Handle output sections with more than 0x7fffffff bytes.
[external/binutils.git] / gold / output.cc
1 // output.cc -- manage the output file for gold
2
3 // Copyright 2006, 2007, 2008 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 <cstdlib>
26 #include <cstring>
27 #include <cerrno>
28 #include <fcntl.h>
29 #include <unistd.h>
30 #include <sys/mman.h>
31 #include <sys/stat.h>
32 #include <algorithm>
33 #include "libiberty.h"   // for unlink_if_ordinary()
34
35 #include "parameters.h"
36 #include "object.h"
37 #include "symtab.h"
38 #include "reloc.h"
39 #include "merge.h"
40 #include "output.h"
41
42 // Some BSD systems still use MAP_ANON instead of MAP_ANONYMOUS
43 #ifndef MAP_ANONYMOUS
44 # define MAP_ANONYMOUS  MAP_ANON
45 #endif
46
47 namespace gold
48 {
49
50 // Output_data variables.
51
52 bool Output_data::allocated_sizes_are_fixed;
53
54 // Output_data methods.
55
56 Output_data::~Output_data()
57 {
58 }
59
60 // Return the default alignment for the target size.
61
62 uint64_t
63 Output_data::default_alignment()
64 {
65   return Output_data::default_alignment_for_size(
66       parameters->target().get_size());
67 }
68
69 // Return the default alignment for a size--32 or 64.
70
71 uint64_t
72 Output_data::default_alignment_for_size(int size)
73 {
74   if (size == 32)
75     return 4;
76   else if (size == 64)
77     return 8;
78   else
79     gold_unreachable();
80 }
81
82 // Output_section_header methods.  This currently assumes that the
83 // segment and section lists are complete at construction time.
84
85 Output_section_headers::Output_section_headers(
86     const Layout* layout,
87     const Layout::Segment_list* segment_list,
88     const Layout::Section_list* section_list,
89     const Layout::Section_list* unattached_section_list,
90     const Stringpool* secnamepool,
91     const Output_section* shstrtab_section)
92   : layout_(layout),
93     segment_list_(segment_list),
94     section_list_(section_list),
95     unattached_section_list_(unattached_section_list),
96     secnamepool_(secnamepool),
97     shstrtab_section_(shstrtab_section)
98 {
99   // Count all the sections.  Start with 1 for the null section.
100   off_t count = 1;
101   if (!parameters->options().relocatable())
102     {
103       for (Layout::Segment_list::const_iterator p = segment_list->begin();
104            p != segment_list->end();
105            ++p)
106         if ((*p)->type() == elfcpp::PT_LOAD)
107           count += (*p)->output_section_count();
108     }
109   else
110     {
111       for (Layout::Section_list::const_iterator p = section_list->begin();
112            p != section_list->end();
113            ++p)
114         if (((*p)->flags() & elfcpp::SHF_ALLOC) != 0)
115           ++count;
116     }
117   count += unattached_section_list->size();
118
119   const int size = parameters->target().get_size();
120   int shdr_size;
121   if (size == 32)
122     shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
123   else if (size == 64)
124     shdr_size = elfcpp::Elf_sizes<64>::shdr_size;
125   else
126     gold_unreachable();
127
128   this->set_data_size(count * shdr_size);
129 }
130
131 // Write out the section headers.
132
133 void
134 Output_section_headers::do_write(Output_file* of)
135 {
136   switch (parameters->size_and_endianness())
137     {
138 #ifdef HAVE_TARGET_32_LITTLE
139     case Parameters::TARGET_32_LITTLE:
140       this->do_sized_write<32, false>(of);
141       break;
142 #endif
143 #ifdef HAVE_TARGET_32_BIG
144     case Parameters::TARGET_32_BIG:
145       this->do_sized_write<32, true>(of);
146       break;
147 #endif
148 #ifdef HAVE_TARGET_64_LITTLE
149     case Parameters::TARGET_64_LITTLE:
150       this->do_sized_write<64, false>(of);
151       break;
152 #endif
153 #ifdef HAVE_TARGET_64_BIG
154     case Parameters::TARGET_64_BIG:
155       this->do_sized_write<64, true>(of);
156       break;
157 #endif
158     default:
159       gold_unreachable();
160     }
161 }
162
163 template<int size, bool big_endian>
164 void
165 Output_section_headers::do_sized_write(Output_file* of)
166 {
167   off_t all_shdrs_size = this->data_size();
168   unsigned char* view = of->get_output_view(this->offset(), all_shdrs_size);
169
170   const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
171   unsigned char* v = view;
172
173   {
174     typename elfcpp::Shdr_write<size, big_endian> oshdr(v);
175     oshdr.put_sh_name(0);
176     oshdr.put_sh_type(elfcpp::SHT_NULL);
177     oshdr.put_sh_flags(0);
178     oshdr.put_sh_addr(0);
179     oshdr.put_sh_offset(0);
180
181     size_t section_count = (this->data_size()
182                             / elfcpp::Elf_sizes<size>::shdr_size);
183     if (section_count < elfcpp::SHN_LORESERVE)
184       oshdr.put_sh_size(0);
185     else
186       oshdr.put_sh_size(section_count);
187
188     unsigned int shstrndx = this->shstrtab_section_->out_shndx();
189     if (shstrndx < elfcpp::SHN_LORESERVE)
190       oshdr.put_sh_link(0);
191     else
192       oshdr.put_sh_link(shstrndx);
193
194     oshdr.put_sh_info(0);
195     oshdr.put_sh_addralign(0);
196     oshdr.put_sh_entsize(0);
197   }
198
199   v += shdr_size;
200
201   unsigned int shndx = 1;
202   if (!parameters->options().relocatable())
203     {
204       for (Layout::Segment_list::const_iterator p =
205              this->segment_list_->begin();
206            p != this->segment_list_->end();
207            ++p)
208         v = (*p)->write_section_headers<size, big_endian>(this->layout_,
209                                                           this->secnamepool_,
210                                                           v,
211                                                           &shndx);
212     }
213   else
214     {
215       for (Layout::Section_list::const_iterator p =
216              this->section_list_->begin();
217            p != this->section_list_->end();
218            ++p)
219         {
220           // We do unallocated sections below, except that group
221           // sections have to come first.
222           if (((*p)->flags() & elfcpp::SHF_ALLOC) == 0
223               && (*p)->type() != elfcpp::SHT_GROUP)
224             continue;
225           gold_assert(shndx == (*p)->out_shndx());
226           elfcpp::Shdr_write<size, big_endian> oshdr(v);
227           (*p)->write_header(this->layout_, this->secnamepool_, &oshdr);
228           v += shdr_size;
229           ++shndx;
230         }
231     }
232
233   for (Layout::Section_list::const_iterator p =
234          this->unattached_section_list_->begin();
235        p != this->unattached_section_list_->end();
236        ++p)
237     {
238       // For a relocatable link, we did unallocated group sections
239       // above, since they have to come first.
240       if ((*p)->type() == elfcpp::SHT_GROUP
241           && parameters->options().relocatable())
242         continue;
243       gold_assert(shndx == (*p)->out_shndx());
244       elfcpp::Shdr_write<size, big_endian> oshdr(v);
245       (*p)->write_header(this->layout_, this->secnamepool_, &oshdr);
246       v += shdr_size;
247       ++shndx;
248     }
249
250   of->write_output_view(this->offset(), all_shdrs_size, view);
251 }
252
253 // Output_segment_header methods.
254
255 Output_segment_headers::Output_segment_headers(
256     const Layout::Segment_list& segment_list)
257   : segment_list_(segment_list)
258 {
259   const int size = parameters->target().get_size();
260   int phdr_size;
261   if (size == 32)
262     phdr_size = elfcpp::Elf_sizes<32>::phdr_size;
263   else if (size == 64)
264     phdr_size = elfcpp::Elf_sizes<64>::phdr_size;
265   else
266     gold_unreachable();
267
268   this->set_data_size(segment_list.size() * phdr_size);
269 }
270
271 void
272 Output_segment_headers::do_write(Output_file* of)
273 {
274   switch (parameters->size_and_endianness())
275     {
276 #ifdef HAVE_TARGET_32_LITTLE
277     case Parameters::TARGET_32_LITTLE:
278       this->do_sized_write<32, false>(of);
279       break;
280 #endif
281 #ifdef HAVE_TARGET_32_BIG
282     case Parameters::TARGET_32_BIG:
283       this->do_sized_write<32, true>(of);
284       break;
285 #endif
286 #ifdef HAVE_TARGET_64_LITTLE
287     case Parameters::TARGET_64_LITTLE:
288       this->do_sized_write<64, false>(of);
289       break;
290 #endif
291 #ifdef HAVE_TARGET_64_BIG
292     case Parameters::TARGET_64_BIG:
293       this->do_sized_write<64, true>(of);
294       break;
295 #endif
296     default:
297       gold_unreachable();
298     }
299 }
300
301 template<int size, bool big_endian>
302 void
303 Output_segment_headers::do_sized_write(Output_file* of)
304 {
305   const int phdr_size = elfcpp::Elf_sizes<size>::phdr_size;
306   off_t all_phdrs_size = this->segment_list_.size() * phdr_size;
307   gold_assert(all_phdrs_size == this->data_size());
308   unsigned char* view = of->get_output_view(this->offset(),
309                                             all_phdrs_size);
310   unsigned char* v = view;
311   for (Layout::Segment_list::const_iterator p = this->segment_list_.begin();
312        p != this->segment_list_.end();
313        ++p)
314     {
315       elfcpp::Phdr_write<size, big_endian> ophdr(v);
316       (*p)->write_header(&ophdr);
317       v += phdr_size;
318     }
319
320   gold_assert(v - view == all_phdrs_size);
321
322   of->write_output_view(this->offset(), all_phdrs_size, view);
323 }
324
325 // Output_file_header methods.
326
327 Output_file_header::Output_file_header(const Target* target,
328                                        const Symbol_table* symtab,
329                                        const Output_segment_headers* osh,
330                                        const char* entry)
331   : target_(target),
332     symtab_(symtab),
333     segment_header_(osh),
334     section_header_(NULL),
335     shstrtab_(NULL),
336     entry_(entry)
337 {
338   const int size = parameters->target().get_size();
339   int ehdr_size;
340   if (size == 32)
341     ehdr_size = elfcpp::Elf_sizes<32>::ehdr_size;
342   else if (size == 64)
343     ehdr_size = elfcpp::Elf_sizes<64>::ehdr_size;
344   else
345     gold_unreachable();
346
347   this->set_data_size(ehdr_size);
348 }
349
350 // Set the section table information for a file header.
351
352 void
353 Output_file_header::set_section_info(const Output_section_headers* shdrs,
354                                      const Output_section* shstrtab)
355 {
356   this->section_header_ = shdrs;
357   this->shstrtab_ = shstrtab;
358 }
359
360 // Write out the file header.
361
362 void
363 Output_file_header::do_write(Output_file* of)
364 {
365   gold_assert(this->offset() == 0);
366
367   switch (parameters->size_and_endianness())
368     {
369 #ifdef HAVE_TARGET_32_LITTLE
370     case Parameters::TARGET_32_LITTLE:
371       this->do_sized_write<32, false>(of);
372       break;
373 #endif
374 #ifdef HAVE_TARGET_32_BIG
375     case Parameters::TARGET_32_BIG:
376       this->do_sized_write<32, true>(of);
377       break;
378 #endif
379 #ifdef HAVE_TARGET_64_LITTLE
380     case Parameters::TARGET_64_LITTLE:
381       this->do_sized_write<64, false>(of);
382       break;
383 #endif
384 #ifdef HAVE_TARGET_64_BIG
385     case Parameters::TARGET_64_BIG:
386       this->do_sized_write<64, true>(of);
387       break;
388 #endif
389     default:
390       gold_unreachable();
391     }
392 }
393
394 // Write out the file header with appropriate size and endianess.
395
396 template<int size, bool big_endian>
397 void
398 Output_file_header::do_sized_write(Output_file* of)
399 {
400   gold_assert(this->offset() == 0);
401
402   int ehdr_size = elfcpp::Elf_sizes<size>::ehdr_size;
403   unsigned char* view = of->get_output_view(0, ehdr_size);
404   elfcpp::Ehdr_write<size, big_endian> oehdr(view);
405
406   unsigned char e_ident[elfcpp::EI_NIDENT];
407   memset(e_ident, 0, elfcpp::EI_NIDENT);
408   e_ident[elfcpp::EI_MAG0] = elfcpp::ELFMAG0;
409   e_ident[elfcpp::EI_MAG1] = elfcpp::ELFMAG1;
410   e_ident[elfcpp::EI_MAG2] = elfcpp::ELFMAG2;
411   e_ident[elfcpp::EI_MAG3] = elfcpp::ELFMAG3;
412   if (size == 32)
413     e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS32;
414   else if (size == 64)
415     e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS64;
416   else
417     gold_unreachable();
418   e_ident[elfcpp::EI_DATA] = (big_endian
419                               ? elfcpp::ELFDATA2MSB
420                               : elfcpp::ELFDATA2LSB);
421   e_ident[elfcpp::EI_VERSION] = elfcpp::EV_CURRENT;
422   // FIXME: Some targets may need to set EI_OSABI and EI_ABIVERSION.
423   oehdr.put_e_ident(e_ident);
424
425   elfcpp::ET e_type;
426   if (parameters->options().relocatable())
427     e_type = elfcpp::ET_REL;
428   else if (parameters->options().shared())
429     e_type = elfcpp::ET_DYN;
430   else
431     e_type = elfcpp::ET_EXEC;
432   oehdr.put_e_type(e_type);
433
434   oehdr.put_e_machine(this->target_->machine_code());
435   oehdr.put_e_version(elfcpp::EV_CURRENT);
436
437   oehdr.put_e_entry(this->entry<size>());
438
439   if (this->segment_header_ == NULL)
440     oehdr.put_e_phoff(0);
441   else
442     oehdr.put_e_phoff(this->segment_header_->offset());
443
444   oehdr.put_e_shoff(this->section_header_->offset());
445
446   // FIXME: The target needs to set the flags.
447   oehdr.put_e_flags(0);
448
449   oehdr.put_e_ehsize(elfcpp::Elf_sizes<size>::ehdr_size);
450
451   if (this->segment_header_ == NULL)
452     {
453       oehdr.put_e_phentsize(0);
454       oehdr.put_e_phnum(0);
455     }
456   else
457     {
458       oehdr.put_e_phentsize(elfcpp::Elf_sizes<size>::phdr_size);
459       oehdr.put_e_phnum(this->segment_header_->data_size()
460                         / elfcpp::Elf_sizes<size>::phdr_size);
461     }
462
463   oehdr.put_e_shentsize(elfcpp::Elf_sizes<size>::shdr_size);
464   size_t section_count = (this->section_header_->data_size()
465                           / elfcpp::Elf_sizes<size>::shdr_size);
466
467   if (section_count < elfcpp::SHN_LORESERVE)
468     oehdr.put_e_shnum(this->section_header_->data_size()
469                       / elfcpp::Elf_sizes<size>::shdr_size);
470   else
471     oehdr.put_e_shnum(0);
472
473   unsigned int shstrndx = this->shstrtab_->out_shndx();
474   if (shstrndx < elfcpp::SHN_LORESERVE)
475     oehdr.put_e_shstrndx(this->shstrtab_->out_shndx());
476   else
477     oehdr.put_e_shstrndx(elfcpp::SHN_XINDEX);
478
479   of->write_output_view(0, ehdr_size, view);
480 }
481
482 // Return the value to use for the entry address.  THIS->ENTRY_ is the
483 // symbol specified on the command line, if any.
