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[/] [open8_urisc/] [trunk/] [gnu/] [binutils/] [gold/] [layout.cc] - Blame information for rev 53

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1 27 khays
// layout.cc -- lay out output file sections for 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 <algorithm>
28
#include <iostream>
29
#include <fstream>
30
#include <utility>
31
#include <fcntl.h>
32
#include <fnmatch.h>
33
#include <unistd.h>
34
#include "libiberty.h"
35
#include "md5.h"
36
#include "sha1.h"
37
 
38
#include "parameters.h"
39
#include "options.h"
40
#include "mapfile.h"
41
#include "script.h"
42
#include "script-sections.h"
43
#include "output.h"
44
#include "symtab.h"
45
#include "dynobj.h"
46
#include "ehframe.h"
47
#include "compressed_output.h"
48
#include "reduced_debug_output.h"
49
#include "reloc.h"
50
#include "descriptors.h"
51
#include "plugin.h"
52
#include "incremental.h"
53
#include "layout.h"
54
 
55
namespace gold
56
{
57
 
58
// Class Free_list.
59
 
60
// The total number of free lists used.
61
unsigned int Free_list::num_lists = 0;
62
// The total number of free list nodes used.
63
unsigned int Free_list::num_nodes = 0;
64
// The total number of calls to Free_list::remove.
65
unsigned int Free_list::num_removes = 0;
66
// The total number of nodes visited during calls to Free_list::remove.
67
unsigned int Free_list::num_remove_visits = 0;
68
// The total number of calls to Free_list::allocate.
69
unsigned int Free_list::num_allocates = 0;
70
// The total number of nodes visited during calls to Free_list::allocate.
71
unsigned int Free_list::num_allocate_visits = 0;
72
 
73
// Initialize the free list.  Creates a single free list node that
74
// describes the entire region of length LEN.  If EXTEND is true,
75
// allocate() is allowed to extend the region beyond its initial
76
// length.
77
 
78
void
79
Free_list::init(off_t len, bool extend)
80
{
81
  this->list_.push_front(Free_list_node(0, len));
82
  this->last_remove_ = this->list_.begin();
83
  this->extend_ = extend;
84
  this->length_ = len;
85
  ++Free_list::num_lists;
86
  ++Free_list::num_nodes;
87
}
88
 
89
// Remove a chunk from the free list.  Because we start with a single
90
// node that covers the entire section, and remove chunks from it one
91
// at a time, we do not need to coalesce chunks or handle cases that
92
// span more than one free node.  We expect to remove chunks from the
93
// free list in order, and we expect to have only a few chunks of free
94
// space left (corresponding to files that have changed since the last
95
// incremental link), so a simple linear list should provide sufficient
96
// performance.
97
 
98
void
99
Free_list::remove(off_t start, off_t end)
100
{
101
  if (start == end)
102
    return;
103
  gold_assert(start < end);
104
 
105
  ++Free_list::num_removes;
106
 
107
  Iterator p = this->last_remove_;
108
  if (p->start_ > start)
109
    p = this->list_.begin();
110
 
111
  for (; p != this->list_.end(); ++p)
112
    {
113
      ++Free_list::num_remove_visits;
114
      // Find a node that wholly contains the indicated region.
115
      if (p->start_ <= start && p->end_ >= end)
116
        {
117
          // Case 1: the indicated region spans the whole node.
118
          // Add some fuzz to avoid creating tiny free chunks.
119
          if (p->start_ + 3 >= start && p->end_ <= end + 3)
120
            p = this->list_.erase(p);
121
          // Case 2: remove a chunk from the start of the node.
122
          else if (p->start_ + 3 >= start)
123
            p->start_ = end;
124
          // Case 3: remove a chunk from the end of the node.
125
          else if (p->end_ <= end + 3)
126
            p->end_ = start;
127
          // Case 4: remove a chunk from the middle, and split
128
          // the node into two.
129
          else
130
            {
131
              Free_list_node newnode(p->start_, start);
132
              p->start_ = end;
133
              this->list_.insert(p, newnode);
134
              ++Free_list::num_nodes;
135
            }
136
          this->last_remove_ = p;
137
          return;
138
        }
139
    }
140
 
141
  // Did not find a node containing the given chunk.  This could happen
142
  // because a small chunk was already removed due to the fuzz.
143
  gold_debug(DEBUG_INCREMENTAL,
144
             "Free_list::remove(%d,%d) not found",
145
             static_cast<int>(start), static_cast<int>(end));
146
}
147
 
148
// Allocate a chunk of size LEN from the free list.  Returns -1ULL
149
// if a sufficiently large chunk of free space is not found.
150
// We use a simple first-fit algorithm.
151
 
152
off_t
153
Free_list::allocate(off_t len, uint64_t align, off_t minoff)
154
{
155
  gold_debug(DEBUG_INCREMENTAL,
156
             "Free_list::allocate(%08lx, %d, %08lx)",
157
             static_cast<long>(len), static_cast<int>(align),
158
             static_cast<long>(minoff));
159
  if (len == 0)
160
    return align_address(minoff, align);
161
 
162
  ++Free_list::num_allocates;
163
 
164
  for (Iterator p = this->list_.begin(); p != this->list_.end(); ++p)
165
    {
166
      ++Free_list::num_allocate_visits;
167
      off_t start = p->start_ > minoff ? p->start_ : minoff;
168
      start = align_address(start, align);
169
      off_t end = start + len;
170
      if (end <= p->end_)
171
        {
172
          if (p->start_ + 3 >= start && p->end_ <= end + 3)
173
            this->list_.erase(p);
174
          else if (p->start_ + 3 >= start)
175
            p->start_ = end;
176
          else if (p->end_ <= end + 3)
177
            p->end_ = start;
178
          else
179
            {
180
              Free_list_node newnode(p->start_, start);
181
              p->start_ = end;
182
              this->list_.insert(p, newnode);
183
              ++Free_list::num_nodes;
184
            }
185
          return start;
186
        }
187
    }
188
  return -1;
189
}
190
 
191
// Dump the free list (for debugging).
192
void
193
Free_list::dump()
194
{
195
  gold_info("Free list:\n     start      end   length\n");
196
  for (Iterator p = this->list_.begin(); p != this->list_.end(); ++p)
197
    gold_info("  %08lx %08lx %08lx", static_cast<long>(p->start_),
198
              static_cast<long>(p->end_),
199
              static_cast<long>(p->end_ - p->start_));
200
}
201
 
202
// Print the statistics for the free lists.
203
void
204
Free_list::print_stats()
205
{
206
  fprintf(stderr, _("%s: total free lists: %u\n"),
207
          program_name, Free_list::num_lists);
208
  fprintf(stderr, _("%s: total free list nodes: %u\n"),
209
          program_name, Free_list::num_nodes);
210
  fprintf(stderr, _("%s: calls to Free_list::remove: %u\n"),
211
          program_name, Free_list::num_removes);
212
  fprintf(stderr, _("%s: nodes visited: %u\n"),
213
          program_name, Free_list::num_remove_visits);
214
  fprintf(stderr, _("%s: calls to Free_list::allocate: %u\n"),
215
          program_name, Free_list::num_allocates);
216
  fprintf(stderr, _("%s: nodes visited: %u\n"),
217
          program_name, Free_list::num_allocate_visits);
218
}
219
 
220
// Layout::Relaxation_debug_check methods.
221
 
222
// Check that sections and special data are in reset states.
223
// We do not save states for Output_sections and special Output_data.
224
// So we check that they have not assigned any addresses or offsets.
225
// clean_up_after_relaxation simply resets their addresses and offsets.
226
void
227
Layout::Relaxation_debug_check::check_output_data_for_reset_values(
228
    const Layout::Section_list& sections,
229
    const Layout::Data_list& special_outputs)
230
{
231
  for(Layout::Section_list::const_iterator p = sections.begin();
232
      p != sections.end();
233
      ++p)
234
    gold_assert((*p)->address_and_file_offset_have_reset_values());
235
 
236
  for(Layout::Data_list::const_iterator p = special_outputs.begin();
237
      p != special_outputs.end();
238
      ++p)
239
    gold_assert((*p)->address_and_file_offset_have_reset_values());
240
}
241
 
242
// Save information of SECTIONS for checking later.
243
 
244
void
245
Layout::Relaxation_debug_check::read_sections(
246
    const Layout::Section_list& sections)
247
{
248
  for(Layout::Section_list::const_iterator p = sections.begin();
249
      p != sections.end();
250
      ++p)
251
    {
252
      Output_section* os = *p;
253
      Section_info info;
254
      info.output_section = os;
255
      info.address = os->is_address_valid() ? os->address() : 0;
256
      info.data_size = os->is_data_size_valid() ? os->data_size() : -1;
257
      info.offset = os->is_offset_valid()? os->offset() : -1 ;
258
      this->section_infos_.push_back(info);
259
    }
260
}
261
 
262
// Verify SECTIONS using previously recorded information.
263
 
264
void
265
Layout::Relaxation_debug_check::verify_sections(
266
    const Layout::Section_list& sections)
267
{
268
  size_t i = 0;
269
  for(Layout::Section_list::const_iterator p = sections.begin();
270
      p != sections.end();
271
      ++p, ++i)
272
    {
273
      Output_section* os = *p;
274
      uint64_t address = os->is_address_valid() ? os->address() : 0;
275
      off_t data_size = os->is_data_size_valid() ? os->data_size() : -1;
276
      off_t offset = os->is_offset_valid()? os->offset() : -1 ;
277
 
278
      if (i >= this->section_infos_.size())
279
        {
280
          gold_fatal("Section_info of %s missing.\n", os->name());
281
        }
282
      const Section_info& info = this->section_infos_[i];
283
      if (os != info.output_section)
284
        gold_fatal("Section order changed.  Expecting %s but see %s\n",
285
                   info.output_section->name(), os->name());
286
      if (address != info.address
287
          || data_size != info.data_size
288
          || offset != info.offset)
289
        gold_fatal("Section %s changed.\n", os->name());
290
    }
291
}
292
 
293
// Layout_task_runner methods.
294
 
295
// Lay out the sections.  This is called after all the input objects
296
// have been read.
297
 
298
void
299
Layout_task_runner::run(Workqueue* workqueue, const Task* task)
300
{
301
  Layout* layout = this->layout_;
302
  off_t file_size = layout->finalize(this->input_objects_,
303
                                     this->symtab_,
304
                                     this->target_,
305
                                     task);
306
 
307
  // Now we know the final size of the output file and we know where
308
  // each piece of information goes.
309
 
310
  if (this->mapfile_ != NULL)
311
    {
312
      this->mapfile_->print_discarded_sections(this->input_objects_);
313
      layout->print_to_mapfile(this->mapfile_);
314
    }
315
 
316
  Output_file* of;
317
  if (layout->incremental_base() == NULL)
318
    {
319
      of = new Output_file(parameters->options().output_file_name());
320
      if (this->options_.oformat_enum() != General_options::OBJECT_FORMAT_ELF)
321
        of->set_is_temporary();
322
      of->open(file_size);
323
    }
324
  else
325
    {
326
      of = layout->incremental_base()->output_file();
327
 
328
      // Apply the incremental relocations for symbols whose values
329
      // have changed.  We do this before we resize the file and start
330
      // writing anything else to it, so that we can read the old
331
      // incremental information from the file before (possibly)
332
      // overwriting it.
333
      if (parameters->incremental_update())
334
        layout->incremental_base()->apply_incremental_relocs(this->symtab_,
335
                                                             this->layout_,
336
                                                             of);
337
 
338
      of->resize(file_size);
339
    }
340
 
341
  // Queue up the final set of tasks.
342
  gold::queue_final_tasks(this->options_, this->input_objects_,
343
                          this->symtab_, layout, workqueue, of);
344
}
345
 
346
// Layout methods.
347
 
348
Layout::Layout(int number_of_input_files, Script_options* script_options)
349
  : number_of_input_files_(number_of_input_files),
350
    script_options_(script_options),
351
    namepool_(),
352
    sympool_(),
353
    dynpool_(),
354
    signatures_(),
355
    section_name_map_(),
356
    segment_list_(),
357
    section_list_(),
358
    unattached_section_list_(),
359
    special_output_list_(),
360
    section_headers_(NULL),
361
    tls_segment_(NULL),
362
    relro_segment_(NULL),
363
    increase_relro_(0),
364
    symtab_section_(NULL),
365
    symtab_xindex_(NULL),
366
    dynsym_section_(NULL),
367
    dynsym_xindex_(NULL),
368
    dynamic_section_(NULL),
369
    dynamic_symbol_(NULL),
370
    dynamic_data_(NULL),
371
    eh_frame_section_(NULL),
372
    eh_frame_data_(NULL),
373
    added_eh_frame_data_(false),
374
    eh_frame_hdr_section_(NULL),
375
    build_id_note_(NULL),
376
    debug_abbrev_(NULL),
377
    debug_info_(NULL),
378
    group_signatures_(),
379
    output_file_size_(-1),
380
    have_added_input_section_(false),
381
    sections_are_attached_(false),
382
    input_requires_executable_stack_(false),
383
    input_with_gnu_stack_note_(false),
384
    input_without_gnu_stack_note_(false),
385
    has_static_tls_(false),
386
    any_postprocessing_sections_(false),
387
    resized_signatures_(false),
388
    have_stabstr_section_(false),
389
    incremental_inputs_(NULL),
390
    record_output_section_data_from_script_(false),
391
    script_output_section_data_list_(),
392
    segment_states_(NULL),
393
    relaxation_debug_check_(NULL),
394
    incremental_base_(NULL),
395
    free_list_()
396
{
397
  // Make space for more than enough segments for a typical file.
398
  // This is just for efficiency--it's OK if we wind up needing more.
399
  this->segment_list_.reserve(12);
400
 
401
  // We expect two unattached Output_data objects: the file header and
402
  // the segment headers.
403
  this->special_output_list_.reserve(2);
404
 
405
  // Initialize structure needed for an incremental build.
406
  if (parameters->incremental())
407
    this->incremental_inputs_ = new Incremental_inputs;
408
 
409
  // The section name pool is worth optimizing in all cases, because
410
  // it is small, but there are often overlaps due to .rel sections.
411
  this->namepool_.set_optimize();
412
}
413
 
414
// For incremental links, record the base file to be modified.
415
 
416
void
417
Layout::set_incremental_base(Incremental_binary* base)
418
{
419
  this->incremental_base_ = base;
420
  this->free_list_.init(base->output_file()->filesize(), true);
421
}
422
 
423
// Hash a key we use to look up an output section mapping.
424
 
425
size_t
426
Layout::Hash_key::operator()(const Layout::Key& k) const
427
{
428
 return k.first + k.second.first + k.second.second;
429
}
430
 
431
// Returns whether the given section is in the list of
432
// debug-sections-used-by-some-version-of-gdb.  Currently,
433
// we've checked versions of gdb up to and including 6.7.1.
434
 
435
static const char* gdb_sections[] =
436
{ ".debug_abbrev",
437
  // ".debug_aranges",   // not used by gdb as of 6.7.1
438
  ".debug_frame",
439
  ".debug_info",
440
  ".debug_types",
441
  ".debug_line",
442
  ".debug_loc",
443
  ".debug_macinfo",
444
  // ".debug_pubnames",  // not used by gdb as of 6.7.1
445
  ".debug_ranges",
446
  ".debug_str",
447
};
448
 
449
static const char* lines_only_debug_sections[] =
450
{ ".debug_abbrev",
451
  // ".debug_aranges",   // not used by gdb as of 6.7.1
452
  // ".debug_frame",
453
  ".debug_info",
454
  // ".debug_types",
455
  ".debug_line",
456
  // ".debug_loc",
457
  // ".debug_macinfo",
458
  // ".debug_pubnames",  // not used by gdb as of 6.7.1
459
  // ".debug_ranges",
460
  ".debug_str",
461
};
462
 
463
static inline bool
464
is_gdb_debug_section(const char* str)
465
{
466
  // We can do this faster: binary search or a hashtable.  But why bother?
467
  for (size_t i = 0; i < sizeof(gdb_sections)/sizeof(*gdb_sections); ++i)
468
    if (strcmp(str, gdb_sections[i]) == 0)
469
      return true;
470
  return false;
471
}
472
 
473
static inline bool
474
is_lines_only_debug_section(const char* str)
475
{
476
  // We can do this faster: binary search or a hashtable.  But why bother?
477
  for (size_t i = 0;
478
       i < sizeof(lines_only_debug_sections)/sizeof(*lines_only_debug_sections);
479
       ++i)
480
    if (strcmp(str, lines_only_debug_sections[i]) == 0)
481
      return true;
482
  return false;
483
}
484
 
485
// Sometimes we compress sections.  This is typically done for
486
// sections that are not part of normal program execution (such as
487
// .debug_* sections), and where the readers of these sections know
488
// how to deal with compressed sections.  This routine doesn't say for
489
// certain whether we'll compress -- it depends on commandline options
490
// as well -- just whether this section is a candidate for compression.
491
// (The Output_compressed_section class decides whether to compress
492
// a given section, and picks the name of the compressed section.)
493
 
494
static bool
495
is_compressible_debug_section(const char* secname)
496
{
497
  return (is_prefix_of(".debug", secname));
498
}
499
 
500
// We may see compressed debug sections in input files.  Return TRUE
501
// if this is the name of a compressed debug section.
502
 
503
bool
504
is_compressed_debug_section(const char* secname)
505
{
506
  return (is_prefix_of(".zdebug", secname));
507
}
508
 
509
// Whether to include this section in the link.
510
 
511
template<int size, bool big_endian>
512
bool
513
Layout::include_section(Sized_relobj_file<size, big_endian>*, const char* name,
514
                        const elfcpp::Shdr<size, big_endian>& shdr)
515
{
516
  if (shdr.get_sh_flags() & elfcpp::SHF_EXCLUDE)
517
    return false;
518
 
519
  switch (shdr.get_sh_type())
520
    {
521
    case elfcpp::SHT_NULL:
522
    case elfcpp::SHT_SYMTAB:
523
    case elfcpp::SHT_DYNSYM:
524
    case elfcpp::SHT_HASH:
525
    case elfcpp::SHT_DYNAMIC:
526
    case elfcpp::SHT_SYMTAB_SHNDX:
527
      return false;
528
 
529
    case elfcpp::SHT_STRTAB:
530
      // Discard the sections which have special meanings in the ELF
531
      // ABI.  Keep others (e.g., .stabstr).  We could also do this by
532
      // checking the sh_link fields of the appropriate sections.
533
      return (strcmp(name, ".dynstr") != 0
534
              && strcmp(name, ".strtab") != 0
535
              && strcmp(name, ".shstrtab") != 0);
536
 
537
    case elfcpp::SHT_RELA:
538
    case elfcpp::SHT_REL:
539
    case elfcpp::SHT_GROUP:
540
      // If we are emitting relocations these should be handled
541
      // elsewhere.
542
      gold_assert(!parameters->options().relocatable()
543
                  && !parameters->options().emit_relocs());
544
      return false;
545
 
546
    case elfcpp::SHT_PROGBITS:
547
      if (parameters->options().strip_debug()
548
          && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
549
        {
550
          if (is_debug_info_section(name))
551
            return false;
552
        }
553
      if (parameters->options().strip_debug_non_line()
554
          && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
555
        {
556
          // Debugging sections can only be recognized by name.
557
          if (is_prefix_of(".debug", name)
558
              && !is_lines_only_debug_section(name))
559
            return false;
560
        }
561
      if (parameters->options().strip_debug_gdb()
562
          && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
563
        {
564
          // Debugging sections can only be recognized by name.
565
          if (is_prefix_of(".debug", name)
566
              && !is_gdb_debug_section(name))
567
            return false;
568
        }
569
      if (parameters->options().strip_lto_sections()
570
          && !parameters->options().relocatable()
571
          && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
572
        {
573
          // Ignore LTO sections containing intermediate code.
574
          if (is_prefix_of(".gnu.lto_", name))
575
            return false;
576
        }
577
      // The GNU linker strips .gnu_debuglink sections, so we do too.
578
      // This is a feature used to keep debugging information in
579
      // separate files.
580
      if (strcmp(name, ".gnu_debuglink") == 0)
581
        return false;
582
      return true;
583
 
584
    default:
585
      return true;
586
    }
587
}
588
 
589
// Return an output section named NAME, or NULL if there is none.
590
 
591
Output_section*
592
Layout::find_output_section(const char* name) const
593
{
594
  for (Section_list::const_iterator p = this->section_list_.begin();
595
       p != this->section_list_.end();
596
       ++p)
597
    if (strcmp((*p)->name(), name) == 0)
598
      return *p;
599
  return NULL;
600
}
601
 
602
// Return an output segment of type TYPE, with segment flags SET set
603
// and segment flags CLEAR clear.  Return NULL if there is none.
604
 
605
Output_segment*
606
Layout::find_output_segment(elfcpp::PT type, elfcpp::Elf_Word set,
607
                            elfcpp::Elf_Word clear) const
608
{
609
  for (Segment_list::const_iterator p = this->segment_list_.begin();
610
       p != this->segment_list_.end();
611
       ++p)
612
    if (static_cast<elfcpp::PT>((*p)->type()) == type
613
        && ((*p)->flags() & set) == set
614
        && ((*p)->flags() & clear) == 0)
615
      return *p;
616
  return NULL;
617
}
618
 
619
// Return the output section to use for section NAME with type TYPE
620
// and section flags FLAGS.  NAME must be canonicalized in the string
621
// pool, and NAME_KEY is the key.  IS_INTERP is true if this is the
622
// .interp section.  IS_DYNAMIC_LINKER_SECTION is true if this section
623
// is used by the dynamic linker.  IS_RELRO is true for a relro
624
// section.  IS_LAST_RELRO is true for the last relro section.
625
// IS_FIRST_NON_RELRO is true for the first non-relro section.
626
 
627
Output_section*
628
Layout::get_output_section(const char* name, Stringpool::Key name_key,
629
                           elfcpp::Elf_Word type, elfcpp::Elf_Xword flags,
630
                           Output_section_order order, bool is_relro)
631
{
632
  elfcpp::Elf_Xword lookup_flags = flags;
633
 
634
  // Ignoring SHF_WRITE and SHF_EXECINSTR here means that we combine
635
  // read-write with read-only sections.  Some other ELF linkers do
636
  // not do this.  FIXME: Perhaps there should be an option
637
  // controlling this.
638
  lookup_flags &= ~(elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR);
639
 
640
  const Key key(name_key, std::make_pair(type, lookup_flags));
641
  const std::pair<Key, Output_section*> v(key, NULL);
642
  std::pair<Section_name_map::iterator, bool> ins(
643
    this->section_name_map_.insert(v));
644
 
645
  if (!ins.second)
646
    return ins.first->second;
647
  else
648
    {
649
      // This is the first time we've seen this name/type/flags
650
      // combination.  For compatibility with the GNU linker, we
651
      // combine sections with contents and zero flags with sections
652
      // with non-zero flags.  This is a workaround for cases where
653
      // assembler code forgets to set section flags.  FIXME: Perhaps
654
      // there should be an option to control this.
655
      Output_section* os = NULL;
656
 
657
      if (type == elfcpp::SHT_PROGBITS)
658
        {
659
          if (flags == 0)
660
            {
661
              Output_section* same_name = this->find_output_section(name);
662
              if (same_name != NULL
663
                  && same_name->type() == elfcpp::SHT_PROGBITS
664
                  && (same_name->flags() & elfcpp::SHF_TLS) == 0)
665
                os = same_name;
666
            }
667
          else if ((flags & elfcpp::SHF_TLS) == 0)
668
            {
669
              elfcpp::Elf_Xword zero_flags = 0;
670
              const Key zero_key(name_key, std::make_pair(type, zero_flags));
671
              Section_name_map::iterator p =
672
                  this->section_name_map_.find(zero_key);
673
              if (p != this->section_name_map_.end())
674
                os = p->second;
675
            }
676
        }
677
 
678
      if (os == NULL)
679
        os = this->make_output_section(name, type, flags, order, is_relro);
680
 
681
      ins.first->second = os;
682
      return os;
683
    }
684
}
685
 
686
// Pick the output section to use for section NAME, in input file
687
// RELOBJ, with type TYPE and flags FLAGS.  RELOBJ may be NULL for a
688
// linker created section.  IS_INPUT_SECTION is true if we are
689
// choosing an output section for an input section found in a input
690
// file.  IS_INTERP is true if this is the .interp section.
691
// IS_DYNAMIC_LINKER_SECTION is true if this section is used by the
692
// dynamic linker.  IS_RELRO is true for a relro section.
693
// IS_LAST_RELRO is true for the last relro section.
694
// IS_FIRST_NON_RELRO is true for the first non-relro section.  This
695
// will return NULL if the input section should be discarded.
696
 
