(i)) == symtab_shndx)
93
        {
94
          this->read_symtab_xindex<size, big_endian>(object, i, NULL);
95
          return;
96
        }
97
    }
98
 
99
  object->error(_("missing SHT_SYMTAB_SHNDX section"));
100
}
101
 
102
// Read in the symtab_xindex_ array, given the section index of the
103
// SHT_SYMTAB_SHNDX section.  If PSHDRS is not NULL, it points at the
104
// section headers.
105
 
106
template<int size, bool big_endian>
107
void
108
Xindex::read_symtab_xindex(Object* object, unsigned int xindex_shndx,
109
                           const unsigned char* pshdrs)
110
{
111
  section_size_type bytecount;
112
  const unsigned char* contents;
113
  if (pshdrs == NULL)
114
    contents = object->section_contents(xindex_shndx, &bytecount, false);
115
  else
116
    {
117
      const unsigned char* p = (pshdrs
118
                                + (xindex_shndx
119
                                   * elfcpp::Elf_sizes<size>::shdr_size));
120
      typename elfcpp::Shdr<size, big_endian> shdr(p);
121
      bytecount = convert_to_section_size_type(shdr.get_sh_size());
122
      contents = object->get_view(shdr.get_sh_offset(), bytecount, true, false);
123
    }
124
 
125
  gold_assert(this->symtab_xindex_.empty());
126
  this->symtab_xindex_.reserve(bytecount / 4);
127
  for (section_size_type i = 0; i < bytecount; i += 4)
128
    {
129
      unsigned int shndx = elfcpp::Swap<32, big_endian>::readval(contents + i);
130
      // We preadjust the section indexes we save.
131
      this->symtab_xindex_.push_back(this->adjust_shndx(shndx));
132
    }
133
}
134
 
135
// Symbol symndx has a section of SHN_XINDEX; return the real section
136
// index.
137
 
138
unsigned int
139
Xindex::sym_xindex_to_shndx(Object* object, unsigned int symndx)
140
{
141
  if (symndx >= this->symtab_xindex_.size())
142
    {
143
      object->error(_("symbol %u out of range for SHT_SYMTAB_SHNDX section"),
144
                    symndx);
145
      return elfcpp::SHN_UNDEF;
146
    }
147
  unsigned int shndx = this->symtab_xindex_[symndx];
148
  if (shndx < elfcpp::SHN_LORESERVE || shndx >= object->shnum())
149
    {
150
      object->error(_("extended index for symbol %u out of range: %u"),
151
                    symndx, shndx);
152
      return elfcpp::SHN_UNDEF;
153
    }
154
  return shndx;
155
}
156
 
157
// Class Object.
158
 
159
// Report an error for this object file.  This is used by the
160
// elfcpp::Elf_file interface, and also called by the Object code
161
// itself.
162
 
163
void
164
Object::error(const char* format, ...) const
165
{
166
  va_list args;
167
  va_start(args, format);
168
  char* buf = NULL;
169
  if (vasprintf(&buf, format, args) < 0)
170
    gold_nomem();
171
  va_end(args);
172
  gold_error(_("%s: %s"), this->name().c_str(), buf);
173
  free(buf);
174
}
175
 
176
// Return a view of the contents of a section.
177
 
178
const unsigned char*
179
Object::section_contents(unsigned int shndx, section_size_type* plen,
180
                         bool cache)
181
{
182
  Location loc(this->do_section_contents(shndx));
183
  *plen = convert_to_section_size_type(loc.data_size);
184
  if (*plen == 0)
185
    {
186
      static const unsigned char empty[1] = { '\0' };
187
      return empty;
188
    }
189
  return this->get_view(loc.file_offset, *plen, true, cache);
190
}
191
 
192
// Read the section data into SD.  This is code common to Sized_relobj_file
193
// and Sized_dynobj, so we put it into Object.
194
 
195
template<int size, bool big_endian>
196
void
197
Object::read_section_data(elfcpp::Elf_file<size, big_endian, Object>* elf_file,
198
                          Read_symbols_data* sd)
199
{
200
  const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
201
 
202
  // Read the section headers.
203
  const off_t shoff = elf_file->shoff();
204
  const unsigned int shnum = this->shnum();
205
  sd->section_headers = this->get_lasting_view(shoff, shnum * shdr_size,
206
                                               true, true);
207
 
208
  // Read the section names.
209
  const unsigned char* pshdrs = sd->section_headers->data();
210
  const unsigned char* pshdrnames = pshdrs + elf_file->shstrndx() * shdr_size;
211
  typename elfcpp::Shdr<size, big_endian> shdrnames(pshdrnames);
212
 
213
  if (shdrnames.get_sh_type() != elfcpp::SHT_STRTAB)
214
    this->error(_("section name section has wrong type: %u"),
215
                static_cast<unsigned int>(shdrnames.get_sh_type()));
216
 
217
  sd->section_names_size =
218
    convert_to_section_size_type(shdrnames.get_sh_size());
219
  sd->section_names = this->get_lasting_view(shdrnames.get_sh_offset(),
220
                                             sd->section_names_size, false,
221
                                             false);
222
}
223
 
224
// If NAME is the name of a special .gnu.warning section, arrange for
225
// the warning to be issued.  SHNDX is the section index.  Return
226
// whether it is a warning section.
227
 
228
bool
229
Object::handle_gnu_warning_section(const char* name, unsigned int shndx,
230
                                   Symbol_table* symtab)
231
{
232
  const char warn_prefix[] = ".gnu.warning.";
233
  const int warn_prefix_len = sizeof warn_prefix - 1;
234
  if (strncmp(name, warn_prefix, warn_prefix_len) == 0)
235
    {
236
      // Read the section contents to get the warning text.  It would
237
      // be nicer if we only did this if we have to actually issue a
238
      // warning.  Unfortunately, warnings are issued as we relocate
239
      // sections.  That means that we can not lock the object then,
240
      // as we might try to issue the same warning multiple times
241
      // simultaneously.
242
      section_size_type len;
243
      const unsigned char* contents = this->section_contents(shndx, &len,
244
                                                             false);
245
      if (len == 0)
246
        {
247
          const char* warning = name + warn_prefix_len;
248
          contents = reinterpret_cast<const unsigned char*>(warning);
249
          len = strlen(warning);
250
        }
251
      std::string warning(reinterpret_cast<const char*>(contents), len);
252
      symtab->add_warning(name + warn_prefix_len, this, warning);
253
      return true;
254
    }
255
  return false;
256
}
257
 
258
// If NAME is the name of the special section which indicates that
259
// this object was compiled with -fsplit-stack, mark it accordingly.
260
 
261
bool
262
Object::handle_split_stack_section(const char* name)
263
{
264
  if (strcmp(name, ".note.GNU-split-stack") == 0)
265
    {
266
      this->uses_split_stack_ = true;
267
      return true;
268
    }
269
  if (strcmp(name, ".note.GNU-no-split-stack") == 0)
270
    {
271
      this->has_no_split_stack_ = true;
272
      return true;
273
    }
274
  return false;
275
}
276
 
277
// Class Relobj
278
 
279
// To copy the symbols data read from the file to a local data structure.
280
// This function is called from do_layout only while doing garbage 
281
// collection.
282
 
283
void
284
Relobj::copy_symbols_data(Symbols_data* gc_sd, Read_symbols_data* sd,
285
                          unsigned int section_header_size)
286
{
287
  gc_sd->section_headers_data =
288
         new unsigned char[(section_header_size)];
289
  memcpy(gc_sd->section_headers_data, sd->section_headers->data(),
290
         section_header_size);
291
  gc_sd->section_names_data =
292
         new unsigned char[sd->section_names_size];
293
  memcpy(gc_sd->section_names_data, sd->section_names->data(),
294
         sd->section_names_size);
295
  gc_sd->section_names_size = sd->section_names_size;
296
  if (sd->symbols != NULL)
297
    {
298
      gc_sd->symbols_data =
299
             new unsigned char[sd->symbols_size];
300
      memcpy(gc_sd->symbols_data, sd->symbols->data(),
301
            sd->symbols_size);
302
    }
303
  else
304
    {
305
      gc_sd->symbols_data = NULL;
306
    }
307
  gc_sd->symbols_size = sd->symbols_size;
308
  gc_sd->external_symbols_offset = sd->external_symbols_offset;
309
  if (sd->symbol_names != NULL)
310
    {
311
      gc_sd->symbol_names_data =
312
             new unsigned char[sd->symbol_names_size];
313
      memcpy(gc_sd->symbol_names_data, sd->symbol_names->data(),
314
            sd->symbol_names_size);
315
    }
316
  else
317
    {
318
      gc_sd->symbol_names_data = NULL;
319
    }
320
  gc_sd->symbol_names_size = sd->symbol_names_size;
321
}
322
 
323
// This function determines if a particular section name must be included
324
// in the link.  This is used during garbage collection to determine the
325
// roots of the worklist.
326
 
327
bool
328
Relobj::is_section_name_included(const char* name)
329
{
330
  if (is_prefix_of(".ctors", name)
331
      || is_prefix_of(".dtors", name)
332
      || is_prefix_of(".note", name)
333
      || is_prefix_of(".init", name)
334
      || is_prefix_of(".fini", name)
335
      || is_prefix_of(".gcc_except_table", name)
336
      || is_prefix_of(".jcr", name)
337
      || is_prefix_of(".preinit_array", name)
338
      || (is_prefix_of(".text", name)
339
          && strstr(name, "personality"))
340
      || (is_prefix_of(".data", name)
341
          &&  strstr(name, "personality"))
342
      || (is_prefix_of(".gnu.linkonce.d", name)
343
          && strstr(name, "personality")))
344
    {
345
      return true;
346
    }
347
  return false;
348
}
349
 
350
// Finalize the incremental relocation information.  Allocates a block
351
// of relocation entries for each symbol, and sets the reloc_bases_
352
// array to point to the first entry in each block.  If CLEAR_COUNTS
353
// is TRUE, also clear the per-symbol relocation counters.
354
 
355
void
356
Relobj::finalize_incremental_relocs(Layout* layout, bool clear_counts)
357
{
358
  unsigned int nsyms = this->get_global_symbols()->size();
359
  this->reloc_bases_ = new unsigned int[nsyms];
360
 
361
  gold_assert(this->reloc_bases_ != NULL);
362
  gold_assert(layout->incremental_inputs() != NULL);
363
 
364
  unsigned int rindex = layout->incremental_inputs()->get_reloc_count();
365
  for (unsigned int i = 0; i < nsyms; ++i)
366
    {
367
      this->reloc_bases_[i] = rindex;
368
      rindex += this->reloc_counts_[i];
369
      if (clear_counts)
370
        this->reloc_counts_[i] = 0;
371
    }
372
  layout->incremental_inputs()->set_reloc_count(rindex);
373
}
374
 
375
// Class Sized_relobj.
376
 
377
// Iterate over local symbols, calling a visitor class V for each GOT offset
378
// associated with a local symbol.
379
 
380
template<int size, bool big_endian>
381
void
382
Sized_relobj<size, big_endian>::do_for_all_local_got_entries(
383
    Got_offset_list::Visitor* v) const
384
{
385
  unsigned int nsyms = this->local_symbol_count();
386
  for (unsigned int i = 0; i < nsyms; i++)
387
    {
388
      Local_got_offsets::const_iterator p = this->local_got_offsets_.find(i);
389
      if (p != this->local_got_offsets_.end())
390
        {
391
          const Got_offset_list* got_offsets = p->second;
392
          got_offsets->for_all_got_offsets(v);
393
        }
394
    }
395
}
396
 
397
// Class Sized_relobj_file.
398
 
399
template<int size, bool big_endian>
400
Sized_relobj_file<size, big_endian>::Sized_relobj_file(
401
    const std::string& name,
402
    Input_file* input_file,
403
    off_t offset,
404
    const elfcpp::Ehdr<size, big_endian>& ehdr)
405
  : Sized_relobj<size, big_endian>(name, input_file, offset),
406
    elf_file_(this, ehdr),
407
    symtab_shndx_(-1U),
408
    local_symbol_count_(0),
409
    output_local_symbol_count_(0),
410
    output_local_dynsym_count_(0),
411
    symbols_(),
412
    defined_count_(0),
413
    local_symbol_offset_(0),
414
    local_dynsym_offset_(0),
415
    local_values_(),
416
    local_plt_offsets_(),
417
    kept_comdat_sections_(),
418
    has_eh_frame_(false),
419
    discarded_eh_frame_shndx_(-1U),
420
    deferred_layout_(),
421
    deferred_layout_relocs_(),
422
    compressed_sections_()
423
{
424 159 khays
  this->e_type_ = ehdr.get_e_type();
425 27 khays
}
426
 
427
template<int size, bool big_endian>
428
Sized_relobj_file<size, big_endian>::~Sized_relobj_file()
429
{
430
}
431
 
432
// Set up an object file based on the file header.  This sets up the
433
// section information.
434
 
435
template<int size, bool big_endian>
436
void
437
Sized_relobj_file<size, big_endian>::do_setup()
438
{
439
  const unsigned int shnum = this->elf_file_.shnum();
440
  this->set_shnum(shnum);
441
}
442
 
443
// Find the SHT_SYMTAB section, given the section headers.  The ELF
444
// standard says that maybe in the future there can be more than one
445
// SHT_SYMTAB section.  Until somebody figures out how that could
446
// work, we assume there is only one.
447
 
448
template<int size, bool big_endian>
449
void
450
Sized_relobj_file<size, big_endian>::find_symtab(const unsigned char* pshdrs)
451
{
452
  const unsigned int shnum = this->shnum();
453
  this->symtab_shndx_ = 0;
454
  if (shnum > 0)
455
    {
456
      // Look through the sections in reverse order, since gas tends
457
      // to put the symbol table at the end.
458
      const unsigned char* p = pshdrs + shnum * This::shdr_size;
459
      unsigned int i = shnum;
460
      unsigned int xindex_shndx = 0;
461
      unsigned int xindex_link = 0;
462
      while (i > 0)
463
        {
464
          --i;
465
          p -= This::shdr_size;
466
          typename This::Shdr shdr(p);
467
          if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB)
468
            {
469
              this->symtab_shndx_ = i;
470
              if (xindex_shndx > 0 && xindex_link == i)
471
                {
472
                  Xindex* xindex =
473
                    new Xindex(this->elf_file_.large_shndx_offset());
474
                  xindex->read_symtab_xindex<size, big_endian>(this,
475
                                                               xindex_shndx,
476
                                                               pshdrs);
477
                  this->set_xindex(xindex);
478
                }
479
              break;
480
            }
481
 