484
485 template<int size>
486 typename elfcpp::Elf_types<size>::Elf_Addr
487 Output_file_header::entry()
488 {
489   const bool should_issue_warning = (this->entry_ != NULL
490                                      && !parameters->options().relocatable()
491                                      && !parameters->options().shared());
492
493   // FIXME: Need to support target specific entry symbol.
494   const char* entry = this->entry_;
495   if (entry == NULL)
496     entry = "_start";
497
498   Symbol* sym = this->symtab_->lookup(entry);
499
500   typename Sized_symbol<size>::Value_type v;
501   if (sym != NULL)
502     {
503       Sized_symbol<size>* ssym;
504       ssym = this->symtab_->get_sized_symbol<size>(sym);
505       if (!ssym->is_defined() && should_issue_warning)
506         gold_warning("entry symbol '%s' exists but is not defined", entry);
507       v = ssym->value();
508     }
509   else
510     {
511       // We couldn't find the entry symbol.  See if we can parse it as
512       // a number.  This supports, e.g., -e 0x1000.
513       char* endptr;
514       v = strtoull(entry, &endptr, 0);
515       if (*endptr != '\0')
516         {
517           if (should_issue_warning)
518             gold_warning("cannot find entry symbol '%s'", entry);
519           v = 0;
520         }
521     }
522
523   return v;
524 }
525
526 // Output_data_const methods.
527
528 void
529 Output_data_const::do_write(Output_file* of)
530 {
531   of->write(this->offset(), this->data_.data(), this->data_.size());
532 }
533
534 // Output_data_const_buffer methods.
535
536 void
537 Output_data_const_buffer::do_write(Output_file* of)
538 {
539   of->write(this->offset(), this->p_, this->data_size());
540 }
541
542 // Output_section_data methods.
543
544 // Record the output section, and set the entry size and such.
545
546 void
547 Output_section_data::set_output_section(Output_section* os)
548 {
549   gold_assert(this->output_section_ == NULL);
550   this->output_section_ = os;
551   this->do_adjust_output_section(os);
552 }
553
554 // Return the section index of the output section.
555
556 unsigned int
557 Output_section_data::do_out_shndx() const
558 {
559   gold_assert(this->output_section_ != NULL);
560   return this->output_section_->out_shndx();
561 }
562
563 // Set the alignment, which means we may need to update the alignment
564 // of the output section.
565
566 void
567 Output_section_data::set_addralign(uint64_t addralign)
568 {
569   this->addralign_ = addralign;
570   if (this->output_section_ != NULL
571       && this->output_section_->addralign() < addralign)
572     this->output_section_->set_addralign(addralign);
573 }
574
575 // Output_data_strtab methods.
576
577 // Set the final data size.
578
579 void
580 Output_data_strtab::set_final_data_size()
581 {
582   this->strtab_->set_string_offsets();
583   this->set_data_size(this->strtab_->get_strtab_size());
584 }
585
586 // Write out a string table.
587
588 void
589 Output_data_strtab::do_write(Output_file* of)
590 {
591   this->strtab_->write(of, this->offset());
592 }
593
594 // Output_reloc methods.
595
596 // A reloc against a global symbol.
597
598 template<bool dynamic, int size, bool big_endian>
599 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
600     Symbol* gsym,
601     unsigned int type,
602     Output_data* od,
603     Address address,
604     bool is_relative)
605   : address_(address), local_sym_index_(GSYM_CODE), type_(type),
606     is_relative_(is_relative), is_section_symbol_(false), shndx_(INVALID_CODE)
607 {
608   // this->type_ is a bitfield; make sure TYPE fits.
609   gold_assert(this->type_ == type);
610   this->u1_.gsym = gsym;
611   this->u2_.od = od;
612   if (dynamic)
613     this->set_needs_dynsym_index();
614 }
615
616 template<bool dynamic, int size, bool big_endian>
617 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
618     Symbol* gsym,
619     unsigned int type,
620     Sized_relobj<size, big_endian>* relobj,
621     unsigned int shndx,
622     Address address,
623     bool is_relative)
624   : address_(address), local_sym_index_(GSYM_CODE), type_(type),
625     is_relative_(is_relative), is_section_symbol_(false), shndx_(shndx)
626 {
627   gold_assert(shndx != INVALID_CODE);
628   // this->type_ is a bitfield; make sure TYPE fits.
629   gold_assert(this->type_ == type);
630   this->u1_.gsym = gsym;
631   this->u2_.relobj = relobj;
632   if (dynamic)
633     this->set_needs_dynsym_index();
634 }
635
636 // A reloc against a local symbol.
637
638 template<bool dynamic, int size, bool big_endian>
639 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
640     Sized_relobj<size, big_endian>* relobj,
641     unsigned int local_sym_index,
642     unsigned int type,
643     Output_data* od,
644     Address address,
645     bool is_relative,
646     bool is_section_symbol)
647   : address_(address), local_sym_index_(local_sym_index), type_(type),
648     is_relative_(is_relative), is_section_symbol_(is_section_symbol),
649     shndx_(INVALID_CODE)
650 {
651   gold_assert(local_sym_index != GSYM_CODE
652               && local_sym_index != INVALID_CODE);
653   // this->type_ is a bitfield; make sure TYPE fits.
654   gold_assert(this->type_ == type);
655   this->u1_.relobj = relobj;
656   this->u2_.od = od;
657   if (dynamic)
658     this->set_needs_dynsym_index();
659 }
660
661 template<bool dynamic, int size, bool big_endian>
662 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
663     Sized_relobj<size, big_endian>* relobj,
664     unsigned int local_sym_index,
665     unsigned int type,
666     unsigned int shndx,
667     Address address,
668     bool is_relative,
669     bool is_section_symbol)
670   : address_(address), local_sym_index_(local_sym_index), type_(type),
671     is_relative_(is_relative), is_section_symbol_(is_section_symbol),
672     shndx_(shndx)
673 {
674   gold_assert(local_sym_index != GSYM_CODE
675               && local_sym_index != INVALID_CODE);
676   gold_assert(shndx != INVALID_CODE);
677   // this->type_ is a bitfield; make sure TYPE fits.
678   gold_assert(this->type_ == type);
679   this->u1_.relobj = relobj;
680   this->u2_.relobj = relobj;
681   if (dynamic)
682     this->set_needs_dynsym_index();
683 }
684
685 // A reloc against the STT_SECTION symbol of an output section.
686
687 template<bool dynamic, int size, bool big_endian>
688 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
689     Output_section* os,
690     unsigned int type,
691     Output_data* od,
692     Address address)
693   : address_(address), local_sym_index_(SECTION_CODE), type_(type),
694     is_relative_(false), is_section_symbol_(true), shndx_(INVALID_CODE)
695 {
696   // this->type_ is a bitfield; make sure TYPE fits.
697   gold_assert(this->type_ == type);
698   this->u1_.os = os;
699   this->u2_.od = od;
700   if (dynamic)
701     this->set_needs_dynsym_index();
702   else
703     os->set_needs_symtab_index();
704 }
705
706 template<bool dynamic, int size, bool big_endian>
707 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
708     Output_section* os,
709     unsigned int type,
710     Sized_relobj<size, big_endian>* relobj,
711     unsigned int shndx,
712     Address address)
713   : address_(address), local_sym_index_(SECTION_CODE), type_(type),
714     is_relative_(false), is_section_symbol_(true), shndx_(shndx)
715 {
716   gold_assert(shndx != INVALID_CODE);
717   // this->type_ is a bitfield; make sure TYPE fits.
718   gold_assert(this->type_ == type);
719   this->u1_.os = os;
720   this->u2_.relobj = relobj;
721   if (dynamic)
722     this->set_needs_dynsym_index();
723   else
724     os->set_needs_symtab_index();
725 }
726
727 // Record that we need a dynamic symbol index for this relocation.
728
729 template<bool dynamic, int size, bool big_endian>
730 void
731 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::
732 set_needs_dynsym_index()
733 {
734   if (this->is_relative_)
735     return;
736   switch (this->local_sym_index_)
737     {
738     case INVALID_CODE:
739       gold_unreachable();
740
741     case GSYM_CODE:
742       this->u1_.gsym->set_needs_dynsym_entry();
743       break;
744
745     case SECTION_CODE:
746       this->u1_.os->set_needs_dynsym_index();
747       break;
748
749     case 0:
750       break;
751
752     default:
753       {
754         const unsigned int lsi = this->local_sym_index_;
755         if (!this->is_section_symbol_)
756           this->u1_.relobj->set_needs_output_dynsym_entry(lsi);
757         else
758           this->u1_.relobj->output_section(lsi)->set_needs_dynsym_index();
759       }
760       break;
761     }
762 }
763
764 // Get the symbol index of a relocation.
765
766 template<bool dynamic, int size, bool big_endian>
767 unsigned int
768 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::get_symbol_index()
769   const
770 {
771   unsigned int index;
772   switch (this->local_sym_index_)
773     {
774     case INVALID_CODE:
775       gold_unreachable();
776
777     case GSYM_CODE:
778       if (this->u1_.gsym == NULL)
779         index = 0;
780       else if (dynamic)
781         index = this->u1_.gsym->dynsym_index();
782       else
783         index = this->u1_.gsym->symtab_index();
784       break;
785
786     case SECTION_CODE:
787       if (dynamic)
788         index = this->u1_.os->dynsym_index();
789       else
790         index = this->u1_.os->symtab_index();
791       break;
792
793     case 0:
794       // Relocations without symbols use a symbol index of 0.
795       index = 0;
796       break;
797
798     default:
799       {
800         const unsigned int lsi = this->local_sym_index_;
801         if (!this->is_section_symbol_)
802           {
803             if (dynamic)
804               index = this->u1_.relobj->dynsym_index(lsi);
805             else
806               index = this->u1_.relobj->symtab_index(lsi);
807           }
808         else
809           {
810             Output_section* os = this->u1_.relobj->output_section(lsi);
811             gold_assert(os != NULL);
812             if (dynamic)
813               index = os->dynsym_index();
814             else
815               index = os->symtab_index();
816           }
817       }
818       break;
819     }
820   gold_assert(index != -1U);
821   return index;
822 }
823
824 // For a local section symbol, get the address of the offset ADDEND
825 // within the input section.
826
827 template<bool dynamic, int size, bool big_endian>
828 typename elfcpp::Elf_types<size>::Elf_Addr
829 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::
830   local_section_offset(Addend addend) const
831 {
832   gold_assert(this->local_sym_index_ != GSYM_CODE
833               && this->local_sym_index_ != SECTION_CODE
834               && this->local_sym_index_ != INVALID_CODE
835               && this->is_section_symbol_);
836   const unsigned int lsi = this->local_sym_index_;
837   Output_section* os = this->u1_.relobj->output_section(lsi);
838   gold_assert(os != NULL);
839   Address offset = this->u1_.relobj->get_output_section_offset(lsi);
840   if (offset != -1U)
841     return offset + addend;
842   // This is a merge section.
843   offset = os->output_address(this->u1_.relobj, lsi, addend);
844   gold_assert(offset != -1U);
845   return offset;
846 }
847
848 // Get the output address of a relocation.
849
850 template<bool dynamic, int size, bool big_endian>
851 typename elfcpp::Elf_types<size>::Elf_Addr
852 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::get_address() const
853 {
854   Address address = this->address_;
855   if (this->shndx_ != INVALID_CODE)
856     {
857       Output_section* os = this->u2_.relobj->output_section(this->shndx_);
858       gold_assert(os != NULL);
859       Address off = this->u2_.relobj->get_output_section_offset(this->shndx_);
860       if (off != -1U)
861         address += os->address() + off;
862       else
863         {
864           address = os->output_address(this->u2_.relobj, this->shndx_,
865                                        address);
866           gold_assert(address != -1U);
867         }
868     }
869   else if (this->u2_.od != NULL)
870     address += this->u2_.od->address();
871   return address;
872 }
873
874 // Write out the offset and info fields of a Rel or Rela relocation
875 // entry.
876
877 template<bool dynamic, int size, bool big_endian>
878 template<typename Write_rel>
879 void
880 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::write_rel(
881     Write_rel* wr) const
882 {
883   wr->put_r_offset(this->get_address());
884   unsigned int sym_index = this->is_relative_ ? 0 : this->get_symbol_index();
885   wr->put_r_info(elfcpp::elf_r_info<size>(sym_index, this->type_));
886 }
887
888 // Write out a Rel relocation.
889
890 template<bool dynamic, int size, bool big_endian>
891 void
892 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::write(
893     unsigned char* pov) const
894 {
895   elfcpp::Rel_write<size, big_endian> orel(pov);
896   this->write_rel(&orel);
897 }
898
899 // Get the value of the symbol referred to by a Rel relocation.
900
901 template<bool dynamic, int size, bool big_endian>
902 typename elfcpp::Elf_types<size>::Elf_Addr
903 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::symbol_value(
904     Addend addend) const
905 {
906   if (this->local_sym_index_ == GSYM_CODE)
907     {
908       const Sized_symbol<size>* sym;
909       sym = static_cast<const Sized_symbol<size>*>(this->u1_.gsym);
910       return sym->value() + addend;
911     }
912   gold_assert(this->local_sym_index_ != SECTION_CODE
913               && this->local_sym_index_ != INVALID_CODE
914               && !this->is_section_symbol_);
915   const unsigned int lsi = this->local_sym_index_;
916   const Symbol_value<size>* symval = this->u1_.relobj->local_symbol(lsi);
917   return symval->value(this->u1_.relobj, addend);
918 }
919
920 // Reloc comparison.  This function sorts the dynamic relocs for the
921 // benefit of the dynamic linker.  First we sort all relative relocs
922 // to the front.  Among relative relocs, we sort by output address.
923 // Among non-relative relocs, we sort by symbol index, then by output
924 // address.
925
926 template<bool dynamic, int size, bool big_endian>
927 int
928 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::
929   compare(const Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>& r2)
930     const
931 {
932   if (this->is_relative_)
933     {
934       if (!r2.is_relative_)
935         return -1;
936       // Otherwise sort by reloc address below.
937     }
938   else if (r2.is_relative_)
939     return 1;
940   else
941     {
942       unsigned int sym1 = this->get_symbol_index();
943       unsigned int sym2 = r2.get_symbol_index();
944       if (sym1 < sym2)
945         return -1;
946       else if (sym1 > sym2)
947         return 1;
948       // Otherwise sort by reloc address.
949     }
950
951   section_offset_type addr1 = this->get_address();
952   section_offset_type addr2 = r2.get_address();
953   if (addr1 < addr2)
954     return -1;
955   else if (addr1 > addr2)
956     return 1;
957
958   // Final tie breaker, in order to generate the same output on any
959   // host: reloc type.
960   unsigned int type1 = this->type_;
961   unsigned int type2 = r2.type_;
962   if (type1 < type2)
963     return -1;
964   else if (type1 > type2)
965     return 1;
966
967   // These relocs appear to be exactly the same.
968   return 0;
969 }
970
971 // Write out a Rela relocation.
