Merge branch 'vendor/GCC44'
[dragonfly.git] / contrib / binutils-2.21 / gold / output.cc
1 // output.cc -- manage the output file for gold
2
3 // Copyright 2006, 2007, 2008, 2009, 2010 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"
34
35 #include "parameters.h"
36 #include "object.h"
37 #include "symtab.h"
38 #include "reloc.h"
39 #include "merge.h"
40 #include "descriptors.h"
41 #include "output.h"
42
43 // Some BSD systems still use MAP_ANON instead of MAP_ANONYMOUS
44 #ifndef MAP_ANONYMOUS
45 # define MAP_ANONYMOUS  MAP_ANON
46 #endif
47
48 #ifndef HAVE_POSIX_FALLOCATE
49 // A dummy, non general, version of posix_fallocate.  Here we just set
50 // the file size and hope that there is enough disk space.  FIXME: We
51 // could allocate disk space by walking block by block and writing a
52 // zero byte into each block.
53 static int
54 posix_fallocate(int o, off_t offset, off_t len)
55 {
56   return ftruncate(o, offset + len);
57 }
58 #endif // !defined(HAVE_POSIX_FALLOCATE)
59
60 namespace gold
61 {
62
63 // Output_data variables.
64
65 bool Output_data::allocated_sizes_are_fixed;
66
67 // Output_data methods.
68
69 Output_data::~Output_data()
70 {
71 }
72
73 // Return the default alignment for the target size.
74
75 uint64_t
76 Output_data::default_alignment()
77 {
78   return Output_data::default_alignment_for_size(
79       parameters->target().get_size());
80 }
81
82 // Return the default alignment for a size--32 or 64.
83
84 uint64_t
85 Output_data::default_alignment_for_size(int size)
86 {
87   if (size == 32)
88     return 4;
89   else if (size == 64)
90     return 8;
91   else
92     gold_unreachable();
93 }
94
95 // Output_section_header methods.  This currently assumes that the
96 // segment and section lists are complete at construction time.
97
98 Output_section_headers::Output_section_headers(
99     const Layout* layout,
100     const Layout::Segment_list* segment_list,
101     const Layout::Section_list* section_list,
102     const Layout::Section_list* unattached_section_list,
103     const Stringpool* secnamepool,
104     const Output_section* shstrtab_section)
105   : layout_(layout),
106     segment_list_(segment_list),
107     section_list_(section_list),
108     unattached_section_list_(unattached_section_list),
109     secnamepool_(secnamepool),
110     shstrtab_section_(shstrtab_section)
111 {
112 }
113
114 // Compute the current data size.
115
116 off_t
117 Output_section_headers::do_size() const
118 {
119   // Count all the sections.  Start with 1 for the null section.
120   off_t count = 1;
121   if (!parameters->options().relocatable())
122     {
123       for (Layout::Segment_list::const_iterator p =
124              this->segment_list_->begin();
125            p != this->segment_list_->end();
126            ++p)
127         if ((*p)->type() == elfcpp::PT_LOAD)
128           count += (*p)->output_section_count();
129     }
130   else
131     {
132       for (Layout::Section_list::const_iterator p =
133              this->section_list_->begin();
134            p != this->section_list_->end();
135            ++p)
136         if (((*p)->flags() & elfcpp::SHF_ALLOC) != 0)
137           ++count;
138     }
139   count += this->unattached_section_list_->size();
140
141   const int size = parameters->target().get_size();
142   int shdr_size;
143   if (size == 32)
144     shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
145   else if (size == 64)
146     shdr_size = elfcpp::Elf_sizes<64>::shdr_size;
147   else
148     gold_unreachable();
149
150   return count * shdr_size;
151 }
152
153 // Write out the section headers.
154
155 void
156 Output_section_headers::do_write(Output_file* of)
157 {
158   switch (parameters->size_and_endianness())
159     {
160 #ifdef HAVE_TARGET_32_LITTLE
161     case Parameters::TARGET_32_LITTLE:
162       this->do_sized_write<32, false>(of);
163       break;
164 #endif
165 #ifdef HAVE_TARGET_32_BIG
166     case Parameters::TARGET_32_BIG:
167       this->do_sized_write<32, true>(of);
168       break;
169 #endif
170 #ifdef HAVE_TARGET_64_LITTLE
171     case Parameters::TARGET_64_LITTLE:
172       this->do_sized_write<64, false>(of);
173       break;
174 #endif
175 #ifdef HAVE_TARGET_64_BIG
176     case Parameters::TARGET_64_BIG:
177       this->do_sized_write<64, true>(of);
178       break;
179 #endif
180     default:
181       gold_unreachable();
182     }
183 }
184
185 template<int size, bool big_endian>
186 void
187 Output_section_headers::do_sized_write(Output_file* of)
188 {
189   off_t all_shdrs_size = this->data_size();
190   unsigned char* view = of->get_output_view(this->offset(), all_shdrs_size);
191
192   const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
193   unsigned char* v = view;
194
195   {
196     typename elfcpp::Shdr_write<size, big_endian> oshdr(v);
197     oshdr.put_sh_name(0);
198     oshdr.put_sh_type(elfcpp::SHT_NULL);
199     oshdr.put_sh_flags(0);
200     oshdr.put_sh_addr(0);
201     oshdr.put_sh_offset(0);
202
203     size_t section_count = (this->data_size()
204                             / elfcpp::Elf_sizes<size>::shdr_size);
205     if (section_count < elfcpp::SHN_LORESERVE)
206       oshdr.put_sh_size(0);
207     else
208       oshdr.put_sh_size(section_count);
209
210     unsigned int shstrndx = this->shstrtab_section_->out_shndx();
211     if (shstrndx < elfcpp::SHN_LORESERVE)
212       oshdr.put_sh_link(0);
213     else
214       oshdr.put_sh_link(shstrndx);
215
216     size_t segment_count = this->segment_list_->size();
217     oshdr.put_sh_info(segment_count >= elfcpp::PN_XNUM ? segment_count : 0);
218
219     oshdr.put_sh_addralign(0);
220     oshdr.put_sh_entsize(0);
221   }
222
223   v += shdr_size;
224
225   unsigned int shndx = 1;
226   if (!parameters->options().relocatable())
227     {
228       for (Layout::Segment_list::const_iterator p =
229              this->segment_list_->begin();
230            p != this->segment_list_->end();
231            ++p)
232         v = (*p)->write_section_headers<size, big_endian>(this->layout_,
233                                                           this->secnamepool_,
234                                                           v,
235                                                           &shndx);
236     }
237   else
238     {
239       for (Layout::Section_list::const_iterator p =
240              this->section_list_->begin();
241            p != this->section_list_->end();
242            ++p)
243         {
244           // We do unallocated sections below, except that group
245           // sections have to come first.
246           if (((*p)->flags() & elfcpp::SHF_ALLOC) == 0
247               && (*p)->type() != elfcpp::SHT_GROUP)
248             continue;
249           gold_assert(shndx == (*p)->out_shndx());
250           elfcpp::Shdr_write<size, big_endian> oshdr(v);
251           (*p)->write_header(this->layout_, this->secnamepool_, &oshdr);
252           v += shdr_size;
253           ++shndx;
254         }
255     }
256
257   for (Layout::Section_list::const_iterator p =
258          this->unattached_section_list_->begin();
259        p != this->unattached_section_list_->end();
260        ++p)
261     {
262       // For a relocatable link, we did unallocated group sections
263       // above, since they have to come first.
264       if ((*p)->type() == elfcpp::SHT_GROUP
265           && parameters->options().relocatable())
266         continue;
267       gold_assert(shndx == (*p)->out_shndx());
268       elfcpp::Shdr_write<size, big_endian> oshdr(v);
269       (*p)->write_header(this->layout_, this->secnamepool_, &oshdr);
270       v += shdr_size;
271       ++shndx;
272     }
273
274   of->write_output_view(this->offset(), all_shdrs_size, view);
275 }
276
277 // Output_segment_header methods.
278
279 Output_segment_headers::Output_segment_headers(
280     const Layout::Segment_list& segment_list)
281   : segment_list_(segment_list)
282 {
283 }
284
285 void
286 Output_segment_headers::do_write(Output_file* of)
287 {
288   switch (parameters->size_and_endianness())
289     {
290 #ifdef HAVE_TARGET_32_LITTLE
291     case Parameters::TARGET_32_LITTLE:
292       this->do_sized_write<32, false>(of);
293       break;
294 #endif
295 #ifdef HAVE_TARGET_32_BIG
296     case Parameters::TARGET_32_BIG:
297       this->do_sized_write<32, true>(of);
298       break;
299 #endif
300 #ifdef HAVE_TARGET_64_LITTLE
301     case Parameters::TARGET_64_LITTLE:
302       this->do_sized_write<64, false>(of);
303       break;
304 #endif
305 #ifdef HAVE_TARGET_64_BIG
306     case Parameters::TARGET_64_BIG:
307       this->do_sized_write<64, true>(of);
308       break;
309 #endif
310     default:
311       gold_unreachable();
312     }
313 }
314
315 template<int size, bool big_endian>
316 void
317 Output_segment_headers::do_sized_write(Output_file* of)
318 {
319   const int phdr_size = elfcpp::Elf_sizes<size>::phdr_size;
320   off_t all_phdrs_size = this->segment_list_.size() * phdr_size;
321   gold_assert(all_phdrs_size == this->data_size());
322   unsigned char* view = of->get_output_view(this->offset(),
323                                             all_phdrs_size);
324   unsigned char* v = view;
325   for (Layout::Segment_list::const_iterator p = this->segment_list_.begin();
326        p != this->segment_list_.end();
327        ++p)
328     {
329       elfcpp::Phdr_write<size, big_endian> ophdr(v);
330       (*p)->write_header(&ophdr);
331       v += phdr_size;
332     }
333
334   gold_assert(v - view == all_phdrs_size);
335
336   of->write_output_view(this->offset(), all_phdrs_size, view);
337 }
338
339 off_t
340 Output_segment_headers::do_size() const
341 {
342   const int size = parameters->target().get_size();
343   int phdr_size;
344   if (size == 32)
345     phdr_size = elfcpp::Elf_sizes<32>::phdr_size;
346   else if (size == 64)
347     phdr_size = elfcpp::Elf_sizes<64>::phdr_size;
348   else
349     gold_unreachable();
350
351   return this->segment_list_.size() * phdr_size;
352 }
353
354 // Output_file_header methods.
355
356 Output_file_header::Output_file_header(const Target* target,
357                                        const Symbol_table* symtab,
358                                        const Output_segment_headers* osh,
359                                        const char* entry)
360   : target_(target),
361     symtab_(symtab),
362     segment_header_(osh),
363     section_header_(NULL),
364     shstrtab_(NULL),
365     entry_(entry)
366 {
367   this->set_data_size(this->do_size());
368 }
369
370 // Set the section table information for a file header.
