* output.cc (Output_segment::add_output_section): Remove front
[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     tls_offset_(0)
1741 {
1742   // An unallocated section has no address.  Forcing this means that
1743   // we don't need special treatment for symbols defined in debug
1744   // sections.
1745   if ((flags & elfcpp::SHF_ALLOC) == 0)
1746     this->set_address(0);
1747 }
1748
1749 Output_section::~Output_section()
1750 {
1751 }
1752
1753 // Set the entry size.
1754
1755 void
1756 Output_section::set_entsize(uint64_t v)
1757 {
1758   if (this->entsize_ == 0)
1759     this->entsize_ = v;
1760   else
1761     gold_assert(this->entsize_ == v);
1762 }
1763
1764 // Add the input section SHNDX, with header SHDR, named SECNAME, in
1765 // OBJECT, to the Output_section.  RELOC_SHNDX is the index of a
1766 // relocation section which applies to this section, or 0 if none, or
1767 // -1U if more than one.  Return the offset of the input section
1768 // within the output section.  Return -1 if the input section will
1769 // receive special handling.  In the normal case we don't always keep
1770 // track of input sections for an Output_section.  Instead, each
1771 // Object keeps track of the Output_section for each of its input
1772 // sections.  However, if HAVE_SECTIONS_SCRIPT is true, we do keep
1773 // track of input sections here; this is used when SECTIONS appears in
1774 // a linker script.
1775
1776 template<int size, bool big_endian>
1777 off_t
1778 Output_section::add_input_section(Sized_relobj<size, big_endian>* object,
1779                                   unsigned int shndx,
1780                                   const char* secname,
1781                                   const elfcpp::Shdr<size, big_endian>& shdr,
1782                                   unsigned int reloc_shndx,
1783                                   bool have_sections_script)
1784 {
1785   elfcpp::Elf_Xword addralign = shdr.get_sh_addralign();
1786   if ((addralign & (addralign - 1)) != 0)
1787     {
1788       object->error(_("invalid alignment %lu for section \"%s\""),
1789                     static_cast<unsigned long>(addralign), secname);
1790       addralign = 1;
1791     }
1792
1793   if (addralign > this->addralign_)
1794     this->addralign_ = addralign;
1795
1796   typename elfcpp::Elf_types<size>::Elf_WXword sh_flags = shdr.get_sh_flags();
1797   this->update_flags_for_input_section(sh_flags);
1798
1799   uint64_t entsize = shdr.get_sh_entsize();
1800
1801   // .debug_str is a mergeable string section, but is not always so
1802   // marked by compilers.  Mark manually here so we can optimize.
1803   if (strcmp(secname, ".debug_str") == 0)
1804     {
1805       sh_flags |= (elfcpp::SHF_MERGE | elfcpp::SHF_STRINGS);
1806       entsize = 1;
1807     }
1808
1809   // If this is a SHF_MERGE section, we pass all the input sections to
1810   // a Output_data_merge.  We don't try to handle relocations for such
1811   // a section.
1812   if ((sh_flags & elfcpp::SHF_MERGE) != 0
1813       && reloc_shndx == 0)
1814     {
1815       if (this->add_merge_input_section(object, shndx, sh_flags,
1816                                         entsize, addralign))
1817         {
1818           // Tell the relocation routines that they need to call the
1819           // output_offset method to determine the final address.
1820           return -1;
1821         }
1822     }
1823
1824   off_t offset_in_section = this->current_data_size_for_child();
1825   off_t aligned_offset_in_section = align_address(offset_in_section,
1826                                                   addralign);
1827
1828   if (aligned_offset_in_section > offset_in_section
1829       && !have_sections_script
1830       && (sh_flags & elfcpp::SHF_EXECINSTR) != 0
1831       && object->target()->has_code_fill())
1832     {
1833       // We need to add some fill data.  Using fill_list_ when
1834       // possible is an optimization, since we will often have fill
1835       // sections without input sections.
1836       off_t fill_len = aligned_offset_in_section - offset_in_section;
1837       if (this->input_sections_.empty())
1838         this->fills_.push_back(Fill(offset_in_section, fill_len));
1839       else
1840         {
1841           // FIXME: When relaxing, the size needs to adjust to
1842           // maintain a constant alignment.
1843           std::string fill_data(object->target()->code_fill(fill_len));
1844           Output_data_const* odc = new Output_data_const(fill_data, 1);
1845           this->input_sections_.push_back(Input_section(odc));
1846         }
1847     }
1848
1849   this->set_current_data_size_for_child(aligned_offset_in_section
1850                                         + shdr.get_sh_size());
1851
1852   // We need to keep track of this section if we are already keeping
1853   // track of sections, or if we are relaxing.  Also, if this is a
1854   // section which requires sorting, or which may require sorting in
1855   // the future, we keep track of the sections.  FIXME: Add test for
1856   // relaxing.
1857   if (have_sections_script
1858       || !this->input_sections_.empty()
1859       || this->may_sort_attached_input_sections()
1860       || this->must_sort_attached_input_sections())
1861     this->input_sections_.push_back(Input_section(object, shndx,
1862                                                   shdr.get_sh_size(),
1863                                                   addralign));
1864
1865   return aligned_offset_in_section;
1866 }
1867
1868 // Add arbitrary data to an output section.
1869
1870 void
1871 Output_section::add_output_section_data(Output_section_data* posd)
1872 {
1873   Input_section inp(posd);
1874   this->add_output_section_data(&inp);
1875
1876   if (posd->is_data_size_valid())
1877     {
1878       off_t offset_in_section = this->current_data_size_for_child();
1879       off_t aligned_offset_in_section = align_address(offset_in_section,
1880                                                       posd->addralign());
1881       this->set_current_data_size_for_child(aligned_offset_in_section
1882                                             + posd->data_size());
1883     }
1884 }
1885
1886 // Add arbitrary data to an output section by Input_section.
1887
1888 void
1889 Output_section::add_output_section_data(Input_section* inp)
1890 {
1891   if (this->input_sections_.empty())
1892     this->first_input_offset_ = this->current_data_size_for_child();
1893
1894   this->input_sections_.push_back(*inp);
1895
1896   uint64_t addralign = inp->addralign();
1897   if (addralign > this->addralign_)
1898     this->addralign_ = addralign;
1899
1900   inp->set_output_section(this);
1901 }
1902
1903 // Add a merge section to an output section.
1904
1905 void
1906 Output_section::add_output_merge_section(Output_section_data* posd,
1907                                          bool is_string, uint64_t entsize)
1908 {
1909   Input_section inp(posd, is_string, entsize);
1910   this->add_output_section_data(&inp);
1911 }
1912
1913 // Add an input section to a SHF_MERGE section.
1914
1915 bool
1916 Output_section::add_merge_input_section(Relobj* object, unsigned int shndx,
1917                                         uint64_t flags, uint64_t entsize,
1918                                         uint64_t addralign)
1919 {
1920   bool is_string = (flags & elfcpp::SHF_STRINGS) != 0;
1921
1922   // We only merge strings if the alignment is not more than the
1923   // character size.  This could be handled, but it's unusual.
1924   if (is_string && addralign > entsize)
1925     return false;
1926
1927   Input_section_list::iterator p;
1928   for (p = this->input_sections_.begin();
1929        p != this->input_sections_.end();
1930        ++p)
1931     if (p->is_merge_section(is_string, entsize, addralign))
1932       {
1933         p->add_input_section(object, shndx);
1934         return true;
1935       }
1936
1937   // We handle the actual constant merging in Output_merge_data or
1938   // Output_merge_string_data.
