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