371
372 void
373 Output_file_header::set_section_info(const Output_section_headers* shdrs,
374                                      const Output_section* shstrtab)
375 {
376   this->section_header_ = shdrs;
377   this->shstrtab_ = shstrtab;
378 }
379
380 // Write out the file header.
381
382 void
383 Output_file_header::do_write(Output_file* of)
384 {
385   gold_assert(this->offset() == 0);
386
387   switch (parameters->size_and_endianness())
388     {
389 #ifdef HAVE_TARGET_32_LITTLE
390     case Parameters::TARGET_32_LITTLE:
391       this->do_sized_write<32, false>(of);
392       break;
393 #endif
394 #ifdef HAVE_TARGET_32_BIG
395     case Parameters::TARGET_32_BIG:
396       this->do_sized_write<32, true>(of);
397       break;
398 #endif
399 #ifdef HAVE_TARGET_64_LITTLE
400     case Parameters::TARGET_64_LITTLE:
401       this->do_sized_write<64, false>(of);
402       break;
403 #endif
404 #ifdef HAVE_TARGET_64_BIG
405     case Parameters::TARGET_64_BIG:
406       this->do_sized_write<64, true>(of);
407       break;
408 #endif
409     default:
410       gold_unreachable();
411     }
412 }
413
414 // Write out the file header with appropriate size and endianess.
415
416 template<int size, bool big_endian>
417 void
418 Output_file_header::do_sized_write(Output_file* of)
419 {
420   gold_assert(this->offset() == 0);
421
422   int ehdr_size = elfcpp::Elf_sizes<size>::ehdr_size;
423   unsigned char* view = of->get_output_view(0, ehdr_size);
424   elfcpp::Ehdr_write<size, big_endian> oehdr(view);
425
426   unsigned char e_ident[elfcpp::EI_NIDENT];
427   memset(e_ident, 0, elfcpp::EI_NIDENT);
428   e_ident[elfcpp::EI_MAG0] = elfcpp::ELFMAG0;
429   e_ident[elfcpp::EI_MAG1] = elfcpp::ELFMAG1;
430   e_ident[elfcpp::EI_MAG2] = elfcpp::ELFMAG2;
431   e_ident[elfcpp::EI_MAG3] = elfcpp::ELFMAG3;
432   if (size == 32)
433     e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS32;
434   else if (size == 64)
435     e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS64;
436   else
437     gold_unreachable();
438   e_ident[elfcpp::EI_DATA] = (big_endian
439                               ? elfcpp::ELFDATA2MSB
440                               : elfcpp::ELFDATA2LSB);
441   e_ident[elfcpp::EI_VERSION] = elfcpp::EV_CURRENT;
442   oehdr.put_e_ident(e_ident);
443
444   elfcpp::ET e_type;
445   if (parameters->options().relocatable())
446     e_type = elfcpp::ET_REL;
447   else if (parameters->options().output_is_position_independent())
448     e_type = elfcpp::ET_DYN;
449   else
450     e_type = elfcpp::ET_EXEC;
451   oehdr.put_e_type(e_type);
452
453   oehdr.put_e_machine(this->target_->machine_code());
454   oehdr.put_e_version(elfcpp::EV_CURRENT);
455
456   oehdr.put_e_entry(this->entry<size>());
457
458   if (this->segment_header_ == NULL)
459     oehdr.put_e_phoff(0);
460   else
461     oehdr.put_e_phoff(this->segment_header_->offset());
462
463   oehdr.put_e_shoff(this->section_header_->offset());
464   oehdr.put_e_flags(this->target_->processor_specific_flags());
465   oehdr.put_e_ehsize(elfcpp::Elf_sizes<size>::ehdr_size);
466
467   if (this->segment_header_ == NULL)
468     {
469       oehdr.put_e_phentsize(0);
470       oehdr.put_e_phnum(0);
471     }
472   else
473     {
474       oehdr.put_e_phentsize(elfcpp::Elf_sizes<size>::phdr_size);
475       size_t phnum = (this->segment_header_->data_size()
476                       / elfcpp::Elf_sizes<size>::phdr_size);
477       if (phnum > elfcpp::PN_XNUM)
478         phnum = elfcpp::PN_XNUM;
479       oehdr.put_e_phnum(phnum);
480     }
481
482   oehdr.put_e_shentsize(elfcpp::Elf_sizes<size>::shdr_size);
483   size_t section_count = (this->section_header_->data_size()
484                           / elfcpp::Elf_sizes<size>::shdr_size);
485
486   if (section_count < elfcpp::SHN_LORESERVE)
487     oehdr.put_e_shnum(this->section_header_->data_size()
488                       / elfcpp::Elf_sizes<size>::shdr_size);
489   else
490     oehdr.put_e_shnum(0);
491
492   unsigned int shstrndx = this->shstrtab_->out_shndx();
493   if (shstrndx < elfcpp::SHN_LORESERVE)
494     oehdr.put_e_shstrndx(this->shstrtab_->out_shndx());
495   else
496     oehdr.put_e_shstrndx(elfcpp::SHN_XINDEX);
497
498   // Let the target adjust the ELF header, e.g., to set EI_OSABI in
499   // the e_ident field.
500   parameters->target().adjust_elf_header(view, ehdr_size);
501
502   of->write_output_view(0, ehdr_size, view);
503 }
504
505 // Return the value to use for the entry address.  THIS->ENTRY_ is the
506 // symbol specified on the command line, if any.
507
508 template<int size>
509 typename elfcpp::Elf_types<size>::Elf_Addr
510 Output_file_header::entry()
511 {
512   const bool should_issue_warning = (this->entry_ != NULL
513                                      && !parameters->options().relocatable()
514                                      && !parameters->options().shared());
515
516   // FIXME: Need to support target specific entry symbol.
517   const char* entry = this->entry_;
518   if (entry == NULL)
519     entry = "_start";
520
521   Symbol* sym = this->symtab_->lookup(entry);
522
523   typename Sized_symbol<size>::Value_type v;
524   if (sym != NULL)
525     {
526       Sized_symbol<size>* ssym;
527       ssym = this->symtab_->get_sized_symbol<size>(sym);
528       if (!ssym->is_defined() && should_issue_warning)
529         gold_warning("entry symbol '%s' exists but is not defined", entry);
530       v = ssym->value();
531     }
532   else
533     {
534       // We couldn't find the entry symbol.  See if we can parse it as
535       // a number.  This supports, e.g., -e 0x1000.
536       char* endptr;
537       v = strtoull(entry, &endptr, 0);
538       if (*endptr != '\0')
539         {
540           if (should_issue_warning)
541             gold_warning("cannot find entry symbol '%s'", entry);
542           v = 0;
543         }
544     }
545
546   return v;
547 }
548
549 // Compute the current data size.
550
551 off_t
552 Output_file_header::do_size() const
553 {
554   const int size = parameters->target().get_size();
555   if (size == 32)
556     return elfcpp::Elf_sizes<32>::ehdr_size;
557   else if (size == 64)
558     return elfcpp::Elf_sizes<64>::ehdr_size;
559   else
560     gold_unreachable();
561 }
562
563 // Output_data_const methods.
564
565 void
566 Output_data_const::do_write(Output_file* of)
567 {
568   of->write(this->offset(), this->data_.data(), this->data_.size());
569 }
570
571 // Output_data_const_buffer methods.
572
573 void
574 Output_data_const_buffer::do_write(Output_file* of)
575 {
576   of->write(this->offset(), this->p_, this->data_size());
577 }
578
579 // Output_section_data methods.
580
581 // Record the output section, and set the entry size and such.
582
583 void
584 Output_section_data::set_output_section(Output_section* os)
585 {
586   gold_assert(this->output_section_ == NULL);
587   this->output_section_ = os;
588   this->do_adjust_output_section(os);
589 }
590
591 // Return the section index of the output section.
592
593 unsigned int
594 Output_section_data::do_out_shndx() const
595 {
596   gold_assert(this->output_section_ != NULL);
597   return this->output_section_->out_shndx();
598 }
599
600 // Set the alignment, which means we may need to update the alignment
601 // of the output section.
602
603 void
604 Output_section_data::set_addralign(uint64_t addralign)
605 {
606   this->addralign_ = addralign;
607   if (this->output_section_ != NULL
608       && this->output_section_->addralign() < addralign)
609     this->output_section_->set_addralign(addralign);
610 }
611
612 // Output_data_strtab methods.
613
614 // Set the final data size.
615
616 void
617 Output_data_strtab::set_final_data_size()
618 {
619   this->strtab_->set_string_offsets();
620   this->set_data_size(this->strtab_->get_strtab_size());
621 }
622
623 // Write out a string table.
624
625 void
626 Output_data_strtab::do_write(Output_file* of)
627 {
628   this->strtab_->write(of, this->offset());
629 }
630
631 // Output_reloc methods.
632
633 // A reloc against a global symbol.
634
635 template<bool dynamic, int size, bool big_endian>
636 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
637     Symbol* gsym,
638     unsigned int type,
639     Output_data* od,
640     Address address,
641     bool is_relative,
642     bool is_symbolless)
643   : address_(address), local_sym_index_(GSYM_CODE), type_(type),
644     is_relative_(is_relative), is_symbolless_(is_symbolless),
645     is_section_symbol_(false), shndx_(INVALID_CODE)
646 {
647   // this->type_ is a bitfield; make sure TYPE fits.
648   gold_assert(this->type_ == type);
649   this->u1_.gsym = gsym;
650   this->u2_.od = od;
651   if (dynamic)
652     this->set_needs_dynsym_index();
653 }
654
655 template<bool dynamic, int size, bool big_endian>
656 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
657     Symbol* gsym,
658     unsigned int type,
659     Sized_relobj<size, big_endian>* relobj,
660     unsigned int shndx,
661     Address address,
662     bool is_relative,
663     bool is_symbolless)
664   : address_(address), local_sym_index_(GSYM_CODE), type_(type),
665     is_relative_(is_relative), is_symbolless_(is_symbolless),
666     is_section_symbol_(false), shndx_(shndx)
667 {
668   gold_assert(shndx != INVALID_CODE);
669   // this->type_ is a bitfield; make sure TYPE fits.
670   gold_assert(this->type_ == type);
671   this->u1_.gsym = gsym;
672   this->u2_.relobj = relobj;
673   if (dynamic)
674     this->set_needs_dynsym_index();
675 }
676
677 // A reloc against a local symbol.