697
Output_section*
698
Layout::choose_output_section(const Relobj* relobj, const char* name,
699
                              elfcpp::Elf_Word type, elfcpp::Elf_Xword flags,
700
                              bool is_input_section, Output_section_order order,
701
                              bool is_relro)
702
{
703
  // We should not see any input sections after we have attached
704
  // sections to segments.
705
  gold_assert(!is_input_section || !this->sections_are_attached_);
706
 
707
  // Some flags in the input section should not be automatically
708
  // copied to the output section.
709
  flags &= ~ (elfcpp::SHF_INFO_LINK
710
              | elfcpp::SHF_GROUP
711
              | elfcpp::SHF_MERGE
712
              | elfcpp::SHF_STRINGS);
713
 
714
  // We only clear the SHF_LINK_ORDER flag in for
715
  // a non-relocatable link.
716
  if (!parameters->options().relocatable())
717
    flags &= ~elfcpp::SHF_LINK_ORDER;
718
 
719
  if (this->script_options_->saw_sections_clause())
720
    {
721
      // We are using a SECTIONS clause, so the output section is
722
      // chosen based only on the name.
723
 
724
      Script_sections* ss = this->script_options_->script_sections();
725
      const char* file_name = relobj == NULL ? NULL : relobj->name().c_str();
726
      Output_section** output_section_slot;
727
      Script_sections::Section_type script_section_type;
728
      const char* orig_name = name;
729
      name = ss->output_section_name(file_name, name, &output_section_slot,
730
                                     &script_section_type);
731
      if (name == NULL)
732
        {
733
          gold_debug(DEBUG_SCRIPT, _("Unable to create output section '%s' "
734
                                     "because it is not allowed by the "
735
                                     "SECTIONS clause of the linker script"),
736
                     orig_name);
737
          // The SECTIONS clause says to discard this input section.
738
          return NULL;
739
        }
740
 
741
      // We can only handle script section types ST_NONE and ST_NOLOAD.
742
      switch (script_section_type)
743
        {
744
        case Script_sections::ST_NONE:
745
          break;
746
        case Script_sections::ST_NOLOAD:
747
          flags &= elfcpp::SHF_ALLOC;
748
          break;
749
        default:
750
          gold_unreachable();
751
        }
752
 
753
      // If this is an orphan section--one not mentioned in the linker
754
      // script--then OUTPUT_SECTION_SLOT will be NULL, and we do the
755
      // default processing below.
756
 
757
      if (output_section_slot != NULL)
758
        {
759
          if (*output_section_slot != NULL)
760
            {
761
              (*output_section_slot)->update_flags_for_input_section(flags);
762
              return *output_section_slot;
763
            }
764
 
765
          // We don't put sections found in the linker script into
766
          // SECTION_NAME_MAP_.  That keeps us from getting confused
767
          // if an orphan section is mapped to a section with the same
768
          // name as one in the linker script.
769
 
770
          name = this->namepool_.add(name, false, NULL);
771
 
772
          Output_section* os = this->make_output_section(name, type, flags,
773
                                                         order, is_relro);
774
 
775
          os->set_found_in_sections_clause();
776
 
777
          // Special handling for NOLOAD sections.
778
          if (script_section_type == Script_sections::ST_NOLOAD)
779
            {
780
              os->set_is_noload();
781
 
782
              // The constructor of Output_section sets addresses of non-ALLOC
783
              // sections to 0 by default.  We don't want that for NOLOAD
784
              // sections even if they have no SHF_ALLOC flag.
785
              if ((os->flags() & elfcpp::SHF_ALLOC) == 0
786
                  && os->is_address_valid())
787
                {
788
                  gold_assert(os->address() == 0
789
                              && !os->is_offset_valid()
790
                              && !os->is_data_size_valid());
791
                  os->reset_address_and_file_offset();
792
                }
793
            }
794
 
795
          *output_section_slot = os;
796
          return os;
797
        }
798
    }
799
 
800
  // FIXME: Handle SHF_OS_NONCONFORMING somewhere.
801
 
802
  size_t len = strlen(name);
803
  char* uncompressed_name = NULL;
804
 
805
  // Compressed debug sections should be mapped to the corresponding
806
  // uncompressed section.
807
  if (is_compressed_debug_section(name))
808
    {
809
      uncompressed_name = new char[len];
810
      uncompressed_name[0] = '.';
811
      gold_assert(name[0] == '.' && name[1] == 'z');
812
      strncpy(&uncompressed_name[1], &name[2], len - 2);
813
      uncompressed_name[len - 1] = '\0';
814
      len -= 1;
815
      name = uncompressed_name;
816
    }
817
 
818
  // Turn NAME from the name of the input section into the name of the
819
  // output section.
820
  if (is_input_section
821
      && !this->script_options_->saw_sections_clause()
822
      && !parameters->options().relocatable())
823
    name = Layout::output_section_name(name, &len);
824
 
825
  Stringpool::Key name_key;
826
  name = this->namepool_.add_with_length(name, len, true, &name_key);
827
 
828
  if (uncompressed_name != NULL)
829
    delete[] uncompressed_name;
830
 
831
  // Find or make the output section.  The output section is selected
832
  // based on the section name, type, and flags.
833
  return this->get_output_section(name, name_key, type, flags, order, is_relro);
834
}
835
 
836
// For incremental links, record the initial fixed layout of a section
837
// from the base file, and return a pointer to the Output_section.
838
 
839
template<int size, bool big_endian>
840
Output_section*
841
Layout::init_fixed_output_section(const char* name,
842
                                  elfcpp::Shdr<size, big_endian>& shdr)
843
{
844
  unsigned int sh_type = shdr.get_sh_type();
845
 
846
  // We preserve the layout of PROGBITS, NOBITS, and NOTE sections.
847
  // All others will be created from scratch and reallocated.
848
  if (sh_type != elfcpp::SHT_PROGBITS
849
      && sh_type != elfcpp::SHT_NOBITS
850
      && sh_type != elfcpp::SHT_NOTE)
851
    return NULL;
852
 
853
  typename elfcpp::Elf_types<size>::Elf_Addr sh_addr = shdr.get_sh_addr();
854
  typename elfcpp::Elf_types<size>::Elf_Off sh_offset = shdr.get_sh_offset();
855
  typename elfcpp::Elf_types<size>::Elf_WXword sh_size = shdr.get_sh_size();
856
  typename elfcpp::Elf_types<size>::Elf_WXword sh_flags = shdr.get_sh_flags();
857
  typename elfcpp::Elf_types<size>::Elf_WXword sh_addralign =
858
      shdr.get_sh_addralign();
859
 
860
  // Make the output section.
861
  Stringpool::Key name_key;
862
  name = this->namepool_.add(name, true, &name_key);
863
  Output_section* os = this->get_output_section(name, name_key, sh_type,
864
                                                sh_flags, ORDER_INVALID, false);
865
  os->set_fixed_layout(sh_addr, sh_offset, sh_size, sh_addralign);
866
  if (sh_type != elfcpp::SHT_NOBITS)
867
    this->free_list_.remove(sh_offset, sh_offset + sh_size);
868
  return os;
869
}
870
 
871
// Return the output section to use for input section SHNDX, with name
872
// NAME, with header HEADER, from object OBJECT.  RELOC_SHNDX is the
873
// index of a relocation section which applies to this section, or 0
874
// if none, or -1U if more than one.  RELOC_TYPE is the type of the
875
// relocation section if there is one.  Set *OFF to the offset of this
876
// input section without the output section.  Return NULL if the
877
// section should be discarded.  Set *OFF to -1 if the section
878
// contents should not be written directly to the output file, but
879
// will instead receive special handling.
880
 
881
template<int size, bool big_endian>
882
Output_section*
883
Layout::layout(Sized_relobj_file<size, big_endian>* object, unsigned int shndx,
884
               const char* name, const elfcpp::Shdr<size, big_endian>& shdr,
885
               unsigned int reloc_shndx, unsigned int, off_t* off)
886
{
887
  *off = 0;
888
 
889
  if (!this->include_section(object, name, shdr))
890
    return NULL;
891
 
892
  Output_section* os;
893
 
894
  // Sometimes .init_array*, .preinit_array* and .fini_array* do not have
895
  // correct section types.  Force them here.
896
  elfcpp::Elf_Word sh_type = shdr.get_sh_type();
897
  if (sh_type == elfcpp::SHT_PROGBITS)
898
    {
899
      static const char init_array_prefix[] = ".init_array";
900
      static const char preinit_array_prefix[] = ".preinit_array";
901
      static const char fini_array_prefix[] = ".fini_array";
902
      static size_t init_array_prefix_size = sizeof(init_array_prefix) - 1;
903
      static size_t preinit_array_prefix_size =
904
        sizeof(preinit_array_prefix) - 1;
905
      static size_t fini_array_prefix_size = sizeof(fini_array_prefix) - 1;
906
 
907
      if (strncmp(name, init_array_prefix, init_array_prefix_size) == 0)
908
        sh_type = elfcpp::SHT_INIT_ARRAY;
909
      else if (strncmp(name, preinit_array_prefix, preinit_array_prefix_size)
910
               == 0)
911
        sh_type = elfcpp::SHT_PREINIT_ARRAY;
912
      else if (strncmp(name, fini_array_prefix, fini_array_prefix_size) == 0)
913
        sh_type = elfcpp::SHT_FINI_ARRAY;
914
    }
915
 
916
  // In a relocatable link a grouped section must not be combined with
917
  // any other sections.
918
  if (parameters->options().relocatable()
919
      && (shdr.get_sh_flags() & elfcpp::SHF_GROUP) != 0)
920
    {
921
      name = this->namepool_.add(name, true, NULL);
922
      os = this->make_output_section(name, sh_type, shdr.get_sh_flags(),
923
                                     ORDER_INVALID, false);
924
    }
925
  else
926
    {
927
      os = this->choose_output_section(object, name, sh_type,
928
                                       shdr.get_sh_flags(), true,
929
                                       ORDER_INVALID, false);
930
      if (os == NULL)
931
        return NULL;
932
    }
933
 
934
  // By default the GNU linker sorts input sections whose names match
935
  // .ctor.*, .dtor.*, .init_array.*, or .fini_array.*.  The sections
936
  // are sorted by name.  This is used to implement constructor
937
  // priority ordering.  We are compatible.
938
  if (!this->script_options_->saw_sections_clause()
939
      && (is_prefix_of(".ctors.", name)
940
          || is_prefix_of(".dtors.", name)
941
          || is_prefix_of(".init_array.", name)
942
          || is_prefix_of(".fini_array.", name)))
943
    os->set_must_sort_attached_input_sections();
944
 
945
  // FIXME: Handle SHF_LINK_ORDER somewhere.
946
 
947
  elfcpp::Elf_Xword orig_flags = os->flags();
948
 
949
  *off = os->add_input_section(this, object, shndx, name, shdr, reloc_shndx,
950
                               this->script_options_->saw_sections_clause());
951
 
952
  // If the flags changed, we may have to change the order.
953
  if ((orig_flags & elfcpp::SHF_ALLOC) != 0)
954
    {
955
      orig_flags &= (elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR);
956
      elfcpp::Elf_Xword new_flags =
957
        os->flags() & (elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR);
958
      if (orig_flags != new_flags)
959
        os->set_order(this->default_section_order(os, false));
960
    }
961
 
962
  this->have_added_input_section_ = true;
963
 
964
  return os;
965
}
966
 
967
// Handle a relocation section when doing a relocatable link.
968
 
969
template<int size, bool big_endian>
970
Output_section*
971
Layout::layout_reloc(Sized_relobj_file<size, big_endian>* object,
972
                     unsigned int,
973
                     const elfcpp::Shdr<size, big_endian>& shdr,
974
                     Output_section* data_section,
975
                     Relocatable_relocs* rr)
976
{
977
  gold_assert(parameters->options().relocatable()
978
              || parameters->options().emit_relocs());
979
 
980
  int sh_type = shdr.get_sh_type();
981
 
982
  std::string name;
983
  if (sh_type == elfcpp::SHT_REL)
984
    name = ".rel";
985
  else if (sh_type == elfcpp::SHT_RELA)
986
    name = ".rela";
987
  else
988
    gold_unreachable();
989
  name += data_section->name();
990
 
991
  // In a relocatable link relocs for a grouped section must not be
992
  // combined with other reloc sections.
993
  Output_section* os;
994
  if (!parameters->options().relocatable()
995
      || (data_section->flags() & elfcpp::SHF_GROUP) == 0)
996
    os = this->choose_output_section(object, name.c_str(), sh_type,
997
                                     shdr.get_sh_flags(), false,
998
                                     ORDER_INVALID, false);
999
  else
1000
    {
1001
      const char* n = this->namepool_.add(name.c_str(), true, NULL);
1002
      os = this->make_output_section(n, sh_type, shdr.get_sh_flags(),
1003
                                     ORDER_INVALID, false);
1004
    }
1005
 
1006
  os->set_should_link_to_symtab();
1007
  os->set_info_section(data_section);
1008
 
1009
  Output_section_data* posd;
1010
  if (sh_type == elfcpp::SHT_REL)
1011
    {
1012
      os->set_entsize(elfcpp::Elf_sizes<size>::rel_size);
1013
      posd = new Output_relocatable_relocs<elfcpp::SHT_REL,
1014
                                           size,
1015
                                           big_endian>(rr);
1016
    }
1017
  else if (sh_type == elfcpp::SHT_RELA)
1018
    {
1019
      os->set_entsize(elfcpp::Elf_sizes<size>::rela_size);
1020
      posd = new Output_relocatable_relocs<elfcpp::SHT_RELA,
1021
                                           size,
1022
                                           big_endian>(rr);
1023
    }
1024
  else
1025
    gold_unreachable();
1026
 
1027
  os->add_output_section_data(posd);
1028
  rr->set_output_data(posd);
1029
 
1030
  return os;
1031
}
1032
 
1033
// Handle a group section when doing a relocatable link.
1034
 
1035
template<int size, bool big_endian>
1036
void
1037
Layout::layout_group(Symbol_table* symtab,
1038
                     Sized_relobj_file<size, big_endian>* object,
1039
                     unsigned int,
1040
                     const char* group_section_name,
1041
                     const char* signature,
1042
                     const elfcpp::Shdr<size, big_endian>& shdr,
1043
                     elfcpp::Elf_Word flags,
1044
                     std::vector<unsigned int>* shndxes)
1045
{
1046
  gold_assert(parameters->options().relocatable());
1047
  gold_assert(shdr.get_sh_type() == elfcpp::SHT_GROUP);
1048
  group_section_name = this->namepool_.add(group_section_name, true, NULL);
1049
  Output_section* os = this->make_output_section(group_section_name,
1050
                                                 elfcpp::SHT_GROUP,
1051
                                                 shdr.get_sh_flags(),
1052
                                                 ORDER_INVALID, false);
1053
 
1054
  // We need to find a symbol with the signature in the symbol table.
1055
  // If we don't find one now, we need to look again later.
1056
  Symbol* sym = symtab->lookup(signature, NULL);
1057
  if (sym != NULL)
1058
    os->set_info_symndx(sym);
1059
  else
1060
    {
1061
      // Reserve some space to minimize reallocations.
1062
      if (this->group_signatures_.empty())
1063
        this->group_signatures_.reserve(this->number_of_input_files_ * 16);
1064
 
1065
      // We will wind up using a symbol whose name is the signature.
1066
      // So just put the signature in the symbol name pool to save it.
1067
      signature = symtab->canonicalize_name(signature);
1068
      this->group_signatures_.push_back(Group_signature(os, signature));
1069
    }
1070
 
1071
  os->set_should_link_to_symtab();
1072
  os->set_entsize(4);
1073
 
1074
  section_size_type entry_count =
1075
    convert_to_section_size_type(shdr.get_sh_size() / 4);
1076
  Output_section_data* posd =
1077
    new Output_data_group<size, big_endian>(object, entry_count, flags,
1078
                                            shndxes);
1079
  os->add_output_section_data(posd);
1080
}
1081
 
1082
// Special GNU handling of sections name .eh_frame.  They will
1083
// normally hold exception frame data as defined by the C++ ABI
1084
// (http://codesourcery.com/cxx-abi/).
1085
 
1086
template<int size, bool big_endian>
1087
Output_section*
1088
Layout::layout_eh_frame(Sized_relobj_file<size, big_endian>* object,
1089
                        const unsigned char* symbols,
1090
                        off_t symbols_size,
1091
                        const unsigned char* symbol_names,
1092
                        off_t symbol_names_size,
1093
                        unsigned int shndx,
1094
                        const elfcpp::Shdr<size, big_endian>& shdr,
1095
                        unsigned int reloc_shndx, unsigned int reloc_type,
1096
                        off_t* off)
1097
{
1098
  gold_assert(shdr.get_sh_type() == elfcpp::SHT_PROGBITS);
1099
  gold_assert((shdr.get_sh_flags() & elfcpp::SHF_ALLOC) != 0);
1100
 
1101
  const char* const name = ".eh_frame";
1102
  Output_section* os = this->choose_output_section(object, name,
1103
                                                   elfcpp::SHT_PROGBITS,
1104
                                                   elfcpp::SHF_ALLOC, false,
1105
                                                   ORDER_EHFRAME, false);
1106
  if (os == NULL)
1107
    return NULL;
1108
 
1109
  if (this->eh_frame_section_ == NULL)
1110
    {
1111
      this->eh_frame_section_ = os;
1112
      this->eh_frame_data_ = new Eh_frame();
1113
 
1114
      // For incremental linking, we do not optimize .eh_frame sections
1115
      // or create a .eh_frame_hdr section.
1116
      if (parameters->options().eh_frame_hdr() && !parameters->incremental())
1117
        {
1118
          Output_section* hdr_os =
1119
            this->choose_output_section(NULL, ".eh_frame_hdr",
1120
                                        elfcpp::SHT_PROGBITS,
1121
                                        elfcpp::SHF_ALLOC, false,
1122
                                        ORDER_EHFRAME, false);
1123
 
1124
          if (hdr_os != NULL)
1125
            {
1126
              Eh_frame_hdr* hdr_posd = new Eh_frame_hdr(os,
1127
                                                        this->eh_frame_data_);
1128
              hdr_os->add_output_section_data(hdr_posd);
1129
 
1130
              hdr_os->set_after_input_sections();
1131
 
1132
              if (!this->script_options_->saw_phdrs_clause())
1133
                {
1134
                  Output_segment* hdr_oseg;
1135
                  hdr_oseg = this->make_output_segment(elfcpp::PT_GNU_EH_FRAME,
1136
                                                       elfcpp::PF_R);
1137
                  hdr_oseg->add_output_section_to_nonload(hdr_os,
1138
                                                          elfcpp::PF_R);
1139
                }
1140
 
1141
              this->eh_frame_data_->set_eh_frame_hdr(hdr_posd);
1142
            }
1143
        }
1144
    }
1145
 
1146
  gold_assert(this->eh_frame_section_ == os);
1147
 
1148
  if (!parameters->incremental()
1149
      && this->eh_frame_data_->add_ehframe_input_section(object,
1150
                                                         symbols,
1151
                                                         symbols_size,
1152
                                                         symbol_names,
1153
                                                         symbol_names_size,
1154
                                                         shndx,
1155
                                                         reloc_shndx,
1156
                                                         reloc_type))
1157
    {
1158
      os->update_flags_for_input_section(shdr.get_sh_flags());
1159
 
1160
      // A writable .eh_frame section is a RELRO section.
1161
      if ((shdr.get_sh_flags() & elfcpp::SHF_WRITE) != 0)
1162
        os->set_is_relro();
1163
 
1164
      // We found a .eh_frame section we are going to optimize, so now
1165
      // we can add the set of optimized sections to the output
1166
      // section.  We need to postpone adding this until we've found a
1167
      // section we can optimize so that the .eh_frame section in
1168
      // crtbegin.o winds up at the start of the output section.
1169
      if (!this->added_eh_frame_data_)
1170
        {
1171
          os->add_output_section_data(this->eh_frame_data_);
1172
          this->added_eh_frame_data_ = true;
1173
        }
1174
      *off = -1;
1175
    }
1176
  else
1177
    {
1178
      // We couldn't handle this .eh_frame section for some reason.
1179
      // Add it as a normal section.
1180
      bool saw_sections_clause = this->script_options_->saw_sections_clause();
1181
      *off = os->add_input_section(this, object, shndx, name, shdr, reloc_shndx,
1182
                                   saw_sections_clause);
1183
      this->have_added_input_section_ = true;
1184
    }
1185
 
1186
  return os;
1187
}
1188
 
1189
// Add POSD to an output section using NAME, TYPE, and FLAGS.  Return
1190
// the output section.
1191
 
1192
Output_section*
1193
Layout::add_output_section_data(const char* name, elfcpp::Elf_Word type,
1194
                                elfcpp::Elf_Xword flags,
1195
                                Output_section_data* posd,
1196
                                Output_section_order order, bool is_relro)
1197
{
1198
  Output_section* os = this->choose_output_section(NULL, name, type, flags,
1199
                                                   false, order, is_relro);
1200
  if (os != NULL)
1201
    os->add_output_section_data(posd);
1202
  return os;
1203
}
1204
 
1205
// Map section flags to segment flags.
1206
 
1207
elfcpp::Elf_Word
1208
Layout::section_flags_to_segment(elfcpp::Elf_Xword flags)
1209
{
1210
  elfcpp::Elf_Word ret = elfcpp::PF_R;
1211
  if ((flags & elfcpp::SHF_WRITE) != 0)
1212
    ret |= elfcpp::PF_W;
1213
  if ((flags & elfcpp::SHF_EXECINSTR) != 0)
1214
    ret |= elfcpp::PF_X;
1215
  return ret;
1216
}
1217
 
1218
// Make a new Output_section, and attach it to segments as
1219
// appropriate.  ORDER is the order in which this section should
1220
// appear in the output segment.  IS_RELRO is true if this is a relro
1221
// (read-only after relocations) section.
1222
 
1223
Output_section*
1224
Layout::make_output_section(const char* name, elfcpp::Elf_Word type,
1225
                            elfcpp::Elf_Xword flags,
1226
                            Output_section_order order, bool is_relro)
1227
{
1228
  Output_section* os;
1229
  if ((flags & elfcpp::SHF_ALLOC) == 0
1230
      && strcmp(parameters->options().compress_debug_sections(), "none") != 0
1231
      && is_compressible_debug_section(name))
1232
    os = new Output_compressed_section(&parameters->options(), name, type,
1233
                                       flags);
1234
  else if ((flags & elfcpp::SHF_ALLOC) == 0
1235
           && parameters->options().strip_debug_non_line()
1236
           && strcmp(".debug_abbrev", name) == 0)
1237
    {
1238
      os = this->debug_abbrev_ = new Output_reduced_debug_abbrev_section(
1239
          name, type, flags);
1240
      if (this->debug_info_)
1241
        this->debug_info_->set_abbreviations(this->debug_abbrev_);
1242
    }
1243
  else if ((flags & elfcpp::SHF_ALLOC) == 0
1244
           && parameters->options().strip_debug_non_line()
1245
           && strcmp(".debug_info", name) == 0)
1246
    {
1247
      os = this->debug_info_ = new Output_reduced_debug_info_section(
1248
          name, type, flags);
1249
      if (this->debug_abbrev_)
1250
        this->debug_info_->set_abbreviations(this->debug_abbrev_);
1251
    }
1252
  else
1253
    {
1254
      // FIXME: const_cast is ugly.
1255
      Target* target = const_cast<Target*>(&parameters->target());
1256
      os = target->make_output_section(name, type, flags);
1257
    }
1258
 
1259
  // With -z relro, we have to recognize the special sections by name.
1260
  // There is no other way.
1261
  bool is_relro_local = false;
1262
  if (!this->script_options_->saw_sections_clause()
1263
      && parameters->options().relro()
1264
      && type == elfcpp::SHT_PROGBITS
1265
      && (flags & elfcpp::SHF_ALLOC) != 0
1266
      && (flags & elfcpp::SHF_WRITE) != 0)
1267
    {
1268
      if (strcmp(name, ".data.rel.ro") == 0)
1269
        is_relro = true;
1270
      else if (strcmp(name, ".data.rel.ro.local") == 0)
1271
        {
1272
          is_relro = true;
1273
          is_relro_local = true;
1274
        }
1275
      else if (type == elfcpp::SHT_INIT_ARRAY
1276
               || type == elfcpp::SHT_FINI_ARRAY
1277
               || type == elfcpp::SHT_PREINIT_ARRAY)
1278
        is_relro = true;
1279
      else if (strcmp(name, ".ctors") == 0
1280
               || strcmp(name, ".dtors") == 0
1281
               || strcmp(name, ".jcr") == 0)
1282
        is_relro = true;
1283
    }
1284
 
1285
  if (is_relro)
1286
    os->set_is_relro();
1287
 
1288
  if (order == ORDER_INVALID && (flags & elfcpp::SHF_ALLOC) != 0)
1289
    order = this->default_section_order(os, is_relro_local);
1290
 