972
973 template<bool dynamic, int size, bool big_endian>
974 void
975 Output_reloc<elfcpp::SHT_RELA, dynamic, size, big_endian>::write(
976     unsigned char* pov) const
977 {
978   elfcpp::Rela_write<size, big_endian> orel(pov);
979   this->rel_.write_rel(&orel);
980   Addend addend = this->addend_;
981   if (this->rel_.is_relative())
982     addend = this->rel_.symbol_value(addend);
983   else if (this->rel_.is_local_section_symbol())
984     addend = this->rel_.local_section_offset(addend);
985   orel.put_r_addend(addend);
986 }
987
988 // Output_data_reloc_base methods.
989
990 // Adjust the output section.
991
992 template<int sh_type, bool dynamic, int size, bool big_endian>
993 void
994 Output_data_reloc_base<sh_type, dynamic, size, big_endian>
995     ::do_adjust_output_section(Output_section* os)
996 {
997   if (sh_type == elfcpp::SHT_REL)
998     os->set_entsize(elfcpp::Elf_sizes<size>::rel_size);
999   else if (sh_type == elfcpp::SHT_RELA)
1000     os->set_entsize(elfcpp::Elf_sizes<size>::rela_size);
1001   else
1002     gold_unreachable();
1003   if (dynamic)
1004     os->set_should_link_to_dynsym();
1005   else
1006     os->set_should_link_to_symtab();
1007 }
1008
1009 // Write out relocation data.
1010
1011 template<int sh_type, bool dynamic, int size, bool big_endian>
1012 void
1013 Output_data_reloc_base<sh_type, dynamic, size, big_endian>::do_write(
1014     Output_file* of)
1015 {
1016   const off_t off = this->offset();
1017   const off_t oview_size = this->data_size();
1018   unsigned char* const oview = of->get_output_view(off, oview_size);
1019
1020   if (this->sort_relocs_)
1021     {
1022       gold_assert(dynamic);
1023       std::sort(this->relocs_.begin(), this->relocs_.end(),
1024                 Sort_relocs_comparison());
1025     }
1026
1027   unsigned char* pov = oview;
1028   for (typename Relocs::const_iterator p = this->relocs_.begin();
1029        p != this->relocs_.end();
1030        ++p)
1031     {
1032       p->write(pov);
1033       pov += reloc_size;
1034     }
1035
1036   gold_assert(pov - oview == oview_size);
1037
1038   of->write_output_view(off, oview_size, oview);
1039
1040   // We no longer need the relocation entries.
1041   this->relocs_.clear();
1042 }
1043
1044 // Class Output_relocatable_relocs.
1045
1046 template<int sh_type, int size, bool big_endian>
1047 void
1048 Output_relocatable_relocs<sh_type, size, big_endian>::set_final_data_size()
1049 {
1050   this->set_data_size(this->rr_->output_reloc_count()
1051                       * Reloc_types<sh_type, size, big_endian>::reloc_size);
1052 }
1053
1054 // class Output_data_group.
1055
1056 template<int size, bool big_endian>
1057 Output_data_group<size, big_endian>::Output_data_group(
1058     Sized_relobj<size, big_endian>* relobj,
1059     section_size_type entry_count,
1060     elfcpp::Elf_Word flags,
1061     std::vector<unsigned int>* input_shndxes)
1062   : Output_section_data(entry_count * 4, 4),
1063     relobj_(relobj),
1064     flags_(flags)
1065 {
1066   this->input_shndxes_.swap(*input_shndxes);
1067 }
1068
1069 // Write out the section group, which means translating the section
1070 // indexes to apply to the output file.
1071
1072 template<int size, bool big_endian>
1073 void
1074 Output_data_group<size, big_endian>::do_write(Output_file* of)
1075 {
1076   const off_t off = this->offset();
1077   const section_size_type oview_size =
1078     convert_to_section_size_type(this->data_size());
1079   unsigned char* const oview = of->get_output_view(off, oview_size);
1080
1081   elfcpp::Elf_Word* contents = reinterpret_cast<elfcpp::Elf_Word*>(oview);
1082   elfcpp::Swap<32, big_endian>::writeval(contents, this->flags_);
1083   ++contents;
1084
1085   for (std::vector<unsigned int>::const_iterator p =
1086          this->input_shndxes_.begin();
1087        p != this->input_shndxes_.end();
1088        ++p, ++contents)
1089     {
1090       Output_section* os = this->relobj_->output_section(*p);
1091
1092       unsigned int output_shndx;
1093       if (os != NULL)
1094         output_shndx = os->out_shndx();
1095       else
1096         {
1097           this->relobj_->error(_("section group retained but "
1098                                  "group element discarded"));
1099           output_shndx = 0;
1100         }
1101
1102       elfcpp::Swap<32, big_endian>::writeval(contents, output_shndx);
1103     }
1104
1105   size_t wrote = reinterpret_cast<unsigned char*>(contents) - oview;
1106   gold_assert(wrote == oview_size);
1107
1108   of->write_output_view(off, oview_size, oview);
1109
1110   // We no longer need this information.
1111   this->input_shndxes_.clear();
1112 }
1113
1114 // Output_data_got::Got_entry methods.
1115
1116 // Write out the entry.
1117
1118 template<int size, bool big_endian>
1119 void
1120 Output_data_got<size, big_endian>::Got_entry::write(unsigned char* pov) const
1121 {
1122   Valtype val = 0;
1123
1124   switch (this->local_sym_index_)
1125     {
1126     case GSYM_CODE:
1127       {
1128         // If the symbol is resolved locally, we need to write out the
1129         // link-time value, which will be relocated dynamically by a
1130         // RELATIVE relocation.
1131         Symbol* gsym = this->u_.gsym;
1132         Sized_symbol<size>* sgsym;
1133         // This cast is a bit ugly.  We don't want to put a
1134         // virtual method in Symbol, because we want Symbol to be
1135         // as small as possible.
1136         sgsym = static_cast<Sized_symbol<size>*>(gsym);
1137         val = sgsym->value();
1138       }
1139       break;
1140
1141     case CONSTANT_CODE:
1142       val = this->u_.constant;
1143       break;
1144
1145     default:
1146       {
1147         const unsigned int lsi = this->local_sym_index_;
1148         const Symbol_value<size>* symval = this->u_.object->local_symbol(lsi);
1149         val = symval->value(this->u_.object, 0);
1150       }
1151       break;
1152     }
1153
1154   elfcpp::Swap<size, big_endian>::writeval(pov, val);
1155 }
1156
1157 // Output_data_got methods.
1158
1159 // Add an entry for a global symbol to the GOT.  This returns true if
1160 // this is a new GOT entry, false if the symbol already had a GOT
1161 // entry.
1162
1163 template<int size, bool big_endian>
1164 bool
1165 Output_data_got<size, big_endian>::add_global(
1166     Symbol* gsym,
1167     unsigned int got_type)
1168 {
1169   if (gsym->has_got_offset(got_type))
1170     return false;
1171
1172   this->entries_.push_back(Got_entry(gsym));
1173   this->set_got_size();
1174   gsym->set_got_offset(got_type, this->last_got_offset());
1175   return true;
1176 }
1177
1178 // Add an entry for a global symbol to the GOT, and add a dynamic
1179 // relocation of type R_TYPE for the GOT entry.
1180 template<int size, bool big_endian>
1181 void
1182 Output_data_got<size, big_endian>::add_global_with_rel(
1183     Symbol* gsym,
1184     unsigned int got_type,
1185     Rel_dyn* rel_dyn,
1186     unsigned int r_type)
1187 {
1188   if (gsym->has_got_offset(got_type))
1189     return;
1190
1191   this->entries_.push_back(Got_entry());
1192   this->set_got_size();
1193   unsigned int got_offset = this->last_got_offset();
1194   gsym->set_got_offset(got_type, got_offset);
1195   rel_dyn->add_global(gsym, r_type, this, got_offset);
1196 }
1197
1198 template<int size, bool big_endian>
1199 void
1200 Output_data_got<size, big_endian>::add_global_with_rela(
1201     Symbol* gsym,
1202     unsigned int got_type,
1203     Rela_dyn* rela_dyn,
1204     unsigned int r_type)
1205 {
1206   if (gsym->has_got_offset(got_type))
1207     return;
1208
1209   this->entries_.push_back(Got_entry());
1210   this->set_got_size();
1211   unsigned int got_offset = this->last_got_offset();
1212   gsym->set_got_offset(got_type, got_offset);
1213   rela_dyn->add_global(gsym, r_type, this, got_offset, 0);
1214 }
1215
1216 // Add a pair of entries for a global symbol to the GOT, and add
1217 // dynamic relocations of type R_TYPE_1 and R_TYPE_2, respectively.
1218 // If R_TYPE_2 == 0, add the second entry with no relocation.
1219 template<int size, bool big_endian>
1220 void
1221 Output_data_got<size, big_endian>::add_global_pair_with_rel(
1222     Symbol* gsym,
1223     unsigned int got_type,
1224     Rel_dyn* rel_dyn,
1225     unsigned int r_type_1,
1226     unsigned int r_type_2)
1227 {
1228   if (gsym->has_got_offset(got_type))
1229     return;
1230
1231   this->entries_.push_back(Got_entry());
1232   unsigned int got_offset = this->last_got_offset();
1233   gsym->set_got_offset(got_type, got_offset);
1234   rel_dyn->add_global(gsym, r_type_1, this, got_offset);
1235
1236   this->entries_.push_back(Got_entry());
1237   if (r_type_2 != 0)
1238     {
1239       got_offset = this->last_got_offset();
1240       rel_dyn->add_global(gsym, r_type_2, this, got_offset);
1241     }
1242
1243   this->set_got_size();
1244 }
1245
1246 template<int size, bool big_endian>
1247 void
1248 Output_data_got<size, big_endian>::add_global_pair_with_rela(
1249     Symbol* gsym,
1250     unsigned int got_type,
1251     Rela_dyn* rela_dyn,
1252     unsigned int r_type_1,
1253     unsigned int r_type_2)
1254 {
1255   if (gsym->has_got_offset(got_type))
1256     return;
1257
1258   this->entries_.push_back(Got_entry());
1259   unsigned int got_offset = this->last_got_offset();
1260   gsym->set_got_offset(got_type, got_offset);
1261   rela_dyn->add_global(gsym, r_type_1, this, got_offset, 0);
1262
1263   this->entries_.push_back(Got_entry());
1264   if (r_type_2 != 0)
1265     {
1266       got_offset = this->last_got_offset();
1267       rela_dyn->add_global(gsym, r_type_2, this, got_offset, 0);
1268     }
1269
1270   this->set_got_size();
1271 }
1272
1273 // Add an entry for a local symbol to the GOT.  This returns true if
1274 // this is a new GOT entry, false if the symbol already has a GOT
1275 // entry.
1276
1277 template<int size, bool big_endian>
1278 bool
1279 Output_data_got<size, big_endian>::add_local(
1280     Sized_relobj<size, big_endian>* object,
1281     unsigned int symndx,
1282     unsigned int got_type)
1283 {
1284   if (object->local_has_got_offset(symndx, got_type))
1285     return false;
1286
1287   this->entries_.push_back(Got_entry(object, symndx));
1288   this->set_got_size();
1289   object->set_local_got_offset(symndx, got_type, this->last_got_offset());
1290   return true;
1291 }
1292
1293 // Add an entry for a local symbol to the GOT, and add a dynamic
1294 // relocation of type R_TYPE for the GOT entry.
1295 template<int size, bool big_endian>
1296 void
1297 Output_data_got<size, big_endian>::add_local_with_rel(
1298     Sized_relobj<size, big_endian>* object,
1299     unsigned int symndx,
1300     unsigned int got_type,
1301     Rel_dyn* rel_dyn,
1302     unsigned int r_type)
1303 {
1304   if (object->local_has_got_offset(symndx, got_type))
1305     return;
1306
1307   this->entries_.push_back(Got_entry());
1308   this->set_got_size();
1309   unsigned int got_offset = this->last_got_offset();
1310   object->set_local_got_offset(symndx, got_type, got_offset);
1311   rel_dyn->add_local(object, symndx, r_type, this, got_offset);
1312 }
1313
1314 template<int size, bool big_endian>
1315 void
1316 Output_data_got<size, big_endian>::add_local_with_rela(
1317     Sized_relobj<size, big_endian>* object,
1318     unsigned int symndx,
1319     unsigned int got_type,
1320     Rela_dyn* rela_dyn,
1321     unsigned int r_type)
1322 {
1323   if (object->local_has_got_offset(symndx, got_type))
1324     return;
1325
1326   this->entries_.push_back(Got_entry());
1327   this->set_got_size();
1328   unsigned int got_offset = this->last_got_offset();
1329   object->set_local_got_offset(symndx, got_type, got_offset);
1330   rela_dyn->add_local(object, symndx, r_type, this, got_offset, 0);
1331 }
1332
1333 // Add a pair of entries for a local symbol to the GOT, and add
1334 // dynamic relocations of type R_TYPE_1 and R_TYPE_2, respectively.
1335 // If R_TYPE_2 == 0, add the second entry with no relocation.
1336 template<int size, bool big_endian>
1337 void
1338 Output_data_got<size, big_endian>::add_local_pair_with_rel(
1339     Sized_relobj<size, big_endian>* object,
1340     unsigned int symndx,
1341     unsigned int shndx,
1342     unsigned int got_type,
1343     Rel_dyn* rel_dyn,
1344     unsigned int r_type_1,
1345     unsigned int r_type_2)
1346 {
1347   if (object->local_has_got_offset(symndx, got_type))
1348     return;
1349
1350   this->entries_.push_back(Got_entry());
1351   unsigned int got_offset = this->last_got_offset();
1352   object->set_local_got_offset(symndx, got_type, got_offset);
1353   Output_section* os = object->output_section(shndx);
1354   rel_dyn->add_output_section(os, r_type_1, this, got_offset);
1355
1356   this->entries_.push_back(Got_entry(object, symndx));
1357   if (r_type_2 != 0)
1358     {
1359       got_offset = this->last_got_offset();
1360       rel_dyn->add_output_section(os, r_type_2, this, got_offset);
1361     }
1362
1363   this->set_got_size();
1364 }
1365
1366 template<int size, bool big_endian>
1367 void
1368 Output_data_got<size, big_endian>::add_local_pair_with_rela(
1369     Sized_relobj<size, big_endian>* object,
1370     unsigned int symndx,
1371     unsigned int shndx,
1372     unsigned int got_type,
1373     Rela_dyn* rela_dyn,
1374     unsigned int r_type_1,
1375     unsigned int r_type_2)
1376 {
1377   if (object->local_has_got_offset(symndx, got_type))
1378     return;
1379
1380   this->entries_.push_back(Got_entry());
1381   unsigned int got_offset = this->last_got_offset();
1382   object->set_local_got_offset(symndx, got_type, got_offset);
1383   Output_section* os = object->output_section(shndx);
1384   rela_dyn->add_output_section(os, r_type_1, this, got_offset, 0);
1385
1386   this->entries_.push_back(Got_entry(object, symndx));
1387   if (r_type_2 != 0)
1388     {
1389       got_offset = this->last_got_offset();
1390       rela_dyn->add_output_section(os, r_type_2, this, got_offset, 0);
1391     }
1392
1393   this->set_got_size();
1394 }
1395
1396 // Write out the GOT.