678
679 template<bool dynamic, int size, bool big_endian>
680 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
681     Sized_relobj<size, big_endian>* relobj,
682     unsigned int local_sym_index,
683     unsigned int type,
684     Output_data* od,
685     Address address,
686     bool is_relative,
687     bool is_symbolless,
688     bool is_section_symbol)
689   : address_(address), local_sym_index_(local_sym_index), type_(type),
690     is_relative_(is_relative), is_symbolless_(is_symbolless),
691     is_section_symbol_(is_section_symbol), shndx_(INVALID_CODE)
692 {
693   gold_assert(local_sym_index != GSYM_CODE
694               && local_sym_index != INVALID_CODE);
695   // this->type_ is a bitfield; make sure TYPE fits.
696   gold_assert(this->type_ == type);
697   this->u1_.relobj = relobj;
698   this->u2_.od = od;
699   if (dynamic)
700     this->set_needs_dynsym_index();
701 }
702
703 template<bool dynamic, int size, bool big_endian>
704 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
705     Sized_relobj<size, big_endian>* relobj,
706     unsigned int local_sym_index,
707     unsigned int type,
708     unsigned int shndx,
709     Address address,
710     bool is_relative,
711     bool is_symbolless,
712     bool is_section_symbol)
713   : address_(address), local_sym_index_(local_sym_index), type_(type),
714     is_relative_(is_relative), is_symbolless_(is_symbolless),
715     is_section_symbol_(is_section_symbol), shndx_(shndx)
716 {
717   gold_assert(local_sym_index != GSYM_CODE
718               && local_sym_index != INVALID_CODE);
719   gold_assert(shndx != INVALID_CODE);
720   // this->type_ is a bitfield; make sure TYPE fits.
721   gold_assert(this->type_ == type);
722   this->u1_.relobj = relobj;
723   this->u2_.relobj = relobj;
724   if (dynamic)
725     this->set_needs_dynsym_index();
726 }
727
728 // A reloc against the STT_SECTION symbol of an output section.
729
730 template<bool dynamic, int size, bool big_endian>
731 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
732     Output_section* os,
733     unsigned int type,
734     Output_data* od,
735     Address address)
736   : address_(address), local_sym_index_(SECTION_CODE), type_(type),
737     is_relative_(false), is_symbolless_(false),
738     is_section_symbol_(true), shndx_(INVALID_CODE)
739 {
740   // this->type_ is a bitfield; make sure TYPE fits.
741   gold_assert(this->type_ == type);
742   this->u1_.os = os;
743   this->u2_.od = od;
744   if (dynamic)
745     this->set_needs_dynsym_index();
746   else
747     os->set_needs_symtab_index();
748 }
749
750 template<bool dynamic, int size, bool big_endian>
751 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
752     Output_section* os,
753     unsigned int type,
754     Sized_relobj<size, big_endian>* relobj,
755     unsigned int shndx,
756     Address address)
757   : address_(address), local_sym_index_(SECTION_CODE), type_(type),
758     is_relative_(false), is_symbolless_(false),
759     is_section_symbol_(true), shndx_(shndx)
760 {
761   gold_assert(shndx != INVALID_CODE);
762   // this->type_ is a bitfield; make sure TYPE fits.
763   gold_assert(this->type_ == type);
764   this->u1_.os = os;
765   this->u2_.relobj = relobj;
766   if (dynamic)
767     this->set_needs_dynsym_index();
768   else
769     os->set_needs_symtab_index();
770 }
771
772 // An absolute relocation.
773
774 template<bool dynamic, int size, bool big_endian>
775 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
776     unsigned int type,
777     Output_data* od,
778     Address address)
779   : address_(address), local_sym_index_(0), type_(type),
780     is_relative_(false), is_symbolless_(false),
781     is_section_symbol_(false), shndx_(INVALID_CODE)
782 {
783   // this->type_ is a bitfield; make sure TYPE fits.
784   gold_assert(this->type_ == type);
785   this->u1_.relobj = NULL;
786   this->u2_.od = od;
787 }
788
789 template<bool dynamic, int size, bool big_endian>
790 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
791     unsigned int type,
792     Sized_relobj<size, big_endian>* relobj,
793     unsigned int shndx,
794     Address address)
795   : address_(address), local_sym_index_(0), type_(type),
796     is_relative_(false), is_symbolless_(false),
797     is_section_symbol_(false), shndx_(shndx)
798 {
799   gold_assert(shndx != INVALID_CODE);
800   // this->type_ is a bitfield; make sure TYPE fits.
801   gold_assert(this->type_ == type);
802   this->u1_.relobj = NULL;
803   this->u2_.relobj = relobj;
804 }
805
806 // A target specific relocation.
807
808 template<bool dynamic, int size, bool big_endian>
809 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
810     unsigned int type,
811     void* arg,
812     Output_data* od,
813     Address address)
814   : address_(address), local_sym_index_(TARGET_CODE), type_(type),
815     is_relative_(false), is_symbolless_(false),
816     is_section_symbol_(false), shndx_(INVALID_CODE)
817 {
818   // this->type_ is a bitfield; make sure TYPE fits.
819   gold_assert(this->type_ == type);
820   this->u1_.arg = arg;
821   this->u2_.od = od;
822 }
823
824 template<bool dynamic, int size, bool big_endian>
825 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
826     unsigned int type,
827     void* arg,
828     Sized_relobj<size, big_endian>* relobj,
829     unsigned int shndx,
830     Address address)
831   : address_(address), local_sym_index_(TARGET_CODE), type_(type),
832     is_relative_(false), is_symbolless_(false),
833     is_section_symbol_(false), shndx_(shndx)
834 {
835   gold_assert(shndx != INVALID_CODE);
836   // this->type_ is a bitfield; make sure TYPE fits.
837   gold_assert(this->type_ == type);
838   this->u1_.arg = arg;
839   this->u2_.relobj = relobj;
840 }
841
842 // Record that we need a dynamic symbol index for this relocation.
843
844 template<bool dynamic, int size, bool big_endian>
845 void
846 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::
847 set_needs_dynsym_index()
848 {
849   if (this->is_symbolless_)
850     return;
851   switch (this->local_sym_index_)
852     {
853     case INVALID_CODE:
854       gold_unreachable();
855
856     case GSYM_CODE:
857       this->u1_.gsym->set_needs_dynsym_entry();
858       break;
859
860     case SECTION_CODE:
861       this->u1_.os->set_needs_dynsym_index();
862       break;
863
864     case TARGET_CODE:
865       // The target must take care of this if necessary.
866       break;
867
868     case 0:
869       break;
870
871     default:
872       {
873         const unsigned int lsi = this->local_sym_index_;
874         if (!this->is_section_symbol_)
875           this->u1_.relobj->set_needs_output_dynsym_entry(lsi);
876         else
877           this->u1_.relobj->output_section(lsi)->set_needs_dynsym_index();
878       }
879       break;
880     }
881 }
882
883 // Get the symbol index of a relocation.
884
885 template<bool dynamic, int size, bool big_endian>
886 unsigned int
887 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::get_symbol_index()
888   const
889 {
890   unsigned int index;
891   if (this->is_symbolless_)
892     return 0;
893   switch (this->local_sym_index_)
894     {
895     case INVALID_CODE:
896       gold_unreachable();
897
898     case GSYM_CODE:
899       if (this->u1_.gsym == NULL)
900         index = 0;
901       else if (dynamic)
902         index = this->u1_.gsym->dynsym_index();
903       else
904         index = this->u1_.gsym->symtab_index();
905       break;
906
907     case SECTION_CODE:
908       if (dynamic)
909         index = this->u1_.os->dynsym_index();
910       else
911         index = this->u1_.os->symtab_index();
912       break;
913
914     case TARGET_CODE:
915       index = parameters->target().reloc_symbol_index(this->u1_.arg,
916                                                       this->type_);
917       break;
918
919     case 0:
920       // Relocations without symbols use a symbol index of 0.
921       index = 0;
922       break;
923
924     default:
925       {
926         const unsigned int lsi = this->local_sym_index_;
927         if (!this->is_section_symbol_)
928           {
929             if (dynamic)
930               index = this->u1_.relobj->dynsym_index(lsi);
931             else
932               index = this->u1_.relobj->symtab_index(lsi);
933           }
934         else
935           {
936             Output_section* os = this->u1_.relobj->output_section(lsi);
937             gold_assert(os != NULL);
938             if (dynamic)
939               index = os->dynsym_index();
940             else
941               index = os->symtab_index();
942           }
943       }
944       break;
945     }
946   gold_assert(index != -1U);
947   return index;
948 }
949
950 // For a local section symbol, get the address of the offset ADDEND
951 // within the input section.
952
953 template<bool dynamic, int size, bool big_endian>
954 typename elfcpp::Elf_types<size>::Elf_Addr
955 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::
956   local_section_offset(Addend addend) const
957 {
958   gold_assert(this->local_sym_index_ != GSYM_CODE
959               && this->local_sym_index_ != SECTION_CODE
960               && this->local_sym_index_ != TARGET_CODE
961               && this->local_sym_index_ != INVALID_CODE
962               && this->local_sym_index_ != 0
963               && this->is_section_symbol_);
964   const unsigned int lsi = this->local_sym_index_;
965   Output_section* os = this->u1_.relobj->output_section(lsi);
966   gold_assert(os != NULL);
967   Address offset = this->u1_.relobj->get_output_section_offset(lsi);
968   if (offset != invalid_address)
969     return offset + addend;
970   // This is a merge section.
971   offset = os->output_address(this->u1_.relobj, lsi, addend);
972   gold_assert(offset != invalid_address);
973   return offset;
974 }
975
976 // Get the output address of a relocation.
977
978 template<bool dynamic, int size, bool big_endian>
979 typename elfcpp::Elf_types<size>::Elf_Addr
980 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::get_address() const
981 {
982   Address address = this->address_;
983   if (this->shndx_ != INVALID_CODE)
984     {
985       Output_section* os = this->u2_.relobj->output_section(this->shndx_);
986       gold_assert(os != NULL);
987       Address off = this->u2_.relobj->get_output_section_offset(this->shndx_);
988       if (off != invalid_address)
989         address += os->address() + off;
990       else
991         {
992           address = os->output_address(this->u2_.relobj, this->shndx_,
993                                        address);
994           gold_assert(address != invalid_address);
995         }
996     }
997   else if (this->u2_.od != NULL)
998     address += this->u2_.od->address();
999   return address;
1000 }
1001
1002 // Write out the offset and info fields of a Rel or Rela relocation
1003 // entry.
1004
1005 template<bool dynamic, int size, bool big_endian>
1006 template<typename Write_rel>
1007 void
1008 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::write_rel(
1009     Write_rel* wr) const
1010 {
1011   wr->put_r_offset(this->get_address());
1012   unsigned int sym_index = this->get_symbol_index();
1013   wr->put_r_info(elfcpp::elf_r_info<size>(sym_index, this->type_));
1014 }
1015
1016 // Write out a Rel relocation.