1291
  os->set_order(order);
1292
 
1293
  parameters->target().new_output_section(os);
1294
 
1295
  this->section_list_.push_back(os);
1296
 
1297
  // The GNU linker by default sorts some sections by priority, so we
1298
  // do the same.  We need to know that this might happen before we
1299
  // attach any input sections.
1300
  if (!this->script_options_->saw_sections_clause()
1301
      && (strcmp(name, ".ctors") == 0
1302
          || strcmp(name, ".dtors") == 0
1303
          || strcmp(name, ".init_array") == 0
1304
          || strcmp(name, ".fini_array") == 0))
1305
    os->set_may_sort_attached_input_sections();
1306
 
1307
  // Check for .stab*str sections, as .stab* sections need to link to
1308
  // them.
1309
  if (type == elfcpp::SHT_STRTAB
1310
      && !this->have_stabstr_section_
1311
      && strncmp(name, ".stab", 5) == 0
1312
      && strcmp(name + strlen(name) - 3, "str") == 0)
1313
    this->have_stabstr_section_ = true;
1314
 
1315
  // If we have already attached the sections to segments, then we
1316
  // need to attach this one now.  This happens for sections created
1317
  // directly by the linker.
1318
  if (this->sections_are_attached_)
1319
    this->attach_section_to_segment(os);
1320
 
1321
  return os;
1322
}
1323
 
1324
// Return the default order in which a section should be placed in an
1325
// output segment.  This function captures a lot of the ideas in
1326
// ld/scripttempl/elf.sc in the GNU linker.  Note that the order of a
1327
// linker created section is normally set when the section is created;
1328
// this function is used for input sections.
1329
 
1330
Output_section_order
1331
Layout::default_section_order(Output_section* os, bool is_relro_local)
1332
{
1333
  gold_assert((os->flags() & elfcpp::SHF_ALLOC) != 0);
1334
  bool is_write = (os->flags() & elfcpp::SHF_WRITE) != 0;
1335
  bool is_execinstr = (os->flags() & elfcpp::SHF_EXECINSTR) != 0;
1336
  bool is_bss = false;
1337
 
1338
  switch (os->type())
1339
    {
1340
    default:
1341
    case elfcpp::SHT_PROGBITS:
1342
      break;
1343
    case elfcpp::SHT_NOBITS:
1344
      is_bss = true;
1345
      break;
1346
    case elfcpp::SHT_RELA:
1347
    case elfcpp::SHT_REL:
1348
      if (!is_write)
1349
        return ORDER_DYNAMIC_RELOCS;
1350
      break;
1351
    case elfcpp::SHT_HASH:
1352
    case elfcpp::SHT_DYNAMIC:
1353
    case elfcpp::SHT_SHLIB:
1354
    case elfcpp::SHT_DYNSYM:
1355
    case elfcpp::SHT_GNU_HASH:
1356
    case elfcpp::SHT_GNU_verdef:
1357
    case elfcpp::SHT_GNU_verneed:
1358
    case elfcpp::SHT_GNU_versym:
1359
      if (!is_write)
1360
        return ORDER_DYNAMIC_LINKER;
1361
      break;
1362
    case elfcpp::SHT_NOTE:
1363
      return is_write ? ORDER_RW_NOTE : ORDER_RO_NOTE;
1364
    }
1365
 
1366
  if ((os->flags() & elfcpp::SHF_TLS) != 0)
1367
    return is_bss ? ORDER_TLS_BSS : ORDER_TLS_DATA;
1368
 
1369
  if (!is_bss && !is_write)
1370
    {
1371
      if (is_execinstr)
1372
        {
1373
          if (strcmp(os->name(), ".init") == 0)
1374
            return ORDER_INIT;
1375
          else if (strcmp(os->name(), ".fini") == 0)
1376
            return ORDER_FINI;
1377
        }
1378
      return is_execinstr ? ORDER_TEXT : ORDER_READONLY;
1379
    }
1380
 
1381
  if (os->is_relro())
1382
    return is_relro_local ? ORDER_RELRO_LOCAL : ORDER_RELRO;
1383
 
1384
  if (os->is_small_section())
1385
    return is_bss ? ORDER_SMALL_BSS : ORDER_SMALL_DATA;
1386
  if (os->is_large_section())
1387
    return is_bss ? ORDER_LARGE_BSS : ORDER_LARGE_DATA;
1388
 
1389
  return is_bss ? ORDER_BSS : ORDER_DATA;
1390
}
1391
 
1392
// Attach output sections to segments.  This is called after we have
1393
// seen all the input sections.
1394
 
1395
void
1396
Layout::attach_sections_to_segments()
1397
{
1398
  for (Section_list::iterator p = this->section_list_.begin();
1399
       p != this->section_list_.end();
1400
       ++p)
1401
    this->attach_section_to_segment(*p);
1402
 
1403
  this->sections_are_attached_ = true;
1404
}
1405
 
1406
// Attach an output section to a segment.
1407
 
1408
void
1409
Layout::attach_section_to_segment(Output_section* os)
1410
{
1411
  if ((os->flags() & elfcpp::SHF_ALLOC) == 0)
1412
    this->unattached_section_list_.push_back(os);
1413
  else
1414
    this->attach_allocated_section_to_segment(os);
1415
}
1416
 
1417
// Attach an allocated output section to a segment.
1418
 
1419
void
1420
Layout::attach_allocated_section_to_segment(Output_section* os)
1421
{
1422
  elfcpp::Elf_Xword flags = os->flags();
1423
  gold_assert((flags & elfcpp::SHF_ALLOC) != 0);
1424
 
1425
  if (parameters->options().relocatable())
1426
    return;
1427
 
1428
  // If we have a SECTIONS clause, we can't handle the attachment to
1429
  // segments until after we've seen all the sections.
1430
  if (this->script_options_->saw_sections_clause())
1431
    return;
1432
 
1433
  gold_assert(!this->script_options_->saw_phdrs_clause());
1434
 
1435
  // This output section goes into a PT_LOAD segment.
1436
 
1437
  elfcpp::Elf_Word seg_flags = Layout::section_flags_to_segment(flags);
1438
 
1439
  // Check for --section-start.
1440
  uint64_t addr;
1441
  bool is_address_set = parameters->options().section_start(os->name(), &addr);
1442
 
1443
  // In general the only thing we really care about for PT_LOAD
1444
  // segments is whether or not they are writable or executable,
1445
  // so that is how we search for them.
1446
  // Large data sections also go into their own PT_LOAD segment.
1447
  // People who need segments sorted on some other basis will
1448
  // have to use a linker script.
1449
 
1450
  Segment_list::const_iterator p;
1451
  for (p = this->segment_list_.begin();
1452
       p != this->segment_list_.end();
1453
       ++p)
1454
    {
1455
      if ((*p)->type() != elfcpp::PT_LOAD)
1456
        continue;
1457
      if (!parameters->options().omagic()
1458
          && ((*p)->flags() & elfcpp::PF_W) != (seg_flags & elfcpp::PF_W))
1459
        continue;
1460
      if (parameters->options().rosegment()
1461
          && ((*p)->flags() & elfcpp::PF_X) != (seg_flags & elfcpp::PF_X))
1462
        continue;
1463
      // If -Tbss was specified, we need to separate the data and BSS
1464
      // segments.
1465
      if (parameters->options().user_set_Tbss())
1466
        {
1467
          if ((os->type() == elfcpp::SHT_NOBITS)
1468
              == (*p)->has_any_data_sections())
1469
            continue;
1470
        }
1471
      if (os->is_large_data_section() && !(*p)->is_large_data_segment())
1472
        continue;
1473
 
1474
      if (is_address_set)
1475
        {
1476
          if ((*p)->are_addresses_set())
1477
            continue;
1478
 
1479
          (*p)->add_initial_output_data(os);
1480
          (*p)->update_flags_for_output_section(seg_flags);
1481
          (*p)->set_addresses(addr, addr);
1482
          break;
1483
        }
1484
 
1485
      (*p)->add_output_section_to_load(this, os, seg_flags);
1486
      break;
1487
    }
1488
 
1489
  if (p == this->segment_list_.end())
1490
    {
1491
      Output_segment* oseg = this->make_output_segment(elfcpp::PT_LOAD,
1492
                                                       seg_flags);
1493
      if (os->is_large_data_section())
1494
        oseg->set_is_large_data_segment();
1495
      oseg->add_output_section_to_load(this, os, seg_flags);
1496
      if (is_address_set)
1497
        oseg->set_addresses(addr, addr);
1498
    }
1499
 
1500
  // If we see a loadable SHT_NOTE section, we create a PT_NOTE
1501
  // segment.
1502
  if (os->type() == elfcpp::SHT_NOTE)
1503
    {
1504
      // See if we already have an equivalent PT_NOTE segment.
1505
      for (p = this->segment_list_.begin();
1506
           p != segment_list_.end();
1507
           ++p)
1508
        {
1509
          if ((*p)->type() == elfcpp::PT_NOTE
1510
              && (((*p)->flags() & elfcpp::PF_W)
1511
                  == (seg_flags & elfcpp::PF_W)))
1512
            {
1513
              (*p)->add_output_section_to_nonload(os, seg_flags);
1514
              break;
1515
            }
1516
        }
1517
 
1518
      if (p == this->segment_list_.end())
1519
        {
1520
          Output_segment* oseg = this->make_output_segment(elfcpp::PT_NOTE,
1521
                                                           seg_flags);
1522
          oseg->add_output_section_to_nonload(os, seg_flags);
1523
        }
1524
    }
1525
 
1526
  // If we see a loadable SHF_TLS section, we create a PT_TLS
1527
  // segment.  There can only be one such segment.
1528
  if ((flags & elfcpp::SHF_TLS) != 0)
1529
    {
1530
      if (this->tls_segment_ == NULL)
1531
        this->make_output_segment(elfcpp::PT_TLS, seg_flags);
1532
      this->tls_segment_->add_output_section_to_nonload(os, seg_flags);
1533
    }
1534
 
1535
  // If -z relro is in effect, and we see a relro section, we create a
1536
  // PT_GNU_RELRO segment.  There can only be one such segment.
1537
  if (os->is_relro() && parameters->options().relro())
1538
    {
1539
      gold_assert(seg_flags == (elfcpp::PF_R | elfcpp::PF_W));
1540
      if (this->relro_segment_ == NULL)
1541
        this->make_output_segment(elfcpp::PT_GNU_RELRO, seg_flags);
1542
      this->relro_segment_->add_output_section_to_nonload(os, seg_flags);
1543
    }
1544
}
1545
 
1546
// Make an output section for a script.
1547
 
1548
Output_section*
1549
Layout::make_output_section_for_script(
1550
    const char* name,
1551
    Script_sections::Section_type section_type)
1552
{
1553
  name = this->namepool_.add(name, false, NULL);
1554
  elfcpp::Elf_Xword sh_flags = elfcpp::SHF_ALLOC;
1555
  if (section_type == Script_sections::ST_NOLOAD)
1556
    sh_flags = 0;
1557
  Output_section* os = this->make_output_section(name, elfcpp::SHT_PROGBITS,
1558
                                                 sh_flags, ORDER_INVALID,
1559
                                                 false);
1560
  os->set_found_in_sections_clause();
1561
  if (section_type == Script_sections::ST_NOLOAD)
1562
    os->set_is_noload();
1563
  return os;
1564
}
1565
 
1566
// Return the number of segments we expect to see.
1567
 
1568
size_t
1569
Layout::expected_segment_count() const
1570
{
1571
  size_t ret = this->segment_list_.size();
1572
 
1573
  // If we didn't see a SECTIONS clause in a linker script, we should
1574
  // already have the complete list of segments.  Otherwise we ask the
1575
  // SECTIONS clause how many segments it expects, and add in the ones
1576
  // we already have (PT_GNU_STACK, PT_GNU_EH_FRAME, etc.)
1577
 
1578
  if (!this->script_options_->saw_sections_clause())
1579
    return ret;
1580
  else
1581
    {
1582
      const Script_sections* ss = this->script_options_->script_sections();
1583
      return ret + ss->expected_segment_count(this);
1584
    }
1585
}
1586
 
1587
// Handle the .note.GNU-stack section at layout time.  SEEN_GNU_STACK
1588
// is whether we saw a .note.GNU-stack section in the object file.
1589
// GNU_STACK_FLAGS is the section flags.  The flags give the
1590
// protection required for stack memory.  We record this in an
1591
// executable as a PT_GNU_STACK segment.  If an object file does not
1592
// have a .note.GNU-stack segment, we must assume that it is an old
1593
// object.  On some targets that will force an executable stack.
1594
 
1595
void
1596
Layout::layout_gnu_stack(bool seen_gnu_stack, uint64_t gnu_stack_flags,
1597
                         const Object* obj)
1598
{
1599
  if (!seen_gnu_stack)
1600
    {
1601
      this->input_without_gnu_stack_note_ = true;
1602
      if (parameters->options().warn_execstack()
1603
          && parameters->target().is_default_stack_executable())
1604
        gold_warning(_("%s: missing .note.GNU-stack section"
1605
                       " implies executable stack"),
1606
                     obj->name().c_str());
1607
    }
1608
  else
1609
    {
1610
      this->input_with_gnu_stack_note_ = true;
1611
      if ((gnu_stack_flags & elfcpp::SHF_EXECINSTR) != 0)
1612
        {
1613
          this->input_requires_executable_stack_ = true;
1614
          if (parameters->options().warn_execstack()
1615
              || parameters->options().is_stack_executable())
1616
            gold_warning(_("%s: requires executable stack"),
1617
                         obj->name().c_str());
1618
        }
1619
    }
1620
}
1621
 
1622
// Create automatic note sections.
1623
 
1624
void
1625
Layout::create_notes()
1626
{
1627
  this->create_gold_note();
1628
  this->create_executable_stack_info();
1629
  this->create_build_id();
1630
}
1631
 
1632
// Create the dynamic sections which are needed before we read the
1633
// relocs.
1634
 
1635
void
1636
Layout::create_initial_dynamic_sections(Symbol_table* symtab)
1637
{
1638
  if (parameters->doing_static_link())
1639
    return;
1640
 
1641
  this->dynamic_section_ = this->choose_output_section(NULL, ".dynamic",
1642
                                                       elfcpp::SHT_DYNAMIC,
1643
                                                       (elfcpp::SHF_ALLOC
1644
                                                        | elfcpp::SHF_WRITE),
1645
                                                       false, ORDER_RELRO,
1646
                                                       true);
1647
 
1648
  this->dynamic_symbol_ =
1649
    symtab->define_in_output_data("_DYNAMIC", NULL, Symbol_table::PREDEFINED,
1650
                                  this->dynamic_section_, 0, 0,
1651
                                  elfcpp::STT_OBJECT, elfcpp::STB_LOCAL,
1652
                                  elfcpp::STV_HIDDEN, 0, false, false);
1653
 
1654
  this->dynamic_data_ =  new Output_data_dynamic(&this->dynpool_);
1655
 
1656
  this->dynamic_section_->add_output_section_data(this->dynamic_data_);
1657
}
1658
 
1659
// For each output section whose name can be represented as C symbol,
1660
// define __start and __stop symbols for the section.  This is a GNU
1661
// extension.
1662
 
1663
void
1664
Layout::define_section_symbols(Symbol_table* symtab)
1665
{
1666
  for (Section_list::const_iterator p = this->section_list_.begin();
1667
       p != this->section_list_.end();
1668
       ++p)
1669
    {
1670
      const char* const name = (*p)->name();
1671
      if (is_cident(name))
1672
        {
1673
          const std::string name_string(name);
1674
          const std::string start_name(cident_section_start_prefix
1675
                                       + name_string);
1676
          const std::string stop_name(cident_section_stop_prefix
1677
                                      + name_string);
1678
 
1679
          symtab->define_in_output_data(start_name.c_str(),
1680
                                        NULL, // version
1681
                                        Symbol_table::PREDEFINED,
1682
                                        *p,
1683
                                        0, // value
1684
                                        0, // symsize
1685
                                        elfcpp::STT_NOTYPE,
1686
                                        elfcpp::STB_GLOBAL,
1687
                                        elfcpp::STV_DEFAULT,
1688
                                        0, // nonvis
1689
                                        false, // offset_is_from_end
1690
                                        true); // only_if_ref
1691
 
1692
          symtab->define_in_output_data(stop_name.c_str(),
1693
                                        NULL, // version
1694
                                        Symbol_table::PREDEFINED,
1695
                                        *p,
1696
                                        0, // value
1697
                                        0, // symsize
1698
                                        elfcpp::STT_NOTYPE,
1699
                                        elfcpp::STB_GLOBAL,
1700
                                        elfcpp::STV_DEFAULT,
1701
                                        0, // nonvis
1702
                                        true, // offset_is_from_end
1703
                                        true); // only_if_ref
1704
        }
1705
    }
1706
}
1707
 
1708
// Define symbols for group signatures.
1709
 
1710
void
1711
Layout::define_group_signatures(Symbol_table* symtab)
1712
{
1713
  for (Group_signatures::iterator p = this->group_signatures_.begin();
1714
       p != this->group_signatures_.end();
1715
       ++p)
1716
    {
1717
      Symbol* sym = symtab->lookup(p->signature, NULL);
1718
      if (sym != NULL)
1719
        p->section->set_info_symndx(sym);
1720
      else
1721
        {
1722
          // Force the name of the group section to the group
1723
          // signature, and use the group's section symbol as the
1724
          // signature symbol.
1725
          if (strcmp(p->section->name(), p->signature) != 0)
1726
            {
1727
              const char* name = this->namepool_.add(p->signature,
1728
                                                     true, NULL);
1729
              p->section->set_name(name);
1730
            }
1731
          p->section->set_needs_symtab_index();
1732
          p->section->set_info_section_symndx(p->section);
1733
        }
1734
    }
1735
 
1736
  this->group_signatures_.clear();
1737
}
1738
 
1739
// Find the first read-only PT_LOAD segment, creating one if
1740
// necessary.
1741
 
1742
Output_segment*
1743
Layout::find_first_load_seg()
1744
{
1745
  Output_segment* best = NULL;
1746
  for (Segment_list::const_iterator p = this->segment_list_.begin();
1747
       p != this->segment_list_.end();
1748
       ++p)
1749
    {
1750
      if ((*p)->type() == elfcpp::PT_LOAD
1751
          && ((*p)->flags() & elfcpp::PF_R) != 0
1752
          && (parameters->options().omagic()
1753
              || ((*p)->flags() & elfcpp::PF_W) == 0))
1754
        {
1755
          if (best == NULL || this->segment_precedes(*p, best))
1756
            best = *p;
1757
        }
1758
    }
1759
  if (best != NULL)
1760
    return best;
1761
 
1762
  gold_assert(!this->script_options_->saw_phdrs_clause());
1763
 
1764
  Output_segment* load_seg = this->make_output_segment(elfcpp::PT_LOAD,
1765
                                                       elfcpp::PF_R);
1766
  return load_seg;
1767
}
1768
 
1769
// Save states of all current output segments.  Store saved states
1770
// in SEGMENT_STATES.
1771
 
1772
void
1773
Layout::save_segments(Segment_states* segment_states)
1774
{
1775
  for (Segment_list::const_iterator p = this->segment_list_.begin();
1776
       p != this->segment_list_.end();
1777
       ++p)
1778
    {
1779
      Output_segment* segment = *p;
1780
      // Shallow copy.
1781
      Output_segment* copy = new Output_segment(*segment);
1782
      (*segment_states)[segment] = copy;
1783
    }
1784
}
1785
 
1786
// Restore states of output segments and delete any segment not found in
1787
// SEGMENT_STATES.
1788
 
1789
void
1790
Layout::restore_segments(const Segment_states* segment_states)
1791
{
1792
  // Go through the segment list and remove any segment added in the
1793
  // relaxation loop.
1794
  this->tls_segment_ = NULL;
1795
  this->relro_segment_ = NULL;
1796
  Segment_list::iterator list_iter = this->segment_list_.begin();
1797
  while (list_iter != this->segment_list_.end())
1798
    {
1799
      Output_segment* segment = *list_iter;
1800
      Segment_states::const_iterator states_iter =
1801
          segment_states->find(segment);
1802
      if (states_iter != segment_states->end())
1803
        {
1804
          const Output_segment* copy = states_iter->second;
1805
          // Shallow copy to restore states.
1806
          *segment = *copy;
1807
 
1808
          // Also fix up TLS and RELRO segment pointers as appropriate.
1809
          if (segment->type() == elfcpp::PT_TLS)
1810
            this->tls_segment_ = segment;
1811
          else if (segment->type() == elfcpp::PT_GNU_RELRO)
1812
            this->relro_segment_ = segment;
1813
 
1814
          ++list_iter;
1815
        }
1816
      else
1817
        {
1818
          list_iter = this->segment_list_.erase(list_iter);
1819
          // This is a segment created during section layout.  It should be
1820
          // safe to remove it since we should have removed all pointers to it.
1821
          delete segment;
1822
        }
1823
    }
1824
}
1825
 
1826
// Clean up after relaxation so that sections can be laid out again.
1827
 
1828
void
1829
Layout::clean_up_after_relaxation()
1830
{
1831
  // Restore the segments to point state just prior to the relaxation loop.
1832
  Script_sections* script_section = this->script_options_->script_sections();
1833
  script_section->release_segments();
1834
  this->restore_segments(this->segment_states_);
1835
 
1836
  // Reset section addresses and file offsets
1837
  for (Section_list::iterator p = this->section_list_.begin();
1838
       p != this->section_list_.end();
1839
       ++p)
1840
    {
1841
      (*p)->restore_states();
1842
 
1843
      // If an input section changes size because of relaxation,
1844
      // we need to adjust the section offsets of all input sections.
1845
      // after such a section.
1846
      if ((*p)->section_offsets_need_adjustment())
1847
        (*p)->adjust_section_offsets();
1848
 
1849
      (*p)->reset_address_and_file_offset();
1850
    }
1851
 
1852
  // Reset special output object address and file offsets.
1853
  for (Data_list::iterator p = this->special_output_list_.begin();
1854
       p != this->special_output_list_.end();
1855
       ++p)
1856
    (*p)->reset_address_and_file_offset();
1857
 
1858
  // A linker script may have created some output section data objects.
1859
  // They are useless now.
1860
  for (Output_section_data_list::const_iterator p =
1861
         this->script_output_section_data_list_.begin();
1862
       p != this->script_output_section_data_list_.end();
1863
       ++p)
1864
    delete *p;
1865
  this->script_output_section_data_list_.clear();
1866
}
1867
 
1868
// Prepare for relaxation.
1869
 
1870
void
1871
Layout::prepare_for_relaxation()
1872
{
1873
  // Create an relaxation debug check if in debugging mode.
1874
  if (is_debugging_enabled(DEBUG_RELAXATION))
1875
    this->relaxation_debug_check_ = new Relaxation_debug_check();
1876
 
1877
  // Save segment states.
1878
  this->segment_states_ = new Segment_states();
1879
  this->save_segments(this->segment_states_);
1880
 
1881
  for(Section_list::const_iterator p = this->section_list_.begin();
1882
      p != this->section_list_.end();
1883
      ++p)
1884
    (*p)->save_states();
1885
 
1886
  if (is_debugging_enabled(DEBUG_RELAXATION))
1887
    this->relaxation_debug_check_->check_output_data_for_reset_values(
1888
        this->section_list_, this->special_output_list_);
1889
 
1890
  // Also enable recording of output section data from scripts.
1891
  this->record_output_section_data_from_script_ = true;
1892
}
1893
 
1894
// Relaxation loop body:  If target has no relaxation, this runs only once
1895
// Otherwise, the target relaxation hook is called at the end of
1896
// each iteration.  If the hook returns true, it means re-layout of
1897
// section is required.  
1898
//
1899
// The number of segments created by a linking script without a PHDRS
1900
// clause may be affected by section sizes and alignments.  There is
1901
// a remote chance that relaxation causes different number of PT_LOAD
1902
// segments are created and sections are attached to different segments.
1903
// Therefore, we always throw away all segments created during section
1904
// layout.  In order to be able to restart the section layout, we keep
1905
// a copy of the segment list right before the relaxation loop and use
1906
// that to restore the segments.
1907
// 
1908
// PASS is the current relaxation pass number. 
1909
// SYMTAB is a symbol table.
1910
// PLOAD_SEG is the address of a pointer for the load segment.
1911
// PHDR_SEG is a pointer to the PHDR segment.
1912
// SEGMENT_HEADERS points to the output segment header.
1913
// FILE_HEADER points to the output file header.
1914
// PSHNDX is the address to store the output section index.
1915
 