1939   Output_section_data* posd;
1940   if (!is_string)
1941     posd = new Output_merge_data(entsize, addralign);
1942   else
1943     {
1944       switch (entsize)
1945         {
1946         case 1:
1947           posd = new Output_merge_string<char>(addralign);
1948           break;
1949         case 2:
1950           posd = new Output_merge_string<uint16_t>(addralign);
1951           break;
1952         case 4:
1953           posd = new Output_merge_string<uint32_t>(addralign);
1954           break;
1955         default:
1956           return false;
1957         }
1958     }
1959
1960   this->add_output_merge_section(posd, is_string, entsize);
1961   posd->add_input_section(object, shndx);
1962
1963   return true;
1964 }
1965
1966 // Given an address OFFSET relative to the start of input section
1967 // SHNDX in OBJECT, return whether this address is being included in
1968 // the final link.  This should only be called if SHNDX in OBJECT has
1969 // a special mapping.
1970
1971 bool
1972 Output_section::is_input_address_mapped(const Relobj* object,
1973                                         unsigned int shndx,
1974                                         off_t offset) const
1975 {
1976   gold_assert(object->is_section_specially_mapped(shndx));
1977
1978   for (Input_section_list::const_iterator p = this->input_sections_.begin();
1979        p != this->input_sections_.end();
1980        ++p)
1981     {
1982       section_offset_type output_offset;
1983       if (p->output_offset(object, shndx, offset, &output_offset))
1984         return output_offset != -1;
1985     }
1986
1987   // By default we assume that the address is mapped.  This should
1988   // only be called after we have passed all sections to Layout.  At
1989   // that point we should know what we are discarding.
1990   return true;
1991 }
1992
1993 // Given an address OFFSET relative to the start of input section
1994 // SHNDX in object OBJECT, return the output offset relative to the
1995 // start of the input section in the output section.  This should only
1996 // be called if SHNDX in OBJECT has a special mapping.
1997
1998 section_offset_type
1999 Output_section::output_offset(const Relobj* object, unsigned int shndx,
2000                               section_offset_type offset) const
2001 {
2002   gold_assert(object->is_section_specially_mapped(shndx));
2003   // This can only be called meaningfully when layout is complete.
2004   gold_assert(Output_data::is_layout_complete());
2005
2006   for (Input_section_list::const_iterator p = this->input_sections_.begin();
2007        p != this->input_sections_.end();
2008        ++p)
2009     {
2010       section_offset_type output_offset;
2011       if (p->output_offset(object, shndx, offset, &output_offset))
2012         return output_offset;
2013     }
2014   gold_unreachable();
2015 }
2016
2017 // Return the output virtual address of OFFSET relative to the start
2018 // of input section SHNDX in object OBJECT.
2019
2020 uint64_t
2021 Output_section::output_address(const Relobj* object, unsigned int shndx,
2022                                off_t offset) const
2023 {
2024   gold_assert(object->is_section_specially_mapped(shndx));
2025
2026   uint64_t addr = this->address() + this->first_input_offset_;
2027   for (Input_section_list::const_iterator p = this->input_sections_.begin();
2028        p != this->input_sections_.end();
2029        ++p)
2030     {
2031       addr = align_address(addr, p->addralign());
2032       section_offset_type output_offset;
2033       if (p->output_offset(object, shndx, offset, &output_offset))
2034         {
2035           if (output_offset == -1)
2036             return -1U;
2037           return addr + output_offset;
2038         }
2039       addr += p->data_size();
2040     }
2041
2042   // If we get here, it means that we don't know the mapping for this
2043   // input section.  This might happen in principle if
2044   // add_input_section were called before add_output_section_data.
2045   // But it should never actually happen.
2046
2047   gold_unreachable();
2048 }
2049
2050 // Return the output address of the start of the merged section for
2051 // input section SHNDX in object OBJECT.
2052
2053 uint64_t
2054 Output_section::starting_output_address(const Relobj* object,
2055                                         unsigned int shndx) const
2056 {
2057   gold_assert(object->is_section_specially_mapped(shndx));
2058
2059   uint64_t addr = this->address() + this->first_input_offset_;
2060   for (Input_section_list::const_iterator p = this->input_sections_.begin();
2061        p != this->input_sections_.end();
2062        ++p)
2063     {
2064       addr = align_address(addr, p->addralign());
2065
2066       // It would be nice if we could use the existing output_offset
2067       // method to get the output offset of input offset 0.
2068       // Unfortunately we don't know for sure that input offset 0 is
2069       // mapped at all.
2070       if (p->is_merge_section_for(object, shndx))
2071         return addr;
2072
2073       addr += p->data_size();
2074     }
2075   gold_unreachable();
2076 }
2077
2078 // Set the data size of an Output_section.  This is where we handle
2079 // setting the addresses of any Output_section_data objects.
2080
2081 void
2082 Output_section::set_final_data_size()
2083 {
2084   if (this->input_sections_.empty())
2085     {
2086       this->set_data_size(this->current_data_size_for_child());
2087       return;
2088     }
2089
2090   if (this->must_sort_attached_input_sections())
2091     this->sort_attached_input_sections();
2092
2093   uint64_t address = this->address();
2094   off_t startoff = this->offset();
2095   off_t off = startoff + this->first_input_offset_;
2096   for (Input_section_list::iterator p = this->input_sections_.begin();
2097        p != this->input_sections_.end();
2098        ++p)
2099     {
2100       off = align_address(off, p->addralign());
2101       p->set_address_and_file_offset(address + (off - startoff), off,
2102                                      startoff);
2103       off += p->data_size();
2104     }
2105
2106   this->set_data_size(off - startoff);
2107 }
2108
2109 // Reset the address and file offset.
2110
2111 void
2112 Output_section::do_reset_address_and_file_offset()
2113 {
2114   for (Input_section_list::iterator p = this->input_sections_.begin();
2115        p != this->input_sections_.end();
2116        ++p)
2117     p->reset_address_and_file_offset();
2118 }
2119
2120 // Set the TLS offset.  Called only for SHT_TLS sections.
2121
2122 void
2123 Output_section::do_set_tls_offset(uint64_t tls_base)
2124 {
2125   this->tls_offset_ = this->address() - tls_base;
2126 }
2127
2128 // In a few cases we need to sort the input sections attached to an
2129 // output section.  This is used to implement the type of constructor
2130 // priority ordering implemented by the GNU linker, in which the
2131 // priority becomes part of the section name and the sections are
2132 // sorted by name.  We only do this for an output section if we see an
2133 // attached input section matching ".ctor.*", ".dtor.*",
2134 // ".init_array.*" or ".fini_array.*".
2135
2136 class Output_section::Input_section_sort_entry
2137 {
2138  public:
2139   Input_section_sort_entry()
2140     : input_section_(), index_(-1U), section_has_name_(false),
2141       section_name_()
2142   { }
2143
2144   Input_section_sort_entry(const Input_section& input_section,
2145                            unsigned int index)
2146     : input_section_(input_section), index_(index),
2147       section_has_name_(input_section.is_input_section())
2148   {
2149     if (this->section_has_name_)
2150       {
2151         // This is only called single-threaded from Layout::finalize,
2152         // so it is OK to lock.  Unfortunately we have no way to pass
2153         // in a Task token.
2154         const Task* dummy_task = reinterpret_cast<const Task*>(-1);
2155         Object* obj = input_section.relobj();
2156         Task_lock_obj<Object> tl(dummy_task, obj);
2157
2158         // This is a slow operation, which should be cached in
2159         // Layout::layout if this becomes a speed problem.
2160         this->section_name_ = obj->section_name(input_section.shndx());
2161       }
2162   }
2163
2164   // Return the Input_section.
2165   const Input_section&
2166   input_section() const
2167   {
2168     gold_assert(this->index_ != -1U);
2169     return this->input_section_;
2170   }
2171
2172   // The index of this entry in the original list.  This is used to
2173   // make the sort stable.
2174   unsigned int
2175   index() const
2176   {
2177     gold_assert(this->index_ != -1U);
2178     return this->index_;
2179   }
2180
2181   // Whether there is a section name.