1017
1018 template<bool dynamic, int size, bool big_endian>
1019 void
1020 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::write(
1021     unsigned char* pov) const
1022 {
1023   elfcpp::Rel_write<size, big_endian> orel(pov);
1024   this->write_rel(&orel);
1025 }
1026
1027 // Get the value of the symbol referred to by a Rel relocation.
1028
1029 template<bool dynamic, int size, bool big_endian>
1030 typename elfcpp::Elf_types<size>::Elf_Addr
1031 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::symbol_value(
1032     Addend addend) const
1033 {
1034   if (this->local_sym_index_ == GSYM_CODE)
1035     {
1036       const Sized_symbol<size>* sym;
1037       sym = static_cast<const Sized_symbol<size>*>(this->u1_.gsym);
1038       return sym->value() + addend;
1039     }
1040   gold_assert(this->local_sym_index_ != SECTION_CODE
1041               && this->local_sym_index_ != TARGET_CODE
1042               && this->local_sym_index_ != INVALID_CODE
1043               && this->local_sym_index_ != 0
1044               && !this->is_section_symbol_);
1045   const unsigned int lsi = this->local_sym_index_;
1046   const Symbol_value<size>* symval = this->u1_.relobj->local_symbol(lsi);
1047   return symval->value(this->u1_.relobj, addend);
1048 }
1049
1050 // Reloc comparison.  This function sorts the dynamic relocs for the
1051 // benefit of the dynamic linker.  First we sort all relative relocs
1052 // to the front.  Among relative relocs, we sort by output address.
1053 // Among non-relative relocs, we sort by symbol index, then by output
1054 // address.
1055
1056 template<bool dynamic, int size, bool big_endian>
1057 int
1058 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::
1059   compare(const Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>& r2)
1060     const
1061 {
1062   if (this->is_relative_)
1063     {
1064       if (!r2.is_relative_)
1065         return -1;
1066       // Otherwise sort by reloc address below.
1067     }
1068   else if (r2.is_relative_)
1069     return 1;
1070   else
1071     {
1072       unsigned int sym1 = this->get_symbol_index();
1073       unsigned int sym2 = r2.get_symbol_index();
1074       if (sym1 < sym2)
1075         return -1;
1076       else if (sym1 > sym2)
1077         return 1;
1078       // Otherwise sort by reloc address.
1079     }
1080
1081   section_offset_type addr1 = this->get_address();
1082   section_offset_type addr2 = r2.get_address();
1083   if (addr1 < addr2)
1084     return -1;
1085   else if (addr1 > addr2)
1086     return 1;
1087
1088   // Final tie breaker, in order to generate the same output on any
1089   // host: reloc type.
1090   unsigned int type1 = this->type_;
1091   unsigned int type2 = r2.type_;
1092   if (type1 < type2)
1093     return -1;
1094   else if (type1 > type2)
1095     return 1;
1096
1097   // These relocs appear to be exactly the same.
1098   return 0;
1099 }
1100
1101 // Write out a Rela relocation.
1102
1103 template<bool dynamic, int size, bool big_endian>
1104 void
1105 Output_reloc<elfcpp::SHT_RELA, dynamic, size, big_endian>::write(
1106     unsigned char* pov) const
1107 {
1108   elfcpp::Rela_write<size, big_endian> orel(pov);
1109   this->rel_.write_rel(&orel);
1110   Addend addend = this->addend_;
1111   if (this->rel_.is_target_specific())
1112     addend = parameters->target().reloc_addend(this->rel_.target_arg(),
1113                                                this->rel_.type(), addend);
1114   else if (this->rel_.is_symbolless())
1115     addend = this->rel_.symbol_value(addend);
1116   else if (this->rel_.is_local_section_symbol())
1117     addend = this->rel_.local_section_offset(addend);
1118   orel.put_r_addend(addend);
1119 }
1120
1121 // Output_data_reloc_base methods.
1122
1123 // Adjust the output section.
1124
1125 template<int sh_type, bool dynamic, int size, bool big_endian>
1126 void
1127 Output_data_reloc_base<sh_type, dynamic, size, big_endian>
1128     ::do_adjust_output_section(Output_section* os)
1129 {
1130   if (sh_type == elfcpp::SHT_REL)
1131     os->set_entsize(elfcpp::Elf_sizes<size>::rel_size);
1132   else if (sh_type == elfcpp::SHT_RELA)
1133     os->set_entsize(elfcpp::Elf_sizes<size>::rela_size);
1134   else
1135     gold_unreachable();
1136
1137   // A STT_GNU_IFUNC symbol may require a IRELATIVE reloc when doing a
1138   // static link.  The backends will generate a dynamic reloc section
1139   // to hold this.  In that case we don't want to link to the dynsym
1140   // section, because there isn't one.
1141   if (!dynamic)
1142     os->set_should_link_to_symtab();
1143   else if (parameters->doing_static_link())
1144     ;
1145   else
1146     os->set_should_link_to_dynsym();
1147 }
1148
1149 // Write out relocation data.
1150
1151 template<int sh_type, bool dynamic, int size, bool big_endian>
1152 void
1153 Output_data_reloc_base<sh_type, dynamic, size, big_endian>::do_write(
1154     Output_file* of)
1155 {
1156   const off_t off = this->offset();
1157   const off_t oview_size = this->data_size();
1158   unsigned char* const oview = of->get_output_view(off, oview_size);
1159
1160   if (this->sort_relocs())
1161     {
1162       gold_assert(dynamic);
1163       std::sort(this->relocs_.begin(), this->relocs_.end(),
1164                 Sort_relocs_comparison());
1165     }
1166
1167   unsigned char* pov = oview;
1168   for (typename Relocs::const_iterator p = this->relocs_.begin();
1169        p != this->relocs_.end();
1170        ++p)
1171     {
1172       p->write(pov);
1173       pov += reloc_size;
1174     }
1175
1176   gold_assert(pov - oview == oview_size);
1177
1178   of->write_output_view(off, oview_size, oview);
1179
1180   // We no longer need the relocation entries.
1181   this->relocs_.clear();
1182 }
1183
1184 // Class Output_relocatable_relocs.
1185
1186 template<int sh_type, int size, bool big_endian>
1187 void
1188 Output_relocatable_relocs<sh_type, size, big_endian>::set_final_data_size()
1189 {
1190   this->set_data_size(this->rr_->output_reloc_count()
1191                       * Reloc_types<sh_type, size, big_endian>::reloc_size);
1192 }
1193
1194 // class Output_data_group.
1195
1196 template<int size, bool big_endian>
1197 Output_data_group<size, big_endian>::Output_data_group(
1198     Sized_relobj<size, big_endian>* relobj,
1199     section_size_type entry_count,
1200     elfcpp::Elf_Word flags,
1201     std::vector<unsigned int>* input_shndxes)
1202   : Output_section_data(entry_count * 4, 4, false),
1203     relobj_(relobj),
1204     flags_(flags)
1205 {
1206   this->input_shndxes_.swap(*input_shndxes);
1207 }
1208
1209 // Write out the section group, which means translating the section
1210 // indexes to apply to the output file.
1211
1212 template<int size, bool big_endian>
1213 void
1214 Output_data_group<size, big_endian>::do_write(Output_file* of)
1215 {
1216   const off_t off = this->offset();
1217   const section_size_type oview_size =
1218     convert_to_section_size_type(this->data_size());
1219   unsigned char* const oview = of->get_output_view(off, oview_size);
1220
1221   elfcpp::Elf_Word* contents = reinterpret_cast<elfcpp::Elf_Word*>(oview);
1222   elfcpp::Swap<32, big_endian>::writeval(contents, this->flags_);
1223   ++contents;
1224
1225   for (std::vector<unsigned int>::const_iterator p =
1226          this->input_shndxes_.begin();
1227        p != this->input_shndxes_.end();
1228        ++p, ++contents)
1229     {
1230       Output_section* os = this->relobj_->output_section(*p);
1231
1232       unsigned int output_shndx;
1233       if (os != NULL)
1234         output_shndx = os->out_shndx();
1235       else
1236         {
1237           this->relobj_->error(_("section group retained but "
1238                                  "group element discarded"));
1239           output_shndx = 0;
1240         }
1241
1242       elfcpp::Swap<32, big_endian>::writeval(contents, output_shndx);
1243     }
1244
1245   size_t wrote = reinterpret_cast<unsigned char*>(contents) - oview;
1246   gold_assert(wrote == oview_size);
1247
1248   of->write_output_view(off, oview_size, oview);
1249
1250   // We no longer need this information.
1251   this->input_shndxes_.clear();
1252 }
1253
1254 // Output_data_got::Got_entry methods.
1255
1256 // Write out the entry.
1257
1258 template<int size, bool big_endian>
1259 void
1260 Output_data_got<size, big_endian>::Got_entry::write(unsigned char* pov) const
1261 {
1262   Valtype val = 0;
1263
1264   switch (this->local_sym_index_)
1265     {
1266     case GSYM_CODE:
1267       {
1268         // If the symbol is resolved locally, we need to write out the
1269         // link-time value, which will be relocated dynamically by a
1270         // RELATIVE relocation.
1271         Symbol* gsym = this->u_.gsym;
1272         if (this->use_plt_offset_ && gsym->has_plt_offset())
1273           val = (parameters->target().plt_section_for_global(gsym)->address()
1274                  + gsym->plt_offset());
1275         else
1276           {
1277             Sized_symbol<size>* sgsym;
1278             // This cast is a bit ugly.  We don't want to put a
1279             // virtual method in Symbol, because we want Symbol to be
1280             // as small as possible.
1281             sgsym = static_cast<Sized_symbol<size>*>(gsym);
1282             val = sgsym->value();
1283           }
1284       }
1285       break;
1286
1287     case CONSTANT_CODE:
1288       val = this->u_.constant;
1289       break;
1290
1291     default:
1292       {
1293         const Sized_relobj<size, big_endian>* object = this->u_.object;
1294         const unsigned int lsi = this->local_sym_index_;
1295         const Symbol_value<size>* symval = object->local_symbol(lsi);
1296         if (!this->use_plt_offset_)
1297           val = symval->value(this->u_.object, 0);
1298         else
1299           {
1300             const Output_data* plt =
1301               parameters->target().plt_section_for_local(object, lsi);
1302             val = plt->address() + object->local_plt_offset(lsi);
1303           }
1304       }
1305       break;
1306     }
1307
1308   elfcpp::Swap<size, big_endian>::writeval(pov, val);
1309 }
1310
1311 // Output_data_got methods.
1312
1313 // Add an entry for a global symbol to the GOT.  This returns true if
1314 // this is a new GOT entry, false if the symbol already had a GOT
1315 // entry.