482
          // Try to pick up the SHT_SYMTAB_SHNDX section, if there is
483
          // one.  This will work if it follows the SHT_SYMTAB
484
          // section.
485
          if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB_SHNDX)
486
            {
487
              xindex_shndx = i;
488
              xindex_link = this->adjust_shndx(shdr.get_sh_link());
489
            }
490
        }
491
    }
492
}
493
 
494
// Return the Xindex structure to use for object with lots of
495
// sections.
496
 
497
template<int size, bool big_endian>
498
Xindex*
499
Sized_relobj_file<size, big_endian>::do_initialize_xindex()
500
{
501
  gold_assert(this->symtab_shndx_ != -1U);
502
  Xindex* xindex = new Xindex(this->elf_file_.large_shndx_offset());
503
  xindex->initialize_symtab_xindex<size, big_endian>(this, this->symtab_shndx_);
504
  return xindex;
505
}
506
 
507
// Return whether SHDR has the right type and flags to be a GNU
508
// .eh_frame section.
509
 
510
template<int size, bool big_endian>
511
bool
512
Sized_relobj_file<size, big_endian>::check_eh_frame_flags(
513
    const elfcpp::Shdr<size, big_endian>* shdr) const
514
{
515 159 khays
  elfcpp::Elf_Word sh_type = shdr->get_sh_type();
516
  return ((sh_type == elfcpp::SHT_PROGBITS
517
           || sh_type == elfcpp::SHT_X86_64_UNWIND)
518 27 khays
          && (shdr->get_sh_flags() & elfcpp::SHF_ALLOC) != 0);
519
}
520
 
521
// Return whether there is a GNU .eh_frame section, given the section
522
// headers and the section names.
523
 
524
template<int size, bool big_endian>
525
bool
526
Sized_relobj_file<size, big_endian>::find_eh_frame(
527
    const unsigned char* pshdrs,
528
    const char* names,
529
    section_size_type names_size) const
530
{
531
  const unsigned int shnum = this->shnum();
532
  const unsigned char* p = pshdrs + This::shdr_size;
533
  for (unsigned int i = 1; i < shnum; ++i, p += This::shdr_size)
534
    {
535
      typename This::Shdr shdr(p);
536
      if (this->check_eh_frame_flags(&shdr))
537
        {
538
          if (shdr.get_sh_name() >= names_size)
539
            {
540
              this->error(_("bad section name offset for section %u: %lu"),
541
                          i, static_cast<unsigned long>(shdr.get_sh_name()));
542
              continue;
543
            }
544
 
545
          const char* name = names + shdr.get_sh_name();
546
          if (strcmp(name, ".eh_frame") == 0)
547
            return true;
548
        }
549
    }
550
  return false;
551
}
552
 
553
// Build a table for any compressed debug sections, mapping each section index
554
// to the uncompressed size.
555
 
556
template<int size, bool big_endian>
557
Compressed_section_map*
558
build_compressed_section_map(
559
    const unsigned char* pshdrs,
560
    unsigned int shnum,
561
    const char* names,
562
    section_size_type names_size,
563
    Sized_relobj_file<size, big_endian>* obj)
564
{
565
  Compressed_section_map* uncompressed_sizes = new Compressed_section_map();
566
  const unsigned int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
567
  const unsigned char* p = pshdrs + shdr_size;
568
  for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
569
    {
570
      typename elfcpp::Shdr<size, big_endian> shdr(p);
571
      if (shdr.get_sh_type() == elfcpp::SHT_PROGBITS
572
          && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
573
        {
574
          if (shdr.get_sh_name() >= names_size)
575
            {
576
              obj->error(_("bad section name offset for section %u: %lu"),
577
                         i, static_cast<unsigned long>(shdr.get_sh_name()));
578
              continue;
579
            }
580
 
581
          const char* name = names + shdr.get_sh_name();
582
          if (is_compressed_debug_section(name))
583
            {
584
              section_size_type len;
585
              const unsigned char* contents =
586
                  obj->section_contents(i, &len, false);
587
              uint64_t uncompressed_size = get_uncompressed_size(contents, len);
588
              if (uncompressed_size != -1ULL)
589
                (*uncompressed_sizes)[i] =
590
                    convert_to_section_size_type(uncompressed_size);
591
            }
592
        }
593
    }
594
  return uncompressed_sizes;
595
}
596
 
597
// Read the sections and symbols from an object file.
598
 
599
template<int size, bool big_endian>
600
void
601
Sized_relobj_file<size, big_endian>::do_read_symbols(Read_symbols_data* sd)
602
{
603
  this->read_section_data(&this->elf_file_, sd);
604
 
605
  const unsigned char* const pshdrs = sd->section_headers->data();
606
 
607
  this->find_symtab(pshdrs);
608
 
609
  const unsigned char* namesu = sd->section_names->data();
610
  const char* names = reinterpret_cast<const char*>(namesu);
611
  if (memmem(names, sd->section_names_size, ".eh_frame", 10) != NULL)
612
    {
613
      if (this->find_eh_frame(pshdrs, names, sd->section_names_size))
614
        this->has_eh_frame_ = true;
615
    }
616
  if (memmem(names, sd->section_names_size, ".zdebug_", 8) != NULL)
617
    this->compressed_sections_ =
618
        build_compressed_section_map(pshdrs, this->shnum(), names,
619
                                     sd->section_names_size, this);
620
 
621
  sd->symbols = NULL;
622
  sd->symbols_size = 0;
623
  sd->external_symbols_offset = 0;
624
  sd->symbol_names = NULL;
625
  sd->symbol_names_size = 0;
626
 
627
  if (this->symtab_shndx_ == 0)
628
    {
629
      // No symbol table.  Weird but legal.
630
      return;
631
    }
632
 
633
  // Get the symbol table section header.
634
  typename This::Shdr symtabshdr(pshdrs
635
                                 + this->symtab_shndx_ * This::shdr_size);
636
  gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
637
 
638
  // If this object has a .eh_frame section, we need all the symbols.
639
  // Otherwise we only need the external symbols.  While it would be
640
  // simpler to just always read all the symbols, I've seen object
641
  // files with well over 2000 local symbols, which for a 64-bit
642
  // object file format is over 5 pages that we don't need to read
643
  // now.
644
 
645
  const int sym_size = This::sym_size;
646
  const unsigned int loccount = symtabshdr.get_sh_info();
647
  this->local_symbol_count_ = loccount;
648
  this->local_values_.resize(loccount);
649
  section_offset_type locsize = loccount * sym_size;
650
  off_t dataoff = symtabshdr.get_sh_offset();
651
  section_size_type datasize =
652
    convert_to_section_size_type(symtabshdr.get_sh_size());
653
  off_t extoff = dataoff + locsize;
654
  section_size_type extsize = datasize - locsize;
655
 
656
  off_t readoff = this->has_eh_frame_ ? dataoff : extoff;
657
  section_size_type readsize = this->has_eh_frame_ ? datasize : extsize;
658
 
659
  if (readsize == 0)
660
    {
661
      // No external symbols.  Also weird but also legal.
662
      return;
663
    }
664
 
665
  File_view* fvsymtab = this->get_lasting_view(readoff, readsize, true, false);
666
 
667
  // Read the section header for the symbol names.
668
  unsigned int strtab_shndx = this->adjust_shndx(symtabshdr.get_sh_link());
669
  if (strtab_shndx >= this->shnum())
670
    {
671
      this->error(_("invalid symbol table name index: %u"), strtab_shndx);
672
      return;
673
    }
674
  typename This::Shdr strtabshdr(pshdrs + strtab_shndx * This::shdr_size);
675
  if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
676
    {
677
      this->error(_("symbol table name section has wrong type: %u"),
678
                  static_cast<unsigned int>(strtabshdr.get_sh_type()));
679
      return;
680
    }
681
 
682
  // Read the symbol names.
683
  File_view* fvstrtab = this->get_lasting_view(strtabshdr.get_sh_offset(),
684
                                               strtabshdr.get_sh_size(),
685
                                               false, true);
686
 
687
  sd->symbols = fvsymtab;
688
  sd->symbols_size = readsize;
689
  sd->external_symbols_offset = this->has_eh_frame_ ? locsize : 0;
690
  sd->symbol_names = fvstrtab;
691
  sd->symbol_names_size =
692
    convert_to_section_size_type(strtabshdr.get_sh_size());
693
}
694
 
695
// Return the section index of symbol SYM.  Set *VALUE to its value in
696
// the object file.  Set *IS_ORDINARY if this is an ordinary section
697
// index, not a special code between SHN_LORESERVE and SHN_HIRESERVE.
698
// Note that for a symbol which is not defined in this object file,
699
// this will set *VALUE to 0 and return SHN_UNDEF; it will not return
700
// the final value of the symbol in the link.
701
 
702
template<int size, bool big_endian>
703
unsigned int
704
Sized_relobj_file<size, big_endian>::symbol_section_and_value(unsigned int sym,
705
                                                              Address* value,
706
                                                              bool* is_ordinary)
707
{
708
  section_size_type symbols_size;
709
  const unsigned char* symbols = this->section_contents(this->symtab_shndx_,
710
                                                        &symbols_size,
711
                                                        false);
712
 
713
  const size_t count = symbols_size / This::sym_size;
714
  gold_assert(sym < count);
715
 
716
  elfcpp::Sym<size, big_endian> elfsym(symbols + sym * This::sym_size);
717
  *value = elfsym.get_st_value();
718
 
719
  return this->adjust_sym_shndx(sym, elfsym.get_st_shndx(), is_ordinary);
720
}
721
 
722
// Return whether to include a section group in the link.  LAYOUT is
723
// used to keep track of which section groups we have already seen.
724
// INDEX is the index of the section group and SHDR is the section
725
// header.  If we do not want to include this group, we set bits in
726
// OMIT for each section which should be discarded.
727
 
728
template<int size, bool big_endian>
729
bool
730
Sized_relobj_file<size, big_endian>::include_section_group(
731
    Symbol_table* symtab,
732
    Layout* layout,
733
    unsigned int index,
734
    const char* name,
735
    const unsigned char* shdrs,
736
    const char* section_names,
737
    section_size_type section_names_size,
738
    std::vector<bool>* omit)
739
{
740
  // Read the section contents.
741
  typename This::Shdr shdr(shdrs + index * This::shdr_size);
742
  const unsigned char* pcon = this->get_view(shdr.get_sh_offset(),
743
                                             shdr.get_sh_size(), true, false);
744
  const elfcpp::Elf_Word* pword =
745
    reinterpret_cast<const elfcpp::Elf_Word*>(pcon);
746
 
747
  // The first word contains flags.  We only care about COMDAT section
748
  // groups.  Other section groups are always included in the link
749
  // just like ordinary sections.
750
  elfcpp::Elf_Word flags = elfcpp::Swap<32, big_endian>::readval(pword);
751
 
752 159 khays
  // Look up the group signature, which is the name of a symbol.  ELF
753
  // uses a symbol name because some group signatures are long, and
754
  // the name is generally already in the symbol table, so it makes
755
  // sense to put the long string just once in .strtab rather than in
756
  // both .strtab and .shstrtab.
757 27 khays
 
758
  // Get the appropriate symbol table header (this will normally be
759
  // the single SHT_SYMTAB section, but in principle it need not be).
760
  const unsigned int link = this->adjust_shndx(shdr.get_sh_link());
761
  typename This::Shdr symshdr(this, this->elf_file_.section_header(link));
762
 
763
  // Read the symbol table entry.
764
  unsigned int symndx = shdr.get_sh_info();
765
  if (symndx >= symshdr.get_sh_size() / This::sym_size)
766
    {
767
      this->error(_("section group %u info %u out of range"),
768
                  index, symndx);
769
      return false;
770
    }
771
  off_t symoff = symshdr.get_sh_offset() + symndx * This::sym_size;
772
  const unsigned char* psym = this->get_view(symoff, This::sym_size, true,
773
                                             false);
774
  elfcpp::Sym<size, big_endian> sym(psym);
775
 
776
  // Read the symbol table names.
777
  section_size_type symnamelen;
778
  const unsigned char* psymnamesu;
779
  psymnamesu = this->section_contents(this->adjust_shndx(symshdr.get_sh_link()),
780
                                      &symnamelen, true);
781
  const char* psymnames = reinterpret_cast<const char*>(psymnamesu);
782
 
783
  // Get the section group signature.
784
  if (sym.get_st_name() >= symnamelen)
785
    {
786
      this->error(_("symbol %u name offset %u out of range"),
787
                  symndx, sym.get_st_name());
788
      return false;
789
    }
790
 
791
  std::string signature(psymnames + sym.get_st_name());
792
 
793
  // It seems that some versions of gas will create a section group
794
  // associated with a section symbol, and then fail to give a name to
795
  // the section symbol.  In such a case, use the name of the section.
796
  if (signature[0] == '\0' && sym.get_st_type() == elfcpp::STT_SECTION)
797
    {
798
      bool is_ordinary;
799
      unsigned int sym_shndx = this->adjust_sym_shndx(symndx,
800
                                                      sym.get_st_shndx(),
801
                                                      &is_ordinary);
802
      if (!is_ordinary || sym_shndx >= this->shnum())
803
        {
804
          this->error(_("symbol %u invalid section index %u"),
805
                      symndx, sym_shndx);
806
          return false;
807
        }
808
      typename This::Shdr member_shdr(shdrs + sym_shndx * This::shdr_size);
809
      if (member_shdr.get_sh_name() < section_names_size)
810
        signature = section_names + member_shdr.get_sh_name();
811
    }
812
 
813
  // Record this section group in the layout, and see whether we've already
814
  // seen one with the same signature.
815
  bool include_group;
816
  bool is_comdat;
817
  Kept_section* kept_section = NULL;
818
 