2182   bool
2183   section_has_name() const
2184   { return this->section_has_name_; }
2185
2186   // The section name.
2187   const std::string&
2188   section_name() const
2189   {
2190     gold_assert(this->section_has_name_);
2191     return this->section_name_;
2192   }
2193
2194   // Return true if the section name has a priority.  This is assumed
2195   // to be true if it has a dot after the initial dot.
2196   bool
2197   has_priority() const
2198   {
2199     gold_assert(this->section_has_name_);
2200     return this->section_name_.find('.', 1);
2201   }
2202
2203   // Return true if this an input file whose base name matches
2204   // FILE_NAME.  The base name must have an extension of ".o", and
2205   // must be exactly FILE_NAME.o or FILE_NAME, one character, ".o".
2206   // This is to match crtbegin.o as well as crtbeginS.o without
2207   // getting confused by other possibilities.  Overall matching the
2208   // file name this way is a dreadful hack, but the GNU linker does it
2209   // in order to better support gcc, and we need to be compatible.
2210   bool
2211   match_file_name(const char* match_file_name) const
2212   {
2213     const std::string& file_name(this->input_section_.relobj()->name());
2214     const char* base_name = lbasename(file_name.c_str());
2215     size_t match_len = strlen(match_file_name);
2216     if (strncmp(base_name, match_file_name, match_len) != 0)
2217       return false;
2218     size_t base_len = strlen(base_name);
2219     if (base_len != match_len + 2 && base_len != match_len + 3)
2220       return false;
2221     return memcmp(base_name + base_len - 2, ".o", 2) == 0;
2222   }
2223
2224  private:
2225   // The Input_section we are sorting.
2226   Input_section input_section_;
2227   // The index of this Input_section in the original list.
2228   unsigned int index_;
2229   // Whether this Input_section has a section name--it won't if this
2230   // is some random Output_section_data.
2231   bool section_has_name_;
2232   // The section name if there is one.
2233   std::string section_name_;
2234 };
2235
2236 // Return true if S1 should come before S2 in the output section.
2237
2238 bool
2239 Output_section::Input_section_sort_compare::operator()(
2240     const Output_section::Input_section_sort_entry& s1,
2241     const Output_section::Input_section_sort_entry& s2) const
2242 {
2243   // crtbegin.o must come first.
2244   bool s1_begin = s1.match_file_name("crtbegin");
2245   bool s2_begin = s2.match_file_name("crtbegin");
2246   if (s1_begin || s2_begin)
2247     {
2248       if (!s1_begin)
2249         return false;
2250       if (!s2_begin)
2251         return true;
2252       return s1.index() < s2.index();
2253     }
2254
2255   // crtend.o must come last.
2256   bool s1_end = s1.match_file_name("crtend");
2257   bool s2_end = s2.match_file_name("crtend");
2258   if (s1_end || s2_end)
2259     {
2260       if (!s1_end)
2261         return true;
2262       if (!s2_end)
2263         return false;
2264       return s1.index() < s2.index();
2265     }
2266
2267   // We sort all the sections with no names to the end.
2268   if (!s1.section_has_name() || !s2.section_has_name())
2269     {
2270       if (s1.section_has_name())
2271         return true;
2272       if (s2.section_has_name())
2273         return false;
2274       return s1.index() < s2.index();
2275     }
2276
2277   // A section with a priority follows a section without a priority.
2278   // The GNU linker does this for all but .init_array sections; until
2279   // further notice we'll assume that that is an mistake.
2280   bool s1_has_priority = s1.has_priority();
2281   bool s2_has_priority = s2.has_priority();
2282   if (s1_has_priority && !s2_has_priority)
2283     return false;
2284   if (!s1_has_priority && s2_has_priority)
2285     return true;
2286
2287   // Otherwise we sort by name.
2288   int compare = s1.section_name().compare(s2.section_name());
2289   if (compare != 0)
2290     return compare < 0;
2291
2292   // Otherwise we keep the input order.
2293   return s1.index() < s2.index();
2294 }
2295
2296 // Sort the input sections attached to an output section.
2297
2298 void
2299 Output_section::sort_attached_input_sections()
2300 {
2301   if (this->attached_input_sections_are_sorted_)
2302     return;
2303
2304   // The only thing we know about an input section is the object and
2305   // the section index.  We need the section name.  Recomputing this
2306   // is slow but this is an unusual case.  If this becomes a speed
2307   // problem we can cache the names as required in Layout::layout.
2308
2309   // We start by building a larger vector holding a copy of each
2310   // Input_section, plus its current index in the list and its name.
2311   std::vector<Input_section_sort_entry> sort_list;
2312
2313   unsigned int i = 0;
2314   for (Input_section_list::iterator p = this->input_sections_.begin();
2315        p != this->input_sections_.end();
2316        ++p, ++i)
2317     sort_list.push_back(Input_section_sort_entry(*p, i));
2318
2319   // Sort the input sections.
2320   std::sort(sort_list.begin(), sort_list.end(), Input_section_sort_compare());
2321
2322   // Copy the sorted input sections back to our list.
2323   this->input_sections_.clear();
2324   for (std::vector<Input_section_sort_entry>::iterator p = sort_list.begin();
2325        p != sort_list.end();
2326        ++p)
2327     this->input_sections_.push_back(p->input_section());
2328
2329   // Remember that we sorted the input sections, since we might get
2330   // called again.
2331   this->attached_input_sections_are_sorted_ = true;
2332 }
2333
2334 // Write the section header to *OSHDR.
2335
2336 template<int size, bool big_endian>
2337 void
2338 Output_section::write_header(const Layout* layout,
2339                              const Stringpool* secnamepool,
2340                              elfcpp::Shdr_write<size, big_endian>* oshdr) const
2341 {
2342   oshdr->put_sh_name(secnamepool->get_offset(this->name_));
2343   oshdr->put_sh_type(this->type_);
2344
2345   elfcpp::Elf_Xword flags = this->flags_;
2346   if (this->info_section_ != NULL && this->info_uses_section_index_)
2347     flags |= elfcpp::SHF_INFO_LINK;
2348   oshdr->put_sh_flags(flags);
2349
2350   oshdr->put_sh_addr(this->address());
2351   oshdr->put_sh_offset(this->offset());
2352   oshdr->put_sh_size(this->data_size());
2353   if (this->link_section_ != NULL)
2354     oshdr->put_sh_link(this->link_section_->out_shndx());
2355   else if (this->should_link_to_symtab_)
2356     oshdr->put_sh_link(layout->symtab_section()->out_shndx());
2357   else if (this->should_link_to_dynsym_)
2358     oshdr->put_sh_link(layout->dynsym_section()->out_shndx());
2359   else
2360     oshdr->put_sh_link(this->link_);
2361
2362   elfcpp::Elf_Word info;
2363   if (this->info_section_ != NULL)
2364     {
2365       if (this->info_uses_section_index_)
2366         info = this->info_section_->out_shndx();
2367       else
2368         info = this->info_section_->symtab_index();
2369     }
2370   else if (this->info_symndx_ != NULL)
2371     info = this->info_symndx_->symtab_index();
2372   else
2373     info = this->info_;
2374   oshdr->put_sh_info(info);
2375
2376   oshdr->put_sh_addralign(this->addralign_);
2377   oshdr->put_sh_entsize(this->entsize_);
2378 }
2379
2380 // Write out the data.  For input sections the data is written out by
2381 // Object::relocate, but we have to handle Output_section_data objects
2382 // here.
2383
2384 void
2385 Output_section::do_write(Output_file* of)
2386 {
2387   gold_assert(!this->requires_postprocessing());
2388
2389   off_t output_section_file_offset = this->offset();
2390   for (Fill_list::iterator p = this->fills_.begin();
2391        p != this->fills_.end();
2392        ++p)
2393     {
2394       std::string fill_data(parameters->target().code_fill(p->length()));
2395       of->write(output_section_file_offset + p->section_offset(),
2396                 fill_data.data(), fill_data.size());
2397     }
2398
2399   for (Input_section_list::iterator p = this->input_sections_.begin();
2400        p != this->input_sections_.end();
2401        ++p)
2402     p->write(of);
2403 }
2404
2405 // If a section requires postprocessing, create the buffer to use.