1316
1317 template<int size, bool big_endian>
1318 bool
1319 Output_data_got<size, big_endian>::add_global(
1320     Symbol* gsym,
1321     unsigned int got_type)
1322 {
1323   if (gsym->has_got_offset(got_type))
1324     return false;
1325
1326   this->entries_.push_back(Got_entry(gsym, false));
1327   this->set_got_size();
1328   gsym->set_got_offset(got_type, this->last_got_offset());
1329   return true;
1330 }
1331
1332 // Like add_global, but use the PLT offset.
1333
1334 template<int size, bool big_endian>
1335 bool
1336 Output_data_got<size, big_endian>::add_global_plt(Symbol* gsym,
1337                                                   unsigned int got_type)
1338 {
1339   if (gsym->has_got_offset(got_type))
1340     return false;
1341
1342   this->entries_.push_back(Got_entry(gsym, true));
1343   this->set_got_size();
1344   gsym->set_got_offset(got_type, this->last_got_offset());
1345   return true;
1346 }
1347
1348 // Add an entry for a global symbol to the GOT, and add a dynamic
1349 // relocation of type R_TYPE for the GOT entry.
1350
1351 template<int size, bool big_endian>
1352 void
1353 Output_data_got<size, big_endian>::add_global_with_rel(
1354     Symbol* gsym,
1355     unsigned int got_type,
1356     Rel_dyn* rel_dyn,
1357     unsigned int r_type)
1358 {
1359   if (gsym->has_got_offset(got_type))
1360     return;
1361
1362   this->entries_.push_back(Got_entry());
1363   this->set_got_size();
1364   unsigned int got_offset = this->last_got_offset();
1365   gsym->set_got_offset(got_type, got_offset);
1366   rel_dyn->add_global(gsym, r_type, this, got_offset);
1367 }
1368
1369 template<int size, bool big_endian>
1370 void
1371 Output_data_got<size, big_endian>::add_global_with_rela(
1372     Symbol* gsym,
1373     unsigned int got_type,
1374     Rela_dyn* rela_dyn,
1375     unsigned int r_type)
1376 {
1377   if (gsym->has_got_offset(got_type))
1378     return;
1379
1380   this->entries_.push_back(Got_entry());
1381   this->set_got_size();
1382   unsigned int got_offset = this->last_got_offset();
1383   gsym->set_got_offset(got_type, got_offset);
1384   rela_dyn->add_global(gsym, r_type, this, got_offset, 0);
1385 }
1386
1387 // Add a pair of entries for a global symbol to the GOT, and add
1388 // dynamic relocations of type R_TYPE_1 and R_TYPE_2, respectively.
1389 // If R_TYPE_2 == 0, add the second entry with no relocation.
1390 template<int size, bool big_endian>
1391 void
1392 Output_data_got<size, big_endian>::add_global_pair_with_rel(
1393     Symbol* gsym,
1394     unsigned int got_type,
1395     Rel_dyn* rel_dyn,
1396     unsigned int r_type_1,
1397     unsigned int r_type_2)
1398 {
1399   if (gsym->has_got_offset(got_type))
1400     return;
1401
1402   this->entries_.push_back(Got_entry());
1403   unsigned int got_offset = this->last_got_offset();
1404   gsym->set_got_offset(got_type, got_offset);
1405   rel_dyn->add_global(gsym, r_type_1, this, got_offset);
1406
1407   this->entries_.push_back(Got_entry());
1408   if (r_type_2 != 0)
1409     {
1410       got_offset = this->last_got_offset();
1411       rel_dyn->add_global(gsym, r_type_2, this, got_offset);
1412     }
1413
1414   this->set_got_size();
1415 }
1416
1417 template<int size, bool big_endian>
1418 void
1419 Output_data_got<size, big_endian>::add_global_pair_with_rela(
1420     Symbol* gsym,
1421     unsigned int got_type,
1422     Rela_dyn* rela_dyn,
1423     unsigned int r_type_1,
1424     unsigned int r_type_2)
1425 {
1426   if (gsym->has_got_offset(got_type))
1427     return;
1428
1429   this->entries_.push_back(Got_entry());
1430   unsigned int got_offset = this->last_got_offset();
1431   gsym->set_got_offset(got_type, got_offset);
1432   rela_dyn->add_global(gsym, r_type_1, this, got_offset, 0);
1433
1434   this->entries_.push_back(Got_entry());
1435   if (r_type_2 != 0)
1436     {
1437       got_offset = this->last_got_offset();
1438       rela_dyn->add_global(gsym, r_type_2, this, got_offset, 0);
1439     }
1440
1441   this->set_got_size();
1442 }
1443
1444 // Add an entry for a local symbol to the GOT.  This returns true if
1445 // this is a new GOT entry, false if the symbol already has a GOT
1446 // entry.
1447
1448 template<int size, bool big_endian>
1449 bool
1450 Output_data_got<size, big_endian>::add_local(
1451     Sized_relobj<size, big_endian>* object,
1452     unsigned int symndx,
1453     unsigned int got_type)
1454 {
1455   if (object->local_has_got_offset(symndx, got_type))
1456     return false;
1457
1458   this->entries_.push_back(Got_entry(object, symndx, false));
1459   this->set_got_size();
1460   object->set_local_got_offset(symndx, got_type, this->last_got_offset());
1461   return true;
1462 }
1463
1464 // Like add_local, but use the PLT offset.
1465
1466 template<int size, bool big_endian>
1467 bool
1468 Output_data_got<size, big_endian>::add_local_plt(
1469     Sized_relobj<size, big_endian>* object,
1470     unsigned int symndx,
1471     unsigned int got_type)
1472 {
1473   if (object->local_has_got_offset(symndx, got_type))
1474     return false;
1475
1476   this->entries_.push_back(Got_entry(object, symndx, true));
1477   this->set_got_size();
1478   object->set_local_got_offset(symndx, got_type, this->last_got_offset());
1479   return true;
1480 }
1481
1482 // Add an entry for a local symbol to the GOT, and add a dynamic
1483 // relocation of type R_TYPE for the GOT entry.
1484
1485 template<int size, bool big_endian>
1486 void
1487 Output_data_got<size, big_endian>::add_local_with_rel(
1488     Sized_relobj<size, big_endian>* object,
1489     unsigned int symndx,
1490     unsigned int got_type,
1491     Rel_dyn* rel_dyn,
1492     unsigned int r_type)
1493 {
1494   if (object->local_has_got_offset(symndx, got_type))
1495     return;
1496
1497   this->entries_.push_back(Got_entry());
1498   this->set_got_size();
1499   unsigned int got_offset = this->last_got_offset();
1500   object->set_local_got_offset(symndx, got_type, got_offset);
1501   rel_dyn->add_local(object, symndx, r_type, this, got_offset);
1502 }
1503
1504 template<int size, bool big_endian>
1505 void
1506 Output_data_got<size, big_endian>::add_local_with_rela(
1507     Sized_relobj<size, big_endian>* object,
1508     unsigned int symndx,
1509     unsigned int got_type,
1510     Rela_dyn* rela_dyn,
1511     unsigned int r_type)
1512 {
1513   if (object->local_has_got_offset(symndx, got_type))
1514     return;
1515
1516   this->entries_.push_back(Got_entry());
1517   this->set_got_size();
1518   unsigned int got_offset = this->last_got_offset();
1519   object->set_local_got_offset(symndx, got_type, got_offset);
1520   rela_dyn->add_local(object, symndx, r_type, this, got_offset, 0);
1521 }
1522
1523 // Add a pair of entries for a local symbol to the GOT, and add
1524 // dynamic relocations of type R_TYPE_1 and R_TYPE_2, respectively.
1525 // If R_TYPE_2 == 0, add the second entry with no relocation.
1526 template<int size, bool big_endian>
1527 void
1528 Output_data_got<size, big_endian>::add_local_pair_with_rel(
1529     Sized_relobj<size, big_endian>* object,
1530     unsigned int symndx,
1531     unsigned int shndx,
1532     unsigned int got_type,
1533     Rel_dyn* rel_dyn,
1534     unsigned int r_type_1,
1535     unsigned int r_type_2)
1536 {
1537   if (object->local_has_got_offset(symndx, got_type))
1538     return;
1539
1540   this->entries_.push_back(Got_entry());
1541   unsigned int got_offset = this->last_got_offset();
1542   object->set_local_got_offset(symndx, got_type, got_offset);
1543   Output_section* os = object->output_section(shndx);
1544   rel_dyn->add_output_section(os, r_type_1, this, got_offset);
1545
1546   this->entries_.push_back(Got_entry(object, symndx, false));
1547   if (r_type_2 != 0)
1548     {
1549       got_offset = this->last_got_offset();
1550       rel_dyn->add_output_section(os, r_type_2, this, got_offset);
1551     }
1552
1553   this->set_got_size();
1554 }
1555
1556 template<int size, bool big_endian>
1557 void
1558 Output_data_got<size, big_endian>::add_local_pair_with_rela(
1559     Sized_relobj<size, big_endian>* object,
1560     unsigned int symndx,
1561     unsigned int shndx,
1562     unsigned int got_type,
1563     Rela_dyn* rela_dyn,
1564     unsigned int r_type_1,
1565     unsigned int r_type_2)
1566 {
1567   if (object->local_has_got_offset(symndx, got_type))
1568     return;
1569
1570   this->entries_.push_back(Got_entry());
1571   unsigned int got_offset = this->last_got_offset();
1572   object->set_local_got_offset(symndx, got_type, got_offset);
1573   Output_section* os = object->output_section(shndx);
1574   rela_dyn->add_output_section(os, r_type_1, this, got_offset, 0);
1575
1576   this->entries_.push_back(Got_entry(object, symndx, false));
1577   if (r_type_2 != 0)
1578     {
1579       got_offset = this->last_got_offset();
1580       rela_dyn->add_output_section(os, r_type_2, this, got_offset, 0);
1581     }
1582
1583   this->set_got_size();
1584 }
1585
1586 // Write out the GOT.
1587
1588 template<int size, bool big_endian>
1589 void
1590 Output_data_got<size, big_endian>::do_write(Output_file* of)
1591 {
1592   const int add = size / 8;
1593
1594   const off_t off = this->offset();
1595   const off_t oview_size = this->data_size();
1596   unsigned char* const oview = of->get_output_view(off, oview_size);
1597
1598   unsigned char* pov = oview;
1599   for (typename Got_entries::const_iterator p = this->entries_.begin();
1600        p != this->entries_.end();
1601        ++p)
1602     {
1603       p->write(pov);
1604       pov += add;
1605     }
1606
1607   gold_assert(pov - oview == oview_size);
1608
1609   of->write_output_view(off, oview_size, oview);
1610
1611   // We no longer need the GOT entries.