1397
1398 template<int size, bool big_endian>
1399 void
1400 Output_data_got<size, big_endian>::do_write(Output_file* of)
1401 {
1402   const int add = size / 8;
1403
1404   const off_t off = this->offset();
1405   const off_t oview_size = this->data_size();
1406   unsigned char* const oview = of->get_output_view(off, oview_size);
1407
1408   unsigned char* pov = oview;
1409   for (typename Got_entries::const_iterator p = this->entries_.begin();
1410        p != this->entries_.end();
1411        ++p)
1412     {
1413       p->write(pov);
1414       pov += add;
1415     }
1416
1417   gold_assert(pov - oview == oview_size);
1418
1419   of->write_output_view(off, oview_size, oview);
1420
1421   // We no longer need the GOT entries.
1422   this->entries_.clear();
1423 }
1424
1425 // Output_data_dynamic::Dynamic_entry methods.
1426
1427 // Write out the entry.
1428
1429 template<int size, bool big_endian>
1430 void
1431 Output_data_dynamic::Dynamic_entry::write(
1432     unsigned char* pov,
1433     const Stringpool* pool) const
1434 {
1435   typename elfcpp::Elf_types<size>::Elf_WXword val;
1436   switch (this->offset_)
1437     {
1438     case DYNAMIC_NUMBER:
1439       val = this->u_.val;
1440       break;
1441
1442     case DYNAMIC_SECTION_SIZE:
1443       val = this->u_.od->data_size();
1444       break;
1445
1446     case DYNAMIC_SYMBOL:
1447       {
1448         const Sized_symbol<size>* s =
1449           static_cast<const Sized_symbol<size>*>(this->u_.sym);
1450         val = s->value();
1451       }
1452       break;
1453
1454     case DYNAMIC_STRING:
1455       val = pool->get_offset(this->u_.str);
1456       break;
1457
1458     default:
1459       val = this->u_.od->address() + this->offset_;
1460       break;
1461     }
1462
1463   elfcpp::Dyn_write<size, big_endian> dw(pov);
1464   dw.put_d_tag(this->tag_);
1465   dw.put_d_val(val);
1466 }
1467
1468 // Output_data_dynamic methods.
1469
1470 // Adjust the output section to set the entry size.
1471
1472 void
1473 Output_data_dynamic::do_adjust_output_section(Output_section* os)
1474 {
1475   if (parameters->target().get_size() == 32)
1476     os->set_entsize(elfcpp::Elf_sizes<32>::dyn_size);
1477   else if (parameters->target().get_size() == 64)
1478     os->set_entsize(elfcpp::Elf_sizes<64>::dyn_size);
1479   else
1480     gold_unreachable();
1481 }
1482
1483 // Set the final data size.
1484
1485 void
1486 Output_data_dynamic::set_final_data_size()
1487 {
1488   // Add the terminating entry.
1489   this->add_constant(elfcpp::DT_NULL, 0);
1490
1491   int dyn_size;
1492   if (parameters->target().get_size() == 32)
1493     dyn_size = elfcpp::Elf_sizes<32>::dyn_size;
1494   else if (parameters->target().get_size() == 64)
1495     dyn_size = elfcpp::Elf_sizes<64>::dyn_size;
1496   else
1497     gold_unreachable();
1498   this->set_data_size(this->entries_.size() * dyn_size);
1499 }
1500
1501 // Write out the dynamic entries.
1502
1503 void
1504 Output_data_dynamic::do_write(Output_file* of)
1505 {
1506   switch (parameters->size_and_endianness())
1507     {
1508 #ifdef HAVE_TARGET_32_LITTLE
1509     case Parameters::TARGET_32_LITTLE:
1510       this->sized_write<32, false>(of);
1511       break;
1512 #endif
1513 #ifdef HAVE_TARGET_32_BIG
1514     case Parameters::TARGET_32_BIG:
1515       this->sized_write<32, true>(of);
1516       break;
1517 #endif
1518 #ifdef HAVE_TARGET_64_LITTLE
1519     case Parameters::TARGET_64_LITTLE:
1520       this->sized_write<64, false>(of);
1521       break;
1522 #endif
1523 #ifdef HAVE_TARGET_64_BIG
1524     case Parameters::TARGET_64_BIG:
1525       this->sized_write<64, true>(of);
1526       break;
1527 #endif
1528     default:
1529       gold_unreachable();
1530     }
1531 }
1532
1533 template<int size, bool big_endian>
1534 void
1535 Output_data_dynamic::sized_write(Output_file* of)
1536 {
1537   const int dyn_size = elfcpp::Elf_sizes<size>::dyn_size;
1538
1539   const off_t offset = this->offset();
1540   const off_t oview_size = this->data_size();
1541   unsigned char* const oview = of->get_output_view(offset, oview_size);
1542
1543   unsigned char* pov = oview;
1544   for (typename Dynamic_entries::const_iterator p = this->entries_.begin();
1545        p != this->entries_.end();
1546        ++p)
1547     {
1548       p->write<size, big_endian>(pov, this->pool_);
1549       pov += dyn_size;
1550     }
1551
1552   gold_assert(pov - oview == oview_size);
1553
1554   of->write_output_view(offset, oview_size, oview);
1555
1556   // We no longer need the dynamic entries.
1557   this->entries_.clear();
1558 }
1559
1560 // Class Output_symtab_xindex.
1561
1562 void
1563 Output_symtab_xindex::do_write(Output_file* of)
1564 {
1565   const off_t offset = this->offset();
1566   const off_t oview_size = this->data_size();
1567   unsigned char* const oview = of->get_output_view(offset, oview_size);
1568
1569   memset(oview, 0, oview_size);
1570
1571   if (parameters->target().is_big_endian())
1572     this->endian_do_write<true>(oview);
1573   else
1574     this->endian_do_write<false>(oview);
1575
1576   of->write_output_view(offset, oview_size, oview);
1577
1578   // We no longer need the data.
1579   this->entries_.clear();
1580 }
1581
1582 template<bool big_endian>
1583 void
1584 Output_symtab_xindex::endian_do_write(unsigned char* const oview)
1585 {
1586   for (Xindex_entries::const_iterator p = this->entries_.begin();
1587        p != this->entries_.end();
1588        ++p)
1589     elfcpp::Swap<32, big_endian>::writeval(oview + p->first * 4, p->second);
1590 }
1591
1592 // Output_section::Input_section methods.
1593
1594 // Return the data size.  For an input section we store the size here.
1595 // For an Output_section_data, we have to ask it for the size.
1596
1597 off_t
1598 Output_section::Input_section::data_size() const
1599 {
1600   if (this->is_input_section())
1601     return this->u1_.data_size;
1602   else
1603     return this->u2_.posd->data_size();
1604 }
1605
1606 // Set the address and file offset.
1607
1608 void
1609 Output_section::Input_section::set_address_and_file_offset(
1610     uint64_t address,
1611     off_t file_offset,
1612     off_t section_file_offset)
1613 {
1614   if (this->is_input_section())
1615     this->u2_.object->set_section_offset(this->shndx_,
1616                                          file_offset - section_file_offset);
1617   else
1618     this->u2_.posd->set_address_and_file_offset(address, file_offset);
1619 }
1620
1621 // Reset the address and file offset.
1622
1623 void
1624 Output_section::Input_section::reset_address_and_file_offset()
1625 {
1626   if (!this->is_input_section())
1627     this->u2_.posd->reset_address_and_file_offset();
1628 }
1629
1630 // Finalize the data size.
1631
1632 void
1633 Output_section::Input_section::finalize_data_size()
1634 {
1635   if (!this->is_input_section())
1636     this->u2_.posd->finalize_data_size();
1637 }
1638
1639 // Try to turn an input offset into an output offset.  We want to
1640 // return the output offset relative to the start of this
1641 // Input_section in the output section.
1642
1643 inline bool
1644 Output_section::Input_section::output_offset(
1645     const Relobj* object,
1646     unsigned int shndx,
1647     section_offset_type offset,
1648     section_offset_type *poutput) const
1649 {
1650   if (!this->is_input_section())
1651     return this->u2_.posd->output_offset(object, shndx, offset, poutput);
1652   else
1653     {
1654       if (this->shndx_ != shndx || this->u2_.object != object)
1655         return false;
1656       *poutput = offset;
1657       return true;
1658     }
1659 }
1660
1661 // Return whether this is the merge section for the input section
1662 // SHNDX in OBJECT.
1663
1664 inline bool
1665 Output_section::Input_section::is_merge_section_for(const Relobj* object,
1666                                                     unsigned int shndx) const
1667 {
1668   if (this->is_input_section())
1669     return false;
1670   return this->u2_.posd->is_merge_section_for(object, shndx);
1671 }
1672
1673 // Write out the data.  We don't have to do anything for an input
1674 // section--they are handled via Object::relocate--but this is where
1675 // we write out the data for an Output_section_data.
1676
1677 void
1678 Output_section::Input_section::write(Output_file* of)
1679 {
1680   if (!this->is_input_section())
1681     this->u2_.posd->write(of);
1682 }
1683
1684 // Write the data to a buffer.  As for write(), we don't have to do
1685 // anything for an input section.
1686
1687 void
1688 Output_section::Input_section::write_to_buffer(unsigned char* buffer)
1689 {
1690   if (!this->is_input_section())
1691     this->u2_.posd->write_to_buffer(buffer);
1692 }
1693
1694 // Print to a map file.
1695
1696 void
1697 Output_section::Input_section::print_to_mapfile(Mapfile* mapfile) const
1698 {
1699   switch (this->shndx_)
1700     {
1701     case OUTPUT_SECTION_CODE:
1702     case MERGE_DATA_SECTION_CODE:
1703     case MERGE_STRING_SECTION_CODE:
1704       this->u2_.posd->print_to_mapfile(mapfile);
1705       break;
1706
1707     default:
1708       mapfile->print_input_section(this->u2_.object, this->shndx_);
1709       break;
1710     }
1711 }
1712
1713 // Output_section methods.
1714
1715 // Construct an Output_section.  NAME will point into a Stringpool.
1716
1717 Output_section::Output_section(const char* name, elfcpp::Elf_Word type,
1718                                elfcpp::Elf_Xword flags)
1719   : name_(name),
1720     addralign_(0),
1721     entsize_(0),
1722     load_address_(0),
1723     link_section_(NULL),
1724     link_(0),
1725     info_section_(NULL),
1726     info_symndx_(NULL),
1727     info_(0),
1728     type_(type),
1729     flags_(flags),
1730     out_shndx_(-1U),
1731     symtab_index_(0),
1732     dynsym_index_(0),
1733     input_sections_(),
1734     first_input_offset_(0),
1735     fills_(),
1736     postprocessing_buffer_(NULL),
1737     needs_symtab_index_(false),
1738     needs_dynsym_index_(false),
1739     should_link_to_symtab_(false),
1740     should_link_to_dynsym_(false),
1741     after_input_sections_(false),
1742     requires_postprocessing_(false),
1743     found_in_sections_clause_(false),
1744     has_load_address_(false),
1745     info_uses_section_index_(false),
1746     may_sort_attached_input_sections_(false),
1747     must_sort_attached_input_sections_(false),
1748     attached_input_sections_are_sorted_(false),
1749     is_relro_(false),
1750     is_relro_local_(false),
1751     tls_offset_(0)
1752 {
1753   // An unallocated section has no address.  Forcing this means that
1754   // we don't need special treatment for symbols defined in debug
1755   // sections.
1756   if ((flags & elfcpp::SHF_ALLOC) == 0)
1757     this->set_address(0);
1758 }
1759
1760 Output_section::~Output_section()
1761 {
1762 }
1763
1764 // Set the entry size.
1765
1766 void
1767 Output_section::set_entsize(uint64_t v)
1768 {
1769   if (this->entsize_ == 0)
1770     this->entsize_ = v;
1771   else
1772     gold_assert(this->entsize_ == v);
1773 }
1774
1775 // Add the input section SHNDX, with header SHDR, named SECNAME, in
1776 // OBJECT, to the Output_section.  RELOC_SHNDX is the index of a
1777 // relocation section which applies to this section, or 0 if none, or
1778 // -1U if more than one.  Return the offset of the input section
1779 // within the output section.  Return -1 if the input section will
1780 // receive special handling.  In the normal case we don't always keep
1781 // track of input sections for an Output_section.  Instead, each
1782 // Object keeps track of the Output_section for each of its input
1783 // sections.  However, if HAVE_SECTIONS_SCRIPT is true, we do keep
1784 // track of input sections here; this is used when SECTIONS appears in
1785 // a linker script.
1786
1787 template<int size, bool big_endian>
1788 off_t
1789 Output_section::add_input_section(Sized_relobj<size, big_endian>* object,
1790                                   unsigned int shndx,
1791                                   const char* secname,
1792                                   const elfcpp::Shdr<size, big_endian>& shdr,
1793                                   unsigned int reloc_shndx,
1794                                   bool have_sections_script)
1795 {
1796   elfcpp::Elf_Xword addralign = shdr.get_sh_addralign();
1797   if ((addralign & (addralign - 1)) != 0)
1798     {
1799       object->error(_("invalid alignment %lu for section \"%s\""),
1800                     static_cast<unsigned long>(addralign), secname);
1801       addralign = 1;
1802     }
1803
1804   if (addralign > this->addralign_)
1805     this->addralign_ = addralign;
1806
1807   typename elfcpp::Elf_types<size>::Elf_WXword sh_flags = shdr.get_sh_flags();
1808   this->update_flags_for_input_section(sh_flags);
1809
1810   uint64_t entsize = shdr.get_sh_entsize();
1811
1812   // .debug_str is a mergeable string section, but is not always so
1813   // marked by compilers.  Mark manually here so we can optimize.
1814   if (strcmp(secname, ".debug_str") == 0)
1815     {
1816       sh_flags |= (elfcpp::SHF_MERGE | elfcpp::SHF_STRINGS);
1817       entsize = 1;
1818     }
1819
1820   // If this is a SHF_MERGE section, we pass all the input sections to
1821   // a Output_data_merge.  We don't try to handle relocations for such
1822   // a section.
1823   if ((sh_flags & elfcpp::SHF_MERGE) != 0
1824       && reloc_shndx == 0)
1825     {
1826       if (this->add_merge_input_section(object, shndx, sh_flags,
1827                                         entsize, addralign))
1828         {
1829           // Tell the relocation routines that they need to call the
1830           // output_offset method to determine the final address.
1831           return -1;
1832         }
1833     }
1834
1835   off_t offset_in_section = this->current_data_size_for_child();
1836   off_t aligned_offset_in_section = align_address(offset_in_section,
1837                                                   addralign);
1838
1839   if (aligned_offset_in_section > offset_in_section
1840       && !have_sections_script
1841       && (sh_flags & elfcpp::SHF_EXECINSTR) != 0
1842       && object->target()->has_code_fill())
1843     {
1844       // We need to add some fill data.  Using fill_list_ when
1845       // possible is an optimization, since we will often have fill
1846       // sections without input sections.
1847       off_t fill_len = aligned_offset_in_section - offset_in_section;
1848       if (this->input_sections_.empty())
1849         this->fills_.push_back(Fill(offset_in_section, fill_len));
1850       else
1851         {
1852           // FIXME: When relaxing, the size needs to adjust to
1853           // maintain a constant alignment.