1916
off_t inline
1917
Layout::relaxation_loop_body(
1918
    int pass,
1919
    Target* target,
1920
    Symbol_table* symtab,
1921
    Output_segment** pload_seg,
1922
    Output_segment* phdr_seg,
1923
    Output_segment_headers* segment_headers,
1924
    Output_file_header* file_header,
1925
    unsigned int* pshndx)
1926
{
1927
  // If this is not the first iteration, we need to clean up after
1928
  // relaxation so that we can lay out the sections again.
1929
  if (pass != 0)
1930
    this->clean_up_after_relaxation();
1931
 
1932
  // If there is a SECTIONS clause, put all the input sections into
1933
  // the required order.
1934
  Output_segment* load_seg;
1935
  if (this->script_options_->saw_sections_clause())
1936
    load_seg = this->set_section_addresses_from_script(symtab);
1937
  else if (parameters->options().relocatable())
1938
    load_seg = NULL;
1939
  else
1940
    load_seg = this->find_first_load_seg();
1941
 
1942
  if (parameters->options().oformat_enum()
1943
      != General_options::OBJECT_FORMAT_ELF)
1944
    load_seg = NULL;
1945
 
1946
  // If the user set the address of the text segment, that may not be
1947
  // compatible with putting the segment headers and file headers into
1948
  // that segment.
1949
  if (parameters->options().user_set_Ttext())
1950
    load_seg = NULL;
1951
 
1952
  gold_assert(phdr_seg == NULL
1953
              || load_seg != NULL
1954
              || this->script_options_->saw_sections_clause());
1955
 
1956
  // If the address of the load segment we found has been set by
1957
  // --section-start rather than by a script, then adjust the VMA and
1958
  // LMA downward if possible to include the file and section headers.
1959
  uint64_t header_gap = 0;
1960
  if (load_seg != NULL
1961
      && load_seg->are_addresses_set()
1962
      && !this->script_options_->saw_sections_clause()
1963
      && !parameters->options().relocatable())
1964
    {
1965
      file_header->finalize_data_size();
1966
      segment_headers->finalize_data_size();
1967
      size_t sizeof_headers = (file_header->data_size()
1968
                               + segment_headers->data_size());
1969
      const uint64_t abi_pagesize = target->abi_pagesize();
1970
      uint64_t hdr_paddr = load_seg->paddr() - sizeof_headers;
1971
      hdr_paddr &= ~(abi_pagesize - 1);
1972
      uint64_t subtract = load_seg->paddr() - hdr_paddr;
1973
      if (load_seg->paddr() < subtract || load_seg->vaddr() < subtract)
1974
        load_seg = NULL;
1975
      else
1976
        {
1977
          load_seg->set_addresses(load_seg->vaddr() - subtract,
1978
                                  load_seg->paddr() - subtract);
1979
          header_gap = subtract - sizeof_headers;
1980
        }
1981
    }
1982
 
1983
  // Lay out the segment headers.
1984
  if (!parameters->options().relocatable())
1985
    {
1986
      gold_assert(segment_headers != NULL);
1987
      if (header_gap != 0 && load_seg != NULL)
1988
        {
1989
          Output_data_zero_fill* z = new Output_data_zero_fill(header_gap, 1);
1990
          load_seg->add_initial_output_data(z);
1991
        }
1992
      if (load_seg != NULL)
1993
        load_seg->add_initial_output_data(segment_headers);
1994
      if (phdr_seg != NULL)
1995
        phdr_seg->add_initial_output_data(segment_headers);
1996
    }
1997
 
1998
  // Lay out the file header.
1999
  if (load_seg != NULL)
2000
    load_seg->add_initial_output_data(file_header);
2001
 
2002
  if (this->script_options_->saw_phdrs_clause()
2003
      && !parameters->options().relocatable())
2004
    {
2005
      // Support use of FILEHDRS and PHDRS attachments in a PHDRS
2006
      // clause in a linker script.
2007
      Script_sections* ss = this->script_options_->script_sections();
2008
      ss->put_headers_in_phdrs(file_header, segment_headers);
2009
    }
2010
 
2011
  // We set the output section indexes in set_segment_offsets and
2012
  // set_section_indexes.
2013
  *pshndx = 1;
2014
 
2015
  // Set the file offsets of all the segments, and all the sections
2016
  // they contain.
2017
  off_t off;
2018
  if (!parameters->options().relocatable())
2019
    off = this->set_segment_offsets(target, load_seg, pshndx);
2020
  else
2021
    off = this->set_relocatable_section_offsets(file_header, pshndx);
2022
 
2023
   // Verify that the dummy relaxation does not change anything.
2024
  if (is_debugging_enabled(DEBUG_RELAXATION))
2025
    {
2026
      if (pass == 0)
2027
        this->relaxation_debug_check_->read_sections(this->section_list_);
2028
      else
2029
        this->relaxation_debug_check_->verify_sections(this->section_list_);
2030
    }
2031
 
2032
  *pload_seg = load_seg;
2033
  return off;
2034
}
2035
 
2036
// Search the list of patterns and find the postion of the given section
2037
// name in the output section.  If the section name matches a glob
2038
// pattern and a non-glob name, then the non-glob position takes
2039
// precedence.  Return 0 if no match is found.
2040
 
2041
unsigned int
2042
Layout::find_section_order_index(const std::string& section_name)
2043
{
2044
  Unordered_map<std::string, unsigned int>::iterator map_it;
2045
  map_it = this->input_section_position_.find(section_name);
2046
  if (map_it != this->input_section_position_.end())
2047
    return map_it->second;
2048
 
2049
  // Absolute match failed.  Linear search the glob patterns.
2050
  std::vector<std::string>::iterator it;
2051
  for (it = this->input_section_glob_.begin();
2052
       it != this->input_section_glob_.end();
2053
       ++it)
2054
    {
2055
       if (fnmatch((*it).c_str(), section_name.c_str(), FNM_NOESCAPE) == 0)
2056
         {
2057
           map_it = this->input_section_position_.find(*it);
2058
           gold_assert(map_it != this->input_section_position_.end());
2059
           return map_it->second;
2060
         }
2061
    }
2062
  return 0;
2063
}
2064
 
2065
// Read the sequence of input sections from the file specified with
2066
// --section-ordering-file.
2067
 
2068
void
2069
Layout::read_layout_from_file()
2070
{
2071
  const char* filename = parameters->options().section_ordering_file();
2072
  std::ifstream in;
2073
  std::string line;
2074
 
2075
  in.open(filename);
2076
  if (!in)
2077
    gold_fatal(_("unable to open --section-ordering-file file %s: %s"),
2078
               filename, strerror(errno));
2079
 
2080
  std::getline(in, line);   // this chops off the trailing \n, if any
2081
  unsigned int position = 1;
2082
 
2083
  while (in)
2084
    {
2085
      if (!line.empty() && line[line.length() - 1] == '\r')   // Windows
2086
        line.resize(line.length() - 1);
2087
      // Ignore comments, beginning with '#'
2088
      if (line[0] == '#')
2089
        {
2090
          std::getline(in, line);
2091
          continue;
2092
        }
2093
      this->input_section_position_[line] = position;
2094
      // Store all glob patterns in a vector.
2095
      if (is_wildcard_string(line.c_str()))
2096
        this->input_section_glob_.push_back(line);
2097
      position++;
2098
      std::getline(in, line);
2099
    }
2100
}
2101
 
2102
// Finalize the layout.  When this is called, we have created all the
2103
// output sections and all the output segments which are based on
2104
// input sections.  We have several things to do, and we have to do
2105
// them in the right order, so that we get the right results correctly
2106
// and efficiently.
2107
 
2108
// 1) Finalize the list of output segments and create the segment
2109
// table header.
2110
 
2111
// 2) Finalize the dynamic symbol table and associated sections.
2112
 
2113
// 3) Determine the final file offset of all the output segments.
2114
 
2115
// 4) Determine the final file offset of all the SHF_ALLOC output
2116
// sections.
2117
 
2118
// 5) Create the symbol table sections and the section name table
2119
// section.
2120
 
2121
// 6) Finalize the symbol table: set symbol values to their final
2122
// value and make a final determination of which symbols are going
2123
// into the output symbol table.
2124
 
2125
// 7) Create the section table header.
2126
 
2127
// 8) Determine the final file offset of all the output sections which
2128
// are not SHF_ALLOC, including the section table header.
2129
 
2130
// 9) Finalize the ELF file header.
2131
 
2132
// This function returns the size of the output file.
2133
 
2134
off_t
2135
Layout::finalize(const Input_objects* input_objects, Symbol_table* symtab,
2136
                 Target* target, const Task* task)
2137
{
2138
  target->finalize_sections(this, input_objects, symtab);
2139
 
2140
  this->count_local_symbols(task, input_objects);
2141
 
2142
  this->link_stabs_sections();
2143
 
2144
  Output_segment* phdr_seg = NULL;
2145
  if (!parameters->options().relocatable() && !parameters->doing_static_link())
2146
    {
2147
      // There was a dynamic object in the link.  We need to create
2148
      // some information for the dynamic linker.
2149
 
2150
      // Create the PT_PHDR segment which will hold the program
2151
      // headers.
2152
      if (!this->script_options_->saw_phdrs_clause())
2153
        phdr_seg = this->make_output_segment(elfcpp::PT_PHDR, elfcpp::PF_R);
2154
 
2155
      // Create the dynamic symbol table, including the hash table.
2156
      Output_section* dynstr;
2157
      std::vector<Symbol*> dynamic_symbols;
2158
      unsigned int local_dynamic_count;
2159
      Versions versions(*this->script_options()->version_script_info(),
2160
                        &this->dynpool_);
2161
      this->create_dynamic_symtab(input_objects, symtab, &dynstr,
2162
                                  &local_dynamic_count, &dynamic_symbols,
2163
                                  &versions);
2164
 
2165
      // Create the .interp section to hold the name of the
2166
      // interpreter, and put it in a PT_INTERP segment.
2167
      if (!parameters->options().shared())
2168
        this->create_interp(target);
2169
 
2170
      // Finish the .dynamic section to hold the dynamic data, and put
2171
      // it in a PT_DYNAMIC segment.
2172
      this->finish_dynamic_section(input_objects, symtab);
2173
 
2174
      // We should have added everything we need to the dynamic string
2175
      // table.
2176
      this->dynpool_.set_string_offsets();
2177
 
2178
      // Create the version sections.  We can't do this until the
2179
      // dynamic string table is complete.
2180
      this->create_version_sections(&versions, symtab, local_dynamic_count,
2181
                                    dynamic_symbols, dynstr);
2182
 
2183
      // Set the size of the _DYNAMIC symbol.  We can't do this until
2184
      // after we call create_version_sections.
2185
      this->set_dynamic_symbol_size(symtab);
2186
    }
2187
 
2188
  // Create segment headers.
2189
  Output_segment_headers* segment_headers =
2190
    (parameters->options().relocatable()
2191
     ? NULL
2192
     : new Output_segment_headers(this->segment_list_));
2193
 
2194
  // Lay out the file header.
2195
  Output_file_header* file_header = new Output_file_header(target, symtab,
2196
                                                           segment_headers);
2197
 
2198
  this->special_output_list_.push_back(file_header);
2199
  if (segment_headers != NULL)
2200
    this->special_output_list_.push_back(segment_headers);
2201
 
2202
  // Find approriate places for orphan output sections if we are using
2203
  // a linker script.
2204
  if (this->script_options_->saw_sections_clause())
2205
    this->place_orphan_sections_in_script();
2206
 
2207
  Output_segment* load_seg;
2208
  off_t off;
2209
  unsigned int shndx;
2210
  int pass = 0;
2211
 
2212
  // Take a snapshot of the section layout as needed.
2213
  if (target->may_relax())
2214
    this->prepare_for_relaxation();
2215
 
2216
  // Run the relaxation loop to lay out sections.
2217
  do
2218
    {
2219
      off = this->relaxation_loop_body(pass, target, symtab, &load_seg,
2220
                                       phdr_seg, segment_headers, file_header,
2221
                                       &shndx);
2222
      pass++;
2223
    }
2224
  while (target->may_relax()
2225
         && target->relax(pass, input_objects, symtab, this, task));
2226
 
2227
  // Set the file offsets of all the non-data sections we've seen so
2228
  // far which don't have to wait for the input sections.  We need
2229
  // this in order to finalize local symbols in non-allocated
2230
  // sections.
2231
  off = this->set_section_offsets(off, BEFORE_INPUT_SECTIONS_PASS);
2232
 
2233
  // Set the section indexes of all unallocated sections seen so far,
2234
  // in case any of them are somehow referenced by a symbol.
2235
  shndx = this->set_section_indexes(shndx);
2236
 
2237
  // Create the symbol table sections.
2238
  this->create_symtab_sections(input_objects, symtab, shndx, &off);
2239
  if (!parameters->doing_static_link())
2240
    this->assign_local_dynsym_offsets(input_objects);
2241
 
2242
  // Process any symbol assignments from a linker script.  This must
2243
  // be called after the symbol table has been finalized.
2244
  this->script_options_->finalize_symbols(symtab, this);
2245
 
2246
  // Create the incremental inputs sections.
2247
  if (this->incremental_inputs_)
2248
    {
2249
      this->incremental_inputs_->finalize();
2250
      this->create_incremental_info_sections(symtab);
2251
    }
2252
 
2253
  // Create the .shstrtab section.
2254
  Output_section* shstrtab_section = this->create_shstrtab();
2255
 
2256
  // Set the file offsets of the rest of the non-data sections which
2257
  // don't have to wait for the input sections.
2258
  off = this->set_section_offsets(off, BEFORE_INPUT_SECTIONS_PASS);
2259
 
2260
  // Now that all sections have been created, set the section indexes
2261
  // for any sections which haven't been done yet.
2262
  shndx = this->set_section_indexes(shndx);
2263
 
2264
  // Create the section table header.
2265
  this->create_shdrs(shstrtab_section, &off);
2266
 
2267
  // If there are no sections which require postprocessing, we can
2268
  // handle the section names now, and avoid a resize later.
2269
  if (!this->any_postprocessing_sections_)
2270
    {
2271
      off = this->set_section_offsets(off,
2272
                                      POSTPROCESSING_SECTIONS_PASS);
2273
      off =
2274
          this->set_section_offsets(off,
2275
                                    STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS);
2276
    }
2277
 
2278
  file_header->set_section_info(this->section_headers_, shstrtab_section);
2279
 
2280
  // Now we know exactly where everything goes in the output file
2281
  // (except for non-allocated sections which require postprocessing).
2282
  Output_data::layout_complete();
2283
 
2284
  this->output_file_size_ = off;
2285
 
2286
  return off;
2287
}
2288
 
2289
// Create a note header following the format defined in the ELF ABI.
2290
// NAME is the name, NOTE_TYPE is the type, SECTION_NAME is the name
2291
// of the section to create, DESCSZ is the size of the descriptor.
2292
// ALLOCATE is true if the section should be allocated in memory.
2293
// This returns the new note section.  It sets *TRAILING_PADDING to
2294
// the number of trailing zero bytes required.
2295
 
2296
Output_section*
2297
Layout::create_note(const char* name, int note_type,
2298
                    const char* section_name, size_t descsz,
2299
                    bool allocate, size_t* trailing_padding)
2300
{
2301
  // Authorities all agree that the values in a .note field should
2302
  // be aligned on 4-byte boundaries for 32-bit binaries.  However,
2303
  // they differ on what the alignment is for 64-bit binaries.
2304
  // The GABI says unambiguously they take 8-byte alignment:
2305
  //    http://sco.com/developers/gabi/latest/ch5.pheader.html#note_section
2306
  // Other documentation says alignment should always be 4 bytes:
2307
  //    http://www.netbsd.org/docs/kernel/elf-notes.html#note-format
2308
  // GNU ld and GNU readelf both support the latter (at least as of
2309
  // version 2.16.91), and glibc always generates the latter for
2310
  // .note.ABI-tag (as of version 1.6), so that's the one we go with
2311
  // here.
2312
#ifdef GABI_FORMAT_FOR_DOTNOTE_SECTION   // This is not defined by default.
2313
  const int size = parameters->target().get_size();
2314
#else
2315
  const int size = 32;
2316
#endif
2317
 
2318
  // The contents of the .note section.
2319
  size_t namesz = strlen(name) + 1;
2320
  size_t aligned_namesz = align_address(namesz, size / 8);
2321
  size_t aligned_descsz = align_address(descsz, size / 8);
2322
 
2323
  size_t notehdrsz = 3 * (size / 8) + aligned_namesz;
2324
 
2325
  unsigned char* buffer = new unsigned char[notehdrsz];
2326
  memset(buffer, 0, notehdrsz);
2327
 
2328
  bool is_big_endian = parameters->target().is_big_endian();
2329
 
2330
  if (size == 32)
2331
    {
2332
      if (!is_big_endian)
2333
        {
2334
          elfcpp::Swap<32, false>::writeval(buffer, namesz);
2335
          elfcpp::Swap<32, false>::writeval(buffer + 4, descsz);
2336
          elfcpp::Swap<32, false>::writeval(buffer + 8, note_type);
2337
        }
2338
      else
2339
        {
2340
          elfcpp::Swap<32, true>::writeval(buffer, namesz);
2341
          elfcpp::Swap<32, true>::writeval(buffer + 4, descsz);
2342
          elfcpp::Swap<32, true>::writeval(buffer + 8, note_type);
2343
        }
2344
    }
2345
  else if (size == 64)
2346
    {
2347
      if (!is_big_endian)
2348
        {
2349
          elfcpp::Swap<64, false>::writeval(buffer, namesz);
2350
          elfcpp::Swap<64, false>::writeval(buffer + 8, descsz);
2351
          elfcpp::Swap<64, false>::writeval(buffer + 16, note_type);
2352
        }
2353
      else
2354
        {
2355
          elfcpp::Swap<64, true>::writeval(buffer, namesz);
2356
          elfcpp::Swap<64, true>::writeval(buffer + 8, descsz);
2357
          elfcpp::Swap<64, true>::writeval(buffer + 16, note_type);
2358
        }
2359
    }
2360
  else
2361
    gold_unreachable();
2362
 
2363
  memcpy(buffer + 3 * (size / 8), name, namesz);
2364
 
2365
  elfcpp::Elf_Xword flags = 0;
2366
  Output_section_order order = ORDER_INVALID;
2367
  if (allocate)
2368
    {
2369
      flags = elfcpp::SHF_ALLOC;
2370
      order = ORDER_RO_NOTE;
2371
    }
2372
  Output_section* os = this->choose_output_section(NULL, section_name,
2373
                                                   elfcpp::SHT_NOTE,
2374
                                                   flags, false, order, false);
2375
  if (os == NULL)
2376
    return NULL;
2377
 
2378
  Output_section_data* posd = new Output_data_const_buffer(buffer, notehdrsz,
2379
                                                           size / 8,
2380
                                                           "** note header");
2381
  os->add_output_section_data(posd);
2382
 
2383
  *trailing_padding = aligned_descsz - descsz;
2384
 
2385
  return os;
2386
}
2387
 
2388
// For an executable or shared library, create a note to record the
2389
// version of gold used to create the binary.
2390
 
2391
void
2392
Layout::create_gold_note()
2393
{
2394
  if (parameters->options().relocatable()
2395
      || parameters->incremental_update())
2396
    return;
2397
 
2398
  std::string desc = std::string("gold ") + gold::get_version_string();
2399
 
2400
  size_t trailing_padding;
2401
  Output_section* os = this->create_note("GNU", elfcpp::NT_GNU_GOLD_VERSION,
2402
                                         ".note.gnu.gold-version", desc.size(),
2403
                                         false, &trailing_padding);
2404
  if (os == NULL)
2405
    return;
2406
 
2407
  Output_section_data* posd = new Output_data_const(desc, 4);
2408
  os->add_output_section_data(posd);
2409
 
2410
  if (trailing_padding > 0)
2411
    {
2412
      posd = new Output_data_zero_fill(trailing_padding, 0);
2413
      os->add_output_section_data(posd);
2414
    }
2415
}
2416
 
2417
// Record whether the stack should be executable.  This can be set
2418
// from the command line using the -z execstack or -z noexecstack
2419
// options.  Otherwise, if any input file has a .note.GNU-stack
2420
// section with the SHF_EXECINSTR flag set, the stack should be
2421
// executable.  Otherwise, if at least one input file a
2422
// .note.GNU-stack section, and some input file has no .note.GNU-stack
2423
// section, we use the target default for whether the stack should be
2424
// executable.  Otherwise, we don't generate a stack note.  When
2425
// generating a object file, we create a .note.GNU-stack section with
2426
// the appropriate marking.  When generating an executable or shared
2427
// library, we create a PT_GNU_STACK segment.
2428
 
2429
void
2430
Layout::create_executable_stack_info()
2431
{
2432
  bool is_stack_executable;
2433
  if (parameters->options().is_execstack_set())
2434
    is_stack_executable = parameters->options().is_stack_executable();
2435
  else if (!this->input_with_gnu_stack_note_)
2436
    return;
2437
  else
2438
    {
2439
      if (this->input_requires_executable_stack_)
2440
        is_stack_executable = true;
2441
      else if (this->input_without_gnu_stack_note_)
2442
        is_stack_executable =
2443
          parameters->target().is_default_stack_executable();
2444
      else
2445
        is_stack_executable = false;
2446
    }
2447
 
2448
  if (parameters->options().relocatable())
2449
    {
2450
      const char* name = this->namepool_.add(".note.GNU-stack", false, NULL);
2451
      elfcpp::Elf_Xword flags = 0;
2452
      if (is_stack_executable)
2453
        flags |= elfcpp::SHF_EXECINSTR;
2454
      this->make_output_section(name, elfcpp::SHT_PROGBITS, flags,
2455
                                ORDER_INVALID, false);
2456
    }
2457
  else
2458
    {
2459
      if (this->script_options_->saw_phdrs_clause())
2460
        return;
2461
      int flags = elfcpp::PF_R | elfcpp::PF_W;
2462
      if (is_stack_executable)
2463
        flags |= elfcpp::PF_X;
2464
      this->make_output_segment(elfcpp::PT_GNU_STACK, flags);
2465
    }
2466
}
2467
 
2468
// If --build-id was used, set up the build ID note.
2469
 
2470
void
2471
Layout::create_build_id()
2472
{
2473
  if (!parameters->options().user_set_build_id())
2474
    return;
2475
 
2476
  const char* style = parameters->options().build_id();
2477
  if (strcmp(style, "none") == 0)
2478
    return;
2479
 
2480
  // Set DESCSZ to the size of the note descriptor.  When possible,
2481
  // set DESC to the note descriptor contents.
2482
  size_t descsz;
2483
  std::string desc;
2484
  if (strcmp(style, "md5") == 0)
2485
    descsz = 128 / 8;
2486
  else if (strcmp(style, "sha1") == 0)
2487
    descsz = 160 / 8;
2488
  else if (strcmp(style, "uuid") == 0)
2489
    {
2490
      const size_t uuidsz = 128 / 8;
2491
 
2492
      char buffer[uuidsz];
2493
      memset(buffer, 0, uuidsz);
2494
 
2495
      int descriptor = open_descriptor(-1, "/dev/urandom", O_RDONLY);
2496
      if (descriptor < 0)
2497
        gold_error(_("--build-id=uuid failed: could not open /dev/urandom: %s"),
2498
                   strerror(errno));
2499
      else
2500
        {
2501
          ssize_t got = ::read(descriptor, buffer, uuidsz);
2502
          release_descriptor(descriptor, true);
2503
          if (got < 0)
2504
            gold_error(_("/dev/urandom: read failed: %s"), strerror(errno));
2505
          else if (static_cast<size_t>(got) != uuidsz)
2506
            gold_error(_("/dev/urandom: expected %zu bytes, got %zd bytes"),
2507
                       uuidsz, got);
2508
        }
2509
 
2510
      desc.assign(buffer, uuidsz);
2511
      descsz = uuidsz;
2512
    }
2513
  else if (strncmp(style, "0x", 2) == 0)
2514
    {
2515
      hex_init();
2516
      const char* p = style + 2;
2517
      while (*p != '\0')
2518
        {
2519
          if (hex_p(p[0]) && hex_p(p[1]))
2520
            {
2521
              char c = (hex_value(p[0]) << 4) | hex_value(p[1]);
2522
              desc += c;
2523
              p += 2;
2524
            }
2525
          else if (*p == '-' || *p == ':')
2526
            ++p;
2527
          else
2528
            gold_fatal(_("--build-id argument '%s' not a valid hex number"),
2529
                       style);
2530
        }
2531
      descsz = desc.size();
2532
    }
2533
  else
2534
    gold_fatal(_("unrecognized --build-id argument '%s'"), style);
2535
 
2536
  // Create the note.
2537
  size_t trailing_padding;
2538
  Output_section* os = this->create_note("GNU", elfcpp::NT_GNU_BUILD_ID,
2539
                                         ".note.gnu.build-id", descsz, true,
2540
                                         &trailing_padding);
2541
  if (os == NULL)
2542
    return;
2543
 