1612   this->entries_.clear();
1613 }
1614
1615 // Output_data_dynamic::Dynamic_entry methods.
1616
1617 // Write out the entry.
1618
1619 template<int size, bool big_endian>
1620 void
1621 Output_data_dynamic::Dynamic_entry::write(
1622     unsigned char* pov,
1623     const Stringpool* pool) const
1624 {
1625   typename elfcpp::Elf_types<size>::Elf_WXword val;
1626   switch (this->offset_)
1627     {
1628     case DYNAMIC_NUMBER:
1629       val = this->u_.val;
1630       break;
1631
1632     case DYNAMIC_SECTION_SIZE:
1633       val = this->u_.od->data_size();
1634       if (this->od2 != NULL)
1635         val += this->od2->data_size();
1636       break;
1637
1638     case DYNAMIC_SYMBOL:
1639       {
1640         const Sized_symbol<size>* s =
1641           static_cast<const Sized_symbol<size>*>(this->u_.sym);
1642         val = s->value();
1643       }
1644       break;
1645
1646     case DYNAMIC_STRING:
1647       val = pool->get_offset(this->u_.str);
1648       break;
1649
1650     default:
1651       val = this->u_.od->address() + this->offset_;
1652       break;
1653     }
1654
1655   elfcpp::Dyn_write<size, big_endian> dw(pov);
1656   dw.put_d_tag(this->tag_);
1657   dw.put_d_val(val);
1658 }
1659
1660 // Output_data_dynamic methods.
1661
1662 // Adjust the output section to set the entry size.
1663
1664 void
1665 Output_data_dynamic::do_adjust_output_section(Output_section* os)
1666 {
1667   if (parameters->target().get_size() == 32)
1668     os->set_entsize(elfcpp::Elf_sizes<32>::dyn_size);
1669   else if (parameters->target().get_size() == 64)
1670     os->set_entsize(elfcpp::Elf_sizes<64>::dyn_size);
1671   else
1672     gold_unreachable();
1673 }
1674
1675 // Set the final data size.
1676
1677 void
1678 Output_data_dynamic::set_final_data_size()
1679 {
1680   // Add the terminating entry if it hasn't been added.
1681   // Because of relaxation, we can run this multiple times.
1682   if (this->entries_.empty() || this->entries_.back().tag() != elfcpp::DT_NULL)
1683     {
1684       int extra = parameters->options().spare_dynamic_tags();
1685       for (int i = 0; i < extra; ++i)
1686         this->add_constant(elfcpp::DT_NULL, 0);
1687       this->add_constant(elfcpp::DT_NULL, 0);
1688     }
1689
1690   int dyn_size;
1691   if (parameters->target().get_size() == 32)
1692     dyn_size = elfcpp::Elf_sizes<32>::dyn_size;
1693   else if (parameters->target().get_size() == 64)
1694     dyn_size = elfcpp::Elf_sizes<64>::dyn_size;
1695   else
1696     gold_unreachable();
1697   this->set_data_size(this->entries_.size() * dyn_size);
1698 }
1699
1700 // Write out the dynamic entries.
1701
1702 void
1703 Output_data_dynamic::do_write(Output_file* of)
1704 {
1705   switch (parameters->size_and_endianness())
1706     {
1707 #ifdef HAVE_TARGET_32_LITTLE
1708     case Parameters::TARGET_32_LITTLE:
1709       this->sized_write<32, false>(of);
1710       break;
1711 #endif
1712 #ifdef HAVE_TARGET_32_BIG
1713     case Parameters::TARGET_32_BIG:
1714       this->sized_write<32, true>(of);
1715       break;
1716 #endif
1717 #ifdef HAVE_TARGET_64_LITTLE
1718     case Parameters::TARGET_64_LITTLE:
1719       this->sized_write<64, false>(of);
1720       break;
1721 #endif
1722 #ifdef HAVE_TARGET_64_BIG
1723     case Parameters::TARGET_64_BIG:
1724       this->sized_write<64, true>(of);
1725       break;
1726 #endif
1727     default:
1728       gold_unreachable();
1729     }
1730 }
1731
1732 template<int size, bool big_endian>
1733 void
1734 Output_data_dynamic::sized_write(Output_file* of)
1735 {
1736   const int dyn_size = elfcpp::Elf_sizes<size>::dyn_size;
1737
1738   const off_t offset = this->offset();
1739   const off_t oview_size = this->data_size();
1740   unsigned char* const oview = of->get_output_view(offset, oview_size);
1741
1742   unsigned char* pov = oview;
1743   for (typename Dynamic_entries::const_iterator p = this->entries_.begin();
1744        p != this->entries_.end();
1745        ++p)
1746     {
1747       p->write<size, big_endian>(pov, this->pool_);
1748       pov += dyn_size;
1749     }
1750
1751   gold_assert(pov - oview == oview_size);
1752
1753   of->write_output_view(offset, oview_size, oview);
1754
1755   // We no longer need the dynamic entries.
1756   this->entries_.clear();
1757 }
1758
1759 // Class Output_symtab_xindex.
1760
1761 void
1762 Output_symtab_xindex::do_write(Output_file* of)
1763 {
1764   const off_t offset = this->offset();
1765   const off_t oview_size = this->data_size();
1766   unsigned char* const oview = of->get_output_view(offset, oview_size);
1767
1768   memset(oview, 0, oview_size);
1769
1770   if (parameters->target().is_big_endian())
1771     this->endian_do_write<true>(oview);
1772   else
1773     this->endian_do_write<false>(oview);
1774
1775   of->write_output_view(offset, oview_size, oview);
1776
1777   // We no longer need the data.
1778   this->entries_.clear();
1779 }
1780
1781 template<bool big_endian>
1782 void
1783 Output_symtab_xindex::endian_do_write(unsigned char* const oview)
1784 {
1785   for (Xindex_entries::const_iterator p = this->entries_.begin();
1786        p != this->entries_.end();
1787        ++p)
1788     {
1789       unsigned int symndx = p->first;
1790       gold_assert(symndx * 4 < this->data_size());
1791       elfcpp::Swap<32, big_endian>::writeval(oview + symndx * 4, p->second);
1792     }
1793 }
1794
1795 // Output_section::Input_section methods.
1796
1797 // Return the data size.  For an input section we store the size here.
1798 // For an Output_section_data, we have to ask it for the size.
1799
1800 off_t
1801 Output_section::Input_section::data_size() const
1802 {
1803   if (this->is_input_section())
1804     return this->u1_.data_size;
1805   else
1806     return this->u2_.posd->data_size();
1807 }
1808
1809 // Return the object for an input section.
1810
1811 Relobj*
1812 Output_section::Input_section::relobj() const
1813 {
1814   if (this->is_input_section())
1815     return this->u2_.object;
1816   else if (this->is_merge_section())
1817     {
1818       gold_assert(this->u2_.pomb->first_relobj() != NULL);
1819       return this->u2_.pomb->first_relobj();
1820     }
1821   else if (this->is_relaxed_input_section())
1822     return this->u2_.poris->relobj();
1823   else
1824     gold_unreachable();
1825 }
1826
1827 // Return the input section index for an input section.
1828
1829 unsigned int
1830 Output_section::Input_section::shndx() const
1831 {
1832   if (this->is_input_section())
1833     return this->shndx_;
1834   else if (this->is_merge_section())
1835     {
1836       gold_assert(this->u2_.pomb->first_relobj() != NULL);
1837       return this->u2_.pomb->first_shndx();
1838     }
1839   else if (this->is_relaxed_input_section())
1840     return this->u2_.poris->shndx();
1841   else
1842     gold_unreachable();
1843 }
1844
1845 // Set the address and file offset.
1846
1847 void
1848 Output_section::Input_section::set_address_and_file_offset(
1849     uint64_t address,
1850     off_t file_offset,
1851     off_t section_file_offset)
1852 {
1853   if (this->is_input_section())
1854     this->u2_.object->set_section_offset(this->shndx_,
1855                                          file_offset - section_file_offset);
1856   else
1857     this->u2_.posd->set_address_and_file_offset(address, file_offset);
1858 }
1859
1860 // Reset the address and file offset.
1861
1862 void
1863 Output_section::Input_section::reset_address_and_file_offset()
1864 {
1865   if (!this->is_input_section())
1866     this->u2_.posd->reset_address_and_file_offset();
1867 }
1868
1869 // Finalize the data size.
1870
1871 void
1872 Output_section::Input_section::finalize_data_size()
1873 {
1874   if (!this->is_input_section())
1875     this->u2_.posd->finalize_data_size();
1876 }
1877
1878 // Try to turn an input offset into an output offset.  We want to
1879 // return the output offset relative to the start of this
1880 // Input_section in the output section.
1881
1882 inline bool
1883 Output_section::Input_section::output_offset(
1884     const Relobj* object,
1885     unsigned int shndx,
1886     section_offset_type offset,
1887     section_offset_type* poutput) const
1888 {
1889   if (!this->is_input_section())
1890     return this->u2_.posd->output_offset(object, shndx, offset, poutput);
1891   else
1892     {
1893       if (this->shndx_ != shndx || this->u2_.object != object)
1894         return false;
1895       *poutput = offset;
1896       return true;
1897     }
1898 }
1899
1900 // Return whether this is the merge section for the input section
1901 // SHNDX in OBJECT.
1902
1903 inline bool
1904 Output_section::Input_section::is_merge_section_for(const Relobj* object,
1905                                                     unsigned int shndx) const
1906 {
1907   if (this->is_input_section())
1908     return false;
1909   return this->u2_.posd->is_merge_section_for(object, shndx);
1910 }
1911
1912 // Write out the data.  We don't have to do anything for an input
1913 // section--they are handled via Object::relocate--but this is where
1914 // we write out the data for an Output_section_data.
1915
1916 void
1917 Output_section::Input_section::write(Output_file* of)
1918 {
1919   if (!this->is_input_section())
1920     this->u2_.posd->write(of);
1921 }
1922
1923 // Write the data to a buffer.  As for write(), we don't have to do
1924 // anything for an input section.
1925
1926 void
1927 Output_section::Input_section::write_to_buffer(unsigned char* buffer)
1928 {
1929   if (!this->is_input_section())
1930     this->u2_.posd->write_to_buffer(buffer);
1931 }
1932
1933 // Print to a map file.