1854           std::string fill_data(object->target()->code_fill(fill_len));
1855           Output_data_const* odc = new Output_data_const(fill_data, 1);
1856           this->input_sections_.push_back(Input_section(odc));
1857         }
1858     }
1859
1860   this->set_current_data_size_for_child(aligned_offset_in_section
1861                                         + shdr.get_sh_size());
1862
1863   // We need to keep track of this section if we are already keeping
1864   // track of sections, or if we are relaxing.  Also, if this is a
1865   // section which requires sorting, or which may require sorting in
1866   // the future, we keep track of the sections.  FIXME: Add test for
1867   // relaxing.
1868   if (have_sections_script
1869       || !this->input_sections_.empty()
1870       || this->may_sort_attached_input_sections()
1871       || this->must_sort_attached_input_sections()
1872       || parameters->options().user_set_Map())
1873     this->input_sections_.push_back(Input_section(object, shndx,
1874                                                   shdr.get_sh_size(),
1875                                                   addralign));
1876
1877   return aligned_offset_in_section;
1878 }
1879
1880 // Add arbitrary data to an output section.
1881
1882 void
1883 Output_section::add_output_section_data(Output_section_data* posd)
1884 {
1885   Input_section inp(posd);
1886   this->add_output_section_data(&inp);
1887
1888   if (posd->is_data_size_valid())
1889     {
1890       off_t offset_in_section = this->current_data_size_for_child();
1891       off_t aligned_offset_in_section = align_address(offset_in_section,
1892                                                       posd->addralign());
1893       this->set_current_data_size_for_child(aligned_offset_in_section
1894                                             + posd->data_size());
1895     }
1896 }
1897
1898 // Add arbitrary data to an output section by Input_section.
1899
1900 void
1901 Output_section::add_output_section_data(Input_section* inp)
1902 {
1903   if (this->input_sections_.empty())
1904     this->first_input_offset_ = this->current_data_size_for_child();
1905
1906   this->input_sections_.push_back(*inp);
1907
1908   uint64_t addralign = inp->addralign();
1909   if (addralign > this->addralign_)
1910     this->addralign_ = addralign;
1911
1912   inp->set_output_section(this);
1913 }
1914
1915 // Add a merge section to an output section.
1916
1917 void
1918 Output_section::add_output_merge_section(Output_section_data* posd,
1919                                          bool is_string, uint64_t entsize)
1920 {
1921   Input_section inp(posd, is_string, entsize);
1922   this->add_output_section_data(&inp);
1923 }
1924
1925 // Add an input section to a SHF_MERGE section.
1926
1927 bool
1928 Output_section::add_merge_input_section(Relobj* object, unsigned int shndx,
1929                                         uint64_t flags, uint64_t entsize,
1930                                         uint64_t addralign)
1931 {
1932   bool is_string = (flags & elfcpp::SHF_STRINGS) != 0;
1933
1934   // We only merge strings if the alignment is not more than the
1935   // character size.  This could be handled, but it's unusual.
1936   if (is_string && addralign > entsize)
1937     return false;
1938
1939   Input_section_list::iterator p;
1940   for (p = this->input_sections_.begin();
1941        p != this->input_sections_.end();
1942        ++p)
1943     if (p->is_merge_section(is_string, entsize, addralign))
1944       {
1945         p->add_input_section(object, shndx);
1946         return true;
1947       }
1948
1949   // We handle the actual constant merging in Output_merge_data or
1950   // Output_merge_string_data.
1951   Output_section_data* posd;
1952   if (!is_string)
1953     posd = new Output_merge_data(entsize, addralign);
1954   else
1955     {
1956       switch (entsize)
1957         {
1958         case 1:
1959           posd = new Output_merge_string<char>(addralign);
1960           break;
1961         case 2:
1962           posd = new Output_merge_string<uint16_t>(addralign);
1963           break;
1964         case 4:
1965           posd = new Output_merge_string<uint32_t>(addralign);
1966           break;
1967         default:
1968           return false;
1969         }
1970     }
1971
1972   this->add_output_merge_section(posd, is_string, entsize);
1973   posd->add_input_section(object, shndx);
1974
1975   return true;
1976 }
1977
1978 // Given an address OFFSET relative to the start of input section
1979 // SHNDX in OBJECT, return whether this address is being included in
1980 // the final link.  This should only be called if SHNDX in OBJECT has
1981 // a special mapping.
1982
1983 bool
1984 Output_section::is_input_address_mapped(const Relobj* object,
1985                                         unsigned int shndx,
1986                                         off_t offset) const
1987 {
1988   for (Input_section_list::const_iterator p = this->input_sections_.begin();
1989        p != this->input_sections_.end();
1990        ++p)
1991     {
1992       section_offset_type output_offset;
1993       if (p->output_offset(object, shndx, offset, &output_offset))
1994         return output_offset != -1;
1995     }
1996
1997   // By default we assume that the address is mapped.  This should
1998   // only be called after we have passed all sections to Layout.  At
1999   // that point we should know what we are discarding.
2000   return true;
2001 }
2002
2003 // Given an address OFFSET relative to the start of input section
2004 // SHNDX in object OBJECT, return the output offset relative to the
2005 // start of the input section in the output section.  This should only
2006 // be called if SHNDX in OBJECT has a special mapping.
2007
2008 section_offset_type
2009 Output_section::output_offset(const Relobj* object, unsigned int shndx,
2010                               section_offset_type offset) const
2011 {
2012   // This can only be called meaningfully when layout is complete.
2013   gold_assert(Output_data::is_layout_complete());
2014
2015   for (Input_section_list::const_iterator p = this->input_sections_.begin();
2016        p != this->input_sections_.end();
2017        ++p)
2018     {
2019       section_offset_type output_offset;
2020       if (p->output_offset(object, shndx, offset, &output_offset))
2021         return output_offset;
2022     }
2023   gold_unreachable();
2024 }
2025
2026 // Return the output virtual address of OFFSET relative to the start
2027 // of input section SHNDX in object OBJECT.
2028
2029 uint64_t
2030 Output_section::output_address(const Relobj* object, unsigned int shndx,
2031                                off_t offset) const
2032 {
2033   uint64_t addr = this->address() + this->first_input_offset_;
2034   for (Input_section_list::const_iterator p = this->input_sections_.begin();
2035        p != this->input_sections_.end();
2036        ++p)
2037     {
2038       addr = align_address(addr, p->addralign());
2039       section_offset_type output_offset;
2040       if (p->output_offset(object, shndx, offset, &output_offset))
2041         {
2042           if (output_offset == -1)
2043             return -1U;
2044           return addr + output_offset;
2045         }
2046       addr += p->data_size();
2047     }
2048
2049   // If we get here, it means that we don't know the mapping for this
2050   // input section.  This might happen in principle if
2051   // add_input_section were called before add_output_section_data.
2052   // But it should never actually happen.
2053
2054   gold_unreachable();
2055 }
2056
2057 // Return the output address of the start of the merged section for
2058 // input section SHNDX in object OBJECT.
2059
2060 uint64_t
2061 Output_section::starting_output_address(const Relobj* object,
2062                                         unsigned int shndx) const
2063 {
2064   uint64_t addr = this->address() + this->first_input_offset_;
2065   for (Input_section_list::const_iterator p = this->input_sections_.begin();
2066        p != this->input_sections_.end();
2067        ++p)
2068     {
2069       addr = align_address(addr, p->addralign());
2070
2071       // It would be nice if we could use the existing output_offset
2072       // method to get the output offset of input offset 0.
2073       // Unfortunately we don't know for sure that input offset 0 is
2074       // mapped at all.
2075       if (p->is_merge_section_for(object, shndx))
2076         return addr;
2077
2078       addr += p->data_size();
2079     }
2080   gold_unreachable();
2081 }
2082
2083 // Set the data size of an Output_section.  This is where we handle
2084 // setting the addresses of any Output_section_data objects.
2085
2086 void
2087 Output_section::set_final_data_size()
2088 {
2089   if (this->input_sections_.empty())
2090     {
2091       this->set_data_size(this->current_data_size_for_child());
2092       return;
2093     }
2094
2095   if (this->must_sort_attached_input_sections())
2096     this->sort_attached_input_sections();
2097
2098   uint64_t address = this->address();
2099   off_t startoff = this->offset();
2100   off_t off = startoff + this->first_input_offset_;
2101   for (Input_section_list::iterator p = this->input_sections_.begin();
2102        p != this->input_sections_.end();
2103        ++p)
2104     {
2105       off = align_address(off, p->addralign());
2106       p->set_address_and_file_offset(address + (off - startoff), off,
2107                                      startoff);
2108       off += p->data_size();
2109     }
2110
2111   this->set_data_size(off - startoff);
2112 }
2113
2114 // Reset the address and file offset.
2115
2116 void
2117 Output_section::do_reset_address_and_file_offset()
2118 {
2119   for (Input_section_list::iterator p = this->input_sections_.begin();
2120        p != this->input_sections_.end();
2121        ++p)
2122     p->reset_address_and_file_offset();
2123 }
2124
2125 // Set the TLS offset.  Called only for SHT_TLS sections.
2126
2127 void
2128 Output_section::do_set_tls_offset(uint64_t tls_base)
2129 {
2130   this->tls_offset_ = this->address() - tls_base;
2131 }
2132
2133 // In a few cases we need to sort the input sections attached to an
2134 // output section.  This is used to implement the type of constructor
2135 // priority ordering implemented by the GNU linker, in which the
2136 // priority becomes part of the section name and the sections are
2137 // sorted by name.  We only do this for an output section if we see an
2138 // attached input section matching ".ctor.*", ".dtor.*",
2139 // ".init_array.*" or ".fini_array.*".
2140
2141 class Output_section::Input_section_sort_entry
2142 {
2143  public:
2144   Input_section_sort_entry()
2145     : input_section_(), index_(-1U), section_has_name_(false),
2146       section_name_()
2147   { }
2148
2149   Input_section_sort_entry(const Input_section& input_section,
2150                            unsigned int index)
2151     : input_section_(input_section), index_(index),
2152       section_has_name_(input_section.is_input_section())
2153   {
2154     if (this->section_has_name_)
2155       {
2156         // This is only called single-threaded from Layout::finalize,
2157         // so it is OK to lock.  Unfortunately we have no way to pass
2158         // in a Task token.
2159         const Task* dummy_task = reinterpret_cast<const Task*>(-1);
2160         Object* obj = input_section.relobj();
2161         Task_lock_obj<Object> tl(dummy_task, obj);
2162
2163         // This is a slow operation, which should be cached in
2164         // Layout::layout if this becomes a speed problem.
2165         this->section_name_ = obj->section_name(input_section.shndx());
2166       }
2167   }
2168
2169   // Return the Input_section.
2170   const Input_section&
2171   input_section() const
2172   {
2173     gold_assert(this->index_ != -1U);
2174     return this->input_section_;
2175   }
2176
2177   // The index of this entry in the original list.  This is used to
2178   // make the sort stable.
2179   unsigned int
2180   index() const
2181   {
2182     gold_assert(this->index_ != -1U);
2183     return this->index_;
2184   }
2185
2186   // Whether there is a section name.
2187   bool
2188   section_has_name() const
2189   { return this->section_has_name_; }
2190
2191   // The section name.
2192   const std::string&
2193   section_name() const
2194   {
2195     gold_assert(this->section_has_name_);
2196     return this->section_name_;
2197   }
2198
2199   // Return true if the section name has a priority.  This is assumed
2200   // to be true if it has a dot after the initial dot.
2201   bool
2202   has_priority() const
2203   {
2204     gold_assert(this->section_has_name_);
2205     return this->section_name_.find('.', 1);
2206   }
2207
2208   // Return true if this an input file whose base name matches
2209   // FILE_NAME.  The base name must have an extension of ".o", and
2210   // must be exactly FILE_NAME.o or FILE_NAME, one character, ".o".
2211   // This is to match crtbegin.o as well as crtbeginS.o without
2212   // getting confused by other possibilities.  Overall matching the
2213   // file name this way is a dreadful hack, but the GNU linker does it
2214   // in order to better support gcc, and we need to be compatible.
2215   bool
2216   match_file_name(const char* match_file_name) const
2217   {
2218     const std::string& file_name(this->input_section_.relobj()->name());
2219     const char* base_name = lbasename(file_name.c_str());
2220     size_t match_len = strlen(match_file_name);
2221     if (strncmp(base_name, match_file_name, match_len) != 0)
2222       return false;
2223     size_t base_len = strlen(base_name);
2224     if (base_len != match_len + 2 && base_len != match_len + 3)
2225       return false;
2226     return memcmp(base_name + base_len - 2, ".o", 2) == 0;
2227   }
2228
2229  private:
2230   // The Input_section we are sorting.
2231   Input_section input_section_;
2232   // The index of this Input_section in the original list.
2233   unsigned int index_;
2234   // Whether this Input_section has a section name--it won't if this
2235   // is some random Output_section_data.
2236   bool section_has_name_;
2237   // The section name if there is one.
2238   std::string section_name_;
2239 };
2240
2241 // Return true if S1 should come before S2 in the output section.
2242
2243 bool
2244 Output_section::Input_section_sort_compare::operator()(
2245     const Output_section::Input_section_sort_entry& s1,
2246     const Output_section::Input_section_sort_entry& s2) const
2247 {
2248   // crtbegin.o must come first.
2249   bool s1_begin = s1.match_file_name("crtbegin");
2250   bool s2_begin = s2.match_file_name("crtbegin");
2251   if (s1_begin || s2_begin)
2252     {
2253       if (!s1_begin)
2254         return false;
2255       if (!s2_begin)
2256         return true;
2257       return s1.index() < s2.index();
2258     }
2259
2260   // crtend.o must come last.
2261   bool s1_end = s1.match_file_name("crtend");
2262   bool s2_end = s2.match_file_name("crtend");
2263   if (s1_end || s2_end)
2264     {
2265       if (!s1_end)
2266         return true;
2267       if (!s2_end)
2268         return false;
2269       return s1.index() < s2.index();
2270     }
2271
2272   // We sort all the sections with no names to the end.
2273   if (!s1.section_has_name() || !s2.section_has_name())
2274     {
2275       if (s1.section_has_name())
2276         return true;
2277       if (s2.section_has_name())
2278         return false;
2279       return s1.index() < s2.index();
2280     }
2281
2282   // A section with a priority follows a section without a priority.
2283   // The GNU linker does this for all but .init_array sections; until
2284   // further notice we'll assume that that is an mistake.
2285   bool s1_has_priority = s1.has_priority();
2286   bool s2_has_priority = s2.has_priority();
2287   if (s1_has_priority && !s2_has_priority)
2288     return false;
2289   if (!s1_has_priority && s2_has_priority)
2290     return true;
2291
2292   // Otherwise we sort by name.
2293   int compare = s1.section_name().compare(s2.section_name());
2294   if (compare != 0)
2295     return compare < 0;
2296
2297   // Otherwise we keep the input order.
2298   return s1.index() < s2.index();
2299 }
2300
2301 // Sort the input sections attached to an output section.
2302
2303 void
2304 Output_section::sort_attached_input_sections()
2305 {
2306   if (this->attached_input_sections_are_sorted_)
2307     return;
2308
2309   // The only thing we know about an input section is the object and
2310   // the section index.  We need the section name.  Recomputing this
2311   // is slow but this is an unusual case.  If this becomes a speed
2312   // problem we can cache the names as required in Layout::layout.
2313
2314   // We start by building a larger vector holding a copy of each
2315   // Input_section, plus its current index in the list and its name.