819
  if ((flags & elfcpp::GRP_COMDAT) == 0)
820
    {
821
      include_group = true;
822
      is_comdat = false;
823
    }
824
  else
825
    {
826
      include_group = layout->find_or_add_kept_section(signature,
827
                                                       this, index, true,
828
                                                       true, &kept_section);
829
      is_comdat = true;
830
    }
831
 
832
  if (is_comdat && include_group)
833
    {
834
      Incremental_inputs* incremental_inputs = layout->incremental_inputs();
835
      if (incremental_inputs != NULL)
836
        incremental_inputs->report_comdat_group(this, signature.c_str());
837
    }
838
 
839
  size_t count = shdr.get_sh_size() / sizeof(elfcpp::Elf_Word);
840
 
841
  std::vector<unsigned int> shndxes;
842
  bool relocate_group = include_group && parameters->options().relocatable();
843
  if (relocate_group)
844
    shndxes.reserve(count - 1);
845
 
846
  for (size_t i = 1; i < count; ++i)
847
    {
848
      elfcpp::Elf_Word shndx =
849
        this->adjust_shndx(elfcpp::Swap<32, big_endian>::readval(pword + i));
850
 
851
      if (relocate_group)
852
        shndxes.push_back(shndx);
853
 
854
      if (shndx >= this->shnum())
855
        {
856
          this->error(_("section %u in section group %u out of range"),
857
                      shndx, index);
858
          continue;
859
        }
860
 
861
      // Check for an earlier section number, since we're going to get
862
      // it wrong--we may have already decided to include the section.
863
      if (shndx < index)
864
        this->error(_("invalid section group %u refers to earlier section %u"),
865
                    index, shndx);
866
 
867
      // Get the name of the member section.
868
      typename This::Shdr member_shdr(shdrs + shndx * This::shdr_size);
869
      if (member_shdr.get_sh_name() >= section_names_size)
870
        {
871
          // This is an error, but it will be diagnosed eventually
872
          // in do_layout, so we don't need to do anything here but
873
          // ignore it.
874
          continue;
875
        }
876
      std::string mname(section_names + member_shdr.get_sh_name());
877
 
878
      if (include_group)
879
        {
880
          if (is_comdat)
881
            kept_section->add_comdat_section(mname, shndx,
882
                                             member_shdr.get_sh_size());
883
        }
884
      else
885
        {
886
          (*omit)[shndx] = true;
887
 
888
          if (is_comdat)
889
            {
890
              Relobj* kept_object = kept_section->object();
891
              if (kept_section->is_comdat())
892
                {
893
                  // Find the corresponding kept section, and store
894
                  // that info in the discarded section table.
895
                  unsigned int kept_shndx;
896
                  uint64_t kept_size;
897
                  if (kept_section->find_comdat_section(mname, &kept_shndx,
898
                                                        &kept_size))
899
                    {
900
                      // We don't keep a mapping for this section if
901
                      // it has a different size.  The mapping is only
902
                      // used for relocation processing, and we don't
903
                      // want to treat the sections as similar if the
904
                      // sizes are different.  Checking the section
905
                      // size is the approach used by the GNU linker.
906
                      if (kept_size == member_shdr.get_sh_size())
907
                        this->set_kept_comdat_section(shndx, kept_object,
908
                                                      kept_shndx);
909
                    }
910
                }
911
              else
912
                {
913
                  // The existing section is a linkonce section.  Add
914
                  // a mapping if there is exactly one section in the
915
                  // group (which is true when COUNT == 2) and if it
916
                  // is the same size.
917
                  if (count == 2
918
                      && (kept_section->linkonce_size()
919
                          == member_shdr.get_sh_size()))
920
                    this->set_kept_comdat_section(shndx, kept_object,
921
                                                  kept_section->shndx());
922
                }
923
            }
924
        }
925
    }
926
 
927
  if (relocate_group)
928
    layout->layout_group(symtab, this, index, name, signature.c_str(),
929
                         shdr, flags, &shndxes);
930
 
931
  return include_group;
932
}
933
 
934
// Whether to include a linkonce section in the link.  NAME is the
935
// name of the section and SHDR is the section header.
936
 
937
// Linkonce sections are a GNU extension implemented in the original
938
// GNU linker before section groups were defined.  The semantics are
939
// that we only include one linkonce section with a given name.  The
940
// name of a linkonce section is normally .gnu.linkonce.T.SYMNAME,
941
// where T is the type of section and SYMNAME is the name of a symbol.
942
// In an attempt to make linkonce sections interact well with section
943
// groups, we try to identify SYMNAME and use it like a section group
944
// signature.  We want to block section groups with that signature,
945
// but not other linkonce sections with that signature.  We also use
946
// the full name of the linkonce section as a normal section group
947
// signature.
948
 
949
template<int size, bool big_endian>
950
bool
951
Sized_relobj_file<size, big_endian>::include_linkonce_section(
952
    Layout* layout,
953
    unsigned int index,
954
    const char* name,
955
    const elfcpp::Shdr<size, big_endian>& shdr)
956
{
957
  typename elfcpp::Elf_types<size>::Elf_WXword sh_size = shdr.get_sh_size();
958
  // In general the symbol name we want will be the string following
959
  // the last '.'.  However, we have to handle the case of
960
  // .gnu.linkonce.t.__i686.get_pc_thunk.bx, which was generated by
961
  // some versions of gcc.  So we use a heuristic: if the name starts
962
  // with ".gnu.linkonce.t.", we use everything after that.  Otherwise
963
  // we look for the last '.'.  We can't always simply skip
964
  // ".gnu.linkonce.X", because we have to deal with cases like
965
  // ".gnu.linkonce.d.rel.ro.local".
966
  const char* const linkonce_t = ".gnu.linkonce.t.";
967
  const char* symname;
968
  if (strncmp(name, linkonce_t, strlen(linkonce_t)) == 0)
969
    symname = name + strlen(linkonce_t);
970
  else
971
    symname = strrchr(name, '.') + 1;
972
  std::string sig1(symname);
973
  std::string sig2(name);
974
  Kept_section* kept1;
975
  Kept_section* kept2;
976
  bool include1 = layout->find_or_add_kept_section(sig1, this, index, false,
977
                                                   false, &kept1);
978
  bool include2 = layout->find_or_add_kept_section(sig2, this, index, false,
979
                                                   true, &kept2);
980
 
981
  if (!include2)
982
    {
983
      // We are not including this section because we already saw the
984
      // name of the section as a signature.  This normally implies
985
      // that the kept section is another linkonce section.  If it is
986
      // the same size, record it as the section which corresponds to
987
      // this one.
988
      if (kept2->object() != NULL
989
          && !kept2->is_comdat()
990
          && kept2->linkonce_size() == sh_size)
991
        this->set_kept_comdat_section(index, kept2->object(), kept2->shndx());
992
    }
993
  else if (!include1)
994
    {
995
      // The section is being discarded on the basis of its symbol
996
      // name.  This means that the corresponding kept section was
997
      // part of a comdat group, and it will be difficult to identify
998
      // the specific section within that group that corresponds to
999
      // this linkonce section.  We'll handle the simple case where
1000
      // the group has only one member section.  Otherwise, it's not
1001
      // worth the effort.
1002
      unsigned int kept_shndx;
1003
      uint64_t kept_size;
1004
      if (kept1->object() != NULL
1005
          && kept1->is_comdat()
1006
          && kept1->find_single_comdat_section(&kept_shndx, &kept_size)
1007
          && kept_size == sh_size)
1008
        this->set_kept_comdat_section(index, kept1->object(), kept_shndx);
1009
    }
1010
  else
1011
    {
1012
      kept1->set_linkonce_size(sh_size);
1013
      kept2->set_linkonce_size(sh_size);
1014
    }
1015
 
1016
  return include1 && include2;
1017
}
1018
 
1019
// Layout an input section.
1020
 
1021
template<int size, bool big_endian>
1022
inline void
1023 159 khays
Sized_relobj_file<size, big_endian>::layout_section(
1024
    Layout* layout,
1025
    unsigned int shndx,
1026
    const char* name,
1027
    const typename This::Shdr& shdr,
1028
    unsigned int reloc_shndx,
1029
    unsigned int reloc_type)
1030 27 khays
{
1031
  off_t offset;
1032
  Output_section* os = layout->layout(this, shndx, name, shdr,
1033
                                          reloc_shndx, reloc_type, &offset);
1034
 
1035
  this->output_sections()[shndx] = os;
1036
  if (offset == -1)
1037
    this->section_offsets()[shndx] = invalid_address;
1038
  else
1039
    this->section_offsets()[shndx] = convert_types<Address, off_t>(offset);
1040
 
1041
  // If this section requires special handling, and if there are
1042
  // relocs that apply to it, then we must do the special handling
1043
  // before we apply the relocs.
1044
  if (offset == -1 && reloc_shndx != 0)
1045
    this->set_relocs_must_follow_section_writes();
1046
}
1047
 
1048 159 khays
// Layout an input .eh_frame section.
1049
 
1050
template<int size, bool big_endian>
1051
void
1052
Sized_relobj_file<size, big_endian>::layout_eh_frame_section(
1053
    Layout* layout,
1054
    const unsigned char* symbols_data,
1055
    section_size_type symbols_size,
1056
    const unsigned char* symbol_names_data,
1057
    section_size_type symbol_names_size,
1058
    unsigned int shndx,
1059
    const typename This::Shdr& shdr,
1060
    unsigned int reloc_shndx,
1061
    unsigned int reloc_type)
1062
{
1063
  gold_assert(this->has_eh_frame_);
1064
 
1065
  off_t offset;
1066
  Output_section* os = layout->layout_eh_frame(this,
1067
                                               symbols_data,
1068
                                               symbols_size,
1069
                                               symbol_names_data,
1070
                                               symbol_names_size,
1071
                                               shndx,
1072
                                               shdr,
1073
                                               reloc_shndx,
1074
                                               reloc_type,
1075
                                               &offset);
1076
  this->output_sections()[shndx] = os;
1077
  if (os == NULL || offset == -1)
1078
    {
1079
      // An object can contain at most one section holding exception
1080
      // frame information.
1081
      gold_assert(this->discarded_eh_frame_shndx_ == -1U);
1082
      this->discarded_eh_frame_shndx_ = shndx;
1083
      this->section_offsets()[shndx] = invalid_address;
1084
    }
1085
  else
1086
    this->section_offsets()[shndx] = convert_types<Address, off_t>(offset);
1087
 
1088
  // If this section requires special handling, and if there are
1089
  // relocs that aply to it, then we must do the special handling
1090
  // before we apply the relocs.
1091
  if (os != NULL && offset == -1 && reloc_shndx != 0)
1092
    this->set_relocs_must_follow_section_writes();
1093
}
1094
 
1095 27 khays
// Lay out the input sections.  We walk through the sections and check
1096
// whether they should be included in the link.  If they should, we
1097
// pass them to the Layout object, which will return an output section
1098
// and an offset.  
1099
// During garbage collection (--gc-sections) and identical code folding 
1100
// (--icf), this function is called twice.  When it is called the first 
1101
// time, it is for setting up some sections as roots to a work-list for
1102
// --gc-sections and to do comdat processing.  Actual layout happens the 
1103
// second time around after all the relevant sections have been determined.  
1104
// The first time, is_worklist_ready or is_icf_ready is false. It is then 
1105
// set to true after the garbage collection worklist or identical code 
1106
// folding is processed and the relevant sections to be kept are 
1107
// determined.  Then, this function is called again to layout the sections.
1108
 
1109
template<int size, bool big_endian>
1110
void
1111
Sized_relobj_file<size, big_endian>::do_layout(Symbol_table* symtab,
1112
                                               Layout* layout,
1113
                                               Read_symbols_data* sd)
1114
{
1115
  const unsigned int shnum = this->shnum();
1116
  bool is_gc_pass_one = ((parameters->options().gc_sections()
1117
                          && !symtab->gc()->is_worklist_ready())
1118
                         || (parameters->options().icf_enabled()
1119
                             && !symtab->icf()->is_icf_ready()));
1120
 
1121
  bool is_gc_pass_two = ((parameters->options().gc_sections()
1122
                          && symtab->gc()->is_worklist_ready())
1123
                         || (parameters->options().icf_enabled()
1124
                             && symtab->icf()->is_icf_ready()));
1125
 
1126
  bool is_gc_or_icf = (parameters->options().gc_sections()
1127
                       || parameters->options().icf_enabled());
1128
 
1129
  // Both is_gc_pass_one and is_gc_pass_two should not be true.
1130
  gold_assert(!(is_gc_pass_one  && is_gc_pass_two));
1131
 
1132
  if (shnum == 0)
1133
    return;
1134
  Symbols_data* gc_sd = NULL;
1135
  if (is_gc_pass_one)
1136
    {
1137
      // During garbage collection save the symbols data to use it when 
1138
      // re-entering this function.   
1139
      gc_sd = new Symbols_data;
1140
      this->copy_symbols_data(gc_sd, sd, This::shdr_size * shnum);
1141
      this->set_symbols_data(gc_sd);
1142
    }
1143
  else if (is_gc_pass_two)
1144
    {
1145
      gc_sd = this->get_symbols_data();
1146
    }
1147
 
1148
  const unsigned char* section_headers_data = NULL;
1149
  section_size_type section_names_size;
1150
  const unsigned char* symbols_data = NULL;
1151
  section_size_type symbols_size;
1152
  const unsigned char* symbol_names_data = NULL;
1153
  section_size_type symbol_names_size;
1154
 
1155
  if (is_gc_or_icf)
1156
    {
1157
      section_headers_data = gc_sd->section_headers_data;
1158
      section_names_size = gc_sd->section_names_size;
1159
      symbols_data = gc_sd->symbols_data;
1160
      symbols_size = gc_sd->symbols_size;
1161
      symbol_names_data = gc_sd->symbol_names_data;
1162
      symbol_names_size = gc_sd->symbol_names_size;
1163
    }
1164
  else
1165
    {
1166
      section_headers_data = sd->section_headers->data();
1167
      section_names_size = sd->section_names_size;
1168
      if (sd->symbols != NULL)
1169
        symbols_data = sd->symbols->data();
1170
      symbols_size = sd->symbols_size;
1171
      if (sd->symbol_names != NULL)
1172
        symbol_names_data = sd->symbol_names->data();
1173
      symbol_names_size = sd->symbol_names_size;
1174
    }
1175
 