1934
1935 void
1936 Output_section::Input_section::print_to_mapfile(Mapfile* mapfile) const
1937 {
1938   switch (this->shndx_)
1939     {
1940     case OUTPUT_SECTION_CODE:
1941     case MERGE_DATA_SECTION_CODE:
1942     case MERGE_STRING_SECTION_CODE:
1943       this->u2_.posd->print_to_mapfile(mapfile);
1944       break;
1945
1946     case RELAXED_INPUT_SECTION_CODE:
1947       {
1948         Output_relaxed_input_section* relaxed_section =
1949           this->relaxed_input_section();
1950         mapfile->print_input_section(relaxed_section->relobj(),
1951                                      relaxed_section->shndx());
1952       }
1953       break;
1954     default:
1955       mapfile->print_input_section(this->u2_.object, this->shndx_);
1956       break;
1957     }
1958 }
1959
1960 // Output_section methods.
1961
1962 // Construct an Output_section.  NAME will point into a Stringpool.
1963
1964 Output_section::Output_section(const char* name, elfcpp::Elf_Word type,
1965                                elfcpp::Elf_Xword flags)
1966   : name_(name),
1967     addralign_(0),
1968     entsize_(0),
1969     load_address_(0),
1970     link_section_(NULL),
1971     link_(0),
1972     info_section_(NULL),
1973     info_symndx_(NULL),
1974     info_(0),
1975     type_(type),
1976     flags_(flags),
1977     order_(ORDER_INVALID),
1978     out_shndx_(-1U),
1979     symtab_index_(0),
1980     dynsym_index_(0),
1981     input_sections_(),
1982     first_input_offset_(0),
1983     fills_(),
1984     postprocessing_buffer_(NULL),
1985     needs_symtab_index_(false),
1986     needs_dynsym_index_(false),
1987     should_link_to_symtab_(false),
1988     should_link_to_dynsym_(false),
1989     after_input_sections_(false),
1990     requires_postprocessing_(false),
1991     found_in_sections_clause_(false),
1992     has_load_address_(false),
1993     info_uses_section_index_(false),
1994     input_section_order_specified_(false),
1995     may_sort_attached_input_sections_(false),
1996     must_sort_attached_input_sections_(false),
1997     attached_input_sections_are_sorted_(false),
1998     is_relro_(false),
1999     is_small_section_(false),
2000     is_large_section_(false),
2001     generate_code_fills_at_write_(false),
2002     is_entsize_zero_(false),
2003     section_offsets_need_adjustment_(false),
2004     is_noload_(false),
2005     always_keeps_input_sections_(false),
2006     tls_offset_(0),
2007     checkpoint_(NULL),
2008     lookup_maps_(new Output_section_lookup_maps)
2009 {
2010   // An unallocated section has no address.  Forcing this means that
2011   // we don't need special treatment for symbols defined in debug
2012   // sections.
2013   if ((flags & elfcpp::SHF_ALLOC) == 0)
2014     this->set_address(0);
2015 }
2016
2017 Output_section::~Output_section()
2018 {
2019   delete this->checkpoint_;
2020 }
2021
2022 // Set the entry size.
2023
2024 void
2025 Output_section::set_entsize(uint64_t v)
2026 {
2027   if (this->is_entsize_zero_)
2028     ;
2029   else if (this->entsize_ == 0)
2030     this->entsize_ = v;
2031   else if (this->entsize_ != v)
2032     {
2033       this->entsize_ = 0;
2034       this->is_entsize_zero_ = 1;
2035     }
2036 }
2037
2038 // Add the input section SHNDX, with header SHDR, named SECNAME, in
2039 // OBJECT, to the Output_section.  RELOC_SHNDX is the index of a
2040 // relocation section which applies to this section, or 0 if none, or
2041 // -1U if more than one.  Return the offset of the input section
2042 // within the output section.  Return -1 if the input section will
2043 // receive special handling.  In the normal case we don't always keep
2044 // track of input sections for an Output_section.  Instead, each
2045 // Object keeps track of the Output_section for each of its input
2046 // sections.  However, if HAVE_SECTIONS_SCRIPT is true, we do keep
2047 // track of input sections here; this is used when SECTIONS appears in
2048 // a linker script.
2049
2050 template<int size, bool big_endian>
2051 off_t
2052 Output_section::add_input_section(Layout* layout,
2053                                   Sized_relobj<size, big_endian>* object,
2054                                   unsigned int shndx,
2055                                   const char* secname,
2056                                   const elfcpp::Shdr<size, big_endian>& shdr,
2057                                   unsigned int reloc_shndx,
2058                                   bool have_sections_script)
2059 {
2060   elfcpp::Elf_Xword addralign = shdr.get_sh_addralign();
2061   if ((addralign & (addralign - 1)) != 0)
2062     {
2063       object->error(_("invalid alignment %lu for section \"%s\""),
2064                     static_cast<unsigned long>(addralign), secname);
2065       addralign = 1;
2066     }
2067
2068   if (addralign > this->addralign_)
2069     this->addralign_ = addralign;
2070
2071   typename elfcpp::Elf_types<size>::Elf_WXword sh_flags = shdr.get_sh_flags();
2072   uint64_t entsize = shdr.get_sh_entsize();
2073
2074   // .debug_str is a mergeable string section, but is not always so
2075   // marked by compilers.  Mark manually here so we can optimize.
2076   if (strcmp(secname, ".debug_str") == 0)
2077     {
2078       sh_flags |= (elfcpp::SHF_MERGE | elfcpp::SHF_STRINGS);
2079       entsize = 1;
2080     }
2081
2082   this->update_flags_for_input_section(sh_flags);
2083   this->set_entsize(entsize);
2084
2085   // If this is a SHF_MERGE section, we pass all the input sections to
2086   // a Output_data_merge.  We don't try to handle relocations for such
2087   // a section.  We don't try to handle empty merge sections--they
2088   // mess up the mappings, and are useless anyhow.
2089   if ((sh_flags & elfcpp::SHF_MERGE) != 0
2090       && reloc_shndx == 0
2091       && shdr.get_sh_size() > 0)
2092     {
2093       // Keep information about merged input sections for rebuilding fast
2094       // lookup maps if we have sections-script or we do relaxation.
2095       bool keeps_input_sections = (this->always_keeps_input_sections_
2096                                    || have_sections_script
2097                                    || parameters->target().may_relax());
2098
2099       if (this->add_merge_input_section(object, shndx, sh_flags, entsize,
2100                                         addralign, keeps_input_sections))
2101         {
2102           // Tell the relocation routines that they need to call the
2103           // output_offset method to determine the final address.
2104           return -1;
2105         }
2106     }
2107
2108   off_t offset_in_section = this->current_data_size_for_child();
2109   off_t aligned_offset_in_section = align_address(offset_in_section,
2110                                                   addralign);
2111
2112   // Determine if we want to delay code-fill generation until the output
2113   // section is written.  When the target is relaxing, we want to delay fill
2114   // generating to avoid adjusting them during relaxation.
2115   if (!this->generate_code_fills_at_write_
2116       && !have_sections_script
2117       && (sh_flags & elfcpp::SHF_EXECINSTR) != 0
2118       && parameters->target().has_code_fill()
2119       && parameters->target().may_relax())
2120     {
2121       gold_assert(this->fills_.empty());
2122       this->generate_code_fills_at_write_ = true;
2123     }
2124
2125   if (aligned_offset_in_section > offset_in_section
2126       && !this->generate_code_fills_at_write_
2127       && !have_sections_script
2128       && (sh_flags & elfcpp::SHF_EXECINSTR) != 0
2129       && parameters->target().has_code_fill())
2130     {
2131       // We need to add some fill data.  Using fill_list_ when
2132       // possible is an optimization, since we will often have fill
2133       // sections without input sections.
2134       off_t fill_len = aligned_offset_in_section - offset_in_section;
2135       if (this->input_sections_.empty())
2136         this->fills_.push_back(Fill(offset_in_section, fill_len));
2137       else
2138         {
2139           std::string fill_data(parameters->target().code_fill(fill_len));
2140           Output_data_const* odc = new Output_data_const(fill_data, 1);
2141           this->input_sections_.push_back(Input_section(odc));
2142         }
2143     }
2144
2145   section_size_type input_section_size = shdr.get_sh_size();
2146   section_size_type uncompressed_size;
2147   if (object->section_is_compressed(shndx, &uncompressed_size))
2148     input_section_size = uncompressed_size;
2149
2150   this->set_current_data_size_for_child(aligned_offset_in_section
2151                                         + input_section_size);
2152
2153   // We need to keep track of this section if we are already keeping
2154   // track of sections, or if we are relaxing.  Also, if this is a
2155   // section which requires sorting, or which may require sorting in
2156   // the future, we keep track of the sections.  If the
2157   // --section-ordering-file option is used to specify the order of
2158   // sections, we need to keep track of sections.
2159   if (this->always_keeps_input_sections_
2160       || have_sections_script
2161       || !this->input_sections_.empty()
2162       || this->may_sort_attached_input_sections()
2163       || this->must_sort_attached_input_sections()
2164       || parameters->options().user_set_Map()
2165       || parameters->target().may_relax()
2166       || parameters->options().section_ordering_file())
2167     {
2168       Input_section isecn(object, shndx, shdr.get_sh_size(), addralign);
2169       if (parameters->options().section_ordering_file())
2170         {
2171           unsigned int section_order_index =
2172             layout->find_section_order_index(std::string(secname));
2173           if (section_order_index != 0)
2174             {
2175               isecn.set_section_order_index(section_order_index);
2176               this->set_input_section_order_specified();
2177             }
2178         }
2179       this->input_sections_.push_back(isecn);
2180     }
2181
2182   return aligned_offset_in_section;
2183 }
2184
2185 // Add arbitrary data to an output section.
2186
2187 void
2188 Output_section::add_output_section_data(Output_section_data* posd)
2189 {
2190   Input_section inp(posd);
2191   this->add_output_section_data(&inp);
2192
2193   if (posd->is_data_size_valid())
2194     {
2195       off_t offset_in_section = this->current_data_size_for_child();
2196       off_t aligned_offset_in_section = align_address(offset_in_section,
2197                                                       posd->addralign());
2198       this->set_current_data_size_for_child(aligned_offset_in_section
2199                                             + posd->data_size());
2200     }
2201 }
2202
2203 // Add a relaxed input section.
2204
2205 void
2206 Output_section::add_relaxed_input_section(Layout* layout,
2207                                           Output_relaxed_input_section* poris,
2208                                           const std::string& name)
2209 {
2210   Input_section inp(poris);
2211
2212   // If the --section-ordering-file option is used to specify the order of
2213   // sections, we need to keep track of sections.