2406
2407 void
2408 Output_section::create_postprocessing_buffer()
2409 {
2410   gold_assert(this->requires_postprocessing());
2411
2412   if (this->postprocessing_buffer_ != NULL)
2413     return;
2414
2415   if (!this->input_sections_.empty())
2416     {
2417       off_t off = this->first_input_offset_;
2418       for (Input_section_list::iterator p = this->input_sections_.begin();
2419            p != this->input_sections_.end();
2420            ++p)
2421         {
2422           off = align_address(off, p->addralign());
2423           p->finalize_data_size();
2424           off += p->data_size();
2425         }
2426       this->set_current_data_size_for_child(off);
2427     }
2428
2429   off_t buffer_size = this->current_data_size_for_child();
2430   this->postprocessing_buffer_ = new unsigned char[buffer_size];
2431 }
2432
2433 // Write all the data of an Output_section into the postprocessing
2434 // buffer.  This is used for sections which require postprocessing,
2435 // such as compression.  Input sections are handled by
2436 // Object::Relocate.
2437
2438 void
2439 Output_section::write_to_postprocessing_buffer()
2440 {
2441   gold_assert(this->requires_postprocessing());
2442
2443   unsigned char* buffer = this->postprocessing_buffer();
2444   for (Fill_list::iterator p = this->fills_.begin();
2445        p != this->fills_.end();
2446        ++p)
2447     {
2448       std::string fill_data(parameters->target().code_fill(p->length()));
2449       memcpy(buffer + p->section_offset(), fill_data.data(),
2450              fill_data.size());
2451     }
2452
2453   off_t off = this->first_input_offset_;
2454   for (Input_section_list::iterator p = this->input_sections_.begin();
2455        p != this->input_sections_.end();
2456        ++p)
2457     {
2458       off = align_address(off, p->addralign());
2459       p->write_to_buffer(buffer + off);
2460       off += p->data_size();
2461     }
2462 }
2463
2464 // Get the input sections for linker script processing.  We leave
2465 // behind the Output_section_data entries.  Note that this may be
2466 // slightly incorrect for merge sections.  We will leave them behind,
2467 // but it is possible that the script says that they should follow
2468 // some other input sections, as in:
2469 //    .rodata { *(.rodata) *(.rodata.cst*) }
2470 // For that matter, we don't handle this correctly:
2471 //    .rodata { foo.o(.rodata.cst*) *(.rodata.cst*) }
2472 // With luck this will never matter.
2473
2474 uint64_t
2475 Output_section::get_input_sections(
2476     uint64_t address,
2477     const std::string& fill,
2478     std::list<std::pair<Relobj*, unsigned int> >* input_sections)
2479 {
2480   uint64_t orig_address = address;
2481
2482   address = align_address(address, this->addralign());
2483
2484   Input_section_list remaining;
2485   for (Input_section_list::iterator p = this->input_sections_.begin();
2486        p != this->input_sections_.end();
2487        ++p)
2488     {
2489       if (p->is_input_section())
2490         input_sections->push_back(std::make_pair(p->relobj(), p->shndx()));
2491       else
2492         {
2493           uint64_t aligned_address = align_address(address, p->addralign());
2494           if (aligned_address != address && !fill.empty())
2495             {
2496               section_size_type length =
2497                 convert_to_section_size_type(aligned_address - address);
2498               std::string this_fill;
2499               this_fill.reserve(length);
2500               while (this_fill.length() + fill.length() <= length)
2501                 this_fill += fill;
2502               if (this_fill.length() < length)
2503                 this_fill.append(fill, 0, length - this_fill.length());
2504
2505               Output_section_data* posd = new Output_data_const(this_fill, 0);
2506               remaining.push_back(Input_section(posd));
2507             }
2508           address = aligned_address;
2509
2510           remaining.push_back(*p);
2511
2512           p->finalize_data_size();
2513           address += p->data_size();
2514         }
2515     }
2516
2517   this->input_sections_.swap(remaining);
2518   this->first_input_offset_ = 0;
2519
2520   uint64_t data_size = address - orig_address;
2521   this->set_current_data_size_for_child(data_size);
2522   return data_size;
2523 }
2524
2525 // Add an input section from a script.
2526
2527 void
2528 Output_section::add_input_section_for_script(Relobj* object,
2529                                              unsigned int shndx,
2530                                              off_t data_size,
2531                                              uint64_t addralign)
2532 {
2533   if (addralign > this->addralign_)
2534     this->addralign_ = addralign;
2535
2536   off_t offset_in_section = this->current_data_size_for_child();
2537   off_t aligned_offset_in_section = align_address(offset_in_section,
2538                                                   addralign);
2539
2540   this->set_current_data_size_for_child(aligned_offset_in_section
2541                                         + data_size);
2542
2543   this->input_sections_.push_back(Input_section(object, shndx,
2544                                                 data_size, addralign));
2545 }
2546
2547 // Print stats for merge sections to stderr.
2548
2549 void
2550 Output_section::print_merge_stats()
2551 {
2552   Input_section_list::iterator p;
2553   for (p = this->input_sections_.begin();
2554        p != this->input_sections_.end();
2555        ++p)
2556     p->print_merge_stats(this->name_);
2557 }
2558
2559 // Output segment methods.
2560
2561 Output_segment::Output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags)
2562   : output_data_(),
2563     output_bss_(),
2564     vaddr_(0),
2565     paddr_(0),
2566     memsz_(0),
2567     max_align_(0),
2568     min_p_align_(0),
2569     offset_(0),
2570     filesz_(0),
2571     type_(type),
2572     flags_(flags),
2573     is_max_align_known_(false),
2574     are_addresses_set_(false)
2575 {
2576 }
2577
2578 // Add an Output_section to an Output_segment.
2579
2580 void
2581 Output_segment::add_output_section(Output_section* os,
2582                                    elfcpp::Elf_Word seg_flags)
2583 {
2584   gold_assert((os->flags() & elfcpp::SHF_ALLOC) != 0);
2585   gold_assert(!this->is_max_align_known_);
2586
2587   // Update the segment flags.
2588   this->flags_ |= seg_flags;
2589
2590   Output_segment::Output_data_list* pdl;
2591   if (os->type() == elfcpp::SHT_NOBITS)
2592     pdl = &this->output_bss_;
2593   else
2594     pdl = &this->output_data_;
2595
2596   // So that PT_NOTE segments will work correctly, we need to ensure
2597   // that all SHT_NOTE sections are adjacent.  This will normally
2598   // happen automatically, because all the SHT_NOTE input sections
2599   // will wind up in the same output section.  However, it is possible
2600   // for multiple SHT_NOTE input sections to have different section
2601   // flags, and thus be in different output sections, but for the
2602   // different section flags to map into the same segment flags and
2603   // thus the same output segment.
2604
2605   // Note that while there may be many input sections in an output
2606   // section, there are normally only a few output sections in an
2607   // output segment.  This loop is expected to be fast.
2608
2609   if (os->type() == elfcpp::SHT_NOTE && !pdl->empty())
2610     {
2611       Output_segment::Output_data_list::iterator p = pdl->end();
2612       do
2613         {
2614           --p;
2615           if ((*p)->is_section_type(elfcpp::SHT_NOTE))
2616             {
2617               ++p;
2618               pdl->insert(p, os);
2619               return;
2620             }
2621         }
2622       while (p != pdl->begin());
2623     }
2624
2625   // Similarly, so that PT_TLS segments will work, we need to group
2626   // SHF_TLS sections.  An SHF_TLS/SHT_NOBITS section is a special
2627   // case: we group the SHF_TLS/SHT_NOBITS sections right after the
2628   // SHF_TLS/SHT_PROGBITS sections.  This lets us set up PT_TLS
2629   // correctly.  SHF_TLS sections get added to both a PT_LOAD segment
2630   // and the PT_TLS segment -- we do this grouping only for the
2631   // PT_LOAD segment.