2316   std::vector<Input_section_sort_entry> sort_list;
2317
2318   unsigned int i = 0;
2319   for (Input_section_list::iterator p = this->input_sections_.begin();
2320        p != this->input_sections_.end();
2321        ++p, ++i)
2322     sort_list.push_back(Input_section_sort_entry(*p, i));
2323
2324   // Sort the input sections.
2325   std::sort(sort_list.begin(), sort_list.end(), Input_section_sort_compare());
2326
2327   // Copy the sorted input sections back to our list.
2328   this->input_sections_.clear();
2329   for (std::vector<Input_section_sort_entry>::iterator p = sort_list.begin();
2330        p != sort_list.end();
2331        ++p)
2332     this->input_sections_.push_back(p->input_section());
2333
2334   // Remember that we sorted the input sections, since we might get
2335   // called again.
2336   this->attached_input_sections_are_sorted_ = true;
2337 }
2338
2339 // Write the section header to *OSHDR.
2340
2341 template<int size, bool big_endian>
2342 void
2343 Output_section::write_header(const Layout* layout,
2344                              const Stringpool* secnamepool,
2345                              elfcpp::Shdr_write<size, big_endian>* oshdr) const
2346 {
2347   oshdr->put_sh_name(secnamepool->get_offset(this->name_));
2348   oshdr->put_sh_type(this->type_);
2349
2350   elfcpp::Elf_Xword flags = this->flags_;
2351   if (this->info_section_ != NULL && this->info_uses_section_index_)
2352     flags |= elfcpp::SHF_INFO_LINK;
2353   oshdr->put_sh_flags(flags);
2354
2355   oshdr->put_sh_addr(this->address());
2356   oshdr->put_sh_offset(this->offset());
2357   oshdr->put_sh_size(this->data_size());
2358   if (this->link_section_ != NULL)
2359     oshdr->put_sh_link(this->link_section_->out_shndx());
2360   else if (this->should_link_to_symtab_)
2361     oshdr->put_sh_link(layout->symtab_section()->out_shndx());
2362   else if (this->should_link_to_dynsym_)
2363     oshdr->put_sh_link(layout->dynsym_section()->out_shndx());
2364   else
2365     oshdr->put_sh_link(this->link_);
2366
2367   elfcpp::Elf_Word info;
2368   if (this->info_section_ != NULL)
2369     {
2370       if (this->info_uses_section_index_)
2371         info = this->info_section_->out_shndx();
2372       else
2373         info = this->info_section_->symtab_index();
2374     }
2375   else if (this->info_symndx_ != NULL)
2376     info = this->info_symndx_->symtab_index();
2377   else
2378     info = this->info_;
2379   oshdr->put_sh_info(info);
2380
2381   oshdr->put_sh_addralign(this->addralign_);
2382   oshdr->put_sh_entsize(this->entsize_);
2383 }
2384
2385 // Write out the data.  For input sections the data is written out by
2386 // Object::relocate, but we have to handle Output_section_data objects
2387 // here.
2388
2389 void
2390 Output_section::do_write(Output_file* of)
2391 {
2392   gold_assert(!this->requires_postprocessing());
2393
2394   off_t output_section_file_offset = this->offset();
2395   for (Fill_list::iterator p = this->fills_.begin();
2396        p != this->fills_.end();
2397        ++p)
2398     {
2399       std::string fill_data(parameters->target().code_fill(p->length()));
2400       of->write(output_section_file_offset + p->section_offset(),
2401                 fill_data.data(), fill_data.size());
2402     }
2403
2404   for (Input_section_list::iterator p = this->input_sections_.begin();
2405        p != this->input_sections_.end();
2406        ++p)
2407     p->write(of);
2408 }
2409
2410 // If a section requires postprocessing, create the buffer to use.
2411
2412 void
2413 Output_section::create_postprocessing_buffer()
2414 {
2415   gold_assert(this->requires_postprocessing());
2416
2417   if (this->postprocessing_buffer_ != NULL)
2418     return;
2419
2420   if (!this->input_sections_.empty())
2421     {
2422       off_t off = this->first_input_offset_;
2423       for (Input_section_list::iterator p = this->input_sections_.begin();
2424            p != this->input_sections_.end();
2425            ++p)
2426         {
2427           off = align_address(off, p->addralign());
2428           p->finalize_data_size();
2429           off += p->data_size();
2430         }
2431       this->set_current_data_size_for_child(off);
2432     }
2433
2434   off_t buffer_size = this->current_data_size_for_child();
2435   this->postprocessing_buffer_ = new unsigned char[buffer_size];
2436 }
2437
2438 // Write all the data of an Output_section into the postprocessing
2439 // buffer.  This is used for sections which require postprocessing,
2440 // such as compression.  Input sections are handled by
2441 // Object::Relocate.
2442
2443 void
2444 Output_section::write_to_postprocessing_buffer()
2445 {
2446   gold_assert(this->requires_postprocessing());
2447
2448   unsigned char* buffer = this->postprocessing_buffer();
2449   for (Fill_list::iterator p = this->fills_.begin();
2450        p != this->fills_.end();
2451        ++p)
2452     {
2453       std::string fill_data(parameters->target().code_fill(p->length()));
2454       memcpy(buffer + p->section_offset(), fill_data.data(),
2455              fill_data.size());
2456     }
2457
2458   off_t off = this->first_input_offset_;
2459   for (Input_section_list::iterator p = this->input_sections_.begin();
2460        p != this->input_sections_.end();
2461        ++p)
2462     {
2463       off = align_address(off, p->addralign());
2464       p->write_to_buffer(buffer + off);
2465       off += p->data_size();
2466     }
2467 }
2468
2469 // Get the input sections for linker script processing.  We leave
2470 // behind the Output_section_data entries.  Note that this may be
2471 // slightly incorrect for merge sections.  We will leave them behind,
2472 // but it is possible that the script says that they should follow
2473 // some other input sections, as in:
2474 //    .rodata { *(.rodata) *(.rodata.cst*) }
2475 // For that matter, we don't handle this correctly:
2476 //    .rodata { foo.o(.rodata.cst*) *(.rodata.cst*) }
2477 // With luck this will never matter.
2478
2479 uint64_t
2480 Output_section::get_input_sections(
2481     uint64_t address,
2482     const std::string& fill,
2483     std::list<std::pair<Relobj*, unsigned int> >* input_sections)
2484 {
2485   uint64_t orig_address = address;
2486
2487   address = align_address(address, this->addralign());
2488
2489   Input_section_list remaining;
2490   for (Input_section_list::iterator p = this->input_sections_.begin();
2491        p != this->input_sections_.end();
2492        ++p)
2493     {
2494       if (p->is_input_section())
2495         input_sections->push_back(std::make_pair(p->relobj(), p->shndx()));
2496       else
2497         {
2498           uint64_t aligned_address = align_address(address, p->addralign());
2499           if (aligned_address != address && !fill.empty())
2500             {
2501               section_size_type length =
2502                 convert_to_section_size_type(aligned_address - address);
2503               std::string this_fill;
2504               this_fill.reserve(length);
2505               while (this_fill.length() + fill.length() <= length)
2506                 this_fill += fill;
2507               if (this_fill.length() < length)
2508                 this_fill.append(fill, 0, length - this_fill.length());
2509
2510               Output_section_data* posd = new Output_data_const(this_fill, 0);
2511               remaining.push_back(Input_section(posd));
2512             }
2513           address = aligned_address;
2514
2515           remaining.push_back(*p);
2516
2517           p->finalize_data_size();
2518           address += p->data_size();
2519         }
2520     }
2521
2522   this->input_sections_.swap(remaining);
2523   this->first_input_offset_ = 0;
2524
2525   uint64_t data_size = address - orig_address;
2526   this->set_current_data_size_for_child(data_size);
2527   return data_size;
2528 }
2529
2530 // Add an input section from a script.
2531
2532 void
2533 Output_section::add_input_section_for_script(Relobj* object,
2534                                              unsigned int shndx,
2535                                              off_t data_size,
2536                                              uint64_t addralign)
2537 {
2538   if (addralign > this->addralign_)
2539     this->addralign_ = addralign;
2540
2541   off_t offset_in_section = this->current_data_size_for_child();
2542   off_t aligned_offset_in_section = align_address(offset_in_section,
2543                                                   addralign);
2544
2545   this->set_current_data_size_for_child(aligned_offset_in_section
2546                                         + data_size);
2547
2548   this->input_sections_.push_back(Input_section(object, shndx,
2549                                                 data_size, addralign));
2550 }
2551
2552 // Print to the map file.
2553
2554 void
2555 Output_section::do_print_to_mapfile(Mapfile* mapfile) const
2556 {
2557   mapfile->print_output_section(this);
2558
2559   for (Input_section_list::const_iterator p = this->input_sections_.begin();
2560        p != this->input_sections_.end();
2561        ++p)
2562     p->print_to_mapfile(mapfile);
2563 }
2564
2565 // Print stats for merge sections to stderr.
2566
2567 void
2568 Output_section::print_merge_stats()
2569 {
2570   Input_section_list::iterator p;
2571   for (p = this->input_sections_.begin();
2572        p != this->input_sections_.end();
2573        ++p)
2574     p->print_merge_stats(this->name_);
2575 }
2576
2577 // Output segment methods.
2578
2579 Output_segment::Output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags)
2580   : output_data_(),
2581     output_bss_(),
2582     vaddr_(0),
2583     paddr_(0),
2584     memsz_(0),
2585     max_align_(0),
2586     min_p_align_(0),
2587     offset_(0),
2588     filesz_(0),
2589     type_(type),
2590     flags_(flags),
2591     is_max_align_known_(false),
2592     are_addresses_set_(false)
2593 {
2594 }
2595
2596 // Add an Output_section to an Output_segment.
2597
2598 void
2599 Output_segment::add_output_section(Output_section* os,
2600                                    elfcpp::Elf_Word seg_flags)
2601 {
2602   gold_assert((os->flags() & elfcpp::SHF_ALLOC) != 0);
2603   gold_assert(!this->is_max_align_known_);
2604
2605   // Update the segment flags.
2606   this->flags_ |= seg_flags;
2607
2608   Output_segment::Output_data_list* pdl;
2609   if (os->type() == elfcpp::SHT_NOBITS)
2610     pdl = &this->output_bss_;
2611   else
2612     pdl = &this->output_data_;
2613
2614   // So that PT_NOTE segments will work correctly, we need to ensure
2615   // that all SHT_NOTE sections are adjacent.  This will normally
2616   // happen automatically, because all the SHT_NOTE input sections
2617   // will wind up in the same output section.  However, it is possible
2618   // for multiple SHT_NOTE input sections to have different section
2619   // flags, and thus be in different output sections, but for the
2620   // different section flags to map into the same segment flags and
2621   // thus the same output segment.
2622
2623   // Note that while there may be many input sections in an output
2624   // section, there are normally only a few output sections in an
2625   // output segment.  This loop is expected to be fast.
2626
2627   if (os->type() == elfcpp::SHT_NOTE && !pdl->empty())
2628     {
2629       Output_segment::Output_data_list::iterator p = pdl->end();
2630       do
2631         {
2632           --p;
2633           if ((*p)->is_section_type(elfcpp::SHT_NOTE))
2634             {
2635               ++p;
2636               pdl->insert(p, os);
2637               return;
2638             }
2639         }
2640       while (p != pdl->begin());
2641     }
2642
2643   // Similarly, so that PT_TLS segments will work, we need to group
2644   // SHF_TLS sections.  An SHF_TLS/SHT_NOBITS section is a special
2645   // case: we group the SHF_TLS/SHT_NOBITS sections right after the
2646   // SHF_TLS/SHT_PROGBITS sections.  This lets us set up PT_TLS
2647   // correctly.  SHF_TLS sections get added to both a PT_LOAD segment
2648   // and the PT_TLS segment -- we do this grouping only for the
2649   // PT_LOAD segment.
2650   if (this->type_ != elfcpp::PT_TLS
2651       && (os->flags() & elfcpp::SHF_TLS) != 0
2652       && !this->output_data_.empty())
2653     {
2654       pdl = &this->output_data_;
2655       bool nobits = os->type() == elfcpp::SHT_NOBITS;
2656       bool sawtls = false;
2657       Output_segment::Output_data_list::iterator p = pdl->end();
2658       do
2659         {
2660           --p;
2661           bool insert;
2662           if ((*p)->is_section_flag_set(elfcpp::SHF_TLS))
2663             {
2664               sawtls = true;
2665               // Put a NOBITS section after the first TLS section.
2666               // Put a PROGBITS section after the first TLS/PROGBITS
2667               // section.
2668               insert = nobits || !(*p)->is_section_type(elfcpp::SHT_NOBITS);
2669             }
2670           else
2671             {
2672               // If we've gone past the TLS sections, but we've seen a
2673               // TLS section, then we need to insert this section now.
2674               insert = sawtls;
2675             }
2676
2677           if (insert)
2678             {
2679               ++p;
2680               pdl->insert(p, os);
2681               return;
2682             }
2683         }
2684       while (p != pdl->begin());
2685
2686       // There are no TLS sections yet; put this one at the requested
2687       // location in the section list.
2688     }
2689
2690   // For the PT_GNU_RELRO segment, we need to group relro sections,
2691   // and we need to put them before any non-relro sections.  Also,
2692   // relro local sections go before relro non-local sections.
2693   if (parameters->options().relro() && os->is_relro())
2694     {
2695       gold_assert(pdl == &this->output_data_);
2696       Output_segment::Output_data_list::iterator p;
2697       for (p = pdl->begin(); p != pdl->end(); ++p)
2698         {
2699           if (!(*p)->is_section())
2700             break;
2701
2702           Output_section* pos = (*p)->output_section();
2703           if (!pos->is_relro()
2704               || (os->is_relro_local() && !pos->is_relro_local()))
2705             break;
2706         }
2707
2708       pdl->insert(p, os);
2709       return;
2710     }
2711
2712   pdl->push_back(os);
2713 }
2714
2715 // Remove an Output_section from this segment.  It is an error if it
2716 // is not present.
2717
2718 void
2719 Output_segment::remove_output_section(Output_section* os)
2720 {
2721   // We only need this for SHT_PROGBITS.
2722   gold_assert(os->type() == elfcpp::SHT_PROGBITS);
2723   for (Output_data_list::iterator p = this->output_data_.begin();
2724        p != this->output_data_.end();
2725        ++p)
2726    {
2727      if (*p == os)
2728        {
2729          this->output_data_.erase(p);
2730          return;
2731        }
2732    }
2733   gold_unreachable();
2734 }
2735
2736 // Add an Output_data (which is not an Output_section) to the start of
2737 // a segment.
2738
2739 void
2740 Output_segment::add_initial_output_data(Output_data* od)
2741 {
2742   gold_assert(!this->is_max_align_known_);
2743   this->output_data_.push_front(od);
2744 }
2745
2746 // Return whether the first data section is a relro section.
2747
2748 bool
2749 Output_segment::is_first_section_relro() const
2750 {
2751   return (!this->output_data_.empty()
2752           && this->output_data_.front()->is_section()
2753           && this->output_data_.front()->output_section()->is_relro());
2754 }
2755
2756 // Return the maximum alignment of the Output_data in Output_segment.