1176
  // Get the section headers.
1177
  const unsigned char* shdrs = section_headers_data;
1178
  const unsigned char* pshdrs;
1179
 
1180
  // Get the section names.
1181
  const unsigned char* pnamesu = (is_gc_or_icf)
1182
                                 ? gc_sd->section_names_data
1183
                                 : sd->section_names->data();
1184
 
1185
  const char* pnames = reinterpret_cast<const char*>(pnamesu);
1186
 
1187
  // If any input files have been claimed by plugins, we need to defer
1188
  // actual layout until the replacement files have arrived.
1189
  const bool should_defer_layout =
1190
      (parameters->options().has_plugins()
1191
       && parameters->options().plugins()->should_defer_layout());
1192
  unsigned int num_sections_to_defer = 0;
1193
 
1194
  // For each section, record the index of the reloc section if any.
1195
  // Use 0 to mean that there is no reloc section, -1U to mean that
1196
  // there is more than one.
1197
  std::vector<unsigned int> reloc_shndx(shnum, 0);
1198
  std::vector<unsigned int> reloc_type(shnum, elfcpp::SHT_NULL);
1199
  // Skip the first, dummy, section.
1200
  pshdrs = shdrs + This::shdr_size;
1201
  for (unsigned int i = 1; i < shnum; ++i, pshdrs += This::shdr_size)
1202
    {
1203
      typename This::Shdr shdr(pshdrs);
1204
 
1205
      // Count the number of sections whose layout will be deferred.
1206
      if (should_defer_layout && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC))
1207
        ++num_sections_to_defer;
1208
 
1209
      unsigned int sh_type = shdr.get_sh_type();
1210
      if (sh_type == elfcpp::SHT_REL || sh_type == elfcpp::SHT_RELA)
1211
        {
1212
          unsigned int target_shndx = this->adjust_shndx(shdr.get_sh_info());
1213
          if (target_shndx == 0 || target_shndx >= shnum)
1214
            {
1215
              this->error(_("relocation section %u has bad info %u"),
1216
                          i, target_shndx);
1217
              continue;
1218
            }
1219
 
1220
          if (reloc_shndx[target_shndx] != 0)
1221
            reloc_shndx[target_shndx] = -1U;
1222
          else
1223
            {
1224
              reloc_shndx[target_shndx] = i;
1225
              reloc_type[target_shndx] = sh_type;
1226
            }
1227
        }
1228
    }
1229
 
1230
  Output_sections& out_sections(this->output_sections());
1231
  std::vector<Address>& out_section_offsets(this->section_offsets());
1232
 
1233
  if (!is_gc_pass_two)
1234
    {
1235
      out_sections.resize(shnum);
1236
      out_section_offsets.resize(shnum);
1237
    }
1238
 
1239
  // If we are only linking for symbols, then there is nothing else to
1240
  // do here.
1241
  if (this->input_file()->just_symbols())
1242
    {
1243
      if (!is_gc_pass_two)
1244
        {
1245
          delete sd->section_headers;
1246
          sd->section_headers = NULL;
1247
          delete sd->section_names;
1248
          sd->section_names = NULL;
1249
        }
1250
      return;
1251
    }
1252
 
1253
  if (num_sections_to_defer > 0)
1254
    {
1255
      parameters->options().plugins()->add_deferred_layout_object(this);
1256
      this->deferred_layout_.reserve(num_sections_to_defer);
1257
    }
1258
 
1259
  // Whether we've seen a .note.GNU-stack section.
1260
  bool seen_gnu_stack = false;
1261
  // The flags of a .note.GNU-stack section.
1262
  uint64_t gnu_stack_flags = 0;
1263
 
1264
  // Keep track of which sections to omit.
1265
  std::vector<bool> omit(shnum, false);
1266
 
1267
  // Keep track of reloc sections when emitting relocations.
1268
  const bool relocatable = parameters->options().relocatable();
1269
  const bool emit_relocs = (relocatable
1270
                            || parameters->options().emit_relocs());
1271
  std::vector<unsigned int> reloc_sections;
1272
 
1273
  // Keep track of .eh_frame sections.
1274
  std::vector<unsigned int> eh_frame_sections;
1275
 
1276
  // Skip the first, dummy, section.
1277
  pshdrs = shdrs + This::shdr_size;
1278
  for (unsigned int i = 1; i < shnum; ++i, pshdrs += This::shdr_size)
1279
    {
1280
      typename This::Shdr shdr(pshdrs);
1281
 
1282
      if (shdr.get_sh_name() >= section_names_size)
1283
        {
1284
          this->error(_("bad section name offset for section %u: %lu"),
1285
                      i, static_cast<unsigned long>(shdr.get_sh_name()));
1286
          return;
1287
        }
1288
 
1289
      const char* name = pnames + shdr.get_sh_name();
1290
 
1291
      if (!is_gc_pass_two)
1292
        {
1293
          if (this->handle_gnu_warning_section(name, i, symtab))
1294
            {
1295 159 khays
              if (!relocatable && !parameters->options().shared())
1296 27 khays
                omit[i] = true;
1297
            }
1298
 
1299
          // The .note.GNU-stack section is special.  It gives the
1300
          // protection flags that this object file requires for the stack
1301
          // in memory.
1302
          if (strcmp(name, ".note.GNU-stack") == 0)
1303
            {
1304
              seen_gnu_stack = true;
1305
              gnu_stack_flags |= shdr.get_sh_flags();
1306
              omit[i] = true;
1307
            }
1308
 
1309
          // The .note.GNU-split-stack section is also special.  It
1310
          // indicates that the object was compiled with
1311
          // -fsplit-stack.
1312
          if (this->handle_split_stack_section(name))
1313
            {
1314 159 khays
              if (!relocatable && !parameters->options().shared())
1315 27 khays
                omit[i] = true;
1316
            }
1317
 
1318
          // Skip attributes section.
1319
          if (parameters->target().is_attributes_section(name))
1320
            {
1321
              omit[i] = true;
1322
            }
1323
 
1324
          bool discard = omit[i];
1325
          if (!discard)
1326
            {
1327
              if (shdr.get_sh_type() == elfcpp::SHT_GROUP)
1328
                {
1329
                  if (!this->include_section_group(symtab, layout, i, name,
1330
                                                   shdrs, pnames,
1331
                                                   section_names_size,
1332
                                                   &omit))
1333
                    discard = true;
1334
                }
1335
              else if ((shdr.get_sh_flags() & elfcpp::SHF_GROUP) == 0
1336
                       && Layout::is_linkonce(name))
1337
                {
1338
                  if (!this->include_linkonce_section(layout, i, name, shdr))
1339
                    discard = true;
1340
                }
1341
            }
1342
 
1343
          // Add the section to the incremental inputs layout.
1344
          Incremental_inputs* incremental_inputs = layout->incremental_inputs();
1345
          if (incremental_inputs != NULL
1346
              && !discard
1347 163 khays
              && can_incremental_update(shdr.get_sh_type()))
1348 148 khays
            {
1349
              off_t sh_size = shdr.get_sh_size();
1350
              section_size_type uncompressed_size;
1351
              if (this->section_is_compressed(i, &uncompressed_size))
1352
                sh_size = uncompressed_size;
1353
              incremental_inputs->report_input_section(this, i, name, sh_size);
1354
            }
1355 27 khays
 
1356
          if (discard)
1357
            {
1358
              // Do not include this section in the link.
1359
              out_sections[i] = NULL;
1360
              out_section_offsets[i] = invalid_address;
1361
              continue;
1362
            }
1363
        }
1364
 
1365
      if (is_gc_pass_one && parameters->options().gc_sections())
1366
        {
1367
          if (this->is_section_name_included(name)
1368
              || shdr.get_sh_type() == elfcpp::SHT_INIT_ARRAY
1369
              || shdr.get_sh_type() == elfcpp::SHT_FINI_ARRAY)
1370
            {
1371
              symtab->gc()->worklist().push(Section_id(this, i));
1372
            }
1373
          // If the section name XXX can be represented as a C identifier
1374
          // it cannot be discarded if there are references to
1375
          // __start_XXX and __stop_XXX symbols.  These need to be
1376
          // specially handled.
1377
          if (is_cident(name))
1378
            {
1379
              symtab->gc()->add_cident_section(name, Section_id(this, i));
1380
            }
1381
        }
1382
 
1383
      // When doing a relocatable link we are going to copy input
1384
      // reloc sections into the output.  We only want to copy the
1385
      // ones associated with sections which are not being discarded.
1386
      // However, we don't know that yet for all sections.  So save
1387
      // reloc sections and process them later. Garbage collection is
1388
      // not triggered when relocatable code is desired.
1389
      if (emit_relocs
1390
          && (shdr.get_sh_type() == elfcpp::SHT_REL
1391
              || shdr.get_sh_type() == elfcpp::SHT_RELA))
1392
        {
1393
          reloc_sections.push_back(i);
1394
          continue;
1395
        }
1396
 
1397
      if (relocatable && shdr.get_sh_type() == elfcpp::SHT_GROUP)
1398
        continue;
1399
 
1400
      // The .eh_frame section is special.  It holds exception frame
1401
      // information that we need to read in order to generate the
1402
      // exception frame header.  We process these after all the other
1403
      // sections so that the exception frame reader can reliably
1404
      // determine which sections are being discarded, and discard the
1405
      // corresponding information.
1406
      if (!relocatable
1407
          && strcmp(name, ".eh_frame") == 0
1408
          && this->check_eh_frame_flags(&shdr))
1409
        {
1410
          if (is_gc_pass_one)
1411
            {
1412
              out_sections[i] = reinterpret_cast<Output_section*>(1);
1413
              out_section_offsets[i] = invalid_address;
1414
            }
1415 159 khays
          else if (should_defer_layout)
1416
            this->deferred_layout_.push_back(Deferred_layout(i, name,
1417
                                                             pshdrs,
1418
                                                             reloc_shndx[i],
1419
                                                             reloc_type[i]));
1420
          else
1421 27 khays
            eh_frame_sections.push_back(i);
1422
          continue;
1423
        }
1424
 
1425
      if (is_gc_pass_two && parameters->options().gc_sections())
1426
        {
1427
          // This is executed during the second pass of garbage 
1428
          // collection. do_layout has been called before and some 
1429
          // sections have been already discarded. Simply ignore 
1430
          // such sections this time around.
1431
          if (out_sections[i] == NULL)
1432
            {
1433
              gold_assert(out_section_offsets[i] == invalid_address);
1434
              continue;
1435
            }
1436
          if (((shdr.get_sh_flags() & elfcpp::SHF_ALLOC) != 0)
1437
              && symtab->gc()->is_section_garbage(this, i))
1438
              {
1439
                if (parameters->options().print_gc_sections())
1440
                  gold_info(_("%s: removing unused section from '%s'"
1441
                              " in file '%s'"),
1442
                            program_name, this->section_name(i).c_str(),
1443
                            this->name().c_str());
1444
                out_sections[i] = NULL;
1445
                out_section_offsets[i] = invalid_address;
1446
                continue;
1447
              }
1448
        }
1449
 
1450
      if (is_gc_pass_two && parameters->options().icf_enabled())
1451
        {
1452
          if (out_sections[i] == NULL)
1453
            {
1454
              gold_assert(out_section_offsets[i] == invalid_address);
1455
              continue;
1456
            }
1457
          if (((shdr.get_sh_flags() & elfcpp::SHF_ALLOC) != 0)
1458
              && symtab->icf()->is_section_folded(this, i))
1459
              {
1460
                if (parameters->options().print_icf_sections())
1461
                  {
1462
                    Section_id folded =
1463
                                symtab->icf()->get_folded_section(this, i);
1464
                    Relobj* folded_obj =
1465
                                reinterpret_cast<Relobj*>(folded.first);
1466
                    gold_info(_("%s: ICF folding section '%s' in file '%s'"
1467
                                "into '%s' in file '%s'"),
1468
                              program_name, this->section_name(i).c_str(),
1469
                              this->name().c_str(),
1470
                              folded_obj->section_name(folded.second).c_str(),
1471
                              folded_obj->name().c_str());
1472
                  }
1473
                out_sections[i] = NULL;
1474
                out_section_offsets[i] = invalid_address;
1475
                continue;
1476
              }
1477
        }
1478
 
1479
      // Defer layout here if input files are claimed by plugins.  When gc
1480
      // is turned on this function is called twice.  For the second call
1481
      // should_defer_layout should be false.
1482
      if (should_defer_layout && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC))
1483
        {
1484
          gold_assert(!is_gc_pass_two);
1485
          this->deferred_layout_.push_back(Deferred_layout(i, name,
1486
                                                           pshdrs,
1487
                                                           reloc_shndx[i],
1488
                                                           reloc_type[i]));
1489
          // Put dummy values here; real values will be supplied by
1490
          // do_layout_deferred_sections.
1491
          out_sections[i] = reinterpret_cast<Output_section*>(2);
1492
          out_section_offsets[i] = invalid_address;
1493
          continue;
1494
        }
1495
 
1496
      // During gc_pass_two if a section that was previously deferred is
1497
      // found, do not layout the section as layout_deferred_sections will
1498
      // do it later from gold.cc.
1499
      if (is_gc_pass_two
1500
          && (out_sections[i] == reinterpret_cast<Output_section*>(2)))
1501
        continue;
1502
 
1503
      if (is_gc_pass_one)
1504
        {
1505
          // This is during garbage collection. The out_sections are 
1506
          // assigned in the second call to this function. 
1507
          out_sections[i] = reinterpret_cast<Output_section*>(1);
1508
          out_section_offsets[i] = invalid_address;
1509
        }
1510
      else
1511
        {
1512
          // When garbage collection is switched on the actual layout
1513
          // only happens in the second call.
1514
          this->layout_section(layout, i, name, shdr, reloc_shndx[i],
1515
                               reloc_type[i]);
1516
        }
1517
    }
1518
 
1519
  if (!is_gc_pass_two)
1520
    layout->layout_gnu_stack(seen_gnu_stack, gnu_stack_flags, this);
1521
 