2544
  if (!desc.empty())
2545
    {
2546
      // We know the value already, so we fill it in now.
2547
      gold_assert(desc.size() == descsz);
2548
 
2549
      Output_section_data* posd = new Output_data_const(desc, 4);
2550
      os->add_output_section_data(posd);
2551
 
2552
      if (trailing_padding != 0)
2553
        {
2554
          posd = new Output_data_zero_fill(trailing_padding, 0);
2555
          os->add_output_section_data(posd);
2556
        }
2557
    }
2558
  else
2559
    {
2560
      // We need to compute a checksum after we have completed the
2561
      // link.
2562
      gold_assert(trailing_padding == 0);
2563
      this->build_id_note_ = new Output_data_zero_fill(descsz, 4);
2564
      os->add_output_section_data(this->build_id_note_);
2565
    }
2566
}
2567
 
2568
// If we have both .stabXX and .stabXXstr sections, then the sh_link
2569
// field of the former should point to the latter.  I'm not sure who
2570
// started this, but the GNU linker does it, and some tools depend
2571
// upon it.
2572
 
2573
void
2574
Layout::link_stabs_sections()
2575
{
2576
  if (!this->have_stabstr_section_)
2577
    return;
2578
 
2579
  for (Section_list::iterator p = this->section_list_.begin();
2580
       p != this->section_list_.end();
2581
       ++p)
2582
    {
2583
      if ((*p)->type() != elfcpp::SHT_STRTAB)
2584
        continue;
2585
 
2586
      const char* name = (*p)->name();
2587
      if (strncmp(name, ".stab", 5) != 0)
2588
        continue;
2589
 
2590
      size_t len = strlen(name);
2591
      if (strcmp(name + len - 3, "str") != 0)
2592
        continue;
2593
 
2594
      std::string stab_name(name, len - 3);
2595
      Output_section* stab_sec;
2596
      stab_sec = this->find_output_section(stab_name.c_str());
2597
      if (stab_sec != NULL)
2598
        stab_sec->set_link_section(*p);
2599
    }
2600
}
2601
 
2602
// Create .gnu_incremental_inputs and related sections needed
2603
// for the next run of incremental linking to check what has changed.
2604
 
2605
void
2606
Layout::create_incremental_info_sections(Symbol_table* symtab)
2607
{
2608
  Incremental_inputs* incr = this->incremental_inputs_;
2609
 
2610
  gold_assert(incr != NULL);
2611
 
2612
  // Create the .gnu_incremental_inputs, _symtab, and _relocs input sections.
2613
  incr->create_data_sections(symtab);
2614
 
2615
  // Add the .gnu_incremental_inputs section.
2616
  const char* incremental_inputs_name =
2617
    this->namepool_.add(".gnu_incremental_inputs", false, NULL);
2618
  Output_section* incremental_inputs_os =
2619
    this->make_output_section(incremental_inputs_name,
2620
                              elfcpp::SHT_GNU_INCREMENTAL_INPUTS, 0,
2621
                              ORDER_INVALID, false);
2622
  incremental_inputs_os->add_output_section_data(incr->inputs_section());
2623
 
2624
  // Add the .gnu_incremental_symtab section.
2625
  const char* incremental_symtab_name =
2626
    this->namepool_.add(".gnu_incremental_symtab", false, NULL);
2627
  Output_section* incremental_symtab_os =
2628
    this->make_output_section(incremental_symtab_name,
2629
                              elfcpp::SHT_GNU_INCREMENTAL_SYMTAB, 0,
2630
                              ORDER_INVALID, false);
2631
  incremental_symtab_os->add_output_section_data(incr->symtab_section());
2632
  incremental_symtab_os->set_entsize(4);
2633
 
2634
  // Add the .gnu_incremental_relocs section.
2635
  const char* incremental_relocs_name =
2636
    this->namepool_.add(".gnu_incremental_relocs", false, NULL);
2637
  Output_section* incremental_relocs_os =
2638
    this->make_output_section(incremental_relocs_name,
2639
                              elfcpp::SHT_GNU_INCREMENTAL_RELOCS, 0,
2640
                              ORDER_INVALID, false);
2641
  incremental_relocs_os->add_output_section_data(incr->relocs_section());
2642
  incremental_relocs_os->set_entsize(incr->relocs_entsize());
2643
 
2644
  // Add the .gnu_incremental_got_plt section.
2645
  const char* incremental_got_plt_name =
2646
    this->namepool_.add(".gnu_incremental_got_plt", false, NULL);
2647
  Output_section* incremental_got_plt_os =
2648
    this->make_output_section(incremental_got_plt_name,
2649
                              elfcpp::SHT_GNU_INCREMENTAL_GOT_PLT, 0,
2650
                              ORDER_INVALID, false);
2651
  incremental_got_plt_os->add_output_section_data(incr->got_plt_section());
2652
 
2653
  // Add the .gnu_incremental_strtab section.
2654
  const char* incremental_strtab_name =
2655
    this->namepool_.add(".gnu_incremental_strtab", false, NULL);
2656
  Output_section* incremental_strtab_os = this->make_output_section(incremental_strtab_name,
2657
                                                        elfcpp::SHT_STRTAB, 0,
2658
                                                        ORDER_INVALID, false);
2659
  Output_data_strtab* strtab_data =
2660
      new Output_data_strtab(incr->get_stringpool());
2661
  incremental_strtab_os->add_output_section_data(strtab_data);
2662
 
2663
  incremental_inputs_os->set_after_input_sections();
2664
  incremental_symtab_os->set_after_input_sections();
2665
  incremental_relocs_os->set_after_input_sections();
2666
  incremental_got_plt_os->set_after_input_sections();
2667
 
2668
  incremental_inputs_os->set_link_section(incremental_strtab_os);
2669
  incremental_symtab_os->set_link_section(incremental_inputs_os);
2670
  incremental_relocs_os->set_link_section(incremental_inputs_os);
2671
  incremental_got_plt_os->set_link_section(incremental_inputs_os);
2672
}
2673
 
2674
// Return whether SEG1 should be before SEG2 in the output file.  This
2675
// is based entirely on the segment type and flags.  When this is
2676
// called the segment addresses has normally not yet been set.
2677
 
2678
bool
2679
Layout::segment_precedes(const Output_segment* seg1,
2680
                         const Output_segment* seg2)
2681
{
2682
  elfcpp::Elf_Word type1 = seg1->type();
2683
  elfcpp::Elf_Word type2 = seg2->type();
2684
 
2685
  // The single PT_PHDR segment is required to precede any loadable
2686
  // segment.  We simply make it always first.
2687
  if (type1 == elfcpp::PT_PHDR)
2688
    {
2689
      gold_assert(type2 != elfcpp::PT_PHDR);
2690
      return true;
2691
    }
2692
  if (type2 == elfcpp::PT_PHDR)
2693
    return false;
2694
 
2695
  // The single PT_INTERP segment is required to precede any loadable
2696
  // segment.  We simply make it always second.
2697
  if (type1 == elfcpp::PT_INTERP)
2698
    {
2699
      gold_assert(type2 != elfcpp::PT_INTERP);
2700
      return true;
2701
    }
2702
  if (type2 == elfcpp::PT_INTERP)
2703
    return false;
2704
 
2705
  // We then put PT_LOAD segments before any other segments.
2706
  if (type1 == elfcpp::PT_LOAD && type2 != elfcpp::PT_LOAD)
2707
    return true;
2708
  if (type2 == elfcpp::PT_LOAD && type1 != elfcpp::PT_LOAD)
2709
    return false;
2710
 
2711
  // We put the PT_TLS segment last except for the PT_GNU_RELRO
2712
  // segment, because that is where the dynamic linker expects to find
2713
  // it (this is just for efficiency; other positions would also work
2714
  // correctly).
2715
  if (type1 == elfcpp::PT_TLS
2716
      && type2 != elfcpp::PT_TLS
2717
      && type2 != elfcpp::PT_GNU_RELRO)
2718
    return false;
2719
  if (type2 == elfcpp::PT_TLS
2720
      && type1 != elfcpp::PT_TLS
2721
      && type1 != elfcpp::PT_GNU_RELRO)
2722
    return true;
2723
 
2724
  // We put the PT_GNU_RELRO segment last, because that is where the
2725
  // dynamic linker expects to find it (as with PT_TLS, this is just
2726
  // for efficiency).
2727
  if (type1 == elfcpp::PT_GNU_RELRO && type2 != elfcpp::PT_GNU_RELRO)
2728
    return false;
2729
  if (type2 == elfcpp::PT_GNU_RELRO && type1 != elfcpp::PT_GNU_RELRO)
2730
    return true;
2731
 
2732
  const elfcpp::Elf_Word flags1 = seg1->flags();
2733
  const elfcpp::Elf_Word flags2 = seg2->flags();
2734
 
2735
  // The order of non-PT_LOAD segments is unimportant.  We simply sort
2736
  // by the numeric segment type and flags values.  There should not
2737
  // be more than one segment with the same type and flags.
2738
  if (type1 != elfcpp::PT_LOAD)
2739
    {
2740
      if (type1 != type2)
2741
        return type1 < type2;
2742
      gold_assert(flags1 != flags2);
2743
      return flags1 < flags2;
2744
    }
2745
 
2746
  // If the addresses are set already, sort by load address.
2747
  if (seg1->are_addresses_set())
2748
    {
2749
      if (!seg2->are_addresses_set())
2750
        return true;
2751
 
2752
      unsigned int section_count1 = seg1->output_section_count();
2753
      unsigned int section_count2 = seg2->output_section_count();
2754
      if (section_count1 == 0 && section_count2 > 0)
2755
        return true;
2756
      if (section_count1 > 0 && section_count2 == 0)
2757
        return false;
2758
 
2759
      uint64_t paddr1 = (seg1->are_addresses_set()
2760
                         ? seg1->paddr()
2761
                         : seg1->first_section_load_address());
2762
      uint64_t paddr2 = (seg2->are_addresses_set()
2763
                         ? seg2->paddr()
2764
                         : seg2->first_section_load_address());
2765
 
2766
      if (paddr1 != paddr2)
2767
        return paddr1 < paddr2;
2768
    }
2769
  else if (seg2->are_addresses_set())
2770
    return false;
2771
 
2772
  // A segment which holds large data comes after a segment which does
2773
  // not hold large data.
2774
  if (seg1->is_large_data_segment())
2775
    {
2776
      if (!seg2->is_large_data_segment())
2777
        return false;
2778
    }
2779
  else if (seg2->is_large_data_segment())
2780
    return true;
2781
 
2782
  // Otherwise, we sort PT_LOAD segments based on the flags.  Readonly
2783
  // segments come before writable segments.  Then writable segments
2784
  // with data come before writable segments without data.  Then
2785
  // executable segments come before non-executable segments.  Then
2786
  // the unlikely case of a non-readable segment comes before the
2787
  // normal case of a readable segment.  If there are multiple
2788
  // segments with the same type and flags, we require that the
2789
  // address be set, and we sort by virtual address and then physical
2790
  // address.
2791
  if ((flags1 & elfcpp::PF_W) != (flags2 & elfcpp::PF_W))
2792
    return (flags1 & elfcpp::PF_W) == 0;
2793
  if ((flags1 & elfcpp::PF_W) != 0
2794
      && seg1->has_any_data_sections() != seg2->has_any_data_sections())
2795
    return seg1->has_any_data_sections();
2796
  if ((flags1 & elfcpp::PF_X) != (flags2 & elfcpp::PF_X))
2797
    return (flags1 & elfcpp::PF_X) != 0;
2798
  if ((flags1 & elfcpp::PF_R) != (flags2 & elfcpp::PF_R))
2799
    return (flags1 & elfcpp::PF_R) == 0;
2800
 
2801
  // We shouldn't get here--we shouldn't create segments which we
2802
  // can't distinguish.
2803
  gold_unreachable();
2804
}
2805
 
2806
// Increase OFF so that it is congruent to ADDR modulo ABI_PAGESIZE.
2807
 
2808
static off_t
2809
align_file_offset(off_t off, uint64_t addr, uint64_t abi_pagesize)
2810
{
2811
  uint64_t unsigned_off = off;
2812
  uint64_t aligned_off = ((unsigned_off & ~(abi_pagesize - 1))
2813
                          | (addr & (abi_pagesize - 1)));
2814
  if (aligned_off < unsigned_off)
2815
    aligned_off += abi_pagesize;
2816
  return aligned_off;
2817
}
2818
 
2819
// Set the file offsets of all the segments, and all the sections they
2820
// contain.  They have all been created.  LOAD_SEG must be be laid out
2821
// first.  Return the offset of the data to follow.
2822
 
2823
off_t
2824
Layout::set_segment_offsets(const Target* target, Output_segment* load_seg,
2825
                            unsigned int* pshndx)
2826
{
2827
  // Sort them into the final order.
2828
  std::sort(this->segment_list_.begin(), this->segment_list_.end(),
2829
            Layout::Compare_segments());
2830
 
2831
  // Find the PT_LOAD segments, and set their addresses and offsets
2832
  // and their section's addresses and offsets.
2833
  uint64_t addr;
2834
  if (parameters->options().user_set_Ttext())
2835
    addr = parameters->options().Ttext();
2836
  else if (parameters->options().output_is_position_independent())
2837
    addr = 0;
2838
  else
2839
    addr = target->default_text_segment_address();
2840
  off_t off = 0;
2841
 
2842
  // If LOAD_SEG is NULL, then the file header and segment headers
2843
  // will not be loadable.  But they still need to be at offset 0 in
2844
  // the file.  Set their offsets now.
2845
  if (load_seg == NULL)
2846
    {
2847
      for (Data_list::iterator p = this->special_output_list_.begin();
2848
           p != this->special_output_list_.end();
2849
           ++p)
2850
        {
2851
          off = align_address(off, (*p)->addralign());
2852
          (*p)->set_address_and_file_offset(0, off);
2853
          off += (*p)->data_size();
2854
        }
2855
    }
2856
 
2857
  unsigned int increase_relro = this->increase_relro_;
2858
  if (this->script_options_->saw_sections_clause())
2859
    increase_relro = 0;
2860
 
2861
  const bool check_sections = parameters->options().check_sections();
2862
  Output_segment* last_load_segment = NULL;
2863
 
2864
  for (Segment_list::iterator p = this->segment_list_.begin();
2865
       p != this->segment_list_.end();
2866
       ++p)
2867
    {
2868
      if ((*p)->type() == elfcpp::PT_LOAD)
2869
        {
2870
          if (load_seg != NULL && load_seg != *p)
2871
            gold_unreachable();
2872
          load_seg = NULL;
2873
 
2874
          bool are_addresses_set = (*p)->are_addresses_set();
2875
          if (are_addresses_set)
2876
            {
2877
              // When it comes to setting file offsets, we care about
2878
              // the physical address.
2879
              addr = (*p)->paddr();
2880
            }
2881
          else if (parameters->options().user_set_Tdata()
2882
                   && ((*p)->flags() & elfcpp::PF_W) != 0
2883
                   && (!parameters->options().user_set_Tbss()
2884
                       || (*p)->has_any_data_sections()))
2885
            {
2886
              addr = parameters->options().Tdata();
2887
              are_addresses_set = true;
2888
            }
2889
          else if (parameters->options().user_set_Tbss()
2890
                   && ((*p)->flags() & elfcpp::PF_W) != 0
2891
                   && !(*p)->has_any_data_sections())
2892
            {
2893
              addr = parameters->options().Tbss();
2894
              are_addresses_set = true;
2895
            }
2896
 
2897
          uint64_t orig_addr = addr;
2898
          uint64_t orig_off = off;
2899
 
2900
          uint64_t aligned_addr = 0;
2901
          uint64_t abi_pagesize = target->abi_pagesize();
2902
          uint64_t common_pagesize = target->common_pagesize();
2903
 
2904
          if (!parameters->options().nmagic()
2905
              && !parameters->options().omagic())
2906
            (*p)->set_minimum_p_align(common_pagesize);
2907
 
2908
          if (!are_addresses_set)
2909
            {
2910
              // Skip the address forward one page, maintaining the same
2911
              // position within the page.  This lets us store both segments
2912
              // overlapping on a single page in the file, but the loader will
2913
              // put them on different pages in memory. We will revisit this
2914
              // decision once we know the size of the segment.
2915
 
2916
              addr = align_address(addr, (*p)->maximum_alignment());
2917
              aligned_addr = addr;
2918
 
2919
              if ((addr & (abi_pagesize - 1)) != 0)
2920
                addr = addr + abi_pagesize;
2921
 
2922
              off = orig_off + ((addr - orig_addr) & (abi_pagesize - 1));
2923
            }
2924
 
2925
          if (!parameters->options().nmagic()
2926
              && !parameters->options().omagic())
2927
            off = align_file_offset(off, addr, abi_pagesize);
2928
          else if (load_seg == NULL)
2929
            {
2930
              // This is -N or -n with a section script which prevents
2931
              // us from using a load segment.  We need to ensure that
2932
              // the file offset is aligned to the alignment of the
2933
              // segment.  This is because the linker script
2934
              // implicitly assumed a zero offset.  If we don't align
2935
              // here, then the alignment of the sections in the
2936
              // linker script may not match the alignment of the
2937
              // sections in the set_section_addresses call below,
2938
              // causing an error about dot moving backward.
2939
              off = align_address(off, (*p)->maximum_alignment());
2940
            }
2941
 
2942
          unsigned int shndx_hold = *pshndx;
2943
          bool has_relro = false;
2944
          uint64_t new_addr = (*p)->set_section_addresses(this, false, addr,
2945
                                                          &increase_relro,
2946
                                                          &has_relro,
2947
                                                          &off, pshndx);
2948
 
2949
          // Now that we know the size of this segment, we may be able
2950
          // to save a page in memory, at the cost of wasting some
2951
          // file space, by instead aligning to the start of a new
2952
          // page.  Here we use the real machine page size rather than
2953
          // the ABI mandated page size.  If the segment has been
2954
          // aligned so that the relro data ends at a page boundary,
2955
          // we do not try to realign it.
2956
 
2957
          if (!are_addresses_set
2958
              && !has_relro
2959
              && aligned_addr != addr
2960
              && !parameters->incremental_update())
2961
            {
2962
              uint64_t first_off = (common_pagesize
2963
                                    - (aligned_addr
2964
                                       & (common_pagesize - 1)));
2965
              uint64_t last_off = new_addr & (common_pagesize - 1);
2966
              if (first_off > 0
2967
                  && last_off > 0
2968
                  && ((aligned_addr & ~ (common_pagesize - 1))
2969
                      != (new_addr & ~ (common_pagesize - 1)))
2970
                  && first_off + last_off <= common_pagesize)
2971
                {
2972
                  *pshndx = shndx_hold;
2973
                  addr = align_address(aligned_addr, common_pagesize);
2974
                  addr = align_address(addr, (*p)->maximum_alignment());
2975
                  off = orig_off + ((addr - orig_addr) & (abi_pagesize - 1));
2976
                  off = align_file_offset(off, addr, abi_pagesize);
2977
 
2978
                  increase_relro = this->increase_relro_;
2979
                  if (this->script_options_->saw_sections_clause())
2980
                    increase_relro = 0;
2981
                  has_relro = false;
2982
 
2983
                  new_addr = (*p)->set_section_addresses(this, true, addr,
2984
                                                         &increase_relro,
2985
                                                         &has_relro,
2986
                                                         &off, pshndx);
2987
                }
2988
            }
2989
 
2990
          addr = new_addr;
2991
 
2992
          // Implement --check-sections.  We know that the segments
2993
          // are sorted by LMA.
2994
          if (check_sections && last_load_segment != NULL)
2995
            {
2996
              gold_assert(last_load_segment->paddr() <= (*p)->paddr());
2997
              if (last_load_segment->paddr() + last_load_segment->memsz()
2998
                  > (*p)->paddr())
2999
                {
3000
                  unsigned long long lb1 = last_load_segment->paddr();
3001
                  unsigned long long le1 = lb1 + last_load_segment->memsz();
3002
                  unsigned long long lb2 = (*p)->paddr();
3003
                  unsigned long long le2 = lb2 + (*p)->memsz();
3004
                  gold_error(_("load segment overlap [0x%llx -> 0x%llx] and "
3005
                               "[0x%llx -> 0x%llx]"),
3006
                             lb1, le1, lb2, le2);
3007
                }
3008
            }
3009
          last_load_segment = *p;
3010
        }
3011
    }
3012
 
3013
  // Handle the non-PT_LOAD segments, setting their offsets from their
3014
  // section's offsets.
3015
  for (Segment_list::iterator p = this->segment_list_.begin();
3016
       p != this->segment_list_.end();
3017
       ++p)
3018
    {
3019
      if ((*p)->type() != elfcpp::PT_LOAD)
3020
        (*p)->set_offset((*p)->type() == elfcpp::PT_GNU_RELRO
3021
                         ? increase_relro
3022
                         : 0);
3023
    }
3024
 
3025
  // Set the TLS offsets for each section in the PT_TLS segment.
3026
  if (this->tls_segment_ != NULL)
3027
    this->tls_segment_->set_tls_offsets();
3028
 
3029
  return off;
3030
}
3031
 
3032
// Set the offsets of all the allocated sections when doing a
3033
// relocatable link.  This does the same jobs as set_segment_offsets,
3034
// only for a relocatable link.
3035
 
3036
off_t
3037
Layout::set_relocatable_section_offsets(Output_data* file_header,
3038
                                        unsigned int* pshndx)
3039
{
3040
  off_t off = 0;
3041
 
3042
  file_header->set_address_and_file_offset(0, 0);
3043
  off += file_header->data_size();
3044
 
3045
  for (Section_list::iterator p = this->section_list_.begin();
3046
       p != this->section_list_.end();
3047
       ++p)
3048
    {
3049
      // We skip unallocated sections here, except that group sections
3050
      // have to come first.
3051
      if (((*p)->flags() & elfcpp::SHF_ALLOC) == 0
3052
          && (*p)->type() != elfcpp::SHT_GROUP)
3053
        continue;
3054
 
3055
      off = align_address(off, (*p)->addralign());
3056
 
3057
      // The linker script might have set the address.
3058
      if (!(*p)->is_address_valid())
3059
        (*p)->set_address(0);
3060
      (*p)->set_file_offset(off);
3061
      (*p)->finalize_data_size();
3062
      off += (*p)->data_size();
3063
 
3064
      (*p)->set_out_shndx(*pshndx);
3065
      ++*pshndx;
3066
    }
3067
 
3068
  return off;
3069
}
3070
 
3071
// Set the file offset of all the sections not associated with a
3072
// segment.
3073
 
3074
off_t
3075
Layout::set_section_offsets(off_t off, Layout::Section_offset_pass pass)
3076
{
3077
  off_t startoff = off;
3078
  off_t maxoff = off;
3079
 
3080
  for (Section_list::iterator p = this->unattached_section_list_.begin();
3081
       p != this->unattached_section_list_.end();
3082
       ++p)
3083
    {
3084
      // The symtab section is handled in create_symtab_sections.
3085
      if (*p == this->symtab_section_)
3086
        continue;
3087
 
3088
      // If we've already set the data size, don't set it again.
3089
      if ((*p)->is_offset_valid() && (*p)->is_data_size_valid())
3090
        continue;
3091
 
3092
      if (pass == BEFORE_INPUT_SECTIONS_PASS
3093
          && (*p)->requires_postprocessing())
3094
        {
3095
          (*p)->create_postprocessing_buffer();
3096
          this->any_postprocessing_sections_ = true;
3097
        }
3098
 
3099
      if (pass == BEFORE_INPUT_SECTIONS_PASS
3100
          && (*p)->after_input_sections())
3101
        continue;
3102
      else if (pass == POSTPROCESSING_SECTIONS_PASS
3103
               && (!(*p)->after_input_sections()
3104
                   || (*p)->type() == elfcpp::SHT_STRTAB))
3105
        continue;
3106
      else if (pass == STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS
3107
               && (!(*p)->after_input_sections()
3108
                   || (*p)->type() != elfcpp::SHT_STRTAB))
3109
        continue;
3110
 