2757
2758 uint64_t
2759 Output_segment::maximum_alignment()
2760 {
2761   if (!this->is_max_align_known_)
2762     {
2763       uint64_t addralign;
2764
2765       addralign = Output_segment::maximum_alignment_list(&this->output_data_);
2766       if (addralign > this->max_align_)
2767         this->max_align_ = addralign;
2768
2769       addralign = Output_segment::maximum_alignment_list(&this->output_bss_);
2770       if (addralign > this->max_align_)
2771         this->max_align_ = addralign;
2772
2773       // If -z relro is in effect, and the first section in this
2774       // segment is a relro section, then the segment must be aligned
2775       // to at least the common page size.  This ensures that the
2776       // PT_GNU_RELRO segment will start at a page boundary.
2777       if (parameters->options().relro() && this->is_first_section_relro())
2778         {
2779           addralign = parameters->target().common_pagesize();
2780           if (addralign > this->max_align_)
2781             this->max_align_ = addralign;
2782         }
2783
2784       this->is_max_align_known_ = true;
2785     }
2786
2787   return this->max_align_;
2788 }
2789
2790 // Return the maximum alignment of a list of Output_data.
2791
2792 uint64_t
2793 Output_segment::maximum_alignment_list(const Output_data_list* pdl)
2794 {
2795   uint64_t ret = 0;
2796   for (Output_data_list::const_iterator p = pdl->begin();
2797        p != pdl->end();
2798        ++p)
2799     {
2800       uint64_t addralign = (*p)->addralign();
2801       if (addralign > ret)
2802         ret = addralign;
2803     }
2804   return ret;
2805 }
2806
2807 // Return the number of dynamic relocs applied to this segment.
2808
2809 unsigned int
2810 Output_segment::dynamic_reloc_count() const
2811 {
2812   return (this->dynamic_reloc_count_list(&this->output_data_)
2813           + this->dynamic_reloc_count_list(&this->output_bss_));
2814 }
2815
2816 // Return the number of dynamic relocs applied to an Output_data_list.
2817
2818 unsigned int
2819 Output_segment::dynamic_reloc_count_list(const Output_data_list* pdl) const
2820 {
2821   unsigned int count = 0;
2822   for (Output_data_list::const_iterator p = pdl->begin();
2823        p != pdl->end();
2824        ++p)
2825     count += (*p)->dynamic_reloc_count();
2826   return count;
2827 }
2828
2829 // Set the section addresses for an Output_segment.  If RESET is true,
2830 // reset the addresses first.  ADDR is the address and *POFF is the
2831 // file offset.  Set the section indexes starting with *PSHNDX.
2832 // Return the address of the immediately following segment.  Update
2833 // *POFF and *PSHNDX.
2834
2835 uint64_t
2836 Output_segment::set_section_addresses(const Layout* layout, bool reset,
2837                                       uint64_t addr, off_t* poff,
2838                                       unsigned int* pshndx)
2839 {
2840   gold_assert(this->type_ == elfcpp::PT_LOAD);
2841
2842   if (!reset && this->are_addresses_set_)
2843     {
2844       gold_assert(this->paddr_ == addr);
2845       addr = this->vaddr_;
2846     }
2847   else
2848     {
2849       this->vaddr_ = addr;
2850       this->paddr_ = addr;
2851       this->are_addresses_set_ = true;
2852     }
2853
2854   bool in_tls = false;
2855
2856   bool in_relro = (parameters->options().relro()
2857                    && this->is_first_section_relro());
2858
2859   off_t orig_off = *poff;
2860   this->offset_ = orig_off;
2861
2862   addr = this->set_section_list_addresses(layout, reset, &this->output_data_,
2863                                           addr, poff, pshndx, &in_tls,
2864                                           &in_relro);
2865   this->filesz_ = *poff - orig_off;
2866
2867   off_t off = *poff;
2868
2869   uint64_t ret = this->set_section_list_addresses(layout, reset,
2870                                                   &this->output_bss_,
2871                                                   addr, poff, pshndx,
2872                                                   &in_tls, &in_relro);
2873
2874   // If the last section was a TLS section, align upward to the
2875   // alignment of the TLS segment, so that the overall size of the TLS
2876   // segment is aligned.
2877   if (in_tls)
2878     {
2879       uint64_t segment_align = layout->tls_segment()->maximum_alignment();
2880       *poff = align_address(*poff, segment_align);
2881     }
2882
2883   // If all the sections were relro sections, align upward to the
2884   // common page size.
2885   if (in_relro)
2886     {
2887       uint64_t page_align = parameters->target().common_pagesize();
2888       *poff = align_address(*poff, page_align);
2889     }
2890
2891   this->memsz_ = *poff - orig_off;
2892
2893   // Ignore the file offset adjustments made by the BSS Output_data
2894   // objects.
2895   *poff = off;
2896
2897   return ret;
2898 }
2899
2900 // Set the addresses and file offsets in a list of Output_data
2901 // structures.
2902
2903 uint64_t
2904 Output_segment::set_section_list_addresses(const Layout* layout, bool reset,
2905                                            Output_data_list* pdl,
2906                                            uint64_t addr, off_t* poff,
2907                                            unsigned int* pshndx,
2908                                            bool* in_tls, bool* in_relro)
2909 {
2910   off_t startoff = *poff;
2911
2912   off_t off = startoff;
2913   for (Output_data_list::iterator p = pdl->begin();
2914        p != pdl->end();
2915        ++p)
2916     {
2917       if (reset)
2918         (*p)->reset_address_and_file_offset();
2919
2920       // When using a linker script the section will most likely
2921       // already have an address.
2922       if (!(*p)->is_address_valid())
2923         {
2924           uint64_t align = (*p)->addralign();
2925
2926           if ((*p)->is_section_flag_set(elfcpp::SHF_TLS))
2927             {
2928               // Give the first TLS section the alignment of the
2929               // entire TLS segment.  Otherwise the TLS segment as a
2930               // whole may be misaligned.
2931               if (!*in_tls)
2932                 {
2933                   Output_segment* tls_segment = layout->tls_segment();
2934                   gold_assert(tls_segment != NULL);
2935                   uint64_t segment_align = tls_segment->maximum_alignment();
2936                   gold_assert(segment_align >= align);
2937                   align = segment_align;
2938
2939                   *in_tls = true;
2940                 }
2941             }
2942           else
2943             {
2944               // If this is the first section after the TLS segment,
2945               // align it to at least the alignment of the TLS
2946               // segment, so that the size of the overall TLS segment
2947               // is aligned.
2948               if (*in_tls)
2949                 {
2950                   uint64_t segment_align =
2951                       layout->tls_segment()->maximum_alignment();
2952                   if (segment_align > align)
2953                     align = segment_align;
2954
2955                   *in_tls = false;
2956                 }
2957             }
2958
2959           // If this is a non-relro section after a relro section,
2960           // align it to a common page boundary so that the dynamic
2961           // linker has a page to mark as read-only.
2962           if (*in_relro
2963               && (!(*p)->is_section()
2964                   || !(*p)->output_section()->is_relro()))
2965             {
2966               uint64_t page_align = parameters->target().common_pagesize();
2967               if (page_align > align)
2968                 align = page_align;
2969               *in_relro = false;
2970             }
2971
2972           off = align_address(off, align);
2973           (*p)->set_address_and_file_offset(addr + (off - startoff), off);
2974         }
2975       else
2976         {
2977           // The script may have inserted a skip forward, but it
2978           // better not have moved backward.
2979           gold_assert((*p)->address() >= addr + (off - startoff));
2980           off += (*p)->address() - (addr + (off - startoff));
2981           (*p)->set_file_offset(off);
2982           (*p)->finalize_data_size();
2983         }
2984
2985       // We want to ignore the size of a SHF_TLS or SHT_NOBITS
2986       // section.  Such a section does not affect the size of a
2987       // PT_LOAD segment.
2988       if (!(*p)->is_section_flag_set(elfcpp::SHF_TLS)
2989           || !(*p)->is_section_type(elfcpp::SHT_NOBITS))
2990         off += (*p)->data_size();
2991
2992       if ((*p)->is_section())
2993         {
2994           (*p)->set_out_shndx(*pshndx);
2995           ++*pshndx;
2996         }
2997     }
2998
2999   *poff = off;
3000   return addr + (off - startoff);
3001 }
3002
3003 // For a non-PT_LOAD segment, set the offset from the sections, if
3004 // any.
3005
3006 void
3007 Output_segment::set_offset()
3008 {
3009   gold_assert(this->type_ != elfcpp::PT_LOAD);
3010
3011   gold_assert(!this->are_addresses_set_);
3012
3013   if (this->output_data_.empty() && this->output_bss_.empty())
3014     {
3015       this->vaddr_ = 0;
3016       this->paddr_ = 0;
3017       this->are_addresses_set_ = true;
3018       this->memsz_ = 0;
3019       this->min_p_align_ = 0;
3020       this->offset_ = 0;
3021       this->filesz_ = 0;
3022       return;
3023     }
3024
3025   const Output_data* first;
3026   if (this->output_data_.empty())
3027     first = this->output_bss_.front();
3028   else
3029     first = this->output_data_.front();
3030   this->vaddr_ = first->address();
3031   this->paddr_ = (first->has_load_address()
3032                   ? first->load_address()
3033                   : this->vaddr_);
3034   this->are_addresses_set_ = true;
3035   this->offset_ = first->offset();
3036
3037   if (this->output_data_.empty())
3038     this->filesz_ = 0;
3039   else
3040     {
3041       const Output_data* last_data = this->output_data_.back();
3042       this->filesz_ = (last_data->address()
3043                        + last_data->data_size()
3044                        - this->vaddr_);
3045     }
3046
3047   const Output_data* last;
3048   if (this->output_bss_.empty())
3049     last = this->output_data_.back();
3050   else
3051     last = this->output_bss_.back();
3052   this->memsz_ = (last->address()
3053                   + last->data_size()
3054                   - this->vaddr_);
3055
3056   // If this is a TLS segment, align the memory size.  The code in
3057   // set_section_list ensures that the section after the TLS segment
3058   // is aligned to give us room.
3059   if (this->type_ == elfcpp::PT_TLS)
3060     {
3061       uint64_t segment_align = this->maximum_alignment();
3062       gold_assert(this->vaddr_ == align_address(this->vaddr_, segment_align));
3063       this->memsz_ = align_address(this->memsz_, segment_align);
3064     }
3065
3066   // If this is a RELRO segment, align the memory size.  The code in
3067   // set_section_list ensures that the section after the RELRO segment
3068   // is aligned to give us room.
3069   if (this->type_ == elfcpp::PT_GNU_RELRO)
3070     {
3071       uint64_t page_align = parameters->target().common_pagesize();
3072       gold_assert(this->vaddr_ == align_address(this->vaddr_, page_align));
3073       this->memsz_ = align_address(this->memsz_, page_align);
3074     }
3075 }
3076
3077 // Set the TLS offsets of the sections in the PT_TLS segment.
3078
3079 void
3080 Output_segment::set_tls_offsets()
3081 {
3082   gold_assert(this->type_ == elfcpp::PT_TLS);
3083
3084   for (Output_data_list::iterator p = this->output_data_.begin();
3085        p != this->output_data_.end();
3086        ++p)
3087     (*p)->set_tls_offset(this->vaddr_);
3088
3089   for (Output_data_list::iterator p = this->output_bss_.begin();
3090        p != this->output_bss_.end();
3091        ++p)
3092     (*p)->set_tls_offset(this->vaddr_);
3093 }
3094
3095 // Return the address of the first section.
3096
3097 uint64_t
3098 Output_segment::first_section_load_address() const
3099 {
3100   for (Output_data_list::const_iterator p = this->output_data_.begin();
3101        p != this->output_data_.end();
3102        ++p)
3103     if ((*p)->is_section())
3104       return (*p)->has_load_address() ? (*p)->load_address() : (*p)->address();
3105
3106   for (Output_data_list::const_iterator p = this->output_bss_.begin();
3107        p != this->output_bss_.end();
3108        ++p)
3109     if ((*p)->is_section())
3110       return (*p)->has_load_address() ? (*p)->load_address() : (*p)->address();
3111
3112   gold_unreachable();
3113 }
3114
3115 // Return the number of Output_sections in an Output_segment.
3116
3117 unsigned int
3118 Output_segment::output_section_count() const
3119 {
3120   return (this->output_section_count_list(&this->output_data_)
3121           + this->output_section_count_list(&this->output_bss_));
3122 }
3123
3124 // Return the number of Output_sections in an Output_data_list.
3125
3126 unsigned int
3127 Output_segment::output_section_count_list(const Output_data_list* pdl) const
3128 {
3129   unsigned int count = 0;
3130   for (Output_data_list::const_iterator p = pdl->begin();
3131        p != pdl->end();
3132        ++p)
3133     {
3134       if ((*p)->is_section())
3135         ++count;
3136     }
3137   return count;
3138 }
3139
3140 // Return the section attached to the list segment with the lowest
3141 // load address.  This is used when handling a PHDRS clause in a
3142 // linker script.
3143
3144 Output_section*
3145 Output_segment::section_with_lowest_load_address() const
3146 {
3147   Output_section* found = NULL;
3148   uint64_t found_lma = 0;
3149   this->lowest_load_address_in_list(&this->output_data_, &found, &found_lma);
3150
3151   Output_section* found_data = found;
3152   this->lowest_load_address_in_list(&this->output_bss_, &found, &found_lma);
3153   if (found != found_data && found_data != NULL)
3154     {
3155       gold_error(_("nobits section %s may not precede progbits section %s "
3156                    "in same segment"),
3157                  found->name(), found_data->name());
3158       return NULL;
3159     }
3160
3161   return found;
3162 }
3163
3164 // Look through a list for a section with a lower load address.
3165
3166 void
3167 Output_segment::lowest_load_address_in_list(const Output_data_list* pdl,
3168                                             Output_section** found,
3169                                             uint64_t* found_lma) const
3170 {
3171   for (Output_data_list::const_iterator p = pdl->begin();
3172        p != pdl->end();
3173        ++p)
3174     {
3175       if (!(*p)->is_section())
3176         continue;
3177       Output_section* os = static_cast<Output_section*>(*p);
3178       uint64_t lma = (os->has_load_address()
3179                       ? os->load_address()
3180                       : os->address());
3181       if (*found == NULL || lma < *found_lma)
3182         {
3183           *found = os;
3184           *found_lma = lma;
3185         }
3186     }
3187 }
3188
3189 // Write the segment data into *OPHDR.
3190
3191 template<int size, bool big_endian>
3192 void
3193 Output_segment::write_header(elfcpp::Phdr_write<size, big_endian>* ophdr)
3194 {
3195   ophdr->put_p_type(this->type_);
3196   ophdr->put_p_offset(this->offset_);
3197   ophdr->put_p_vaddr(this->vaddr_);
3198   ophdr->put_p_paddr(this->paddr_);
3199   ophdr->put_p_filesz(this->filesz_);
3200   ophdr->put_p_memsz(this->memsz_);
3201   ophdr->put_p_flags(this->flags_);
3202   ophdr->put_p_align(std::max(this->min_p_align_, this->maximum_alignment()));
3203 }
3204
3205 // Write the section headers into V.
3206
3207 template<int size, bool big_endian>
3208 unsigned char*
3209 Output_segment::write_section_headers(const Layout* layout,
3210                                       const Stringpool* secnamepool,
3211                                       unsigned char* v,
3212                                       unsigned int *pshndx) const
3213 {
3214   // Every section that is attached to a segment must be attached to a
3215   // PT_LOAD segment, so we only write out section headers for PT_LOAD
3216   // segments.