2632   if (this->type_ != elfcpp::PT_TLS
2633       && (os->flags() & elfcpp::SHF_TLS) != 0
2634       && !this->output_data_.empty())
2635     {
2636       pdl = &this->output_data_;
2637       bool nobits = os->type() == elfcpp::SHT_NOBITS;
2638       bool sawtls = false;
2639       Output_segment::Output_data_list::iterator p = pdl->end();
2640       do
2641         {
2642           --p;
2643           bool insert;
2644           if ((*p)->is_section_flag_set(elfcpp::SHF_TLS))
2645             {
2646               sawtls = true;
2647               // Put a NOBITS section after the first TLS section.
2648               // But a PROGBITS section after the first TLS/PROGBITS
2649               // section.
2650               insert = nobits || !(*p)->is_section_type(elfcpp::SHT_NOBITS);
2651             }
2652           else
2653             {
2654               // If we've gone past the TLS sections, but we've seen a
2655               // TLS section, then we need to insert this section now.
2656               insert = sawtls;
2657             }
2658
2659           if (insert)
2660             {
2661               ++p;
2662               pdl->insert(p, os);
2663               return;
2664             }
2665         }
2666       while (p != pdl->begin());
2667
2668       // There are no TLS sections yet; put this one at the requested
2669       // location in the section list.
2670     }
2671
2672   pdl->push_back(os);
2673 }
2674
2675 // Remove an Output_section from this segment.  It is an error if it
2676 // is not present.
2677
2678 void
2679 Output_segment::remove_output_section(Output_section* os)
2680 {
2681   // We only need this for SHT_PROGBITS.
2682   gold_assert(os->type() == elfcpp::SHT_PROGBITS);
2683   for (Output_data_list::iterator p = this->output_data_.begin();
2684        p != this->output_data_.end();
2685        ++p)
2686    {
2687      if (*p == os)
2688        {
2689          this->output_data_.erase(p);
2690          return;
2691        }
2692    }
2693   gold_unreachable();
2694 }
2695
2696 // Add an Output_data (which is not an Output_section) to the start of
2697 // a segment.
2698
2699 void
2700 Output_segment::add_initial_output_data(Output_data* od)
2701 {
2702   gold_assert(!this->is_max_align_known_);
2703   this->output_data_.push_front(od);
2704 }
2705
2706 // Return the maximum alignment of the Output_data in Output_segment.
2707
2708 uint64_t
2709 Output_segment::maximum_alignment()
2710 {
2711   if (!this->is_max_align_known_)
2712     {
2713       uint64_t addralign;
2714
2715       addralign = Output_segment::maximum_alignment_list(&this->output_data_);
2716       if (addralign > this->max_align_)
2717         this->max_align_ = addralign;
2718
2719       addralign = Output_segment::maximum_alignment_list(&this->output_bss_);
2720       if (addralign > this->max_align_)
2721         this->max_align_ = addralign;
2722
2723       this->is_max_align_known_ = true;
2724     }
2725
2726   return this->max_align_;
2727 }
2728
2729 // Return the maximum alignment of a list of Output_data.
2730
2731 uint64_t
2732 Output_segment::maximum_alignment_list(const Output_data_list* pdl)
2733 {
2734   uint64_t ret = 0;
2735   for (Output_data_list::const_iterator p = pdl->begin();
2736        p != pdl->end();
2737        ++p)
2738     {
2739       uint64_t addralign = (*p)->addralign();
2740       if (addralign > ret)
2741         ret = addralign;
2742     }
2743   return ret;
2744 }
2745
2746 // Return the number of dynamic relocs applied to this segment.
2747
2748 unsigned int
2749 Output_segment::dynamic_reloc_count() const
2750 {
2751   return (this->dynamic_reloc_count_list(&this->output_data_)
2752           + this->dynamic_reloc_count_list(&this->output_bss_));
2753 }
2754
2755 // Return the number of dynamic relocs applied to an Output_data_list.
2756
2757 unsigned int
2758 Output_segment::dynamic_reloc_count_list(const Output_data_list* pdl) const
2759 {
2760   unsigned int count = 0;
2761   for (Output_data_list::const_iterator p = pdl->begin();
2762        p != pdl->end();
2763        ++p)
2764     count += (*p)->dynamic_reloc_count();
2765   return count;
2766 }
2767
2768 // Set the section addresses for an Output_segment.  If RESET is true,
2769 // reset the addresses first.  ADDR is the address and *POFF is the
2770 // file offset.  Set the section indexes starting with *PSHNDX.
2771 // Return the address of the immediately following segment.  Update
2772 // *POFF and *PSHNDX.
2773
2774 uint64_t
2775 Output_segment::set_section_addresses(const Layout* layout, bool reset,
2776                                       uint64_t addr, off_t* poff,
2777                                       unsigned int* pshndx)
2778 {
2779   gold_assert(this->type_ == elfcpp::PT_LOAD);
2780
2781   if (!reset && this->are_addresses_set_)
2782     {
2783       gold_assert(this->paddr_ == addr);
2784       addr = this->vaddr_;
2785     }
2786   else
2787     {
2788       this->vaddr_ = addr;
2789       this->paddr_ = addr;
2790       this->are_addresses_set_ = true;
2791     }
2792
2793   bool in_tls = false;
2794
2795   off_t orig_off = *poff;
2796   this->offset_ = orig_off;
2797
2798   addr = this->set_section_list_addresses(layout, reset, &this->output_data_,
2799                                           addr, poff, pshndx, &in_tls);
2800   this->filesz_ = *poff - orig_off;
2801
2802   off_t off = *poff;
2803
2804   uint64_t ret = this->set_section_list_addresses(layout, reset,
2805                                                   &this->output_bss_,
2806                                                   addr, poff, pshndx,
2807                                                   &in_tls);
2808
2809   // If the last section was a TLS section, align upward to the
2810   // alignment of the TLS segment, so that the overall size of the TLS
2811   // segment is aligned.
2812   if (in_tls)
2813     {
2814       uint64_t segment_align = layout->tls_segment()->maximum_alignment();
2815       *poff = align_address(*poff, segment_align);
2816     }
2817
2818   this->memsz_ = *poff - orig_off;
2819
2820   // Ignore the file offset adjustments made by the BSS Output_data
2821   // objects.
2822   *poff = off;
2823
2824   return ret;
2825 }
2826
2827 // Set the addresses and file offsets in a list of Output_data
2828 // structures.
2829
2830 uint64_t
2831 Output_segment::set_section_list_addresses(const Layout* layout, bool reset,
2832                                            Output_data_list* pdl,
2833                                            uint64_t addr, off_t* poff,
2834                                            unsigned int* pshndx,
2835                                            bool* in_tls)
2836 {
2837   off_t startoff = *poff;
2838
2839   off_t off = startoff;
2840   for (Output_data_list::iterator p = pdl->begin();
2841        p != pdl->end();
2842        ++p)
2843     {
2844       if (reset)
2845         (*p)->reset_address_and_file_offset();
2846
2847       // When using a linker script the section will most likely
2848       // already have an address.
2849       if (!(*p)->is_address_valid())
2850         {
2851           uint64_t align = (*p)->addralign();
2852
2853           if ((*p)->is_section_flag_set(elfcpp::SHF_TLS))
2854             {
2855               // Give the first TLS section the alignment of the
2856               // entire TLS segment.  Otherwise the TLS segment as a
2857               // whole may be misaligned.