3111
      if (!parameters->incremental_update())
3112
        {
3113
          off = align_address(off, (*p)->addralign());
3114
          (*p)->set_file_offset(off);
3115
          (*p)->finalize_data_size();
3116
        }
3117
      else
3118
        {
3119
          // Incremental update: allocate file space from free list.
3120
          (*p)->pre_finalize_data_size();
3121
          off_t current_size = (*p)->current_data_size();
3122
          off = this->allocate(current_size, (*p)->addralign(), startoff);
3123
          if (off == -1)
3124
            {
3125
              if (is_debugging_enabled(DEBUG_INCREMENTAL))
3126
                this->free_list_.dump();
3127
              gold_assert((*p)->output_section() != NULL);
3128
              gold_fatal(_("out of patch space for section %s; "
3129
                           "relink with --incremental-full"),
3130
                         (*p)->output_section()->name());
3131
            }
3132
          (*p)->set_file_offset(off);
3133
          (*p)->finalize_data_size();
3134
          if ((*p)->data_size() > current_size)
3135
            {
3136
              gold_assert((*p)->output_section() != NULL);
3137
              gold_fatal(_("%s: section changed size; "
3138
                           "relink with --incremental-full"),
3139
                         (*p)->output_section()->name());
3140
            }
3141
          gold_debug(DEBUG_INCREMENTAL,
3142
                     "set_section_offsets: %08lx %08lx %s",
3143
                     static_cast<long>(off),
3144
                     static_cast<long>((*p)->data_size()),
3145
                     ((*p)->output_section() != NULL
3146
                      ? (*p)->output_section()->name() : "(special)"));
3147
        }
3148
 
3149
      off += (*p)->data_size();
3150
      if (off > maxoff)
3151
        maxoff = off;
3152
 
3153
      // At this point the name must be set.
3154
      if (pass != STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS)
3155
        this->namepool_.add((*p)->name(), false, NULL);
3156
    }
3157
  return maxoff;
3158
}
3159
 
3160
// Set the section indexes of all the sections not associated with a
3161
// segment.
3162
 
3163
unsigned int
3164
Layout::set_section_indexes(unsigned int shndx)
3165
{
3166
  for (Section_list::iterator p = this->unattached_section_list_.begin();
3167
       p != this->unattached_section_list_.end();
3168
       ++p)
3169
    {
3170
      if (!(*p)->has_out_shndx())
3171
        {
3172
          (*p)->set_out_shndx(shndx);
3173
          ++shndx;
3174
        }
3175
    }
3176
  return shndx;
3177
}
3178
 
3179
// Set the section addresses according to the linker script.  This is
3180
// only called when we see a SECTIONS clause.  This returns the
3181
// program segment which should hold the file header and segment
3182
// headers, if any.  It will return NULL if they should not be in a
3183
// segment.
3184
 
3185
Output_segment*
3186
Layout::set_section_addresses_from_script(Symbol_table* symtab)
3187
{
3188
  Script_sections* ss = this->script_options_->script_sections();
3189
  gold_assert(ss->saw_sections_clause());
3190
  return this->script_options_->set_section_addresses(symtab, this);
3191
}
3192
 
3193
// Place the orphan sections in the linker script.
3194
 
3195
void
3196
Layout::place_orphan_sections_in_script()
3197
{
3198
  Script_sections* ss = this->script_options_->script_sections();
3199
  gold_assert(ss->saw_sections_clause());
3200
 
3201
  // Place each orphaned output section in the script.
3202
  for (Section_list::iterator p = this->section_list_.begin();
3203
       p != this->section_list_.end();
3204
       ++p)
3205
    {
3206
      if (!(*p)->found_in_sections_clause())
3207
        ss->place_orphan(*p);
3208
    }
3209
}
3210
 
3211
// Count the local symbols in the regular symbol table and the dynamic
3212
// symbol table, and build the respective string pools.
3213
 
3214
void
3215
Layout::count_local_symbols(const Task* task,
3216
                            const Input_objects* input_objects)
3217
{
3218
  // First, figure out an upper bound on the number of symbols we'll
3219
  // be inserting into each pool.  This helps us create the pools with
3220
  // the right size, to avoid unnecessary hashtable resizing.
3221
  unsigned int symbol_count = 0;
3222
  for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
3223
       p != input_objects->relobj_end();
3224
       ++p)
3225
    symbol_count += (*p)->local_symbol_count();
3226
 
3227
  // Go from "upper bound" to "estimate."  We overcount for two
3228
  // reasons: we double-count symbols that occur in more than one
3229
  // object file, and we count symbols that are dropped from the
3230
  // output.  Add it all together and assume we overcount by 100%.
3231
  symbol_count /= 2;
3232
 
3233
  // We assume all symbols will go into both the sympool and dynpool.
3234
  this->sympool_.reserve(symbol_count);
3235
  this->dynpool_.reserve(symbol_count);
3236
 
3237
  for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
3238
       p != input_objects->relobj_end();
3239
       ++p)
3240
    {
3241
      Task_lock_obj<Object> tlo(task, *p);
3242
      (*p)->count_local_symbols(&this->sympool_, &this->dynpool_);
3243
    }
3244
}
3245
 
3246
// Create the symbol table sections.  Here we also set the final
3247
// values of the symbols.  At this point all the loadable sections are
3248
// fully laid out.  SHNUM is the number of sections so far.
3249
 
3250
void
3251
Layout::create_symtab_sections(const Input_objects* input_objects,
3252
                               Symbol_table* symtab,
3253
                               unsigned int shnum,
3254
                               off_t* poff)
3255
{
3256
  int symsize;
3257
  unsigned int align;
3258
  if (parameters->target().get_size() == 32)
3259
    {
3260
      symsize = elfcpp::Elf_sizes<32>::sym_size;
3261
      align = 4;
3262
    }
3263
  else if (parameters->target().get_size() == 64)
3264
    {
3265
      symsize = elfcpp::Elf_sizes<64>::sym_size;
3266
      align = 8;
3267
    }
3268
  else
3269
    gold_unreachable();
3270
 
3271
  // Compute file offsets relative to the start of the symtab section.
3272
  off_t off = 0;
3273
 
3274
  // Save space for the dummy symbol at the start of the section.  We
3275
  // never bother to write this out--it will just be left as zero.
3276
  off += symsize;
3277
  unsigned int local_symbol_index = 1;
3278
 
3279
  // Add STT_SECTION symbols for each Output section which needs one.
3280
  for (Section_list::iterator p = this->section_list_.begin();
3281
       p != this->section_list_.end();
3282
       ++p)
3283
    {
3284
      if (!(*p)->needs_symtab_index())
3285
        (*p)->set_symtab_index(-1U);
3286
      else
3287
        {
3288
          (*p)->set_symtab_index(local_symbol_index);
3289
          ++local_symbol_index;
3290
          off += symsize;
3291
        }
3292
    }
3293
 
3294
  for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
3295
       p != input_objects->relobj_end();
3296
       ++p)
3297
    {
3298
      unsigned int index = (*p)->finalize_local_symbols(local_symbol_index,
3299
                                                        off, symtab);
3300
      off += (index - local_symbol_index) * symsize;
3301
      local_symbol_index = index;
3302
    }
3303
 
3304
  unsigned int local_symcount = local_symbol_index;
3305
  gold_assert(static_cast<off_t>(local_symcount * symsize) == off);
3306
 
3307
  off_t dynoff;
3308
  size_t dyn_global_index;
3309
  size_t dyncount;
3310
  if (this->dynsym_section_ == NULL)
3311
    {
3312
      dynoff = 0;
3313
      dyn_global_index = 0;
3314
      dyncount = 0;
3315
    }
3316
  else
3317
    {
3318
      dyn_global_index = this->dynsym_section_->info();
3319
      off_t locsize = dyn_global_index * this->dynsym_section_->entsize();
3320
      dynoff = this->dynsym_section_->offset() + locsize;
3321
      dyncount = (this->dynsym_section_->data_size() - locsize) / symsize;
3322
      gold_assert(static_cast<off_t>(dyncount * symsize)
3323
                  == this->dynsym_section_->data_size() - locsize);
3324
    }
3325
 
3326
  off_t global_off = off;
3327
  off = symtab->finalize(off, dynoff, dyn_global_index, dyncount,
3328
                         &this->sympool_, &local_symcount);
3329
 
3330
  if (!parameters->options().strip_all())
3331
    {
3332
      this->sympool_.set_string_offsets();
3333
 
3334
      const char* symtab_name = this->namepool_.add(".symtab", false, NULL);
3335
      Output_section* osymtab = this->make_output_section(symtab_name,
3336
                                                          elfcpp::SHT_SYMTAB,
3337
                                                          0, ORDER_INVALID,
3338
                                                          false);
3339
      this->symtab_section_ = osymtab;
3340
 
3341
      Output_section_data* pos = new Output_data_fixed_space(off, align,
3342
                                                             "** symtab");
3343
      osymtab->add_output_section_data(pos);
3344
 
3345
      // We generate a .symtab_shndx section if we have more than
3346
      // SHN_LORESERVE sections.  Technically it is possible that we
3347
      // don't need one, because it is possible that there are no
3348
      // symbols in any of sections with indexes larger than
3349
      // SHN_LORESERVE.  That is probably unusual, though, and it is
3350
      // easier to always create one than to compute section indexes
3351
      // twice (once here, once when writing out the symbols).
3352
      if (shnum >= elfcpp::SHN_LORESERVE)
3353
        {
3354
          const char* symtab_xindex_name = this->namepool_.add(".symtab_shndx",
3355
                                                               false, NULL);
3356
          Output_section* osymtab_xindex =
3357
            this->make_output_section(symtab_xindex_name,
3358
                                      elfcpp::SHT_SYMTAB_SHNDX, 0,
3359
                                      ORDER_INVALID, false);
3360
 
3361
          size_t symcount = off / symsize;
3362
          this->symtab_xindex_ = new Output_symtab_xindex(symcount);
3363
 
3364
          osymtab_xindex->add_output_section_data(this->symtab_xindex_);
3365
 
3366
          osymtab_xindex->set_link_section(osymtab);
3367
          osymtab_xindex->set_addralign(4);
3368
          osymtab_xindex->set_entsize(4);
3369
 
3370
          osymtab_xindex->set_after_input_sections();
3371
 
3372
          // This tells the driver code to wait until the symbol table
3373
          // has written out before writing out the postprocessing
3374
          // sections, including the .symtab_shndx section.
3375
          this->any_postprocessing_sections_ = true;
3376
        }
3377
 
3378
      const char* strtab_name = this->namepool_.add(".strtab", false, NULL);
3379
      Output_section* ostrtab = this->make_output_section(strtab_name,
3380
                                                          elfcpp::SHT_STRTAB,
3381
                                                          0, ORDER_INVALID,
3382
                                                          false);
3383
 
3384
      Output_section_data* pstr = new Output_data_strtab(&this->sympool_);
3385
      ostrtab->add_output_section_data(pstr);
3386
 
3387
      off_t symtab_off;
3388
      if (!parameters->incremental_update())
3389
        symtab_off = align_address(*poff, align);
3390
      else
3391
        {
3392
          symtab_off = this->allocate(off, align, *poff);
3393
          if (off == -1)
3394
            gold_fatal(_("out of patch space for symbol table; "
3395
                         "relink with --incremental-full"));
3396
          gold_debug(DEBUG_INCREMENTAL,
3397
                     "create_symtab_sections: %08lx %08lx .symtab",
3398
                     static_cast<long>(symtab_off),
3399
                     static_cast<long>(off));
3400
        }
3401
 
3402
      symtab->set_file_offset(symtab_off + global_off);
3403
      osymtab->set_file_offset(symtab_off);
3404
      osymtab->finalize_data_size();
3405
      osymtab->set_link_section(ostrtab);
3406
      osymtab->set_info(local_symcount);
3407
      osymtab->set_entsize(symsize);
3408
 
3409
      if (symtab_off + off > *poff)
3410
        *poff = symtab_off + off;
3411
    }
3412
}
3413
 
3414
// Create the .shstrtab section, which holds the names of the
3415
// sections.  At the time this is called, we have created all the
3416
// output sections except .shstrtab itself.
3417
 
3418
Output_section*
3419
Layout::create_shstrtab()
3420
{
3421
  // FIXME: We don't need to create a .shstrtab section if we are
3422
  // stripping everything.
3423
 
3424
  const char* name = this->namepool_.add(".shstrtab", false, NULL);
3425
 
3426
  Output_section* os = this->make_output_section(name, elfcpp::SHT_STRTAB, 0,
3427
                                                 ORDER_INVALID, false);
3428
 
3429
  if (strcmp(parameters->options().compress_debug_sections(), "none") != 0)
3430
    {
3431
      // We can't write out this section until we've set all the
3432
      // section names, and we don't set the names of compressed
3433
      // output sections until relocations are complete.  FIXME: With
3434
      // the current names we use, this is unnecessary.
3435
      os->set_after_input_sections();
3436
    }
3437
 
3438
  Output_section_data* posd = new Output_data_strtab(&this->namepool_);
3439
  os->add_output_section_data(posd);
3440
 
3441
  return os;
3442
}
3443
 
3444
// Create the section headers.  SIZE is 32 or 64.  OFF is the file
3445
// offset.
3446
 
3447
void
3448
Layout::create_shdrs(const Output_section* shstrtab_section, off_t* poff)
3449
{
3450
  Output_section_headers* oshdrs;
3451
  oshdrs = new Output_section_headers(this,
3452
                                      &this->segment_list_,
3453
                                      &this->section_list_,
3454
                                      &this->unattached_section_list_,
3455
                                      &this->namepool_,
3456
                                      shstrtab_section);
3457
  off_t off;
3458
  if (!parameters->incremental_update())
3459
    off = align_address(*poff, oshdrs->addralign());
3460
  else
3461
    {
3462
      oshdrs->pre_finalize_data_size();
3463
      off = this->allocate(oshdrs->data_size(), oshdrs->addralign(), *poff);
3464
      if (off == -1)
3465
          gold_fatal(_("out of patch space for section header table; "
3466
                       "relink with --incremental-full"));
3467
      gold_debug(DEBUG_INCREMENTAL,
3468
                 "create_shdrs: %08lx %08lx (section header table)",
3469
                 static_cast<long>(off),
3470
                 static_cast<long>(off + oshdrs->data_size()));
3471
    }
3472
  oshdrs->set_address_and_file_offset(0, off);
3473
  off += oshdrs->data_size();
3474
  if (off > *poff)
3475
    *poff = off;
3476
  this->section_headers_ = oshdrs;
3477
}
3478
 
3479
// Count the allocated sections.
3480
 
3481
size_t
3482
Layout::allocated_output_section_count() const
3483
{
3484
  size_t section_count = 0;
3485
  for (Segment_list::const_iterator p = this->segment_list_.begin();
3486
       p != this->segment_list_.end();
3487
       ++p)
3488
    section_count += (*p)->output_section_count();
3489
  return section_count;
3490
}
3491
 
3492
// Create the dynamic symbol table.
3493
 
3494
void
3495
Layout::create_dynamic_symtab(const Input_objects* input_objects,
3496
                              Symbol_table* symtab,
3497
                              Output_section** pdynstr,
3498
                              unsigned int* plocal_dynamic_count,
3499
                              std::vector<Symbol*>* pdynamic_symbols,
3500
                              Versions* pversions)
3501
{
3502
  // Count all the symbols in the dynamic symbol table, and set the
3503
  // dynamic symbol indexes.
3504
 
3505
  // Skip symbol 0, which is always all zeroes.
3506
  unsigned int index = 1;
3507
 
3508
  // Add STT_SECTION symbols for each Output section which needs one.
3509
  for (Section_list::iterator p = this->section_list_.begin();
3510
       p != this->section_list_.end();
3511
       ++p)
3512
    {
3513
      if (!(*p)->needs_dynsym_index())
3514
        (*p)->set_dynsym_index(-1U);
3515
      else
3516
        {
3517
          (*p)->set_dynsym_index(index);
3518
          ++index;
3519
        }
3520
    }
3521
 
3522
  // Count the local symbols that need to go in the dynamic symbol table,
3523
  // and set the dynamic symbol indexes.
3524
  for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
3525
       p != input_objects->relobj_end();
3526
       ++p)
3527
    {
3528
      unsigned int new_index = (*p)->set_local_dynsym_indexes(index);
3529
      index = new_index;
3530
    }
3531
 
3532
  unsigned int local_symcount = index;
3533
  *plocal_dynamic_count = local_symcount;
3534
 
3535
  index = symtab->set_dynsym_indexes(index, pdynamic_symbols,
3536
                                     &this->dynpool_, pversions);
3537
 
3538
  int symsize;
3539
  unsigned int align;
3540
  const int size = parameters->target().get_size();
3541
  if (size == 32)
3542
    {
3543
      symsize = elfcpp::Elf_sizes<32>::sym_size;
3544
      align = 4;
3545
    }
3546
  else if (size == 64)
3547
    {
3548
      symsize = elfcpp::Elf_sizes<64>::sym_size;
3549
      align = 8;
3550
    }
3551
  else
3552
    gold_unreachable();
3553
 
3554
  // Create the dynamic symbol table section.
3555
 
3556
  Output_section* dynsym = this->choose_output_section(NULL, ".dynsym",
3557
                                                       elfcpp::SHT_DYNSYM,
3558
                                                       elfcpp::SHF_ALLOC,
3559
                                                       false,
3560
                                                       ORDER_DYNAMIC_LINKER,
3561
                                                       false);
3562
 
3563
  Output_section_data* odata = new Output_data_fixed_space(index * symsize,
3564
                                                           align,
3565
                                                           "** dynsym");
3566
  dynsym->add_output_section_data(odata);
3567
 
3568
  dynsym->set_info(local_symcount);
3569
  dynsym->set_entsize(symsize);
3570
  dynsym->set_addralign(align);
3571
 
3572
  this->dynsym_section_ = dynsym;
3573
 
3574
  Output_data_dynamic* const odyn = this->dynamic_data_;
3575
  odyn->add_section_address(elfcpp::DT_SYMTAB, dynsym);
3576
  odyn->add_constant(elfcpp::DT_SYMENT, symsize);
3577
 
3578
  // If there are more than SHN_LORESERVE allocated sections, we
3579
  // create a .dynsym_shndx section.  It is possible that we don't
3580
  // need one, because it is possible that there are no dynamic
3581
  // symbols in any of the sections with indexes larger than
3582
  // SHN_LORESERVE.  This is probably unusual, though, and at this
3583
  // time we don't know the actual section indexes so it is
3584
  // inconvenient to check.
3585
  if (this->allocated_output_section_count() >= elfcpp::SHN_LORESERVE)
3586
    {
3587
      Output_section* dynsym_xindex =
3588
        this->choose_output_section(NULL, ".dynsym_shndx",
3589
                                    elfcpp::SHT_SYMTAB_SHNDX,
3590
                                    elfcpp::SHF_ALLOC,
3591
                                    false, ORDER_DYNAMIC_LINKER, false);
3592
 
3593
      this->dynsym_xindex_ = new Output_symtab_xindex(index);
3594
 
3595
      dynsym_xindex->add_output_section_data(this->dynsym_xindex_);
3596
 
3597
      dynsym_xindex->set_link_section(dynsym);
3598
      dynsym_xindex->set_addralign(4);
3599
      dynsym_xindex->set_entsize(4);
3600
 
3601
      dynsym_xindex->set_after_input_sections();
3602
 
3603
      // This tells the driver code to wait until the symbol table has
3604
      // written out before writing out the postprocessing sections,
3605
      // including the .dynsym_shndx section.
3606
      this->any_postprocessing_sections_ = true;
3607
    }
3608
 
3609
  // Create the dynamic string table section.
3610
 
3611
  Output_section* dynstr = this->choose_output_section(NULL, ".dynstr",
3612
                                                       elfcpp::SHT_STRTAB,
3613
                                                       elfcpp::SHF_ALLOC,
3614
                                                       false,
3615
                                                       ORDER_DYNAMIC_LINKER,
3616
                                                       false);
3617
 
3618
  Output_section_data* strdata = new Output_data_strtab(&this->dynpool_);
3619
  dynstr->add_output_section_data(strdata);
3620
 
3621
  dynsym->set_link_section(dynstr);
3622
  this->dynamic_section_->set_link_section(dynstr);
3623
 
3624
  odyn->add_section_address(elfcpp::DT_STRTAB, dynstr);
3625
  odyn->add_section_size(elfcpp::DT_STRSZ, dynstr);
3626
 
3627
  *pdynstr = dynstr;
3628
 
3629
  // Create the hash tables.
3630
 
3631
  if (strcmp(parameters->options().hash_style(), "sysv") == 0
3632
      || strcmp(parameters->options().hash_style(), "both") == 0)
3633
    {
3634
      unsigned char* phash;
3635
      unsigned int hashlen;
3636
      Dynobj::create_elf_hash_table(*pdynamic_symbols, local_symcount,
3637
                                    &phash, &hashlen);
3638
 
3639
      Output_section* hashsec =
3640
        this->choose_output_section(NULL, ".hash", elfcpp::SHT_HASH,
3641
                                    elfcpp::SHF_ALLOC, false,
3642
                                    ORDER_DYNAMIC_LINKER, false);
3643
 
3644
      Output_section_data* hashdata = new Output_data_const_buffer(phash,
3645
                                                                   hashlen,
3646
                                                                   align,
3647
                                                                   "** hash");
3648
      hashsec->add_output_section_data(hashdata);
3649
 
3650
      hashsec->set_link_section(dynsym);
3651
      hashsec->set_entsize(4);
3652
 
3653
      odyn->add_section_address(elfcpp::DT_HASH, hashsec);
3654
    }
3655
 
3656
  if (strcmp(parameters->options().hash_style(), "gnu") == 0
3657
      || strcmp(parameters->options().hash_style(), "both") == 0)
3658
    {
3659
      unsigned char* phash;
3660
      unsigned int hashlen;
3661
      Dynobj::create_gnu_hash_table(*pdynamic_symbols, local_symcount,
3662
                                    &phash, &hashlen);
3663
 
3664
      Output_section* hashsec =
3665
        this->choose_output_section(NULL, ".gnu.hash", elfcpp::SHT_GNU_HASH,
3666
                                    elfcpp::SHF_ALLOC, false,
3667
                                    ORDER_DYNAMIC_LINKER, false);
3668
 
3669
      Output_section_data* hashdata = new Output_data_const_buffer(phash,
3670
                                                                   hashlen,
3671
                                                                   align,
3672
                                                                   "** hash");
3673
      hashsec->add_output_section_data(hashdata);
3674
 
3675
      hashsec->set_link_section(dynsym);
3676
 
3677
      // For a 64-bit target, the entries in .gnu.hash do not have a
3678
      // uniform size, so we only set the entry size for a 32-bit
3679
      // target.
3680
      if (parameters->target().get_size() == 32)
3681
        hashsec->set_entsize(4);
3682
 
3683
      odyn->add_section_address(elfcpp::DT_GNU_HASH, hashsec);
3684
    }
3685
}
3686
 
3687
// Assign offsets to each local portion of the dynamic symbol table.
3688
 
3689
void
3690
Layout::assign_local_dynsym_offsets(const Input_objects* input_objects)
3691
{
3692
  Output_section* dynsym = this->dynsym_section_;
3693
  gold_assert(dynsym != NULL);
3694
 
3695
  off_t off = dynsym->offset();
3696
 
3697
  // Skip the dummy symbol at the start of the section.
3698
  off += dynsym->entsize();
3699
 
3700
  for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
3701
       p != input_objects->relobj_end();
3702
       ++p)
3703
    {
3704
      unsigned int count = (*p)->set_local_dynsym_offset(off);
3705
      off += count * dynsym->entsize();
3706
    }
3707
}
3708
 
3709
// Create the version sections.
3710
 
3711
void
3712
Layout::create_version_sections(const Versions* versions,
3713
                                const Symbol_table* symtab,
3714
                                unsigned int local_symcount,
3715
                                const std::vector<Symbol*>& dynamic_symbols,
3716
                                const Output_section* dynstr)
3717
{
3718
  if (!versions->any_defs() && !versions->any_needs())
3719
    return;
3720
 
3721
  switch (parameters->size_and_endianness())
3722
    {
3723
#ifdef HAVE_TARGET_32_LITTLE
3724
    case Parameters::TARGET_32_LITTLE:
3725
      this->sized_create_version_sections<32, false>(versions, symtab,
3726
                                                     local_symcount,
3727
                                                     dynamic_symbols, dynstr);
3728
      break;
3729
#endif
3730
#ifdef HAVE_TARGET_32_BIG
3731
    case Parameters::TARGET_32_BIG:
3732
      this->sized_create_version_sections<32, true>(versions, symtab,
3733
                                                    local_symcount,
3734
                                                    dynamic_symbols, dynstr);
3735
      break;
3736
#endif
3737
#ifdef HAVE_TARGET_64_LITTLE
3738
    case Parameters::TARGET_64_LITTLE:
3739
      this->sized_create_version_sections<64, false>(versions, symtab,
3740
                                                     local_symcount,
3741
                                                     dynamic_symbols, dynstr);
3742
      break;
3743
#endif
3744
#ifdef HAVE_TARGET_64_BIG
3745
    case Parameters::TARGET_64_BIG:
3746
      this->sized_create_version_sections<64, true>(versions, symtab,
3747
                                                    local_symcount,
3748
                                                    dynamic_symbols, dynstr);
3749
      break;
3750
#endif
3751
    default:
3752
      gold_unreachable();
3753
    }
3754
}
3755
 