1522
  // When doing a relocatable link handle the reloc sections at the
1523
  // end.  Garbage collection  and Identical Code Folding is not 
1524
  // turned on for relocatable code. 
1525
  if (emit_relocs)
1526
    this->size_relocatable_relocs();
1527
 
1528
  gold_assert(!(is_gc_or_icf) || reloc_sections.empty());
1529
 
1530
  for (std::vector<unsigned int>::const_iterator p = reloc_sections.begin();
1531
       p != reloc_sections.end();
1532
       ++p)
1533
    {
1534
      unsigned int i = *p;
1535
      const unsigned char* pshdr;
1536
      pshdr = section_headers_data + i * This::shdr_size;
1537
      typename This::Shdr shdr(pshdr);
1538
 
1539
      unsigned int data_shndx = this->adjust_shndx(shdr.get_sh_info());
1540
      if (data_shndx >= shnum)
1541
        {
1542
          // We already warned about this above.
1543
          continue;
1544
        }
1545
 
1546
      Output_section* data_section = out_sections[data_shndx];
1547
      if (data_section == reinterpret_cast<Output_section*>(2))
1548
        {
1549
          // The layout for the data section was deferred, so we need
1550
          // to defer the relocation section, too.
1551
          const char* name = pnames + shdr.get_sh_name();
1552
          this->deferred_layout_relocs_.push_back(
1553
              Deferred_layout(i, name, pshdr, 0, elfcpp::SHT_NULL));
1554
          out_sections[i] = reinterpret_cast<Output_section*>(2);
1555
          out_section_offsets[i] = invalid_address;
1556
          continue;
1557
        }
1558
      if (data_section == NULL)
1559
        {
1560
          out_sections[i] = NULL;
1561
          out_section_offsets[i] = invalid_address;
1562
          continue;
1563
        }
1564
 
1565
      Relocatable_relocs* rr = new Relocatable_relocs();
1566
      this->set_relocatable_relocs(i, rr);
1567
 
1568
      Output_section* os = layout->layout_reloc(this, i, shdr, data_section,
1569
                                                rr);
1570
      out_sections[i] = os;
1571
      out_section_offsets[i] = invalid_address;
1572
    }
1573
 
1574
  // Handle the .eh_frame sections at the end.
1575
  gold_assert(!is_gc_pass_one || eh_frame_sections.empty());
1576
  for (std::vector<unsigned int>::const_iterator p = eh_frame_sections.begin();
1577
       p != eh_frame_sections.end();
1578
       ++p)
1579
    {
1580
      unsigned int i = *p;
1581
      const unsigned char* pshdr;
1582
      pshdr = section_headers_data + i * This::shdr_size;
1583
      typename This::Shdr shdr(pshdr);
1584
 
1585 159 khays
      this->layout_eh_frame_section(layout,
1586
                                    symbols_data,
1587
                                    symbols_size,
1588
                                    symbol_names_data,
1589
                                    symbol_names_size,
1590
                                    i,
1591
                                    shdr,
1592
                                    reloc_shndx[i],
1593
                                    reloc_type[i]);
1594 27 khays
    }
1595
 
1596
  if (is_gc_pass_two)
1597
    {
1598
      delete[] gc_sd->section_headers_data;
1599
      delete[] gc_sd->section_names_data;
1600
      delete[] gc_sd->symbols_data;
1601
      delete[] gc_sd->symbol_names_data;
1602
      this->set_symbols_data(NULL);
1603
    }
1604
  else
1605
    {
1606
      delete sd->section_headers;
1607
      sd->section_headers = NULL;
1608
      delete sd->section_names;
1609
      sd->section_names = NULL;
1610
    }
1611
}
1612
 
1613
// Layout sections whose layout was deferred while waiting for
1614
// input files from a plugin.
1615
 
1616
template<int size, bool big_endian>
1617
void
1618
Sized_relobj_file<size, big_endian>::do_layout_deferred_sections(Layout* layout)
1619
{
1620
  typename std::vector<Deferred_layout>::iterator deferred;
1621
 
1622
  for (deferred = this->deferred_layout_.begin();
1623
       deferred != this->deferred_layout_.end();
1624
       ++deferred)
1625
    {
1626
      typename This::Shdr shdr(deferred->shdr_data_);
1627
      // If the section is not included, it is because the garbage collector
1628
      // decided it is not needed.  Avoid reverting that decision.
1629
      if (!this->is_section_included(deferred->shndx_))
1630
        continue;
1631
 
1632 159 khays
      if (parameters->options().relocatable()
1633
          || deferred->name_ != ".eh_frame"
1634
          || !this->check_eh_frame_flags(&shdr))
1635
        this->layout_section(layout, deferred->shndx_, deferred->name_.c_str(),
1636
                             shdr, deferred->reloc_shndx_,
1637
                             deferred->reloc_type_);
1638
      else
1639
        {
1640
          // Reading the symbols again here may be slow.
1641
          Read_symbols_data sd;
1642
          this->read_symbols(&sd);
1643
          this->layout_eh_frame_section(layout,
1644
                                        sd.symbols->data(),
1645
                                        sd.symbols_size,
1646
                                        sd.symbol_names->data(),
1647
                                        sd.symbol_names_size,
1648
                                        deferred->shndx_,
1649
                                        shdr,
1650
                                        deferred->reloc_shndx_,
1651
                                        deferred->reloc_type_);
1652
        }
1653 27 khays
    }
1654
 
1655
  this->deferred_layout_.clear();
1656
 
1657
  // Now handle the deferred relocation sections.
1658
 
1659
  Output_sections& out_sections(this->output_sections());
1660
  std::vector<Address>& out_section_offsets(this->section_offsets());
1661
 
1662
  for (deferred = this->deferred_layout_relocs_.begin();
1663
       deferred != this->deferred_layout_relocs_.end();
1664
       ++deferred)
1665
    {
1666
      unsigned int shndx = deferred->shndx_;
1667
      typename This::Shdr shdr(deferred->shdr_data_);
1668
      unsigned int data_shndx = this->adjust_shndx(shdr.get_sh_info());
1669
 
1670
      Output_section* data_section = out_sections[data_shndx];
1671
      if (data_section == NULL)
1672
        {
1673
          out_sections[shndx] = NULL;
1674
          out_section_offsets[shndx] = invalid_address;
1675
          continue;
1676
        }
1677
 
1678
      Relocatable_relocs* rr = new Relocatable_relocs();
1679
      this->set_relocatable_relocs(shndx, rr);
1680
 
1681
      Output_section* os = layout->layout_reloc(this, shndx, shdr,
1682
                                                data_section, rr);
1683
      out_sections[shndx] = os;
1684
      out_section_offsets[shndx] = invalid_address;
1685
    }
1686
}
1687
 
1688
// Add the symbols to the symbol table.
1689
 
1690
template<int size, bool big_endian>
1691
void
1692
Sized_relobj_file<size, big_endian>::do_add_symbols(Symbol_table* symtab,
1693
                                                    Read_symbols_data* sd,
1694
                                                    Layout*)
1695
{
1696
  if (sd->symbols == NULL)
1697
    {
1698
      gold_assert(sd->symbol_names == NULL);
1699
      return;
1700
    }
1701
 
1702
  const int sym_size = This::sym_size;
1703
  size_t symcount = ((sd->symbols_size - sd->external_symbols_offset)
1704
                     / sym_size);
1705
  if (symcount * sym_size != sd->symbols_size - sd->external_symbols_offset)
1706
    {
1707
      this->error(_("size of symbols is not multiple of symbol size"));
1708
      return;
1709
    }
1710
 
1711
  this->symbols_.resize(symcount);
1712
 
1713
  const char* sym_names =
1714
    reinterpret_cast<const char*>(sd->symbol_names->data());
1715
  symtab->add_from_relobj(this,
1716
                          sd->symbols->data() + sd->external_symbols_offset,
1717
                          symcount, this->local_symbol_count_,
1718
                          sym_names, sd->symbol_names_size,
1719
                          &this->symbols_,
1720
                          &this->defined_count_);
1721
 
1722
  delete sd->symbols;
1723
  sd->symbols = NULL;
1724
  delete sd->symbol_names;
1725
  sd->symbol_names = NULL;
1726
}
1727
 
1728
// Find out if this object, that is a member of a lib group, should be included
1729
// in the link. We check every symbol defined by this object. If the symbol
1730
// table has a strong undefined reference to that symbol, we have to include
1731
// the object.
1732
 
1733
template<int size, bool big_endian>
1734
Archive::Should_include
1735
Sized_relobj_file<size, big_endian>::do_should_include_member(
1736
    Symbol_table* symtab,
1737
    Layout* layout,
1738
    Read_symbols_data* sd,
1739
    std::string* why)
1740
{
1741
  char* tmpbuf = NULL;
1742
  size_t tmpbuflen = 0;
1743
  const char* sym_names =
1744
      reinterpret_cast<const char*>(sd->symbol_names->data());
1745
  const unsigned char* syms =
1746
      sd->symbols->data() + sd->external_symbols_offset;
1747
  const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1748
  size_t symcount = ((sd->symbols_size - sd->external_symbols_offset)
1749
                         / sym_size);
1750
 
1751
  const unsigned char* p = syms;
1752
 
1753
  for (size_t i = 0; i < symcount; ++i, p += sym_size)
1754
    {
1755
      elfcpp::Sym<size, big_endian> sym(p);
1756
      unsigned int st_shndx = sym.get_st_shndx();
1757
      if (st_shndx == elfcpp::SHN_UNDEF)
1758
        continue;
1759
 
1760
      unsigned int st_name = sym.get_st_name();
1761
      const char* name = sym_names + st_name;
1762
      Symbol* symbol;
1763
      Archive::Should_include t = Archive::should_include_member(symtab,
1764
                                                                 layout,
1765
                                                                 name,
1766
                                                                 &symbol, why,
1767
                                                                 &tmpbuf,
1768
                                                                 &tmpbuflen);
1769
      if (t == Archive::SHOULD_INCLUDE_YES)
1770
        {
1771
          if (tmpbuf != NULL)
1772
            free(tmpbuf);
1773
          return t;
1774
        }
1775
    }
1776
  if (tmpbuf != NULL)
1777
    free(tmpbuf);
1778
  return Archive::SHOULD_INCLUDE_UNKNOWN;
1779
}
1780
 
1781
// Iterate over global defined symbols, calling a visitor class V for each.
1782
 
1783
template<int size, bool big_endian>
1784
void
1785
Sized_relobj_file<size, big_endian>::do_for_all_global_symbols(
1786
    Read_symbols_data* sd,
1787
    Library_base::Symbol_visitor_base* v)
1788
{
1789
  const char* sym_names =
1790
      reinterpret_cast<const char*>(sd->symbol_names->data());
1791
  const unsigned char* syms =
1792
      sd->symbols->data() + sd->external_symbols_offset;
1793
  const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1794
  size_t symcount = ((sd->symbols_size - sd->external_symbols_offset)
1795
                     / sym_size);
1796
  const unsigned char* p = syms;
1797
 
1798
  for (size_t i = 0; i < symcount; ++i, p += sym_size)
1799
    {
1800
      elfcpp::Sym<size, big_endian> sym(p);
1801
      if (sym.get_st_shndx() != elfcpp::SHN_UNDEF)
1802
        v->visit(sym_names + sym.get_st_name());
1803
    }
1804
}
1805
 
1806
// Return whether the local symbol SYMNDX has a PLT offset.
1807
 
1808
template<int size, bool big_endian>
1809
bool
1810
Sized_relobj_file<size, big_endian>::local_has_plt_offset(
1811
    unsigned int symndx) const
1812
{
1813
  typename Local_plt_offsets::const_iterator p =
1814
    this->local_plt_offsets_.find(symndx);
1815
  return p != this->local_plt_offsets_.end();
1816
}
1817
 
1818
// Get the PLT offset of a local symbol.
1819
 
1820
template<int size, bool big_endian>
1821
unsigned int
1822
Sized_relobj_file<size, big_endian>::local_plt_offset(unsigned int symndx) const
1823
{
1824
  typename Local_plt_offsets::const_iterator p =
1825
    this->local_plt_offsets_.find(symndx);
1826
  gold_assert(p != this->local_plt_offsets_.end());
1827
  return p->second;
1828
}
1829
 
1830
// Set the PLT offset of a local symbol.
1831
 
1832
template<int size, bool big_endian>
1833
void
1834
Sized_relobj_file<size, big_endian>::set_local_plt_offset(
1835
    unsigned int symndx, unsigned int plt_offset)
1836
{
1837
  std::pair<typename Local_plt_offsets::iterator, bool> ins =
1838
    this->local_plt_offsets_.insert(std::make_pair(symndx, plt_offset));
1839
  gold_assert(ins.second);
1840
}
1841
 
1842
// First pass over the local symbols.  Here we add their names to
1843
// *POOL and *DYNPOOL, and we store the symbol value in
1844
// THIS->LOCAL_VALUES_.  This function is always called from a
1845
// singleton thread.  This is followed by a call to
1846
// finalize_local_symbols.
1847
 
1848
template<int size, bool big_endian>
1849
void
1850
Sized_relobj_file<size, big_endian>::do_count_local_symbols(Stringpool* pool,
1851
                                                            Stringpool* dynpool)
1852
{
1853
  gold_assert(this->symtab_shndx_ != -1U);
1854
  if (this->symtab_shndx_ == 0)
1855
    {
1856
      // This object has no symbols.  Weird but legal.
1857
      return;
1858
    }
1859
 
1860
  // Read the symbol table section header.
1861
  const unsigned int symtab_shndx = this->symtab_shndx_;
1862
  typename This::Shdr symtabshdr(this,
1863
                                 this->elf_file_.section_header(symtab_shndx));
1864
  gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
1865
 
1866
  // Read the local symbols.
1867
  const int sym_size = This::sym_size;
1868
  const unsigned int loccount = this->local_symbol_count_;
1869
  gold_assert(loccount == symtabshdr.get_sh_info());
1870
  off_t locsize = loccount * sym_size;
1871
  const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
1872
                                              locsize, true, true);
1873
 
1874
  // Read the symbol names.
1875
  const unsigned int strtab_shndx =
1876
    this->adjust_shndx(symtabshdr.get_sh_link());
1877
  section_size_type strtab_size;
1878
  const unsigned char* pnamesu = this->section_contents(strtab_shndx,
1879
                                                        &strtab_size,
1880
                                                        true);
1881
  const char* pnames = reinterpret_cast<const char*>(pnamesu);
1882
 