2858               if (!*in_tls)
2859                 {
2860                   Output_segment* tls_segment = layout->tls_segment();
2861                   gold_assert(tls_segment != NULL);
2862                   uint64_t segment_align = tls_segment->maximum_alignment();
2863                   gold_assert(segment_align >= align);
2864                   align = segment_align;
2865
2866                   *in_tls = true;
2867                 }
2868             }
2869           else
2870             {
2871               // If this is the first section after the TLS segment,
2872               // align it to at least the alignment of the TLS
2873               // segment, so that the size of the overall TLS segment
2874               // is aligned.
2875               if (*in_tls)
2876                 {
2877                   uint64_t segment_align =
2878                       layout->tls_segment()->maximum_alignment();
2879                   if (segment_align > align)
2880                     align = segment_align;
2881
2882                   *in_tls = false;
2883                 }
2884             }
2885
2886           off = align_address(off, align);
2887           (*p)->set_address_and_file_offset(addr + (off - startoff), off);
2888         }
2889       else
2890         {
2891           // The script may have inserted a skip forward, but it
2892           // better not have moved backward.
2893           gold_assert((*p)->address() >= addr + (off - startoff));
2894           off += (*p)->address() - (addr + (off - startoff));
2895           (*p)->set_file_offset(off);
2896           (*p)->finalize_data_size();
2897         }
2898
2899       // We want to ignore the size of a SHF_TLS or SHT_NOBITS
2900       // section.  Such a section does not affect the size of a
2901       // PT_LOAD segment.
2902       if (!(*p)->is_section_flag_set(elfcpp::SHF_TLS)
2903           || !(*p)->is_section_type(elfcpp::SHT_NOBITS))
2904         off += (*p)->data_size();
2905
2906       if ((*p)->is_section())
2907         {
2908           (*p)->set_out_shndx(*pshndx);
2909           ++*pshndx;
2910         }
2911     }
2912
2913   *poff = off;
2914   return addr + (off - startoff);
2915 }
2916
2917 // For a non-PT_LOAD segment, set the offset from the sections, if
2918 // any.
2919
2920 void
2921 Output_segment::set_offset()
2922 {
2923   gold_assert(this->type_ != elfcpp::PT_LOAD);
2924
2925   gold_assert(!this->are_addresses_set_);
2926
2927   if (this->output_data_.empty() && this->output_bss_.empty())
2928     {
2929       this->vaddr_ = 0;
2930       this->paddr_ = 0;
2931       this->are_addresses_set_ = true;
2932       this->memsz_ = 0;
2933       this->min_p_align_ = 0;
2934       this->offset_ = 0;
2935       this->filesz_ = 0;
2936       return;
2937     }
2938
2939   const Output_data* first;
2940   if (this->output_data_.empty())
2941     first = this->output_bss_.front();
2942   else
2943     first = this->output_data_.front();
2944   this->vaddr_ = first->address();
2945   this->paddr_ = (first->has_load_address()
2946                   ? first->load_address()
2947                   : this->vaddr_);
2948   this->are_addresses_set_ = true;
2949   this->offset_ = first->offset();
2950
2951   if (this->output_data_.empty())
2952     this->filesz_ = 0;
2953   else
2954     {
2955       const Output_data* last_data = this->output_data_.back();
2956       this->filesz_ = (last_data->address()
2957                        + last_data->data_size()
2958                        - this->vaddr_);
2959     }
2960
2961   const Output_data* last;
2962   if (this->output_bss_.empty())
2963     last = this->output_data_.back();
2964   else
2965     last = this->output_bss_.back();
2966   this->memsz_ = (last->address()
2967                   + last->data_size()
2968                   - this->vaddr_);
2969
2970   // If this is a TLS segment, align the memory size.  The code in
2971   // set_section_list ensures that the section after the TLS segment
2972   // is aligned to give us room.
2973   if (this->type_ == elfcpp::PT_TLS)
2974     {
2975       uint64_t segment_align = this->maximum_alignment();
2976       gold_assert(this->vaddr_ == align_address(this->vaddr_, segment_align));
2977       this->memsz_ = align_address(this->memsz_, segment_align);
2978     }
2979 }
2980
2981 // Set the TLS offsets of the sections in the PT_TLS segment.
2982
2983 void
2984 Output_segment::set_tls_offsets()
2985 {
2986   gold_assert(this->type_ == elfcpp::PT_TLS);
2987
2988   for (Output_data_list::iterator p = this->output_data_.begin();
2989        p != this->output_data_.end();
2990        ++p)
2991     (*p)->set_tls_offset(this->vaddr_);
2992
2993   for (Output_data_list::iterator p = this->output_bss_.begin();
2994        p != this->output_bss_.end();
2995        ++p)
2996     (*p)->set_tls_offset(this->vaddr_);
2997 }
2998
2999 // Return the address of the first section.
3000
3001 uint64_t
3002 Output_segment::first_section_load_address() const
3003 {
3004   for (Output_data_list::const_iterator p = this->output_data_.begin();
3005        p != this->output_data_.end();
3006        ++p)
3007     if ((*p)->is_section())
3008       return (*p)->has_load_address() ? (*p)->load_address() : (*p)->address();
3009
3010   for (Output_data_list::const_iterator p = this->output_bss_.begin();
3011        p != this->output_bss_.end();
3012        ++p)
3013     if ((*p)->is_section())
3014       return (*p)->has_load_address() ? (*p)->load_address() : (*p)->address();
3015
3016   gold_unreachable();
3017 }
3018
3019 // Return the number of Output_sections in an Output_segment.
3020
3021 unsigned int
3022 Output_segment::output_section_count() const
3023 {
3024   return (this->output_section_count_list(&this->output_data_)
3025           + this->output_section_count_list(&this->output_bss_));
3026 }
3027
3028 // Return the number of Output_sections in an Output_data_list.
3029
3030 unsigned int
3031 Output_segment::output_section_count_list(const Output_data_list* pdl) const
3032 {
3033   unsigned int count = 0;
3034   for (Output_data_list::const_iterator p = pdl->begin();
3035        p != pdl->end();
3036        ++p)
3037     {
3038       if ((*p)->is_section())
3039         ++count;
3040     }
3041   return count;
3042 }
3043
3044 // Return the section attached to the list segment with the lowest
3045 // load address.  This is used when handling a PHDRS clause in a
3046 // linker script.
3047
3048 Output_section*
3049 Output_segment::section_with_lowest_load_address() const
3050 {
3051   Output_section* found = NULL;
3052   uint64_t found_lma = 0;
3053   this->lowest_load_address_in_list(&this->output_data_, &found, &found_lma);
3054
3055   Output_section* found_data = found;
3056   this->lowest_load_address_in_list(&this->output_bss_, &found, &found_lma);
3057   if (found != found_data && found_data != NULL)
3058     {
3059       gold_error(_("nobits section %s may not precede progbits section %s "
3060                    "in same segment"),
3061                  found->name(), found_data->name());
3062       return NULL;
3063     }
3064
3065   return found;
3066 }
3067
3068 // Look through a list for a section with a lower load address.
3069
3070 void
3071 Output_segment::lowest_load_address_in_list(const Output_data_list* pdl,
3072                                             Output_section** found,
3073                                             uint64_t* found_lma) const
3074 {
3075   for (Output_data_list::const_iterator p = pdl->begin();
3076        p != pdl->end();
3077        ++p)
3078     {
3079       if (!(*p)->is_section())
3080         continue;
3081       Output_section* os = static_cast<Output_section*>(*p);
3082       uint64_t lma = (os->has_load_address()
3083                       ? os->load_address()
3084                       : os->address());
3085       if (*found == NULL || lma < *found_lma)
3086         {
3087           *found = os;
3088           *found_lma = lma;
3089         }
3090     }
3091 }
3092
3093 // Write the segment data into *OPHDR.