3756
// Create the version sections, sized version.
3757
 
3758
template<int size, bool big_endian>
3759
void
3760
Layout::sized_create_version_sections(
3761
    const Versions* versions,
3762
    const Symbol_table* symtab,
3763
    unsigned int local_symcount,
3764
    const std::vector<Symbol*>& dynamic_symbols,
3765
    const Output_section* dynstr)
3766
{
3767
  Output_section* vsec = this->choose_output_section(NULL, ".gnu.version",
3768
                                                     elfcpp::SHT_GNU_versym,
3769
                                                     elfcpp::SHF_ALLOC,
3770
                                                     false,
3771
                                                     ORDER_DYNAMIC_LINKER,
3772
                                                     false);
3773
 
3774
  unsigned char* vbuf;
3775
  unsigned int vsize;
3776
  versions->symbol_section_contents<size, big_endian>(symtab, &this->dynpool_,
3777
                                                      local_symcount,
3778
                                                      dynamic_symbols,
3779
                                                      &vbuf, &vsize);
3780
 
3781
  Output_section_data* vdata = new Output_data_const_buffer(vbuf, vsize, 2,
3782
                                                            "** versions");
3783
 
3784
  vsec->add_output_section_data(vdata);
3785
  vsec->set_entsize(2);
3786
  vsec->set_link_section(this->dynsym_section_);
3787
 
3788
  Output_data_dynamic* const odyn = this->dynamic_data_;
3789
  odyn->add_section_address(elfcpp::DT_VERSYM, vsec);
3790
 
3791
  if (versions->any_defs())
3792
    {
3793
      Output_section* vdsec;
3794
      vdsec= this->choose_output_section(NULL, ".gnu.version_d",
3795
                                         elfcpp::SHT_GNU_verdef,
3796
                                         elfcpp::SHF_ALLOC,
3797
                                         false, ORDER_DYNAMIC_LINKER, false);
3798
 
3799
      unsigned char* vdbuf;
3800
      unsigned int vdsize;
3801
      unsigned int vdentries;
3802
      versions->def_section_contents<size, big_endian>(&this->dynpool_, &vdbuf,
3803
                                                       &vdsize, &vdentries);
3804
 
3805
      Output_section_data* vddata =
3806
        new Output_data_const_buffer(vdbuf, vdsize, 4, "** version defs");
3807
 
3808
      vdsec->add_output_section_data(vddata);
3809
      vdsec->set_link_section(dynstr);
3810
      vdsec->set_info(vdentries);
3811
 
3812
      odyn->add_section_address(elfcpp::DT_VERDEF, vdsec);
3813
      odyn->add_constant(elfcpp::DT_VERDEFNUM, vdentries);
3814
    }
3815
 
3816
  if (versions->any_needs())
3817
    {
3818
      Output_section* vnsec;
3819
      vnsec = this->choose_output_section(NULL, ".gnu.version_r",
3820
                                          elfcpp::SHT_GNU_verneed,
3821
                                          elfcpp::SHF_ALLOC,
3822
                                          false, ORDER_DYNAMIC_LINKER, false);
3823
 
3824
      unsigned char* vnbuf;
3825
      unsigned int vnsize;
3826
      unsigned int vnentries;
3827
      versions->need_section_contents<size, big_endian>(&this->dynpool_,
3828
                                                        &vnbuf, &vnsize,
3829
                                                        &vnentries);
3830
 
3831
      Output_section_data* vndata =
3832
        new Output_data_const_buffer(vnbuf, vnsize, 4, "** version refs");
3833
 
3834
      vnsec->add_output_section_data(vndata);
3835
      vnsec->set_link_section(dynstr);
3836
      vnsec->set_info(vnentries);
3837
 
3838
      odyn->add_section_address(elfcpp::DT_VERNEED, vnsec);
3839
      odyn->add_constant(elfcpp::DT_VERNEEDNUM, vnentries);
3840
    }
3841
}
3842
 
3843
// Create the .interp section and PT_INTERP segment.
3844
 
3845
void
3846
Layout::create_interp(const Target* target)
3847
{
3848
  const char* interp = parameters->options().dynamic_linker();
3849
  if (interp == NULL)
3850
    {
3851
      interp = target->dynamic_linker();
3852
      gold_assert(interp != NULL);
3853
    }
3854
 
3855
  size_t len = strlen(interp) + 1;
3856
 
3857
  Output_section_data* odata = new Output_data_const(interp, len, 1);
3858
 
3859
  Output_section* osec = this->choose_output_section(NULL, ".interp",
3860
                                                     elfcpp::SHT_PROGBITS,
3861
                                                     elfcpp::SHF_ALLOC,
3862
                                                     false, ORDER_INTERP,
3863
                                                     false);
3864
  osec->add_output_section_data(odata);
3865
 
3866
  if (!this->script_options_->saw_phdrs_clause())
3867
    {
3868
      Output_segment* oseg = this->make_output_segment(elfcpp::PT_INTERP,
3869
                                                       elfcpp::PF_R);
3870
      oseg->add_output_section_to_nonload(osec, elfcpp::PF_R);
3871
    }
3872
}
3873
 
3874
// Add dynamic tags for the PLT and the dynamic relocs.  This is
3875
// called by the target-specific code.  This does nothing if not doing
3876
// a dynamic link.
3877
 
3878
// USE_REL is true for REL relocs rather than RELA relocs.
3879
 
3880
// If PLT_GOT is not NULL, then DT_PLTGOT points to it.
3881
 
3882
// If PLT_REL is not NULL, it is used for DT_PLTRELSZ, and DT_JMPREL,
3883
// and we also set DT_PLTREL.  We use PLT_REL's output section, since
3884
// some targets have multiple reloc sections in PLT_REL.
3885
 
3886
// If DYN_REL is not NULL, it is used for DT_REL/DT_RELA,
3887
// DT_RELSZ/DT_RELASZ, DT_RELENT/DT_RELAENT.
3888
 
3889
// If ADD_DEBUG is true, we add a DT_DEBUG entry when generating an
3890
// executable.
3891
 
3892
void
3893
Layout::add_target_dynamic_tags(bool use_rel, const Output_data* plt_got,
3894
                                const Output_data* plt_rel,
3895
                                const Output_data_reloc_generic* dyn_rel,
3896
                                bool add_debug, bool dynrel_includes_plt)
3897
{
3898
  Output_data_dynamic* odyn = this->dynamic_data_;
3899
  if (odyn == NULL)
3900
    return;
3901
 
3902
  if (plt_got != NULL && plt_got->output_section() != NULL)
3903
    odyn->add_section_address(elfcpp::DT_PLTGOT, plt_got);
3904
 
3905
  if (plt_rel != NULL && plt_rel->output_section() != NULL)
3906
    {
3907
      odyn->add_section_size(elfcpp::DT_PLTRELSZ, plt_rel->output_section());
3908
      odyn->add_section_address(elfcpp::DT_JMPREL, plt_rel->output_section());
3909
      odyn->add_constant(elfcpp::DT_PLTREL,
3910
                         use_rel ? elfcpp::DT_REL : elfcpp::DT_RELA);
3911
    }
3912
 
3913
  if (dyn_rel != NULL && dyn_rel->output_section() != NULL)
3914
    {
3915
      odyn->add_section_address(use_rel ? elfcpp::DT_REL : elfcpp::DT_RELA,
3916
                                dyn_rel);
3917
      if (plt_rel != NULL && dynrel_includes_plt)
3918
        odyn->add_section_size(use_rel ? elfcpp::DT_RELSZ : elfcpp::DT_RELASZ,
3919
                               dyn_rel, plt_rel);
3920
      else
3921
        odyn->add_section_size(use_rel ? elfcpp::DT_RELSZ : elfcpp::DT_RELASZ,
3922
                               dyn_rel);
3923
      const int size = parameters->target().get_size();
3924
      elfcpp::DT rel_tag;
3925
      int rel_size;
3926
      if (use_rel)
3927
        {
3928
          rel_tag = elfcpp::DT_RELENT;
3929
          if (size == 32)
3930
            rel_size = Reloc_types<elfcpp::SHT_REL, 32, false>::reloc_size;
3931
          else if (size == 64)
3932
            rel_size = Reloc_types<elfcpp::SHT_REL, 64, false>::reloc_size;
3933
          else
3934
            gold_unreachable();
3935
        }
3936
      else
3937
        {
3938
          rel_tag = elfcpp::DT_RELAENT;
3939
          if (size == 32)
3940
            rel_size = Reloc_types<elfcpp::SHT_RELA, 32, false>::reloc_size;
3941
          else if (size == 64)
3942
            rel_size = Reloc_types<elfcpp::SHT_RELA, 64, false>::reloc_size;
3943
          else
3944
            gold_unreachable();
3945
        }
3946
      odyn->add_constant(rel_tag, rel_size);
3947
 
3948
      if (parameters->options().combreloc())
3949
        {
3950
          size_t c = dyn_rel->relative_reloc_count();
3951
          if (c > 0)
3952
            odyn->add_constant((use_rel
3953
                                ? elfcpp::DT_RELCOUNT
3954
                                : elfcpp::DT_RELACOUNT),
3955
                               c);
3956
        }
3957
    }
3958
 
3959
  if (add_debug && !parameters->options().shared())
3960
    {
3961
      // The value of the DT_DEBUG tag is filled in by the dynamic
3962
      // linker at run time, and used by the debugger.
3963
      odyn->add_constant(elfcpp::DT_DEBUG, 0);
3964
    }
3965
}
3966
 
3967
// Finish the .dynamic section and PT_DYNAMIC segment.
3968
 
3969
void
3970
Layout::finish_dynamic_section(const Input_objects* input_objects,
3971
                               const Symbol_table* symtab)
3972
{
3973
  if (!this->script_options_->saw_phdrs_clause())
3974
    {
3975
      Output_segment* oseg = this->make_output_segment(elfcpp::PT_DYNAMIC,
3976
                                                       (elfcpp::PF_R
3977
                                                        | elfcpp::PF_W));
3978
      oseg->add_output_section_to_nonload(this->dynamic_section_,
3979
                                          elfcpp::PF_R | elfcpp::PF_W);
3980
    }
3981
 
3982
  Output_data_dynamic* const odyn = this->dynamic_data_;
3983
 
3984
  for (Input_objects::Dynobj_iterator p = input_objects->dynobj_begin();
3985
       p != input_objects->dynobj_end();
3986
       ++p)
3987
    {
3988
      if (!(*p)->is_needed() && (*p)->as_needed())
3989
        {
3990
          // This dynamic object was linked with --as-needed, but it
3991
          // is not needed.
3992
          continue;
3993
        }
3994
 
3995
      odyn->add_string(elfcpp::DT_NEEDED, (*p)->soname());
3996
    }
3997
 
3998
  if (parameters->options().shared())
3999
    {
4000
      const char* soname = parameters->options().soname();
4001
      if (soname != NULL)
4002
        odyn->add_string(elfcpp::DT_SONAME, soname);
4003
    }
4004
 
4005
  Symbol* sym = symtab->lookup(parameters->options().init());
4006
  if (sym != NULL && sym->is_defined() && !sym->is_from_dynobj())
4007
    odyn->add_symbol(elfcpp::DT_INIT, sym);
4008
 
4009
  sym = symtab->lookup(parameters->options().fini());
4010
  if (sym != NULL && sym->is_defined() && !sym->is_from_dynobj())
4011
    odyn->add_symbol(elfcpp::DT_FINI, sym);
4012
 
4013
  // Look for .init_array, .preinit_array and .fini_array by checking
4014
  // section types.
4015
  for(Layout::Section_list::const_iterator p = this->section_list_.begin();
4016
      p != this->section_list_.end();
4017
      ++p)
4018
    switch((*p)->type())
4019
      {
4020
      case elfcpp::SHT_FINI_ARRAY:
4021
        odyn->add_section_address(elfcpp::DT_FINI_ARRAY, *p);
4022
        odyn->add_section_size(elfcpp::DT_FINI_ARRAYSZ, *p);
4023
        break;
4024
      case elfcpp::SHT_INIT_ARRAY:
4025
        odyn->add_section_address(elfcpp::DT_INIT_ARRAY, *p);
4026
        odyn->add_section_size(elfcpp::DT_INIT_ARRAYSZ, *p);
4027
        break;
4028
      case elfcpp::SHT_PREINIT_ARRAY:
4029
        odyn->add_section_address(elfcpp::DT_PREINIT_ARRAY, *p);
4030
        odyn->add_section_size(elfcpp::DT_PREINIT_ARRAYSZ, *p);
4031
        break;
4032
      default:
4033
        break;
4034
      }
4035
 
4036
  // Add a DT_RPATH entry if needed.
4037
  const General_options::Dir_list& rpath(parameters->options().rpath());
4038
  if (!rpath.empty())
4039
    {
4040
      std::string rpath_val;
4041
      for (General_options::Dir_list::const_iterator p = rpath.begin();
4042
           p != rpath.end();
4043
           ++p)
4044
        {
4045
          if (rpath_val.empty())
4046
            rpath_val = p->name();
4047
          else
4048
            {
4049
              // Eliminate duplicates.
4050
              General_options::Dir_list::const_iterator q;
4051
              for (q = rpath.begin(); q != p; ++q)
4052
                if (q->name() == p->name())
4053
                  break;
4054
              if (q == p)
4055
                {
4056
                  rpath_val += ':';
4057
                  rpath_val += p->name();
4058
                }
4059
            }
4060
        }
4061
 
4062
      odyn->add_string(elfcpp::DT_RPATH, rpath_val);
4063
      if (parameters->options().enable_new_dtags())
4064
        odyn->add_string(elfcpp::DT_RUNPATH, rpath_val);
4065
    }
4066
 
4067
  // Look for text segments that have dynamic relocations.
4068
  bool have_textrel = false;
4069
  if (!this->script_options_->saw_sections_clause())
4070
    {
4071
      for (Segment_list::const_iterator p = this->segment_list_.begin();
4072
           p != this->segment_list_.end();
4073
           ++p)
4074
        {
4075
          if (((*p)->flags() & elfcpp::PF_W) == 0
4076
              && (*p)->has_dynamic_reloc())
4077
            {
4078
              have_textrel = true;
4079
              break;
4080
            }
4081
        }
4082
    }
4083
  else
4084
    {
4085
      // We don't know the section -> segment mapping, so we are
4086
      // conservative and just look for readonly sections with
4087
      // relocations.  If those sections wind up in writable segments,
4088
      // then we have created an unnecessary DT_TEXTREL entry.
4089
      for (Section_list::const_iterator p = this->section_list_.begin();
4090
           p != this->section_list_.end();
4091
           ++p)
4092
        {
4093
          if (((*p)->flags() & elfcpp::SHF_ALLOC) != 0
4094
              && ((*p)->flags() & elfcpp::SHF_WRITE) == 0
4095
              && ((*p)->has_dynamic_reloc()))
4096
            {
4097
              have_textrel = true;
4098
              break;
4099
            }
4100
        }
4101
    }
4102
 
4103
  // Add a DT_FLAGS entry. We add it even if no flags are set so that
4104
  // post-link tools can easily modify these flags if desired.
4105
  unsigned int flags = 0;
4106
  if (have_textrel)
4107
    {
4108
      // Add a DT_TEXTREL for compatibility with older loaders.
4109
      odyn->add_constant(elfcpp::DT_TEXTREL, 0);
4110
      flags |= elfcpp::DF_TEXTREL;
4111
 
4112
      if (parameters->options().text())
4113
        gold_error(_("read-only segment has dynamic relocations"));
4114
      else if (parameters->options().warn_shared_textrel()
4115
               && parameters->options().shared())
4116
        gold_warning(_("shared library text segment is not shareable"));
4117
    }
4118
  if (parameters->options().shared() && this->has_static_tls())
4119
    flags |= elfcpp::DF_STATIC_TLS;
4120
  if (parameters->options().origin())
4121
    flags |= elfcpp::DF_ORIGIN;
4122
  if (parameters->options().Bsymbolic())
4123
    {
4124
      flags |= elfcpp::DF_SYMBOLIC;
4125
      // Add DT_SYMBOLIC for compatibility with older loaders.
4126
      odyn->add_constant(elfcpp::DT_SYMBOLIC, 0);
4127
    }
4128
  if (parameters->options().now())
4129
    flags |= elfcpp::DF_BIND_NOW;
4130
  odyn->add_constant(elfcpp::DT_FLAGS, flags);
4131
 
4132
  flags = 0;
4133
  if (parameters->options().initfirst())
4134
    flags |= elfcpp::DF_1_INITFIRST;
4135
  if (parameters->options().interpose())
4136
    flags |= elfcpp::DF_1_INTERPOSE;
4137
  if (parameters->options().loadfltr())
4138
    flags |= elfcpp::DF_1_LOADFLTR;
4139
  if (parameters->options().nodefaultlib())
4140
    flags |= elfcpp::DF_1_NODEFLIB;
4141
  if (parameters->options().nodelete())
4142
    flags |= elfcpp::DF_1_NODELETE;
4143
  if (parameters->options().nodlopen())
4144
    flags |= elfcpp::DF_1_NOOPEN;
4145
  if (parameters->options().nodump())
4146
    flags |= elfcpp::DF_1_NODUMP;
4147
  if (!parameters->options().shared())
4148
    flags &= ~(elfcpp::DF_1_INITFIRST
4149
               | elfcpp::DF_1_NODELETE
4150
               | elfcpp::DF_1_NOOPEN);
4151
  if (parameters->options().origin())
4152
    flags |= elfcpp::DF_1_ORIGIN;
4153
  if (parameters->options().now())
4154
    flags |= elfcpp::DF_1_NOW;
4155
  if (flags)
4156
    odyn->add_constant(elfcpp::DT_FLAGS_1, flags);
4157
}
4158
 
4159
// Set the size of the _DYNAMIC symbol table to be the size of the
4160
// dynamic data.
4161
 
4162
void
4163
Layout::set_dynamic_symbol_size(const Symbol_table* symtab)
4164
{
4165
  Output_data_dynamic* const odyn = this->dynamic_data_;
4166
  odyn->finalize_data_size();
4167
  off_t data_size = odyn->data_size();
4168
  const int size = parameters->target().get_size();
4169
  if (size == 32)
4170
    symtab->get_sized_symbol<32>(this->dynamic_symbol_)->set_symsize(data_size);
4171
  else if (size == 64)
4172
    symtab->get_sized_symbol<64>(this->dynamic_symbol_)->set_symsize(data_size);
4173
  else
4174
    gold_unreachable();
4175
}
4176
 
4177
// The mapping of input section name prefixes to output section names.
4178
// In some cases one prefix is itself a prefix of another prefix; in
4179
// such a case the longer prefix must come first.  These prefixes are
4180
// based on the GNU linker default ELF linker script.
4181
 
4182
#define MAPPING_INIT(f, t) { f, sizeof(f) - 1, t, sizeof(t) - 1 }
4183
const Layout::Section_name_mapping Layout::section_name_mapping[] =
4184
{
4185
  MAPPING_INIT(".text.", ".text"),
4186
  MAPPING_INIT(".ctors.", ".ctors"),
4187
  MAPPING_INIT(".dtors.", ".dtors"),
4188
  MAPPING_INIT(".rodata.", ".rodata"),
4189
  MAPPING_INIT(".data.rel.ro.local", ".data.rel.ro.local"),
4190
  MAPPING_INIT(".data.rel.ro", ".data.rel.ro"),
4191
  MAPPING_INIT(".data.", ".data"),
4192
  MAPPING_INIT(".bss.", ".bss"),
4193
  MAPPING_INIT(".tdata.", ".tdata"),
4194
  MAPPING_INIT(".tbss.", ".tbss"),
4195
  MAPPING_INIT(".init_array.", ".init_array"),
4196
  MAPPING_INIT(".fini_array.", ".fini_array"),
4197
  MAPPING_INIT(".sdata.", ".sdata"),
4198
  MAPPING_INIT(".sbss.", ".sbss"),
4199
  // FIXME: In the GNU linker, .sbss2 and .sdata2 are handled
4200
  // differently depending on whether it is creating a shared library.
4201
  MAPPING_INIT(".sdata2.", ".sdata"),
4202
  MAPPING_INIT(".sbss2.", ".sbss"),
4203
  MAPPING_INIT(".lrodata.", ".lrodata"),
4204
  MAPPING_INIT(".ldata.", ".ldata"),
4205
  MAPPING_INIT(".lbss.", ".lbss"),
4206
  MAPPING_INIT(".gcc_except_table.", ".gcc_except_table"),
4207
  MAPPING_INIT(".gnu.linkonce.d.rel.ro.local.", ".data.rel.ro.local"),
4208
  MAPPING_INIT(".gnu.linkonce.d.rel.ro.", ".data.rel.ro"),
4209
  MAPPING_INIT(".gnu.linkonce.t.", ".text"),
4210
  MAPPING_INIT(".gnu.linkonce.r.", ".rodata"),
4211
  MAPPING_INIT(".gnu.linkonce.d.", ".data"),
4212
  MAPPING_INIT(".gnu.linkonce.b.", ".bss"),
4213
  MAPPING_INIT(".gnu.linkonce.s.", ".sdata"),
4214
  MAPPING_INIT(".gnu.linkonce.sb.", ".sbss"),
4215
  MAPPING_INIT(".gnu.linkonce.s2.", ".sdata"),
4216
  MAPPING_INIT(".gnu.linkonce.sb2.", ".sbss"),
4217
  MAPPING_INIT(".gnu.linkonce.wi.", ".debug_info"),
4218
  MAPPING_INIT(".gnu.linkonce.td.", ".tdata"),
4219
  MAPPING_INIT(".gnu.linkonce.tb.", ".tbss"),
4220
  MAPPING_INIT(".gnu.linkonce.lr.", ".lrodata"),
4221
  MAPPING_INIT(".gnu.linkonce.l.", ".ldata"),
4222
  MAPPING_INIT(".gnu.linkonce.lb.", ".lbss"),
4223
  MAPPING_INIT(".ARM.extab", ".ARM.extab"),
4224
  MAPPING_INIT(".gnu.linkonce.armextab.", ".ARM.extab"),
4225
  MAPPING_INIT(".ARM.exidx", ".ARM.exidx"),
4226
  MAPPING_INIT(".gnu.linkonce.armexidx.", ".ARM.exidx"),
4227
};
4228
#undef MAPPING_INIT
4229
 
4230
const int Layout::section_name_mapping_count =
4231
  (sizeof(Layout::section_name_mapping)
4232
   / sizeof(Layout::section_name_mapping[0]));
4233
 
4234
// Choose the output section name to use given an input section name.
4235
// Set *PLEN to the length of the name.  *PLEN is initialized to the
4236
// length of NAME.
4237
 
4238
const char*
4239
Layout::output_section_name(const char* name, size_t* plen)
4240
{
4241
  // gcc 4.3 generates the following sorts of section names when it
4242
  // needs a section name specific to a function:
4243
  //   .text.FN
4244
  //   .rodata.FN
4245
  //   .sdata2.FN
4246
  //   .data.FN
4247
  //   .data.rel.FN
4248
  //   .data.rel.local.FN
4249
  //   .data.rel.ro.FN
4250
  //   .data.rel.ro.local.FN
4251
  //   .sdata.FN
4252
  //   .bss.FN
4253
  //   .sbss.FN
4254
  //   .tdata.FN
4255
  //   .tbss.FN
4256
 
4257
  // The GNU linker maps all of those to the part before the .FN,
4258
  // except that .data.rel.local.FN is mapped to .data, and
4259
  // .data.rel.ro.local.FN is mapped to .data.rel.ro.  The sections
4260
  // beginning with .data.rel.ro.local are grouped together.
4261
 
4262
  // For an anonymous namespace, the string FN can contain a '.'.
4263
 
4264
  // Also of interest: .rodata.strN.N, .rodata.cstN, both of which the
4265
  // GNU linker maps to .rodata.
4266
 
4267
  // The .data.rel.ro sections are used with -z relro.  The sections
4268
  // are recognized by name.  We use the same names that the GNU
4269
  // linker does for these sections.
4270
 
4271
  // It is hard to handle this in a principled way, so we don't even
4272
  // try.  We use a table of mappings.  If the input section name is
4273
  // not found in the table, we simply use it as the output section
4274
  // name.
4275
 
4276
  const Section_name_mapping* psnm = section_name_mapping;
4277
  for (int i = 0; i < section_name_mapping_count; ++i, ++psnm)
4278
    {
4279
      if (strncmp(name, psnm->from, psnm->fromlen) == 0)
4280
        {
4281
          *plen = psnm->tolen;
4282
          return psnm->to;
4283
        }
4284
    }
4285
 