1883
  // Loop over the local symbols.
1884
 
1885
  const Output_sections& out_sections(this->output_sections());
1886
  unsigned int shnum = this->shnum();
1887
  unsigned int count = 0;
1888
  unsigned int dyncount = 0;
1889
  // Skip the first, dummy, symbol.
1890
  psyms += sym_size;
1891
  bool strip_all = parameters->options().strip_all();
1892
  bool discard_all = parameters->options().discard_all();
1893
  bool discard_locals = parameters->options().discard_locals();
1894
  for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
1895
    {
1896
      elfcpp::Sym<size, big_endian> sym(psyms);
1897
 
1898
      Symbol_value<size>& lv(this->local_values_[i]);
1899
 
1900
      bool is_ordinary;
1901
      unsigned int shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(),
1902
                                                  &is_ordinary);
1903
      lv.set_input_shndx(shndx, is_ordinary);
1904
 
1905
      if (sym.get_st_type() == elfcpp::STT_SECTION)
1906
        lv.set_is_section_symbol();
1907
      else if (sym.get_st_type() == elfcpp::STT_TLS)
1908
        lv.set_is_tls_symbol();
1909
      else if (sym.get_st_type() == elfcpp::STT_GNU_IFUNC)
1910
        lv.set_is_ifunc_symbol();
1911
 
1912
      // Save the input symbol value for use in do_finalize_local_symbols().
1913
      lv.set_input_value(sym.get_st_value());
1914
 
1915
      // Decide whether this symbol should go into the output file.
1916
 
1917
      if ((shndx < shnum && out_sections[shndx] == NULL)
1918
          || shndx == this->discarded_eh_frame_shndx_)
1919
        {
1920
          lv.set_no_output_symtab_entry();
1921
          gold_assert(!lv.needs_output_dynsym_entry());
1922
          continue;
1923
        }
1924
 
1925
      if (sym.get_st_type() == elfcpp::STT_SECTION)
1926
        {
1927
          lv.set_no_output_symtab_entry();
1928
          gold_assert(!lv.needs_output_dynsym_entry());
1929
          continue;
1930
        }
1931
 
1932
      if (sym.get_st_name() >= strtab_size)
1933
        {
1934
          this->error(_("local symbol %u section name out of range: %u >= %u"),
1935
                      i, sym.get_st_name(),
1936
                      static_cast<unsigned int>(strtab_size));
1937
          lv.set_no_output_symtab_entry();
1938
          continue;
1939
        }
1940
 
1941
      const char* name = pnames + sym.get_st_name();
1942
 
1943
      // If needed, add the symbol to the dynamic symbol table string pool.
1944
      if (lv.needs_output_dynsym_entry())
1945
        {
1946
          dynpool->add(name, true, NULL);
1947
          ++dyncount;
1948
        }
1949
 
1950
      if (strip_all
1951
          || (discard_all && lv.may_be_discarded_from_output_symtab()))
1952
        {
1953
          lv.set_no_output_symtab_entry();
1954
          continue;
1955
        }
1956
 
1957
      // If --discard-locals option is used, discard all temporary local
1958
      // symbols.  These symbols start with system-specific local label
1959
      // prefixes, typically .L for ELF system.  We want to be compatible
1960
      // with GNU ld so here we essentially use the same check in
1961
      // bfd_is_local_label().  The code is different because we already
1962
      // know that:
1963
      //
1964
      //   - the symbol is local and thus cannot have global or weak binding.
1965
      //   - the symbol is not a section symbol.
1966
      //   - the symbol has a name.
1967
      //
1968
      // We do not discard a symbol if it needs a dynamic symbol entry.
1969
      if (discard_locals
1970
          && sym.get_st_type() != elfcpp::STT_FILE
1971
          && !lv.needs_output_dynsym_entry()
1972
          && lv.may_be_discarded_from_output_symtab()
1973
          && parameters->target().is_local_label_name(name))
1974
        {
1975
          lv.set_no_output_symtab_entry();
1976
          continue;
1977
        }
1978
 
1979
      // Discard the local symbol if -retain_symbols_file is specified
1980
      // and the local symbol is not in that file.
1981
      if (!parameters->options().should_retain_symbol(name))
1982
        {
1983
          lv.set_no_output_symtab_entry();
1984
          continue;
1985
        }
1986
 
1987
      // Add the symbol to the symbol table string pool.
1988
      pool->add(name, true, NULL);
1989
      ++count;
1990
    }
1991
 
1992
  this->output_local_symbol_count_ = count;
1993
  this->output_local_dynsym_count_ = dyncount;
1994
}
1995
 
1996
// Compute the final value of a local symbol.
1997
 
1998
template<int size, bool big_endian>
1999
typename Sized_relobj_file<size, big_endian>::Compute_final_local_value_status
2000
Sized_relobj_file<size, big_endian>::compute_final_local_value_internal(
2001
    unsigned int r_sym,
2002
    const Symbol_value<size>* lv_in,
2003
    Symbol_value<size>* lv_out,
2004
    bool relocatable,
2005
    const Output_sections& out_sections,
2006
    const std::vector<Address>& out_offsets,
2007
    const Symbol_table* symtab)
2008
{
2009
  // We are going to overwrite *LV_OUT, if it has a merged symbol value,
2010
  // we may have a memory leak.
2011
  gold_assert(lv_out->has_output_value());
2012
 
2013
  bool is_ordinary;
2014
  unsigned int shndx = lv_in->input_shndx(&is_ordinary);
2015
 
2016
  // Set the output symbol value.
2017
 
2018
  if (!is_ordinary)
2019
    {
2020
      if (shndx == elfcpp::SHN_ABS || Symbol::is_common_shndx(shndx))
2021
        lv_out->set_output_value(lv_in->input_value());
2022
      else
2023
        {
2024
          this->error(_("unknown section index %u for local symbol %u"),
2025
                      shndx, r_sym);
2026
          lv_out->set_output_value(0);
2027
          return This::CFLV_ERROR;
2028
        }
2029
    }
2030
  else
2031
    {
2032
      if (shndx >= this->shnum())
2033
        {
2034
          this->error(_("local symbol %u section index %u out of range"),
2035
                      r_sym, shndx);
2036
          lv_out->set_output_value(0);
2037
          return This::CFLV_ERROR;
2038
        }
2039
 
2040
      Output_section* os = out_sections[shndx];
2041
      Address secoffset = out_offsets[shndx];
2042
      if (symtab->is_section_folded(this, shndx))
2043
        {
2044
          gold_assert(os == NULL && secoffset == invalid_address);
2045
          // Get the os of the section it is folded onto.
2046
          Section_id folded = symtab->icf()->get_folded_section(this,
2047
                                                                shndx);
2048
          gold_assert(folded.first != NULL);
2049
          Sized_relobj_file<size, big_endian>* folded_obj = reinterpret_cast
2050
            <Sized_relobj_file<size, big_endian>*>(folded.first);
2051
          os = folded_obj->output_section(folded.second);
2052
          gold_assert(os != NULL);
2053
          secoffset = folded_obj->get_output_section_offset(folded.second);
2054
 
2055
          // This could be a relaxed input section.
2056
          if (secoffset == invalid_address)
2057
            {
2058
              const Output_relaxed_input_section* relaxed_section =
2059
                os->find_relaxed_input_section(folded_obj, folded.second);
2060
              gold_assert(relaxed_section != NULL);
2061
              secoffset = relaxed_section->address() - os->address();
2062
            }
2063
        }
2064
 
2065
      if (os == NULL)
2066
        {
2067
          // This local symbol belongs to a section we are discarding.
2068
          // In some cases when applying relocations later, we will
2069
          // attempt to match it to the corresponding kept section,
2070
          // so we leave the input value unchanged here.
2071
          return This::CFLV_DISCARDED;
2072
        }
2073
      else if (secoffset == invalid_address)
2074
        {
2075
          uint64_t start;
2076
 
2077
          // This is a SHF_MERGE section or one which otherwise
2078
          // requires special handling.
2079
          if (shndx == this->discarded_eh_frame_shndx_)
2080
            {
2081
              // This local symbol belongs to a discarded .eh_frame
2082
              // section.  Just treat it like the case in which
2083
              // os == NULL above.
2084
              gold_assert(this->has_eh_frame_);
2085
              return This::CFLV_DISCARDED;
2086
            }
2087
          else if (!lv_in->is_section_symbol())
2088
            {
2089
              // This is not a section symbol.  We can determine
2090
              // the final value now.
2091
              lv_out->set_output_value(
2092
                  os->output_address(this, shndx, lv_in->input_value()));
2093
            }
2094
          else if (!os->find_starting_output_address(this, shndx, &start))
2095
            {
2096
              // This is a section symbol, but apparently not one in a
2097
              // merged section.  First check to see if this is a relaxed
2098
              // input section.  If so, use its address.  Otherwise just
2099
              // use the start of the output section.  This happens with
2100
              // relocatable links when the input object has section
2101
              // symbols for arbitrary non-merge sections.
2102
              const Output_section_data* posd =
2103
                os->find_relaxed_input_section(this, shndx);
2104
              if (posd != NULL)
2105
                {
2106
                  Address relocatable_link_adjustment =
2107
                    relocatable ? os->address() : 0;
2108
                  lv_out->set_output_value(posd->address()
2109
                                           - relocatable_link_adjustment);
2110
                }
2111
              else
2112
                lv_out->set_output_value(os->address());
2113
            }
2114
          else
2115
            {
2116
              // We have to consider the addend to determine the
2117
              // value to use in a relocation.  START is the start
2118
              // of this input section.  If we are doing a relocatable
2119
              // link, use offset from start output section instead of
2120
              // address.
2121
              Address adjusted_start =
2122
                relocatable ? start - os->address() : start;
2123
              Merged_symbol_value<size>* msv =
2124
                new Merged_symbol_value<size>(lv_in->input_value(),
2125
                                              adjusted_start);
2126
              lv_out->set_merged_symbol_value(msv);
2127
            }
2128
        }
2129
      else if (lv_in->is_tls_symbol())
2130
        lv_out->set_output_value(os->tls_offset()
2131
                                 + secoffset
2132
                                 + lv_in->input_value());
2133
      else
2134
        lv_out->set_output_value((relocatable ? 0 : os->address())
2135
                                 + secoffset
2136
                                 + lv_in->input_value());
2137
    }
2138
  return This::CFLV_OK;
2139
}
2140
 
2141
// Compute final local symbol value.  R_SYM is the index of a local
2142
// symbol in symbol table.  LV points to a symbol value, which is
2143
// expected to hold the input value and to be over-written by the
2144
// final value.  SYMTAB points to a symbol table.  Some targets may want
2145
// to know would-be-finalized local symbol values in relaxation.
2146
// Hence we provide this method.  Since this method updates *LV, a
2147
// callee should make a copy of the original local symbol value and
2148
// use the copy instead of modifying an object's local symbols before
2149
// everything is finalized.  The caller should also free up any allocated
2150
// memory in the return value in *LV.
2151
template<int size, bool big_endian>
2152
typename Sized_relobj_file<size, big_endian>::Compute_final_local_value_status
2153
Sized_relobj_file<size, big_endian>::compute_final_local_value(
2154
    unsigned int r_sym,
2155
    const Symbol_value<size>* lv_in,
2156
    Symbol_value<size>* lv_out,
2157
    const Symbol_table* symtab)
2158
{
2159
  // This is just a wrapper of compute_final_local_value_internal.
2160
  const bool relocatable = parameters->options().relocatable();
2161
  const Output_sections& out_sections(this->output_sections());
2162
  const std::vector<Address>& out_offsets(this->section_offsets());
2163
  return this->compute_final_local_value_internal(r_sym, lv_in, lv_out,
2164
                                                  relocatable, out_sections,
2165
                                                  out_offsets, symtab);
2166
}
2167
 
2168
// Finalize the local symbols.  Here we set the final value in
2169
// THIS->LOCAL_VALUES_ and set their output symbol table indexes.
2170
// This function is always called from a singleton thread.  The actual
2171
// output of the local symbols will occur in a separate task.
2172
 
2173
template<int size, bool big_endian>
2174
unsigned int
2175
Sized_relobj_file<size, big_endian>::do_finalize_local_symbols(
2176
    unsigned int index,
2177
    off_t off,
2178
    Symbol_table* symtab)
2179
{
2180
  gold_assert(off == static_cast<off_t>(align_address(off, size >> 3)));
2181
 
2182
  const unsigned int loccount = this->local_symbol_count_;
2183
  this->local_symbol_offset_ = off;
2184
 
2185
  const bool relocatable = parameters->options().relocatable();
2186
  const Output_sections& out_sections(this->output_sections());
2187
  const std::vector<Address>& out_offsets(this->section_offsets());
2188
 
2189
  for (unsigned int i = 1; i < loccount; ++i)
2190
    {
2191
      Symbol_value<size>* lv = &this->local_values_[i];
2192
 
2193
      Compute_final_local_value_status cflv_status =
2194
        this->compute_final_local_value_internal(i, lv, lv, relocatable,
2195
                                                 out_sections, out_offsets,
2196
                                                 symtab);
2197
      switch (cflv_status)
2198
        {
2199
        case CFLV_OK:
2200
          if (!lv->is_output_symtab_index_set())
2201
            {
2202
              lv->set_output_symtab_index(index);
2203
              ++index;
2204
            }
2205
          break;
2206
        case CFLV_DISCARDED:
2207
        case CFLV_ERROR:
2208
          // Do nothing.
2209
          break;
2210
        default:
2211
          gold_unreachable();
2212
        }
2213
    }
2214
  return index;
2215
}
2216
 
2217
// Set the output dynamic symbol table indexes for the local variables.
2218
 
2219
template<int size, bool big_endian>
2220
unsigned int
2221
Sized_relobj_file<size, big_endian>::do_set_local_dynsym_indexes(
2222
    unsigned int index)
2223
{
2224
  const unsigned int loccount = this->local_symbol_count_;
2225
  for (unsigned int i = 1; i < loccount; ++i)
2226
    {
2227
      Symbol_value<size>& lv(this->local_values_[i]);
2228
      if (lv.needs_output_dynsym_entry())
2229
        {
2230
          lv.set_output_dynsym_index(index);
2231
          ++index;
2232
        }
2233
    }
2234
  return index;
2235
}
2236
 