3094
3095 template<int size, bool big_endian>
3096 void
3097 Output_segment::write_header(elfcpp::Phdr_write<size, big_endian>* ophdr)
3098 {
3099   ophdr->put_p_type(this->type_);
3100   ophdr->put_p_offset(this->offset_);
3101   ophdr->put_p_vaddr(this->vaddr_);
3102   ophdr->put_p_paddr(this->paddr_);
3103   ophdr->put_p_filesz(this->filesz_);
3104   ophdr->put_p_memsz(this->memsz_);
3105   ophdr->put_p_flags(this->flags_);
3106   ophdr->put_p_align(std::max(this->min_p_align_, this->maximum_alignment()));
3107 }
3108
3109 // Write the section headers into V.
3110
3111 template<int size, bool big_endian>
3112 unsigned char*
3113 Output_segment::write_section_headers(const Layout* layout,
3114                                       const Stringpool* secnamepool,
3115                                       unsigned char* v,
3116                                       unsigned int *pshndx) const
3117 {
3118   // Every section that is attached to a segment must be attached to a
3119   // PT_LOAD segment, so we only write out section headers for PT_LOAD
3120   // segments.
3121   if (this->type_ != elfcpp::PT_LOAD)
3122     return v;
3123
3124   v = this->write_section_headers_list<size, big_endian>(layout, secnamepool,
3125                                                          &this->output_data_,
3126                                                          v, pshndx);
3127   v = this->write_section_headers_list<size, big_endian>(layout, secnamepool,
3128                                                          &this->output_bss_,
3129                                                          v, pshndx);
3130   return v;
3131 }
3132
3133 template<int size, bool big_endian>
3134 unsigned char*
3135 Output_segment::write_section_headers_list(const Layout* layout,
3136                                            const Stringpool* secnamepool,
3137                                            const Output_data_list* pdl,
3138                                            unsigned char* v,
3139                                            unsigned int* pshndx) const
3140 {
3141   const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
3142   for (Output_data_list::const_iterator p = pdl->begin();
3143        p != pdl->end();
3144        ++p)
3145     {
3146       if ((*p)->is_section())
3147         {
3148           const Output_section* ps = static_cast<const Output_section*>(*p);
3149           gold_assert(*pshndx == ps->out_shndx());
3150           elfcpp::Shdr_write<size, big_endian> oshdr(v);
3151           ps->write_header(layout, secnamepool, &oshdr);
3152           v += shdr_size;
3153           ++*pshndx;
3154         }
3155     }
3156   return v;
3157 }
3158
3159 // Output_file methods.
3160
3161 Output_file::Output_file(const char* name)
3162   : name_(name),
3163     o_(-1),
3164     file_size_(0),
3165     base_(NULL),
3166     map_is_anonymous_(false),
3167     is_temporary_(false)
3168 {
3169 }
3170
3171 // Open the output file.
3172
3173 void
3174 Output_file::open(off_t file_size)
3175 {
3176   this->file_size_ = file_size;
3177
3178   // Unlink the file first; otherwise the open() may fail if the file
3179   // is busy (e.g. it's an executable that's currently being executed).
3180   //
3181   // However, the linker may be part of a system where a zero-length
3182   // file is created for it to write to, with tight permissions (gcc
3183   // 2.95 did something like this).  Unlinking the file would work
3184   // around those permission controls, so we only unlink if the file
3185   // has a non-zero size.  We also unlink only regular files to avoid
3186   // trouble with directories/etc.
3187   //
3188   // If we fail, continue; this command is merely a best-effort attempt
3189   // to improve the odds for open().
3190
3191   // We let the name "-" mean "stdout"
3192   if (!this->is_temporary_)
3193     {
3194       if (strcmp(this->name_, "-") == 0)
3195         this->o_ = STDOUT_FILENO;
3196       else
3197         {
3198           struct stat s;
3199           if (::stat(this->name_, &s) == 0 && s.st_size != 0)
3200             unlink_if_ordinary(this->name_);
3201
3202           int mode = parameters->options().relocatable() ? 0666 : 0777;
3203           int o = ::open(this->name_, O_RDWR | O_CREAT | O_TRUNC, mode);
3204           if (o < 0)
3205             gold_fatal(_("%s: open: %s"), this->name_, strerror(errno));
3206           this->o_ = o;
3207         }
3208     }
3209
3210   this->map();
3211 }
3212
3213 // Resize the output file.
3214
3215 void
3216 Output_file::resize(off_t file_size)
3217 {
3218   // If the mmap is mapping an anonymous memory buffer, this is easy:
3219   // just mremap to the new size.  If it's mapping to a file, we want
3220   // to unmap to flush to the file, then remap after growing the file.
3221   if (this->map_is_anonymous_)
3222     {
3223       void* base = ::mremap(this->base_, this->file_size_, file_size,
3224                             MREMAP_MAYMOVE);
3225       if (base == MAP_FAILED)
3226         gold_fatal(_("%s: mremap: %s"), this->name_, strerror(errno));
3227       this->base_ = static_cast<unsigned char*>(base);
3228       this->file_size_ = file_size;
3229     }
3230   else
3231     {
3232       this->unmap();
3233       this->file_size_ = file_size;
3234       this->map();
3235     }
3236 }
3237
3238 // Map the file into memory.
3239
3240 void
3241 Output_file::map()
3242 {
3243   const int o = this->o_;
3244
3245   // If the output file is not a regular file, don't try to mmap it;
3246   // instead, we'll mmap a block of memory (an anonymous buffer), and
3247   // then later write the buffer to the file.
3248   void* base;
3249   struct stat statbuf;
3250   if (o == STDOUT_FILENO || o == STDERR_FILENO
3251       || ::fstat(o, &statbuf) != 0
3252       || !S_ISREG(statbuf.st_mode)
3253       || this->is_temporary_)
3254     {
3255       this->map_is_anonymous_ = true;
3256       base = ::mmap(NULL, this->file_size_, PROT_READ | PROT_WRITE,
3257                     MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
3258     }
3259   else
3260     {
3261       // Write out one byte to make the file the right size.
3262       if (::lseek(o, this->file_size_ - 1, SEEK_SET) < 0)
3263         gold_fatal(_("%s: lseek: %s"), this->name_, strerror(errno));
3264       char b = 0;
3265       if (::write(o, &b, 1) != 1)
3266         gold_fatal(_("%s: write: %s"), this->name_, strerror(errno));
3267
3268       // Map the file into memory.
3269       this->map_is_anonymous_ = false;
3270       base = ::mmap(NULL, this->file_size_, PROT_READ | PROT_WRITE,
3271                     MAP_SHARED, o, 0);
3272     }
3273   if (base == MAP_FAILED)
3274     gold_fatal(_("%s: mmap: %s"), this->name_, strerror(errno));
3275   this->base_ = static_cast<unsigned char*>(base);
3276 }
3277
3278 // Unmap the file from memory.
3279
3280 void
3281 Output_file::unmap()
3282 {
3283   if (::munmap(this->base_, this->file_size_) < 0)
3284     gold_error(_("%s: munmap: %s"), this->name_, strerror(errno));
3285   this->base_ = NULL;
3286 }
3287
3288 // Close the output file.
3289
3290 void
3291 Output_file::close()
3292 {
3293   // If the map isn't file-backed, we need to write it now.
3294   if (this->map_is_anonymous_ && !this->is_temporary_)
3295     {
3296       size_t bytes_to_write = this->file_size_;
3297       while (bytes_to_write > 0)
3298         {
3299           ssize_t bytes_written = ::write(this->o_, this->base_, bytes_to_write);
3300           if (bytes_written == 0)
3301             gold_error(_("%s: write: unexpected 0 return-value"), this->name_);
3302           else if (bytes_written < 0)
3303             gold_error(_("%s: write: %s"), this->name_, strerror(errno));
3304           else
3305             bytes_to_write -= bytes_written;
3306         }
3307     }
3308   this->unmap();
3309
3310   // We don't close stdout or stderr
3311   if (this->o_ != STDOUT_FILENO
3312       && this->o_ != STDERR_FILENO
3313       && !this->is_temporary_)
3314     if (::close(this->o_) < 0)
3315       gold_error(_("%s: close: %s"), this->name_, strerror(errno));
3316   this->o_ = -1;
3317 }
3318
3319 // Instantiate the templates we need.  We could use the configure
3320 // script to restrict this to only the ones for implemented targets.