4286
  return name;
4287
}
4288
 
4289
// Check if a comdat group or .gnu.linkonce section with the given
4290
// NAME is selected for the link.  If there is already a section,
4291
// *KEPT_SECTION is set to point to the existing section and the
4292
// function returns false.  Otherwise, OBJECT, SHNDX, IS_COMDAT, and
4293
// IS_GROUP_NAME are recorded for this NAME in the layout object,
4294
// *KEPT_SECTION is set to the internal copy and the function returns
4295
// true.
4296
 
4297
bool
4298
Layout::find_or_add_kept_section(const std::string& name,
4299
                                 Relobj* object,
4300
                                 unsigned int shndx,
4301
                                 bool is_comdat,
4302
                                 bool is_group_name,
4303
                                 Kept_section** kept_section)
4304
{
4305
  // It's normal to see a couple of entries here, for the x86 thunk
4306
  // sections.  If we see more than a few, we're linking a C++
4307
  // program, and we resize to get more space to minimize rehashing.
4308
  if (this->signatures_.size() > 4
4309
      && !this->resized_signatures_)
4310
    {
4311
      reserve_unordered_map(&this->signatures_,
4312
                            this->number_of_input_files_ * 64);
4313
      this->resized_signatures_ = true;
4314
    }
4315
 
4316
  Kept_section candidate;
4317
  std::pair<Signatures::iterator, bool> ins =
4318
    this->signatures_.insert(std::make_pair(name, candidate));
4319
 
4320
  if (kept_section != NULL)
4321
    *kept_section = &ins.first->second;
4322
  if (ins.second)
4323
    {
4324
      // This is the first time we've seen this signature.
4325
      ins.first->second.set_object(object);
4326
      ins.first->second.set_shndx(shndx);
4327
      if (is_comdat)
4328
        ins.first->second.set_is_comdat();
4329
      if (is_group_name)
4330
        ins.first->second.set_is_group_name();
4331
      return true;
4332
    }
4333
 
4334
  // We have already seen this signature.
4335
 
4336
  if (ins.first->second.is_group_name())
4337
    {
4338
      // We've already seen a real section group with this signature.
4339
      // If the kept group is from a plugin object, and we're in the
4340
      // replacement phase, accept the new one as a replacement.
4341
      if (ins.first->second.object() == NULL
4342
          && parameters->options().plugins()->in_replacement_phase())
4343
        {
4344
          ins.first->second.set_object(object);
4345
          ins.first->second.set_shndx(shndx);
4346
          return true;
4347
        }
4348
      return false;
4349
    }
4350
  else if (is_group_name)
4351
    {
4352
      // This is a real section group, and we've already seen a
4353
      // linkonce section with this signature.  Record that we've seen
4354
      // a section group, and don't include this section group.
4355
      ins.first->second.set_is_group_name();
4356
      return false;
4357
    }
4358
  else
4359
    {
4360
      // We've already seen a linkonce section and this is a linkonce
4361
      // section.  These don't block each other--this may be the same
4362
      // symbol name with different section types.
4363
      return true;
4364
    }
4365
}
4366
 
4367
// Store the allocated sections into the section list.
4368
 
4369
void
4370
Layout::get_allocated_sections(Section_list* section_list) const
4371
{
4372
  for (Section_list::const_iterator p = this->section_list_.begin();
4373
       p != this->section_list_.end();
4374
       ++p)
4375
    if (((*p)->flags() & elfcpp::SHF_ALLOC) != 0)
4376
      section_list->push_back(*p);
4377
}
4378
 
4379
// Create an output segment.
4380
 
4381
Output_segment*
4382
Layout::make_output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags)
4383
{
4384
  gold_assert(!parameters->options().relocatable());
4385
  Output_segment* oseg = new Output_segment(type, flags);
4386
  this->segment_list_.push_back(oseg);
4387
 
4388
  if (type == elfcpp::PT_TLS)
4389
    this->tls_segment_ = oseg;
4390
  else if (type == elfcpp::PT_GNU_RELRO)
4391
    this->relro_segment_ = oseg;
4392
 
4393
  return oseg;
4394
}
4395
 
4396
// Return the file offset of the normal symbol table.
4397
 
4398
off_t
4399
Layout::symtab_section_offset() const
4400
{
4401
  if (this->symtab_section_ != NULL)
4402
    return this->symtab_section_->offset();
4403
  return 0;
4404
}
4405
 
4406
// Write out the Output_sections.  Most won't have anything to write,
4407
// since most of the data will come from input sections which are
4408
// handled elsewhere.  But some Output_sections do have Output_data.
4409
 
4410
void
4411
Layout::write_output_sections(Output_file* of) const
4412
{
4413
  for (Section_list::const_iterator p = this->section_list_.begin();
4414
       p != this->section_list_.end();
4415
       ++p)
4416
    {
4417
      if (!(*p)->after_input_sections())
4418
        (*p)->write(of);
4419
    }
4420
}
4421
 
4422
// Write out data not associated with a section or the symbol table.
4423
 
4424
void
4425
Layout::write_data(const Symbol_table* symtab, Output_file* of) const
4426
{
4427
  if (!parameters->options().strip_all())
4428
    {
4429
      const Output_section* symtab_section = this->symtab_section_;
4430
      for (Section_list::const_iterator p = this->section_list_.begin();
4431
           p != this->section_list_.end();
4432
           ++p)
4433
        {
4434
          if ((*p)->needs_symtab_index())
4435
            {
4436
              gold_assert(symtab_section != NULL);
4437
              unsigned int index = (*p)->symtab_index();
4438
              gold_assert(index > 0 && index != -1U);
4439
              off_t off = (symtab_section->offset()
4440
                           + index * symtab_section->entsize());
4441
              symtab->write_section_symbol(*p, this->symtab_xindex_, of, off);
4442
            }
4443
        }
4444
    }
4445
 
4446
  const Output_section* dynsym_section = this->dynsym_section_;
4447
  for (Section_list::const_iterator p = this->section_list_.begin();
4448
       p != this->section_list_.end();
4449
       ++p)
4450
    {
4451
      if ((*p)->needs_dynsym_index())
4452
        {
4453
          gold_assert(dynsym_section != NULL);
4454
          unsigned int index = (*p)->dynsym_index();
4455
          gold_assert(index > 0 && index != -1U);
4456
          off_t off = (dynsym_section->offset()
4457
                       + index * dynsym_section->entsize());
4458
          symtab->write_section_symbol(*p, this->dynsym_xindex_, of, off);
4459
        }
4460
    }
4461
 
4462
  // Write out the Output_data which are not in an Output_section.
4463
  for (Data_list::const_iterator p = this->special_output_list_.begin();
4464
       p != this->special_output_list_.end();
4465
       ++p)
4466
    (*p)->write(of);
4467
}
4468
 
4469
// Write out the Output_sections which can only be written after the
4470
// input sections are complete.
4471
 
4472
void
4473
Layout::write_sections_after_input_sections(Output_file* of)
4474
{
4475
  // Determine the final section offsets, and thus the final output
4476
  // file size.  Note we finalize the .shstrab last, to allow the
4477
  // after_input_section sections to modify their section-names before
4478
  // writing.
4479
  if (this->any_postprocessing_sections_)
4480
    {
4481
      off_t off = this->output_file_size_;
4482
      off = this->set_section_offsets(off, POSTPROCESSING_SECTIONS_PASS);
4483
 
4484
      // Now that we've finalized the names, we can finalize the shstrab.
4485
      off =
4486
        this->set_section_offsets(off,
4487
                                  STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS);
4488
 
4489
      if (off > this->output_file_size_)
4490
        {
4491
          of->resize(off);
4492
          this->output_file_size_ = off;
4493
        }
4494
    }
4495
 
4496
  for (Section_list::const_iterator p = this->section_list_.begin();
4497
       p != this->section_list_.end();
4498
       ++p)
4499
    {
4500
      if ((*p)->after_input_sections())
4501
        (*p)->write(of);
4502
    }
4503
 
4504
  this->section_headers_->write(of);
4505
}
4506
 
4507
// If the build ID requires computing a checksum, do so here, and
4508
// write it out.  We compute a checksum over the entire file because
4509
// that is simplest.
4510
 
4511
void
4512
Layout::write_build_id(Output_file* of) const
4513
{
4514
  if (this->build_id_note_ == NULL)
4515
    return;
4516
 
4517
  const unsigned char* iv = of->get_input_view(0, this->output_file_size_);
4518
 
4519
  unsigned char* ov = of->get_output_view(this->build_id_note_->offset(),
4520
                                          this->build_id_note_->data_size());
4521
 
4522
  const char* style = parameters->options().build_id();
4523
  if (strcmp(style, "sha1") == 0)
4524
    {
4525
      sha1_ctx ctx;
4526
      sha1_init_ctx(&ctx);
4527
      sha1_process_bytes(iv, this->output_file_size_, &ctx);
4528
      sha1_finish_ctx(&ctx, ov);
4529
    }
4530
  else if (strcmp(style, "md5") == 0)
4531
    {
4532
      md5_ctx ctx;
4533
      md5_init_ctx(&ctx);
4534
      md5_process_bytes(iv, this->output_file_size_, &ctx);
4535
      md5_finish_ctx(&ctx, ov);
4536
    }
4537
  else
4538
    gold_unreachable();
4539
 
4540
  of->write_output_view(this->build_id_note_->offset(),
4541
                        this->build_id_note_->data_size(),
4542
                        ov);
4543
 
4544
  of->free_input_view(0, this->output_file_size_, iv);
4545
}
4546
 
4547
// Write out a binary file.  This is called after the link is
4548
// complete.  IN is the temporary output file we used to generate the
4549
// ELF code.  We simply walk through the segments, read them from
4550
// their file offset in IN, and write them to their load address in
4551
// the output file.  FIXME: with a bit more work, we could support
4552
// S-records and/or Intel hex format here.
4553
 
4554
void
4555
Layout::write_binary(Output_file* in) const
4556
{
4557
  gold_assert(parameters->options().oformat_enum()
4558
              == General_options::OBJECT_FORMAT_BINARY);
4559
 
4560
  // Get the size of the binary file.
4561
  uint64_t max_load_address = 0;
4562
  for (Segment_list::const_iterator p = this->segment_list_.begin();
4563
       p != this->segment_list_.end();
4564
       ++p)
4565
    {
4566
      if ((*p)->type() == elfcpp::PT_LOAD && (*p)->filesz() > 0)
4567
        {
4568
          uint64_t max_paddr = (*p)->paddr() + (*p)->filesz();
4569
          if (max_paddr > max_load_address)
4570
            max_load_address = max_paddr;
4571
        }
4572
    }
4573
 
4574
  Output_file out(parameters->options().output_file_name());
4575
  out.open(max_load_address);
4576
 
4577
  for (Segment_list::const_iterator p = this->segment_list_.begin();
4578
       p != this->segment_list_.end();
4579
       ++p)
4580
    {
4581
      if ((*p)->type() == elfcpp::PT_LOAD && (*p)->filesz() > 0)
4582
        {
4583
          const unsigned char* vin = in->get_input_view((*p)->offset(),
4584
                                                        (*p)->filesz());
4585
          unsigned char* vout = out.get_output_view((*p)->paddr(),
4586
                                                    (*p)->filesz());
4587
          memcpy(vout, vin, (*p)->filesz());
4588
          out.write_output_view((*p)->paddr(), (*p)->filesz(), vout);
4589
          in->free_input_view((*p)->offset(), (*p)->filesz(), vin);
4590
        }
4591
    }
4592
 
4593
  out.close();
4594
}
4595
 
4596
// Print the output sections to the map file.
4597
 
4598
void
4599
Layout::print_to_mapfile(Mapfile* mapfile) const
4600
{
4601
  for (Segment_list::const_iterator p = this->segment_list_.begin();
4602
       p != this->segment_list_.end();
4603
       ++p)
4604
    (*p)->print_sections_to_mapfile(mapfile);
4605
}
4606
 
4607
// Print statistical information to stderr.  This is used for --stats.
4608
 
4609
void
4610
Layout::print_stats() const
4611
{
4612
  this->namepool_.print_stats("section name pool");
4613
  this->sympool_.print_stats("output symbol name pool");
4614
  this->dynpool_.print_stats("dynamic name pool");
4615
 
4616
  for (Section_list::const_iterator p = this->section_list_.begin();
4617
       p != this->section_list_.end();
4618
       ++p)
4619
    (*p)->print_merge_stats();
4620
}
4621
 
4622
// Write_sections_task methods.
4623
 
4624
// We can always run this task.
4625
 
4626
Task_token*
4627
Write_sections_task::is_runnable()
4628
{
4629
  return NULL;
4630
}
4631
 
4632
// We need to unlock both OUTPUT_SECTIONS_BLOCKER and FINAL_BLOCKER
4633
// when finished.
4634
 
4635
void
4636
Write_sections_task::locks(Task_locker* tl)
4637
{
4638
  tl->add(this, this->output_sections_blocker_);
4639
  tl->add(this, this->final_blocker_);
4640
}
4641
 
4642
// Run the task--write out the data.
4643
 
4644
void
4645
Write_sections_task::run(Workqueue*)
4646
{
4647
  this->layout_->write_output_sections(this->of_);
4648
}
4649
 
4650
// Write_data_task methods.
4651
 
4652
// We can always run this task.
4653
 
4654
Task_token*
4655
Write_data_task::is_runnable()
4656
{
4657
  return NULL;
4658
}
4659
 
4660
// We need to unlock FINAL_BLOCKER when finished.
4661
 
4662
void
4663
Write_data_task::locks(Task_locker* tl)
4664
{
4665
  tl->add(this, this->final_blocker_);
4666
}
4667
 
4668
// Run the task--write out the data.
4669
 
4670
void
4671
Write_data_task::run(Workqueue*)
4672
{
4673
  this->layout_->write_data(this->symtab_, this->of_);
4674
}
4675
 
4676
// Write_symbols_task methods.
4677
 
4678
// We can always run this task.
4679
 
4680
Task_token*
4681
Write_symbols_task::is_runnable()
4682
{
4683
  return NULL;
4684
}
4685
 
4686
// We need to unlock FINAL_BLOCKER when finished.
4687
 
4688
void
4689
Write_symbols_task::locks(Task_locker* tl)
4690
{
4691
  tl->add(this, this->final_blocker_);
4692
}
4693
 
4694
// Run the task--write out the symbols.
4695
 
4696
void
4697
Write_symbols_task::run(Workqueue*)
4698
{
4699
  this->symtab_->write_globals(this->sympool_, this->dynpool_,
4700
                               this->layout_->symtab_xindex(),
4701
                               this->layout_->dynsym_xindex(), this->of_);
4702
}
4703
 
4704
// Write_after_input_sections_task methods.
4705
 
4706
// We can only run this task after the input sections have completed.
4707
 
4708
Task_token*
4709
Write_after_input_sections_task::is_runnable()
4710
{
4711
  if (this->input_sections_blocker_->is_blocked())
4712
    return this->input_sections_blocker_;
4713
  return NULL;
4714
}
4715
 
4716
// We need to unlock FINAL_BLOCKER when finished.
4717
 
4718
void
4719
Write_after_input_sections_task::locks(Task_locker* tl)
4720
{
4721
  tl->add(this, this->final_blocker_);
4722
}
4723
 
4724
// Run the task.
4725
 
4726
void
4727
Write_after_input_sections_task::run(Workqueue*)
4728
{
4729
  this->layout_->write_sections_after_input_sections(this->of_);
4730
}
4731
 
4732
// Close_task_runner methods.
4733
 
4734
// Run the task--close the file.
4735
 
4736
void
4737
Close_task_runner::run(Workqueue*, const Task*)
4738
{
4739
  // If we need to compute a checksum for the BUILD if, we do so here.
4740
  this->layout_->write_build_id(this->of_);
4741
 
4742
  // If we've been asked to create a binary file, we do so here.
4743
  if (this->options_->oformat_enum() != General_options::OBJECT_FORMAT_ELF)
4744
    this->layout_->write_binary(this->of_);
4745
 
4746
  this->of_->close();
4747
}
4748
 
4749
// Instantiate the templates we need.  We could use the configure
4750
// script to restrict this to only the ones for implemented targets.
4751
 
4752
#ifdef HAVE_TARGET_32_LITTLE
4753
template
4754
Output_section*
4755
Layout::init_fixed_output_section<32, false>(
4756
    const char* name,
4757
    elfcpp::Shdr<32, false>& shdr);
4758
#endif
4759
 
4760
#ifdef HAVE_TARGET_32_BIG
4761
template
4762
Output_section*
4763
Layout::init_fixed_output_section<32, true>(
4764
    const char* name,
4765
    elfcpp::Shdr<32, true>& shdr);
4766
#endif
4767
 
4768
#ifdef HAVE_TARGET_64_LITTLE
4769
template
4770
Output_section*
4771
Layout::init_fixed_output_section<64, false>(
4772
    const char* name,
4773
    elfcpp::Shdr<64, false>& shdr);
4774
#endif
4775
 
4776
#ifdef HAVE_TARGET_64_BIG
4777
template
4778
Output_section*
4779
Layout::init_fixed_output_section<64, true>(
4780
    const char* name,
4781
    elfcpp::Shdr<64, true>& shdr);
4782
#endif
4783
 
4784
#ifdef HAVE_TARGET_32_LITTLE
4785
template
4786
Output_section*
4787
Layout::layout<32, false>(Sized_relobj_file<32, false>* object,
4788
                          unsigned int shndx,
4789
                          const char* name,
4790
                          const elfcpp::Shdr<32, false>& shdr,
4791
                          unsigned int, unsigned int, off_t*);
4792
#endif
4793
 
4794
#ifdef HAVE_TARGET_32_BIG
4795
template
4796
Output_section*
4797
Layout::layout<32, true>(Sized_relobj_file<32, true>* object,
4798
                         unsigned int shndx,
4799
                         const char* name,
4800
                         const elfcpp::Shdr<32, true>& shdr,
4801
                         unsigned int, unsigned int, off_t*);
4802
#endif
4803
 
4804
#ifdef HAVE_TARGET_64_LITTLE
4805
template
4806
Output_section*
4807
Layout::layout<64, false>(Sized_relobj_file<64, false>* object,
4808
                          unsigned int shndx,
4809
                          const char* name,
4810
                          const elfcpp::Shdr<64, false>& shdr,
4811
                          unsigned int, unsigned int, off_t*);
4812
#endif
4813
 
4814
#ifdef HAVE_TARGET_64_BIG
4815
template
4816
Output_section*
4817
Layout::layout<64, true>(Sized_relobj_file<64, true>* object,
4818
                         unsigned int shndx,
4819
                         const char* name,
4820
                         const elfcpp::Shdr<64, true>& shdr,
4821
                         unsigned int, unsigned int, off_t*);
4822
#endif
4823
 
4824
#ifdef HAVE_TARGET_32_LITTLE
4825
template
4826
Output_section*
4827
Layout::layout_reloc<32, false>(Sized_relobj_file<32, false>* object,
4828
                                unsigned int reloc_shndx,
4829
                                const elfcpp::Shdr<32, false>& shdr,
4830
                                Output_section* data_section,
4831
                                Relocatable_relocs* rr);
4832
#endif
4833
 
4834
#ifdef HAVE_TARGET_32_BIG
4835
template
4836
Output_section*
4837
Layout::layout_reloc<32, true>(Sized_relobj_file<32, true>* object,
4838
                               unsigned int reloc_shndx,
4839
                               const elfcpp::Shdr<32, true>& shdr,
4840
                               Output_section* data_section,
4841
                               Relocatable_relocs* rr);
4842
#endif
4843
 
4844
#ifdef HAVE_TARGET_64_LITTLE
4845
template
4846
Output_section*
4847
Layout::layout_reloc<64, false>(Sized_relobj_file<64, false>* object,
4848
                                unsigned int reloc_shndx,
4849
                                const elfcpp::Shdr<64, false>& shdr,
4850
                                Output_section* data_section,
4851
                                Relocatable_relocs* rr);
4852
#endif
4853
 
4854
#ifdef HAVE_TARGET_64_BIG
4855
template
4856
Output_section*
4857
Layout::layout_reloc<64, true>(Sized_relobj_file<64, true>* object,
4858
                               unsigned int reloc_shndx,
4859
                               const elfcpp::Shdr<64, true>& shdr,
4860
                               Output_section* data_section,
4861
                               Relocatable_relocs* rr);
4862
#endif
4863
 
4864
#ifdef HAVE_TARGET_32_LITTLE
4865
template
4866
void
4867
Layout::layout_group<32, false>(Symbol_table* symtab,
4868
                                Sized_relobj_file<32, false>* object,
4869
                                unsigned int,
4870
                                const char* group_section_name,
4871
                                const char* signature,
4872
                                const elfcpp::Shdr<32, false>& shdr,
4873
                                elfcpp::Elf_Word flags,
4874
                                std::vector<unsigned int>* shndxes);
4875
#endif
4876
 
4877
#ifdef HAVE_TARGET_32_BIG
4878
template
4879
void
4880
Layout::layout_group<32, true>(Symbol_table* symtab,
4881
                               Sized_relobj_file<32, true>* object,
4882
                               unsigned int,
4883
                               const char* group_section_name,
4884
                               const char* signature,
4885
                               const elfcpp::Shdr<32, true>& shdr,
4886
                               elfcpp::Elf_Word flags,
4887
                               std::vector<unsigned int>* shndxes);
4888
#endif
4889
 
4890
#ifdef HAVE_TARGET_64_LITTLE
4891
template
4892
void
4893
Layout::layout_group<64, false>(Symbol_table* symtab,
4894
                                Sized_relobj_file<64, false>* object,
4895
                                unsigned int,
4896
                                const char* group_section_name,
4897
                                const char* signature,
4898
                                const elfcpp::Shdr<64, false>& shdr,
4899
                                elfcpp::Elf_Word flags,
4900
                                std::vector<unsigned int>* shndxes);
4901
#endif
4902
 
4903
#ifdef HAVE_TARGET_64_BIG
4904
template
4905
void
4906
Layout::layout_group<64, true>(Symbol_table* symtab,
4907
                               Sized_relobj_file<64, true>* object,
4908
                               unsigned int,
4909
                               const char* group_section_name,
4910
                               const char* signature,
4911
                               const elfcpp::Shdr<64, true>& shdr,
4912
                               elfcpp::Elf_Word flags,
4913
                               std::vector<unsigned int>* shndxes);
4914
#endif
4915
 
4916
#ifdef HAVE_TARGET_32_LITTLE
4917
template
4918
Output_section*
4919
Layout::layout_eh_frame<32, false>(Sized_relobj_file<32, false>* object,
4920
                                   const unsigned char* symbols,
4921
                                   off_t symbols_size,
4922
                                   const unsigned char* symbol_names,
4923
                                   off_t symbol_names_size,
4924
                                   unsigned int shndx,
4925
                                   const elfcpp::Shdr<32, false>& shdr,
4926
                                   unsigned int reloc_shndx,
4927
                                   unsigned int reloc_type,
4928
                                   off_t* off);
4929
#endif
4930
 
4931
#ifdef HAVE_TARGET_32_BIG
4932
template
4933
Output_section*
4934
Layout::layout_eh_frame<32, true>(Sized_relobj_file<32, true>* object,
4935
                                  const unsigned char* symbols,
4936
                                  off_t symbols_size,
4937
                                  const unsigned char* symbol_names,
4938
                                  off_t symbol_names_size,
4939
                                  unsigned int shndx,
4940
                                  const elfcpp::Shdr<32, true>& shdr,
4941
                                  unsigned int reloc_shndx,
4942
                                  unsigned int reloc_type,
4943
                                  off_t* off);
4944
#endif
4945
 
4946
#ifdef HAVE_TARGET_64_LITTLE
4947
template
4948
Output_section*
4949
Layout::layout_eh_frame<64, false>(Sized_relobj_file<64, false>* object,
4950
                                   const unsigned char* symbols,
4951
                                   off_t symbols_size,
4952
                                   const unsigned char* symbol_names,
4953
                                   off_t symbol_names_size,
4954
                                   unsigned int shndx,
4955
                                   const elfcpp::Shdr<64, false>& shdr,
4956
                                   unsigned int reloc_shndx,
4957
                                   unsigned int reloc_type,
4958
                                   off_t* off);
4959
#endif
4960
 
4961
#ifdef HAVE_TARGET_64_BIG
4962
template
4963
Output_section*
4964
Layout::layout_eh_frame<64, true>(Sized_relobj_file<64, true>* object,
4965
                                  const unsigned char* symbols,
4966
                                  off_t symbols_size,
4967
                                  const unsigned char* symbol_names,
4968
                                  off_t symbol_names_size,
4969
                                  unsigned int shndx,
4970
                                  const elfcpp::Shdr<64, true>& shdr,
4971
                                  unsigned int reloc_shndx,
4972
                                  unsigned int reloc_type,
4973
                                  off_t* off);
4974
#endif
4975
 
4976
} // End namespace gold.

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