2237
// Set the offset where local dynamic symbol information will be stored.
2238
// Returns the count of local symbols contributed to the symbol table by
2239
// this object.
2240
 
2241
template<int size, bool big_endian>
2242
unsigned int
2243
Sized_relobj_file<size, big_endian>::do_set_local_dynsym_offset(off_t off)
2244
{
2245
  gold_assert(off == static_cast<off_t>(align_address(off, size >> 3)));
2246
  this->local_dynsym_offset_ = off;
2247
  return this->output_local_dynsym_count_;
2248
}
2249
 
2250
// If Symbols_data is not NULL get the section flags from here otherwise
2251
// get it from the file.
2252
 
2253
template<int size, bool big_endian>
2254
uint64_t
2255
Sized_relobj_file<size, big_endian>::do_section_flags(unsigned int shndx)
2256
{
2257
  Symbols_data* sd = this->get_symbols_data();
2258
  if (sd != NULL)
2259
    {
2260
      const unsigned char* pshdrs = sd->section_headers_data
2261
                                    + This::shdr_size * shndx;
2262
      typename This::Shdr shdr(pshdrs);
2263
      return shdr.get_sh_flags();
2264
    }
2265
  // If sd is NULL, read the section header from the file.
2266
  return this->elf_file_.section_flags(shndx);
2267
}
2268
 
2269
// Get the section's ent size from Symbols_data.  Called by get_section_contents
2270
// in icf.cc
2271
 
2272
template<int size, bool big_endian>
2273
uint64_t
2274
Sized_relobj_file<size, big_endian>::do_section_entsize(unsigned int shndx)
2275
{
2276
  Symbols_data* sd = this->get_symbols_data();
2277
  gold_assert(sd != NULL);
2278
 
2279
  const unsigned char* pshdrs = sd->section_headers_data
2280
                                + This::shdr_size * shndx;
2281
  typename This::Shdr shdr(pshdrs);
2282
  return shdr.get_sh_entsize();
2283
}
2284
 
2285
// Write out the local symbols.
2286
 
2287
template<int size, bool big_endian>
2288
void
2289
Sized_relobj_file<size, big_endian>::write_local_symbols(
2290
    Output_file* of,
2291
    const Stringpool* sympool,
2292
    const Stringpool* dynpool,
2293
    Output_symtab_xindex* symtab_xindex,
2294
    Output_symtab_xindex* dynsym_xindex,
2295
    off_t symtab_off)
2296
{
2297
  const bool strip_all = parameters->options().strip_all();
2298
  if (strip_all)
2299
    {
2300
      if (this->output_local_dynsym_count_ == 0)
2301
        return;
2302
      this->output_local_symbol_count_ = 0;
2303
    }
2304
 
2305
  gold_assert(this->symtab_shndx_ != -1U);
2306
  if (this->symtab_shndx_ == 0)
2307
    {
2308
      // This object has no symbols.  Weird but legal.
2309
      return;
2310
    }
2311
 
2312
  // Read the symbol table section header.
2313
  const unsigned int symtab_shndx = this->symtab_shndx_;
2314
  typename This::Shdr symtabshdr(this,
2315
                                 this->elf_file_.section_header(symtab_shndx));
2316
  gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
2317
  const unsigned int loccount = this->local_symbol_count_;
2318
  gold_assert(loccount == symtabshdr.get_sh_info());
2319
 
2320
  // Read the local symbols.
2321
  const int sym_size = This::sym_size;
2322
  off_t locsize = loccount * sym_size;
2323
  const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
2324
                                              locsize, true, false);
2325
 
2326
  // Read the symbol names.
2327
  const unsigned int strtab_shndx =
2328
    this->adjust_shndx(symtabshdr.get_sh_link());
2329
  section_size_type strtab_size;
2330
  const unsigned char* pnamesu = this->section_contents(strtab_shndx,
2331
                                                        &strtab_size,
2332
                                                        false);
2333
  const char* pnames = reinterpret_cast<const char*>(pnamesu);
2334
 
2335
  // Get views into the output file for the portions of the symbol table
2336
  // and the dynamic symbol table that we will be writing.
2337
  off_t output_size = this->output_local_symbol_count_ * sym_size;
2338
  unsigned char* oview = NULL;
2339
  if (output_size > 0)
2340
    oview = of->get_output_view(symtab_off + this->local_symbol_offset_,
2341
                                output_size);
2342
 
2343
  off_t dyn_output_size = this->output_local_dynsym_count_ * sym_size;
2344
  unsigned char* dyn_oview = NULL;
2345
  if (dyn_output_size > 0)
2346
    dyn_oview = of->get_output_view(this->local_dynsym_offset_,
2347
                                    dyn_output_size);
2348
 
2349
  const Output_sections out_sections(this->output_sections());
2350
 
2351
  gold_assert(this->local_values_.size() == loccount);
2352
 
2353
  unsigned char* ov = oview;
2354
  unsigned char* dyn_ov = dyn_oview;
2355
  psyms += sym_size;
2356
  for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
2357
    {
2358
      elfcpp::Sym<size, big_endian> isym(psyms);
2359
 
2360
      Symbol_value<size>& lv(this->local_values_[i]);
2361
 
2362
      bool is_ordinary;
2363
      unsigned int st_shndx = this->adjust_sym_shndx(i, isym.get_st_shndx(),
2364
                                                     &is_ordinary);
2365
      if (is_ordinary)
2366
        {
2367
          gold_assert(st_shndx < out_sections.size());
2368
          if (out_sections[st_shndx] == NULL)
2369
            continue;
2370
          st_shndx = out_sections[st_shndx]->out_shndx();
2371
          if (st_shndx >= elfcpp::SHN_LORESERVE)
2372
            {
2373
              if (lv.has_output_symtab_entry())
2374
                symtab_xindex->add(lv.output_symtab_index(), st_shndx);
2375
              if (lv.has_output_dynsym_entry())
2376
                dynsym_xindex->add(lv.output_dynsym_index(), st_shndx);
2377
              st_shndx = elfcpp::SHN_XINDEX;
2378
            }
2379
        }
2380
 
2381
      // Write the symbol to the output symbol table.
2382
      if (lv.has_output_symtab_entry())
2383
        {
2384
          elfcpp::Sym_write<size, big_endian> osym(ov);
2385
 
2386
          gold_assert(isym.get_st_name() < strtab_size);
2387
          const char* name = pnames + isym.get_st_name();
2388
          osym.put_st_name(sympool->get_offset(name));
2389
          osym.put_st_value(this->local_values_[i].value(this, 0));
2390
          osym.put_st_size(isym.get_st_size());
2391
          osym.put_st_info(isym.get_st_info());
2392
          osym.put_st_other(isym.get_st_other());
2393
          osym.put_st_shndx(st_shndx);
2394
 
2395
          ov += sym_size;
2396
        }
2397
 
2398
      // Write the symbol to the output dynamic symbol table.
2399
      if (lv.has_output_dynsym_entry())
2400
        {
2401
          gold_assert(dyn_ov < dyn_oview + dyn_output_size);
2402
          elfcpp::Sym_write<size, big_endian> osym(dyn_ov);
2403
 
2404
          gold_assert(isym.get_st_name() < strtab_size);
2405
          const char* name = pnames + isym.get_st_name();
2406
          osym.put_st_name(dynpool->get_offset(name));
2407
          osym.put_st_value(this->local_values_[i].value(this, 0));
2408
          osym.put_st_size(isym.get_st_size());
2409
          osym.put_st_info(isym.get_st_info());
2410
          osym.put_st_other(isym.get_st_other());
2411
          osym.put_st_shndx(st_shndx);
2412
 
2413
          dyn_ov += sym_size;
2414
        }
2415
    }
2416
 
2417
 
2418
  if (output_size > 0)
2419
    {
2420
      gold_assert(ov - oview == output_size);
2421
      of->write_output_view(symtab_off + this->local_symbol_offset_,
2422
                            output_size, oview);
2423
    }
2424
 
2425
  if (dyn_output_size > 0)
2426
    {
2427
      gold_assert(dyn_ov - dyn_oview == dyn_output_size);
2428
      of->write_output_view(this->local_dynsym_offset_, dyn_output_size,
2429
                            dyn_oview);
2430
    }
2431
}
2432
 
2433
// Set *INFO to symbolic information about the offset OFFSET in the
2434
// section SHNDX.  Return true if we found something, false if we
2435
// found nothing.
2436
 
2437
template<int size, bool big_endian>
2438
bool
2439
Sized_relobj_file<size, big_endian>::get_symbol_location_info(
2440
    unsigned int shndx,
2441
    off_t offset,
2442
    Symbol_location_info* info)
2443
{
2444
  if (this->symtab_shndx_ == 0)
2445
    return false;
2446
 
2447
  section_size_type symbols_size;
2448
  const unsigned char* symbols = this->section_contents(this->symtab_shndx_,
2449
                                                        &symbols_size,
2450
                                                        false);
2451
 
2452
  unsigned int symbol_names_shndx =
2453
    this->adjust_shndx(this->section_link(this->symtab_shndx_));
2454
  section_size_type names_size;
2455
  const unsigned char* symbol_names_u =
2456
    this->section_contents(symbol_names_shndx, &names_size, false);
2457
  const char* symbol_names = reinterpret_cast<const char*>(symbol_names_u);
2458
 
2459
  const int sym_size = This::sym_size;
2460
  const size_t count = symbols_size / sym_size;
2461
 
2462
  const unsigned char* p = symbols;
2463
  for (size_t i = 0; i < count; ++i, p += sym_size)
2464
    {
2465
      elfcpp::Sym<size, big_endian> sym(p);
2466
 
2467
      if (sym.get_st_type() == elfcpp::STT_FILE)
2468
        {
2469
          if (sym.get_st_name() >= names_size)
2470
            info->source_file = "(invalid)";
2471
          else
2472
            info->source_file = symbol_names + sym.get_st_name();
2473
          continue;
2474
        }
2475
 
2476
      bool is_ordinary;
2477
      unsigned int st_shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(),
2478
                                                     &is_ordinary);
2479
      if (is_ordinary
2480
          && st_shndx == shndx
2481
          && static_cast<off_t>(sym.get_st_value()) <= offset
2482
          && (static_cast<off_t>(sym.get_st_value() + sym.get_st_size())
2483
              > offset))
2484
        {
2485
          if (sym.get_st_name() > names_size)
2486
            info->enclosing_symbol_name = "(invalid)";
2487
          else
2488
            {
2489
              info->enclosing_symbol_name = symbol_names + sym.get_st_name();
2490
              if (parameters->options().do_demangle())
2491
                {
2492
                  char* demangled_name = cplus_demangle(
2493
                      info->enclosing_symbol_name.c_str(),
2494
                      DMGL_ANSI | DMGL_PARAMS);
2495
                  if (demangled_name != NULL)
2496
                    {
2497
                      info->enclosing_symbol_name.assign(demangled_name);
2498
                      free(demangled_name);
2499
                    }
2500
                }
2501
            }
2502
          return true;
2503
        }
2504
    }
2505
 
2506
  return false;
2507
}
2508
 
2509
// Look for a kept section corresponding to the given discarded section,
2510
// and return its output address.  This is used only for relocations in
2511
// debugging sections.  If we can't find the kept section, return 0.
2512
 
2513
template<int size, bool big_endian>
2514
typename Sized_relobj_file<size, big_endian>::Address
2515
Sized_relobj_file<size, big_endian>::map_to_kept_section(
2516
    unsigned int shndx,
2517
    bool* found) const
2518
{
2519
  Relobj* kept_object;
2520
  unsigned int kept_shndx;
2521
  if (this->get_kept_comdat_section(shndx, &kept_object, &kept_shndx))
2522
    {
2523
      Sized_relobj_file<size, big_endian>* kept_relobj =
2524
        static_cast<Sized_relobj_file<size, big_endian>*>(kept_object);
2525
      Output_section* os = kept_relobj->output_section(kept_shndx);
2526
      Address offset = kept_relobj->get_output_section_offset(kept_shndx);
2527
      if (os != NULL && offset != invalid_address)
2528
        {
2529
          *found = true;
2530
          return os->address() + offset;
2531
        }
2532
    }
2533
  *found = false;
2534
  return 0;
2535
}
2536
 
2537
// Get symbol counts.
2538
 
2539
template<int size, bool big_endian>
2540
void
2541
Sized_relobj_file<size, big_endian>::do_get_global_symbol_counts(
2542
    const Symbol_table*,
2543
    size_t* defined,
2544
    size_t* used) const
2545
{
2546
  *defined = this->defined_count_;
2547
  size_t count = 0;
2548
  for (typename Symbols::const_iterator p = this->symbols_.begin();
2549
       p != this->symbols_.end();
2550
       ++p)
2551
    if (*p != NULL
2552
        && (*p)->source() == Symbol::FROM_OBJECT
2553
        && (*p)->object() == this
2554
        && (*p)->is_defined())
2555
      ++count;
2556
  *used = count;
2557
}
2558
 
2559
// Input_objects methods.
2560
 
2561
// Add a regular relocatable object to the list.  Return false if this
2562
// object should be ignored.
2563
 
2564
bool
2565
Input_objects::add_object(Object* obj)
2566
{
2567
  // Print the filename if the -t/--trace option is selected.
2568
  if (parameters->options().trace())
2569
    gold_info("%s", obj->name().c_str());
2570
 
2571
  if (!obj->is_dynamic())
2572
    this->relobj_list_.push_back(static_cast<Relobj*>(obj));
2573
  else
2574
    {
2575
      // See if this is a duplicate SONAME.
2576
      Dynobj* dynobj = static_cast<Dynobj*>(obj);
2577
      const char* soname = dynobj->soname();
2578
 
2579
      std::pair<Unordered_set<std::string>::iterator, bool> ins =
2580
        this->sonames_.insert(soname);
2581
      if (!ins.second)
2582
        {
2583
          // We have already seen a dynamic object with this soname.
2584
          return false;
2585
        }
2586
 