3321
3322 #ifdef HAVE_TARGET_32_LITTLE
3323 template
3324 off_t
3325 Output_section::add_input_section<32, false>(
3326     Sized_relobj<32, false>* object,
3327     unsigned int shndx,
3328     const char* secname,
3329     const elfcpp::Shdr<32, false>& shdr,
3330     unsigned int reloc_shndx,
3331     bool have_sections_script);
3332 #endif
3333
3334 #ifdef HAVE_TARGET_32_BIG
3335 template
3336 off_t
3337 Output_section::add_input_section<32, true>(
3338     Sized_relobj<32, true>* object,
3339     unsigned int shndx,
3340     const char* secname,
3341     const elfcpp::Shdr<32, true>& shdr,
3342     unsigned int reloc_shndx,
3343     bool have_sections_script);
3344 #endif
3345
3346 #ifdef HAVE_TARGET_64_LITTLE
3347 template
3348 off_t
3349 Output_section::add_input_section<64, false>(
3350     Sized_relobj<64, false>* object,
3351     unsigned int shndx,
3352     const char* secname,
3353     const elfcpp::Shdr<64, false>& shdr,
3354     unsigned int reloc_shndx,
3355     bool have_sections_script);
3356 #endif
3357
3358 #ifdef HAVE_TARGET_64_BIG
3359 template
3360 off_t
3361 Output_section::add_input_section<64, true>(
3362     Sized_relobj<64, true>* object,
3363     unsigned int shndx,
3364     const char* secname,
3365     const elfcpp::Shdr<64, true>& shdr,
3366     unsigned int reloc_shndx,
3367     bool have_sections_script);
3368 #endif
3369
3370 #ifdef HAVE_TARGET_32_LITTLE
3371 template
3372 class Output_data_reloc<elfcpp::SHT_REL, false, 32, false>;
3373 #endif
3374
3375 #ifdef HAVE_TARGET_32_BIG
3376 template
3377 class Output_data_reloc<elfcpp::SHT_REL, false, 32, true>;
3378 #endif
3379
3380 #ifdef HAVE_TARGET_64_LITTLE
3381 template
3382 class Output_data_reloc<elfcpp::SHT_REL, false, 64, false>;
3383 #endif
3384
3385 #ifdef HAVE_TARGET_64_BIG
3386 template
3387 class Output_data_reloc<elfcpp::SHT_REL, false, 64, true>;
3388 #endif
3389
3390 #ifdef HAVE_TARGET_32_LITTLE
3391 template
3392 class Output_data_reloc<elfcpp::SHT_REL, true, 32, false>;
3393 #endif
3394
3395 #ifdef HAVE_TARGET_32_BIG
3396 template
3397 class Output_data_reloc<elfcpp::SHT_REL, true, 32, true>;
3398 #endif
3399
3400 #ifdef HAVE_TARGET_64_LITTLE
3401 template
3402 class Output_data_reloc<elfcpp::SHT_REL, true, 64, false>;
3403 #endif
3404
3405 #ifdef HAVE_TARGET_64_BIG
3406 template
3407 class Output_data_reloc<elfcpp::SHT_REL, true, 64, true>;
3408 #endif
3409
3410 #ifdef HAVE_TARGET_32_LITTLE
3411 template
3412 class Output_data_reloc<elfcpp::SHT_RELA, false, 32, false>;
3413 #endif
3414
3415 #ifdef HAVE_TARGET_32_BIG
3416 template
3417 class Output_data_reloc<elfcpp::SHT_RELA, false, 32, true>;
3418 #endif
3419
3420 #ifdef HAVE_TARGET_64_LITTLE
3421 template
3422 class Output_data_reloc<elfcpp::SHT_RELA, false, 64, false>;
3423 #endif
3424
3425 #ifdef HAVE_TARGET_64_BIG
3426 template
3427 class Output_data_reloc<elfcpp::SHT_RELA, false, 64, true>;
3428 #endif
3429
3430 #ifdef HAVE_TARGET_32_LITTLE
3431 template
3432 class Output_data_reloc<elfcpp::SHT_RELA, true, 32, false>;
3433 #endif
3434
3435 #ifdef HAVE_TARGET_32_BIG
3436 template
3437 class Output_data_reloc<elfcpp::SHT_RELA, true, 32, true>;
3438 #endif
3439
3440 #ifdef HAVE_TARGET_64_LITTLE
3441 template
3442 class Output_data_reloc<elfcpp::SHT_RELA, true, 64, false>;
3443 #endif
3444
3445 #ifdef HAVE_TARGET_64_BIG
3446 template
3447 class Output_data_reloc<elfcpp::SHT_RELA, true, 64, true>;
3448 #endif
3449
3450 #ifdef HAVE_TARGET_32_LITTLE
3451 template
3452 class Output_relocatable_relocs<elfcpp::SHT_REL, 32, false>;
3453 #endif
3454
3455 #ifdef HAVE_TARGET_32_BIG
3456 template
3457 class Output_relocatable_relocs<elfcpp::SHT_REL, 32, true>;
3458 #endif
3459
3460 #ifdef HAVE_TARGET_64_LITTLE
3461 template
3462 class Output_relocatable_relocs<elfcpp::SHT_REL, 64, false>;
3463 #endif
3464
3465 #ifdef HAVE_TARGET_64_BIG
3466 template
3467 class Output_relocatable_relocs<elfcpp::SHT_REL, 64, true>;
3468 #endif
3469
3470 #ifdef HAVE_TARGET_32_LITTLE
3471 template
3472 class Output_relocatable_relocs<elfcpp::SHT_RELA, 32, false>;
3473 #endif
3474
3475 #ifdef HAVE_TARGET_32_BIG
3476 template
3477 class Output_relocatable_relocs<elfcpp::SHT_RELA, 32, true>;
3478 #endif
3479
3480 #ifdef HAVE_TARGET_64_LITTLE
3481 template
3482 class Output_relocatable_relocs<elfcpp::SHT_RELA, 64, false>;
3483 #endif
3484
3485 #ifdef HAVE_TARGET_64_BIG
3486 template
3487 class Output_relocatable_relocs<elfcpp::SHT_RELA, 64, true>;
3488 #endif
3489
3490 #ifdef HAVE_TARGET_32_LITTLE
3491 template
3492 class Output_data_group<32, false>;
3493 #endif
3494
3495 #ifdef HAVE_TARGET_32_BIG
3496 template
3497 class Output_data_group<32, true>;
3498 #endif
3499
3500 #ifdef HAVE_TARGET_64_LITTLE
3501 template
3502 class Output_data_group<64, false>;
3503 #endif
3504
3505 #ifdef HAVE_TARGET_64_BIG
3506 template
3507 class Output_data_group<64, true>;
3508 #endif
3509
3510 #ifdef HAVE_TARGET_32_LITTLE
3511 template
3512 class Output_data_got<32, false>;
3513 #endif
3514
3515 #ifdef HAVE_TARGET_32_BIG
3516 template
3517 class Output_data_got<32, true>;
3518 #endif
3519
3520 #ifdef HAVE_TARGET_64_LITTLE
3521 template
3522 class Output_data_got<64, false>;
3523 #endif
3524
3525 #ifdef HAVE_TARGET_64_BIG
3526 template
3527 class Output_data_got<64, true>;
3528 #endif
3529
3530 } // End namespace gold.