3217   if (this->type_ != elfcpp::PT_LOAD)
3218     return v;
3219
3220   v = this->write_section_headers_list<size, big_endian>(layout, secnamepool,
3221                                                          &this->output_data_,
3222                                                          v, pshndx);
3223   v = this->write_section_headers_list<size, big_endian>(layout, secnamepool,
3224                                                          &this->output_bss_,
3225                                                          v, pshndx);
3226   return v;
3227 }
3228
3229 template<int size, bool big_endian>
3230 unsigned char*
3231 Output_segment::write_section_headers_list(const Layout* layout,
3232                                            const Stringpool* secnamepool,
3233                                            const Output_data_list* pdl,
3234                                            unsigned char* v,
3235                                            unsigned int* pshndx) const
3236 {
3237   const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
3238   for (Output_data_list::const_iterator p = pdl->begin();
3239        p != pdl->end();
3240        ++p)
3241     {
3242       if ((*p)->is_section())
3243         {
3244           const Output_section* ps = static_cast<const Output_section*>(*p);
3245           gold_assert(*pshndx == ps->out_shndx());
3246           elfcpp::Shdr_write<size, big_endian> oshdr(v);
3247           ps->write_header(layout, secnamepool, &oshdr);
3248           v += shdr_size;
3249           ++*pshndx;
3250         }
3251     }
3252   return v;
3253 }
3254
3255 // Print the output sections to the map file.
3256
3257 void
3258 Output_segment::print_sections_to_mapfile(Mapfile* mapfile) const
3259 {
3260   if (this->type() != elfcpp::PT_LOAD)
3261     return;
3262   this->print_section_list_to_mapfile(mapfile, &this->output_data_);
3263   this->print_section_list_to_mapfile(mapfile, &this->output_bss_);
3264 }
3265
3266 // Print an output section list to the map file.
3267
3268 void
3269 Output_segment::print_section_list_to_mapfile(Mapfile* mapfile,
3270                                               const Output_data_list* pdl) const
3271 {
3272   for (Output_data_list::const_iterator p = pdl->begin();
3273        p != pdl->end();
3274        ++p)
3275     (*p)->print_to_mapfile(mapfile);
3276 }
3277
3278 // Output_file methods.
3279
3280 Output_file::Output_file(const char* name)
3281   : name_(name),
3282     o_(-1),
3283     file_size_(0),
3284     base_(NULL),
3285     map_is_anonymous_(false),
3286     is_temporary_(false)
3287 {
3288 }
3289
3290 // Open the output file.
3291
3292 void
3293 Output_file::open(off_t file_size)
3294 {
3295   this->file_size_ = file_size;
3296
3297   // Unlink the file first; otherwise the open() may fail if the file
3298   // is busy (e.g. it's an executable that's currently being executed).
3299   //
3300   // However, the linker may be part of a system where a zero-length
3301   // file is created for it to write to, with tight permissions (gcc
3302   // 2.95 did something like this).  Unlinking the file would work
3303   // around those permission controls, so we only unlink if the file
3304   // has a non-zero size.  We also unlink only regular files to avoid
3305   // trouble with directories/etc.
3306   //
3307   // If we fail, continue; this command is merely a best-effort attempt
3308   // to improve the odds for open().
3309
3310   // We let the name "-" mean "stdout"
3311   if (!this->is_temporary_)
3312     {
3313       if (strcmp(this->name_, "-") == 0)
3314         this->o_ = STDOUT_FILENO;
3315       else
3316         {
3317           struct stat s;
3318           if (::stat(this->name_, &s) == 0 && s.st_size != 0)
3319             unlink_if_ordinary(this->name_);
3320
3321           int mode = parameters->options().relocatable() ? 0666 : 0777;
3322           int o = ::open(this->name_, O_RDWR | O_CREAT | O_TRUNC, mode);
3323           if (o < 0)
3324             gold_fatal(_("%s: open: %s"), this->name_, strerror(errno));
3325           this->o_ = o;
3326         }
3327     }
3328
3329   this->map();
3330 }
3331
3332 // Resize the output file.
3333
3334 void
3335 Output_file::resize(off_t file_size)
3336 {
3337   // If the mmap is mapping an anonymous memory buffer, this is easy:
3338   // just mremap to the new size.  If it's mapping to a file, we want
3339   // to unmap to flush to the file, then remap after growing the file.
3340   if (this->map_is_anonymous_)
3341     {
3342       void* base = ::mremap(this->base_, this->file_size_, file_size,
3343                             MREMAP_MAYMOVE);
3344       if (base == MAP_FAILED)
3345         gold_fatal(_("%s: mremap: %s"), this->name_, strerror(errno));
3346       this->base_ = static_cast<unsigned char*>(base);
3347       this->file_size_ = file_size;
3348     }
3349   else
3350     {
3351       this->unmap();
3352       this->file_size_ = file_size;
3353       this->map();
3354     }
3355 }
3356
3357 // Map the file into memory.
3358
3359 void
3360 Output_file::map()
3361 {
3362   const int o = this->o_;
3363
3364   // If the output file is not a regular file, don't try to mmap it;
3365   // instead, we'll mmap a block of memory (an anonymous buffer), and
3366   // then later write the buffer to the file.
3367   void* base;
3368   struct stat statbuf;
3369   if (o == STDOUT_FILENO || o == STDERR_FILENO
3370       || ::fstat(o, &statbuf) != 0
3371       || !S_ISREG(statbuf.st_mode)
3372       || this->is_temporary_)
3373     {
3374       this->map_is_anonymous_ = true;
3375       base = ::mmap(NULL, this->file_size_, PROT_READ | PROT_WRITE,
3376                     MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
3377     }
3378   else
3379     {
3380       // Write out one byte to make the file the right size.
3381       if (::lseek(o, this->file_size_ - 1, SEEK_SET) < 0)
3382         gold_fatal(_("%s: lseek: %s"), this->name_, strerror(errno));
3383       char b = 0;
3384       if (::write(o, &b, 1) != 1)
3385         gold_fatal(_("%s: write: %s"), this->name_, strerror(errno));
3386
3387       // Map the file into memory.
3388       this->map_is_anonymous_ = false;
3389       base = ::mmap(NULL, this->file_size_, PROT_READ | PROT_WRITE,
3390                     MAP_SHARED, o, 0);
3391     }
3392   if (base == MAP_FAILED)
3393     gold_fatal(_("%s: mmap: %s"), this->name_, strerror(errno));
3394   this->base_ = static_cast<unsigned char*>(base);
3395 }
3396
3397 // Unmap the file from memory.
3398
3399 void
3400 Output_file::unmap()
3401 {
3402   if (::munmap(this->base_, this->file_size_) < 0)
3403     gold_error(_("%s: munmap: %s"), this->name_, strerror(errno));
3404   this->base_ = NULL;
3405 }
3406
3407 // Close the output file.
3408
3409 void
3410 Output_file::close()
3411 {
3412   // If the map isn't file-backed, we need to write it now.
3413   if (this->map_is_anonymous_ && !this->is_temporary_)
3414     {
3415       size_t bytes_to_write = this->file_size_;
3416       while (bytes_to_write > 0)
3417         {
3418           ssize_t bytes_written = ::write(this->o_, this->base_, bytes_to_write);
3419           if (bytes_written == 0)
3420             gold_error(_("%s: write: unexpected 0 return-value"), this->name_);
3421           else if (bytes_written < 0)
3422             gold_error(_("%s: write: %s"), this->name_, strerror(errno));
3423           else
3424             bytes_to_write -= bytes_written;
3425         }
3426     }
3427   this->unmap();
3428
3429   // We don't close stdout or stderr
3430   if (this->o_ != STDOUT_FILENO
3431       && this->o_ != STDERR_FILENO
3432       && !this->is_temporary_)
3433     if (::close(this->o_) < 0)
3434       gold_error(_("%s: close: %s"), this->name_, strerror(errno));
3435   this->o_ = -1;
3436 }
3437
3438 // Instantiate the templates we need.  We could use the configure
3439 // script to restrict this to only the ones for implemented targets.
3440
3441 #ifdef HAVE_TARGET_32_LITTLE
3442 template
3443 off_t
3444 Output_section::add_input_section<32, false>(
3445     Sized_relobj<32, false>* object,
3446     unsigned int shndx,
3447     const char* secname,
3448     const elfcpp::Shdr<32, false>& shdr,
3449     unsigned int reloc_shndx,
3450     bool have_sections_script);
3451 #endif
3452
3453 #ifdef HAVE_TARGET_32_BIG
3454 template
3455 off_t
3456 Output_section::add_input_section<32, true>(
3457     Sized_relobj<32, true>* object,
3458     unsigned int shndx,
3459     const char* secname,
3460     const elfcpp::Shdr<32, true>& shdr,
3461     unsigned int reloc_shndx,
3462     bool have_sections_script);
3463 #endif
3464
3465 #ifdef HAVE_TARGET_64_LITTLE
3466 template
3467 off_t
3468 Output_section::add_input_section<64, false>(
3469     Sized_relobj<64, false>* object,
3470     unsigned int shndx,
3471     const char* secname,
3472     const elfcpp::Shdr<64, false>& shdr,
3473     unsigned int reloc_shndx,
3474     bool have_sections_script);
3475 #endif
3476
3477 #ifdef HAVE_TARGET_64_BIG
3478 template
3479 off_t
3480 Output_section::add_input_section<64, true>(
3481     Sized_relobj<64, true>* object,
3482     unsigned int shndx,
3483     const char* secname,
3484     const elfcpp::Shdr<64, true>& shdr,
3485     unsigned int reloc_shndx,
3486     bool have_sections_script);
3487 #endif
3488
3489 #ifdef HAVE_TARGET_32_LITTLE
3490 template
3491 class Output_data_reloc<elfcpp::SHT_REL, false, 32, false>;
3492 #endif
3493
3494 #ifdef HAVE_TARGET_32_BIG
3495 template
3496 class Output_data_reloc<elfcpp::SHT_REL, false, 32, true>;
3497 #endif
3498
3499 #ifdef HAVE_TARGET_64_LITTLE
3500 template
3501 class Output_data_reloc<elfcpp::SHT_REL, false, 64, false>;
3502 #endif
3503
3504 #ifdef HAVE_TARGET_64_BIG
3505 template
3506 class Output_data_reloc<elfcpp::SHT_REL, false, 64, true>;
3507 #endif
3508
3509 #ifdef HAVE_TARGET_32_LITTLE
3510 template
3511 class Output_data_reloc<elfcpp::SHT_REL, true, 32, false>;
3512 #endif
3513
3514 #ifdef HAVE_TARGET_32_BIG
3515 template
3516 class Output_data_reloc<elfcpp::SHT_REL, true, 32, true>;
3517 #endif
3518
3519 #ifdef HAVE_TARGET_64_LITTLE
3520 template
3521 class Output_data_reloc<elfcpp::SHT_REL, true, 64, false>;
3522 #endif
3523
3524 #ifdef HAVE_TARGET_64_BIG
3525 template
3526 class Output_data_reloc<elfcpp::SHT_REL, true, 64, true>;
3527 #endif
3528
3529 #ifdef HAVE_TARGET_32_LITTLE
3530 template
3531 class Output_data_reloc<elfcpp::SHT_RELA, false, 32, false>;
3532 #endif
3533
3534 #ifdef HAVE_TARGET_32_BIG
3535 template
3536 class Output_data_reloc<elfcpp::SHT_RELA, false, 32, true>;
3537 #endif
3538
3539 #ifdef HAVE_TARGET_64_LITTLE
3540 template
3541 class Output_data_reloc<elfcpp::SHT_RELA, false, 64, false>;
3542 #endif
3543
3544 #ifdef HAVE_TARGET_64_BIG
3545 template
3546 class Output_data_reloc<elfcpp::SHT_RELA, false, 64, true>;
3547 #endif
3548
3549 #ifdef HAVE_TARGET_32_LITTLE
3550 template
3551 class Output_data_reloc<elfcpp::SHT_RELA, true, 32, false>;
3552 #endif
3553
3554 #ifdef HAVE_TARGET_32_BIG
3555 template
3556 class Output_data_reloc<elfcpp::SHT_RELA, true, 32, true>;
3557 #endif
3558
3559 #ifdef HAVE_TARGET_64_LITTLE
3560 template
3561 class Output_data_reloc<elfcpp::SHT_RELA, true, 64, false>;
3562 #endif
3563
3564 #ifdef HAVE_TARGET_64_BIG
3565 template
3566 class Output_data_reloc<elfcpp::SHT_RELA, true, 64, true>;
3567 #endif
3568
3569 #ifdef HAVE_TARGET_32_LITTLE
3570 template
3571 class Output_relocatable_relocs<elfcpp::SHT_REL, 32, false>;
3572 #endif
3573
3574 #ifdef HAVE_TARGET_32_BIG
3575 template
3576 class Output_relocatable_relocs<elfcpp::SHT_REL, 32, true>;
3577 #endif
3578
3579 #ifdef HAVE_TARGET_64_LITTLE
3580 template
3581 class Output_relocatable_relocs<elfcpp::SHT_REL, 64, false>;
3582 #endif
3583
3584 #ifdef HAVE_TARGET_64_BIG
3585 template
3586 class Output_relocatable_relocs<elfcpp::SHT_REL, 64, true>;
3587 #endif
3588
3589 #ifdef HAVE_TARGET_32_LITTLE
3590 template
3591 class Output_relocatable_relocs<elfcpp::SHT_RELA, 32, false>;
3592 #endif
3593
3594 #ifdef HAVE_TARGET_32_BIG
3595 template
3596 class Output_relocatable_relocs<elfcpp::SHT_RELA, 32, true>;
3597 #endif
3598
3599 #ifdef HAVE_TARGET_64_LITTLE
3600 template
3601 class Output_relocatable_relocs<elfcpp::SHT_RELA, 64, false>;
3602 #endif
3603
3604 #ifdef HAVE_TARGET_64_BIG
3605 template
3606 class Output_relocatable_relocs<elfcpp::SHT_RELA, 64, true>;
3607 #endif
3608
3609 #ifdef HAVE_TARGET_32_LITTLE
3610 template
3611 class Output_data_group<32, false>;
3612 #endif
3613
3614 #ifdef HAVE_TARGET_32_BIG
3615 template
3616 class Output_data_group<32, true>;
3617 #endif
3618
3619 #ifdef HAVE_TARGET_64_LITTLE
3620 template
3621 class Output_data_group<64, false>;
3622 #endif
3623
3624 #ifdef HAVE_TARGET_64_BIG
3625 template
3626 class Output_data_group<64, true>;
3627 #endif
3628
3629 #ifdef HAVE_TARGET_32_LITTLE
3630 template
3631 class Output_data_got<32, false>;
3632 #endif
3633
3634 #ifdef HAVE_TARGET_32_BIG
3635 template
3636 class Output_data_got<32, true>;
3637 #endif
3638
3639 #ifdef HAVE_TARGET_64_LITTLE
3640 template
3641 class Output_data_got<64, false>;
3642 #endif
3643
3644 #ifdef HAVE_TARGET_64_BIG
3645 template
3646 class Output_data_got<64, true>;
3647 #endif
3648
3649 } // End namespace gold.