2587
      this->dynobj_list_.push_back(dynobj);
2588
    }
2589
 
2590
  // Add this object to the cross-referencer if requested.
2591
  if (parameters->options().user_set_print_symbol_counts()
2592
      || parameters->options().cref())
2593
    {
2594
      if (this->cref_ == NULL)
2595
        this->cref_ = new Cref();
2596
      this->cref_->add_object(obj);
2597
    }
2598
 
2599
  return true;
2600
}
2601
 
2602
// For each dynamic object, record whether we've seen all of its
2603
// explicit dependencies.
2604
 
2605
void
2606
Input_objects::check_dynamic_dependencies() const
2607
{
2608
  bool issued_copy_dt_needed_error = false;
2609
  for (Dynobj_list::const_iterator p = this->dynobj_list_.begin();
2610
       p != this->dynobj_list_.end();
2611
       ++p)
2612
    {
2613
      const Dynobj::Needed& needed((*p)->needed());
2614
      bool found_all = true;
2615
      Dynobj::Needed::const_iterator pneeded;
2616
      for (pneeded = needed.begin(); pneeded != needed.end(); ++pneeded)
2617
        {
2618
          if (this->sonames_.find(*pneeded) == this->sonames_.end())
2619
            {
2620
              found_all = false;
2621
              break;
2622
            }
2623
        }
2624
      (*p)->set_has_unknown_needed_entries(!found_all);
2625
 
2626
      // --copy-dt-needed-entries aka --add-needed is a GNU ld option
2627
      // that gold does not support.  However, they cause no trouble
2628
      // unless there is a DT_NEEDED entry that we don't know about;
2629
      // warn only in that case.
2630
      if (!found_all
2631
          && !issued_copy_dt_needed_error
2632
          && (parameters->options().copy_dt_needed_entries()
2633
              || parameters->options().add_needed()))
2634
        {
2635
          const char* optname;
2636
          if (parameters->options().copy_dt_needed_entries())
2637
            optname = "--copy-dt-needed-entries";
2638
          else
2639
            optname = "--add-needed";
2640
          gold_error(_("%s is not supported but is required for %s in %s"),
2641
                     optname, (*pneeded).c_str(), (*p)->name().c_str());
2642
          issued_copy_dt_needed_error = true;
2643
        }
2644
    }
2645
}
2646
 
2647
// Start processing an archive.
2648
 
2649
void
2650
Input_objects::archive_start(Archive* archive)
2651
{
2652
  if (parameters->options().user_set_print_symbol_counts()
2653
      || parameters->options().cref())
2654
    {
2655
      if (this->cref_ == NULL)
2656
        this->cref_ = new Cref();
2657
      this->cref_->add_archive_start(archive);
2658
    }
2659
}
2660
 
2661
// Stop processing an archive.
2662
 
2663
void
2664
Input_objects::archive_stop(Archive* archive)
2665
{
2666
  if (parameters->options().user_set_print_symbol_counts()
2667
      || parameters->options().cref())
2668
    this->cref_->add_archive_stop(archive);
2669
}
2670
 
2671
// Print symbol counts
2672
 
2673
void
2674
Input_objects::print_symbol_counts(const Symbol_table* symtab) const
2675
{
2676
  if (parameters->options().user_set_print_symbol_counts()
2677
      && this->cref_ != NULL)
2678
    this->cref_->print_symbol_counts(symtab);
2679
}
2680
 
2681
// Print a cross reference table.
2682
 
2683
void
2684
Input_objects::print_cref(const Symbol_table* symtab, FILE* f) const
2685
{
2686
  if (parameters->options().cref() && this->cref_ != NULL)
2687
    this->cref_->print_cref(symtab, f);
2688
}
2689
 
2690
// Relocate_info methods.
2691
 
2692
// Return a string describing the location of a relocation when file
2693
// and lineno information is not available.  This is only used in
2694
// error messages.
2695
 
2696
template<int size, bool big_endian>
2697
std::string
2698
Relocate_info<size, big_endian>::location(size_t, off_t offset) const
2699
{
2700
  Sized_dwarf_line_info<size, big_endian> line_info(this->object);
2701
  std::string ret = line_info.addr2line(this->data_shndx, offset, NULL);
2702
  if (!ret.empty())
2703
    return ret;
2704
 
2705
  ret = this->object->name();
2706
 
2707
  Symbol_location_info info;
2708
  if (this->object->get_symbol_location_info(this->data_shndx, offset, &info))
2709
    {
2710
      if (!info.source_file.empty())
2711
        {
2712
          ret += ":";
2713
          ret += info.source_file;
2714
        }
2715
      size_t len = info.enclosing_symbol_name.length() + 100;
2716
      char* buf = new char[len];
2717
      snprintf(buf, len, _(":function %s"),
2718
               info.enclosing_symbol_name.c_str());
2719
      ret += buf;
2720
      delete[] buf;
2721
      return ret;
2722
    }
2723
 
2724
  ret += "(";
2725
  ret += this->object->section_name(this->data_shndx);
2726
  char buf[100];
2727
  snprintf(buf, sizeof buf, "+0x%lx)", static_cast<long>(offset));
2728
  ret += buf;
2729
  return ret;
2730
}
2731
 
2732
} // End namespace gold.
2733
 
2734
namespace
2735
{
2736
 
2737
using namespace gold;
2738
 
2739
// Read an ELF file with the header and return the appropriate
2740
// instance of Object.
2741
 
2742
template<int size, bool big_endian>
2743
Object*
2744
make_elf_sized_object(const std::string& name, Input_file* input_file,
2745
                      off_t offset, const elfcpp::Ehdr<size, big_endian>& ehdr,
2746
                      bool* punconfigured)
2747
{
2748
  Target* target = select_target(ehdr.get_e_machine(), size, big_endian,
2749
                                 ehdr.get_e_ident()[elfcpp::EI_OSABI],
2750
                                 ehdr.get_e_ident()[elfcpp::EI_ABIVERSION]);
2751
  if (target == NULL)
2752
    gold_fatal(_("%s: unsupported ELF machine number %d"),
2753
               name.c_str(), ehdr.get_e_machine());
2754
 
2755
  if (!parameters->target_valid())
2756
    set_parameters_target(target);
2757
  else if (target != &parameters->target())
2758
    {
2759
      if (punconfigured != NULL)
2760
        *punconfigured = true;
2761
      else
2762
        gold_error(_("%s: incompatible target"), name.c_str());
2763
      return NULL;
2764
    }
2765
 
2766
  return target->make_elf_object<size, big_endian>(name, input_file, offset,
2767
                                                   ehdr);
2768
}
2769
 
2770
} // End anonymous namespace.
2771
 
2772
namespace gold
2773
{
2774
 
2775
// Return whether INPUT_FILE is an ELF object.
2776
 
2777
bool
2778
is_elf_object(Input_file* input_file, off_t offset,
2779
              const unsigned char** start, int* read_size)
2780
{
2781
  off_t filesize = input_file->file().filesize();
2782
  int want = elfcpp::Elf_recognizer::max_header_size;
2783
  if (filesize - offset < want)
2784
    want = filesize - offset;
2785
 
2786
  const unsigned char* p = input_file->file().get_view(offset, 0, want,
2787
                                                       true, false);
2788
  *start = p;
2789
  *read_size = want;
2790
 
2791
  return elfcpp::Elf_recognizer::is_elf_file(p, want);
2792
}
2793
 
2794
// Read an ELF file and return the appropriate instance of Object.
2795
 
2796
Object*
2797
make_elf_object(const std::string& name, Input_file* input_file, off_t offset,
2798
                const unsigned char* p, section_offset_type bytes,
2799
                bool* punconfigured)
2800
{
2801
  if (punconfigured != NULL)
2802
    *punconfigured = false;
2803
 
2804
  std::string error;
2805
  bool big_endian = false;
2806
  int size = 0;
2807
  if (!elfcpp::Elf_recognizer::is_valid_header(p, bytes, &size,
2808
                                               &big_endian, &error))
2809
    {
2810
      gold_error(_("%s: %s"), name.c_str(), error.c_str());
2811
      return NULL;
2812
    }
2813
 
2814
  if (size == 32)
2815
    {
2816
      if (big_endian)
2817
        {
2818
#ifdef HAVE_TARGET_32_BIG
2819
          elfcpp::Ehdr<32, true> ehdr(p);
2820
          return make_elf_sized_object<32, true>(name, input_file,
2821
                                                 offset, ehdr, punconfigured);
2822
#else
2823
          if (punconfigured != NULL)
2824
            *punconfigured = true;
2825
          else
2826
            gold_error(_("%s: not configured to support "
2827
                         "32-bit big-endian object"),
2828
                       name.c_str());
2829
          return NULL;
2830
#endif
2831
        }
2832
      else
2833
        {
2834
#ifdef HAVE_TARGET_32_LITTLE
2835
          elfcpp::Ehdr<32, false> ehdr(p);
2836
          return make_elf_sized_object<32, false>(name, input_file,
2837
                                                  offset, ehdr, punconfigured);
2838
#else
2839
          if (punconfigured != NULL)
2840
            *punconfigured = true;
2841
          else
2842
            gold_error(_("%s: not configured to support "
2843
                         "32-bit little-endian object"),
2844
                       name.c_str());
2845
          return NULL;
2846
#endif
2847
        }
2848
    }
2849
  else if (size == 64)
2850
    {
2851
      if (big_endian)
2852
        {
2853
#ifdef HAVE_TARGET_64_BIG
2854
          elfcpp::Ehdr<64, true> ehdr(p);
2855
          return make_elf_sized_object<64, true>(name, input_file,
2856
                                                 offset, ehdr, punconfigured);
2857
#else
2858
          if (punconfigured != NULL)
2859
            *punconfigured = true;
2860
          else
2861
            gold_error(_("%s: not configured to support "
2862
                         "64-bit big-endian object"),
2863
                       name.c_str());
2864
          return NULL;
2865
#endif
2866
        }
2867
      else
2868
        {
2869
#ifdef HAVE_TARGET_64_LITTLE
2870
          elfcpp::Ehdr<64, false> ehdr(p);
2871
          return make_elf_sized_object<64, false>(name, input_file,
2872
                                                  offset, ehdr, punconfigured);
2873
#else
2874
          if (punconfigured != NULL)
2875
            *punconfigured = true;
2876
          else
2877
            gold_error(_("%s: not configured to support "
2878
                         "64-bit little-endian object"),
2879
                       name.c_str());
2880
          return NULL;
2881
#endif
2882
        }
2883
    }
2884
  else
2885
    gold_unreachable();
2886
}
2887
 
2888
// Instantiate the templates we need.
2889
 
2890
#ifdef HAVE_TARGET_32_LITTLE
2891
template
2892
void
2893
Object::read_section_data<32, false>(elfcpp::Elf_file<32, false, Object>*,
2894
                                     Read_symbols_data*);
2895
#endif
2896
 
2897
#ifdef HAVE_TARGET_32_BIG
2898
template
2899
void
2900
Object::read_section_data<32, true>(elfcpp::Elf_file<32, true, Object>*,
2901
                                    Read_symbols_data*);
2902
#endif
2903
 
2904
#ifdef HAVE_TARGET_64_LITTLE
2905
template
2906
void
2907
Object::read_section_data<64, false>(elfcpp::Elf_file<64, false, Object>*,
2908
                                     Read_symbols_data*);
2909
#endif
2910
 
2911
#ifdef HAVE_TARGET_64_BIG
2912
template
2913
void
2914
Object::read_section_data<64, true>(elfcpp::Elf_file<64, true, Object>*,
2915
                                    Read_symbols_data*);
2916
#endif
2917
 
2918
#ifdef HAVE_TARGET_32_LITTLE
2919
template
2920
class Sized_relobj_file<32, false>;
2921
#endif
2922
 
2923
#ifdef HAVE_TARGET_32_BIG
2924
template
2925
class Sized_relobj_file<32, true>;
2926
#endif
2927
 
2928
#ifdef HAVE_TARGET_64_LITTLE
2929
template
2930
class Sized_relobj_file<64, false>;
2931
#endif
2932
 
2933
#ifdef HAVE_TARGET_64_BIG
2934
template
2935
class Sized_relobj_file<64, true>;
2936
#endif
2937
 
2938
#ifdef HAVE_TARGET_32_LITTLE
2939
template
2940
struct Relocate_info<32, false>;
2941
#endif
2942
 
2943
#ifdef HAVE_TARGET_32_BIG
2944
template
2945
struct Relocate_info<32, true>;
2946
#endif
2947
 
2948
#ifdef HAVE_TARGET_64_LITTLE
2949
template
2950
struct Relocate_info<64, false>;
2951
#endif
2952
 
2953
#ifdef HAVE_TARGET_64_BIG
2954
template
2955
struct Relocate_info<64, true>;
2956
#endif
2957
 
2958
#ifdef HAVE_TARGET_32_LITTLE
2959
template
2960
void
2961
Xindex::initialize_symtab_xindex<32, false>(Object*, unsigned int);
2962
 
2963
template
2964
void
2965
Xindex::read_symtab_xindex<32, false>(Object*, unsigned int,
2966
                                      const unsigned char*);
2967
#endif
2968
 
2969
#ifdef HAVE_TARGET_32_BIG
2970
template
2971
void
2972
Xindex::initialize_symtab_xindex<32, true>(Object*, unsigned int);
2973
 
2974
template
2975
void
2976
Xindex::read_symtab_xindex<32, true>(Object*, unsigned int,
2977
                                     const unsigned char*);
2978
#endif
2979
 
2980
#ifdef HAVE_TARGET_64_LITTLE
2981
template
2982
void
2983
Xindex::initialize_symtab_xindex<64, false>(Object*, unsigned int);
2984
 
2985
template
2986
void
2987
Xindex::read_symtab_xindex<64, false>(Object*, unsigned int,
2988
                                      const unsigned char*);
2989
#endif
2990
 
2991
#ifdef HAVE_TARGET_64_BIG
2992
template
2993
void
2994
Xindex::initialize_symtab_xindex<64, true>(Object*, unsigned int);
2995
 
2996
template
2997
void
2998
Xindex::read_symtab_xindex<64, true>(Object*, unsigned int,
2999
                                     const unsigned char*);
3000
#endif
3001
 
3002
} // End namespace gold.

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