2214   if (parameters->options().section_ordering_file())
2215     {
2216       unsigned int section_order_index =
2217         layout->find_section_order_index(name);
2218       if (section_order_index != 0)
2219         {
2220           inp.set_section_order_index(section_order_index);
2221           this->set_input_section_order_specified();
2222         }
2223     }
2224
2225   this->add_output_section_data(&inp);
2226   if (this->lookup_maps_->is_valid())
2227     this->lookup_maps_->add_relaxed_input_section(poris->relobj(),
2228                                                   poris->shndx(), poris);
2229
2230   // For a relaxed section, we use the current data size.  Linker scripts
2231   // get all the input sections, including relaxed one from an output
2232   // section and add them back to them same output section to compute the
2233   // output section size.  If we do not account for sizes of relaxed input
2234   // sections,  an output section would be incorrectly sized.
2235   off_t offset_in_section = this->current_data_size_for_child();
2236   off_t aligned_offset_in_section = align_address(offset_in_section,
2237                                                   poris->addralign());
2238   this->set_current_data_size_for_child(aligned_offset_in_section
2239                                         + poris->current_data_size());
2240 }
2241
2242 // Add arbitrary data to an output section by Input_section.
2243
2244 void
2245 Output_section::add_output_section_data(Input_section* inp)
2246 {
2247   if (this->input_sections_.empty())
2248     this->first_input_offset_ = this->current_data_size_for_child();
2249
2250   this->input_sections_.push_back(*inp);
2251
2252   uint64_t addralign = inp->addralign();
2253   if (addralign > this->addralign_)
2254     this->addralign_ = addralign;
2255
2256   inp->set_output_section(this);
2257 }
2258
2259 // Add a merge section to an output section.
2260
2261 void
2262 Output_section::add_output_merge_section(Output_section_data* posd,
2263                                          bool is_string, uint64_t entsize)
2264 {
2265   Input_section inp(posd, is_string, entsize);
2266   this->add_output_section_data(&inp);
2267 }
2268
2269 // Add an input section to a SHF_MERGE section.
2270
2271 bool
2272 Output_section::add_merge_input_section(Relobj* object, unsigned int shndx,
2273                                         uint64_t flags, uint64_t entsize,
2274                                         uint64_t addralign,
2275                                         bool keeps_input_sections)
2276 {
2277   bool is_string = (flags & elfcpp::SHF_STRINGS) != 0;
2278
2279   // We only merge strings if the alignment is not more than the
2280   // character size.  This could be handled, but it's unusual.
2281   if (is_string && addralign > entsize)
2282     return false;
2283
2284   // We cannot restore merged input section states.
2285   gold_assert(this->checkpoint_ == NULL);
2286
2287   // Look up merge sections by required properties.
2288   // Currently, we only invalidate the lookup maps in script processing
2289   // and relaxation.  We should not have done either when we reach here.
2290   // So we assume that the lookup maps are valid to simply code.
2291   gold_assert(this->lookup_maps_->is_valid());
2292   Merge_section_properties msp(is_string, entsize, addralign);
2293   Output_merge_base* pomb = this->lookup_maps_->find_merge_section(msp);
2294   bool is_new = false;
2295   if (pomb != NULL)
2296     {
2297       gold_assert(pomb->is_string() == is_string
2298                   && pomb->entsize() == entsize
2299                   && pomb->addralign() == addralign);
2300     }
2301   else
2302     {
2303       // Create a new Output_merge_data or Output_merge_string_data.
2304       if (!is_string)
2305         pomb = new Output_merge_data(entsize, addralign);
2306       else
2307         {
2308           switch (entsize)
2309             {
2310             case 1:
2311               pomb = new Output_merge_string<char>(addralign);
2312               break;
2313             case 2:
2314               pomb = new Output_merge_string<uint16_t>(addralign);
2315               break;
2316             case 4:
2317               pomb = new Output_merge_string<uint32_t>(addralign);
2318               break;
2319             default:
2320               return false;
2321             }
2322         }
2323       // If we need to do script processing or relaxation, we need to keep
2324       // the original input sections to rebuild the fast lookup maps.
2325       if (keeps_input_sections)
2326         pomb->set_keeps_input_sections();
2327       is_new = true;
2328     }
2329
2330   if (pomb->add_input_section(object, shndx))
2331     {
2332       // Add new merge section to this output section and link merge
2333       // section properties to new merge section in map.
2334       if (is_new)
2335         {
2336           this->add_output_merge_section(pomb, is_string, entsize);
2337           this->lookup_maps_->add_merge_section(msp, pomb);
2338         }
2339
2340       // Add input section to new merge section and link input section to new
2341       // merge section in map.
2342       this->lookup_maps_->add_merge_input_section(object, shndx, pomb);
2343       return true;
2344     }
2345   else
2346     {
2347       // If add_input_section failed, delete new merge section to avoid
2348       // exporting empty merge sections in Output_section::get_input_section.
2349       if (is_new)
2350         delete pomb;
2351       return false;
2352     }
2353 }
2354
2355 // Build a relaxation map to speed up relaxation of existing input sections.
2356 // Look up to the first LIMIT elements in INPUT_SECTIONS.
2357
2358 void
2359 Output_section::build_relaxation_map(
2360   const Input_section_list& input_sections,
2361   size_t limit,
2362   Relaxation_map* relaxation_map) const
2363 {
2364   for (size_t i = 0; i < limit; ++i)
2365     {
2366       const Input_section& is(input_sections[i]);
2367       if (is.is_input_section() || is.is_relaxed_input_section())
2368         {
2369           Section_id sid(is.relobj(), is.shndx());
2370           (*relaxation_map)[sid] = i;
2371         }
2372     }
2373 }
2374
2375 // Convert regular input sections in INPUT_SECTIONS into relaxed input
2376 // sections in RELAXED_SECTIONS.  MAP is a prebuilt map from section id
2377 // indices of INPUT_SECTIONS.
2378
2379 void
2380 Output_section::convert_input_sections_in_list_to_relaxed_sections(
2381   const std::vector<Output_relaxed_input_section*>& relaxed_sections,
2382   const Relaxation_map& map,
2383   Input_section_list* input_sections)
2384 {
2385   for (size_t i = 0; i < relaxed_sections.size(); ++i)
2386     {
2387       Output_relaxed_input_section* poris = relaxed_sections[i];
2388       Section_id sid(poris->relobj(), poris->shndx());
2389       Relaxation_map::const_iterator p = map.find(sid);
2390       gold_assert(p != map.end());
2391       gold_assert((*input_sections)[p->second].is_input_section());
2392
2393       // Remember section order index of original input section
2394       // if it is set.  Copy it to the relaxed input section.
2395       unsigned int soi =
2396         (*input_sections)[p->second].section_order_index();
2397       (*input_sections)[p->second] = Input_section(poris);
2398       (*input_sections)[p->second].set_section_order_index(soi);
2399     }
2400 }
2401   
2402 // Convert regular input sections into relaxed input sections. RELAXED_SECTIONS
2403 // is a vector of pointers to Output_relaxed_input_section or its derived
2404 // classes.  The relaxed sections must correspond to existing input sections.
2405
2406 void
2407 Output_section::convert_input_sections_to_relaxed_sections(
2408   const std::vector<Output_relaxed_input_section*>& relaxed_sections)
2409 {
2410   gold_assert(parameters->target().may_relax());
2411
2412   // We want to make sure that restore_states does not undo the effect of
2413   // this.  If there is no checkpoint active, just search the current
2414   // input section list and replace the sections there.  If there is
2415   // a checkpoint, also replace the sections there.
2416   
2417   // By default, we look at the whole list.
2418   size_t limit = this->input_sections_.size();
2419
2420   if (this->checkpoint_ != NULL)
2421     {
2422       // Replace input sections with relaxed input section in the saved
2423       // copy of the input section list.
2424       if (this->checkpoint_->input_sections_saved())
2425         {
2426           Relaxation_map map;
2427           this->build_relaxation_map(
2428                     *(this->checkpoint_->input_sections()),
2429                     this->checkpoint_->input_sections()->size(),
2430                     &map);
2431           this->convert_input_sections_in_list_to_relaxed_sections(
2432                     relaxed_sections,
2433                     map,
2434                     this->checkpoint_->input_sections());
2435         }
2436       else
2437         {
2438           // We have not copied the input section list yet.  Instead, just
2439           // look at the portion that would be saved.
2440           limit = this->checkpoint_->input_sections_size();
2441         }
2442     }
2443
2444   // Convert input sections in input_section_list.
2445   Relaxation_map map;
2446   this->build_relaxation_map(this->input_sections_, limit, &map);
2447   this->convert_input_sections_in_list_to_relaxed_sections(
2448             relaxed_sections,
2449             map,
2450             &this->input_sections_);
2451
2452   // Update fast look-up map.
2453   if (this->lookup_maps_->is_valid())
2454     for (size_t i = 0; i < relaxed_sections.size(); ++i)
2455       {
2456         Output_relaxed_input_section* poris = relaxed_sections[i];
2457         this->lookup_maps_->add_relaxed_input_section(poris->relobj(),
2458                                                       poris->shndx(), poris);
2459       }
2460 }
2461
2462 // Update the output section flags based on input section flags.
2463
2464 void
2465 Output_section::update_flags_for_input_section(elfcpp::Elf_Xword flags)
2466 {
2467   // If we created the section with SHF_ALLOC clear, we set the
2468   // address.  If we are now setting the SHF_ALLOC flag, we need to
2469   // undo that.
2470   if ((this->flags_ & elfcpp::SHF_ALLOC) == 0
2471       && (flags & elfcpp::SHF_ALLOC) != 0)
2472     this->mark_address_invalid();
2473
2474   this->flags_ |= (flags
2475                    & (elfcpp::SHF_WRITE
2476                       | elfcpp::SHF_ALLOC
2477                       | elfcpp::SHF_EXECINSTR));
2478
2479   if ((flags & elfcpp::SHF_MERGE) == 0)
2480     this->flags_ &=~ elfcpp::SHF_MERGE;
2481   else
2482     {
2483       if (this->current_data_size_for_child() == 0)
2484         this->flags_ |= elfcpp::SHF_MERGE;
2485     }
2486
2487   if ((flags & elfcpp::SHF_STRINGS) == 0)
2488     this->flags_ &=~ elfcpp::SHF_STRINGS;
2489   else
2490     {
2491       if (this->current_data_size_for_child() == 0)
2492         this->flags_ |= elfcpp::SHF_STRINGS;
2493     }
2494 }
2495
2496 // Find the merge section into which an input section with index SHNDX in
2497 // OBJECT has been added.  Return NULL if none found.
2498
2499 Output_section_data*
2500 Output_section::find_merge_section(const Relobj* object,
2501                                    unsigned int shndx) const
2502 {
2503   if (!this->lookup_maps_->is_valid())
2504     this->build_lookup_maps();
2505   return this->lookup_maps_->find_merge_section(object, shndx);
2506 }
2507
2508 // Build the lookup maps for merge and relaxed sections.  This is needs
2509 // to be declared as a const methods so that it is callable with a const
2510 // Output_section pointer.  The method only updates states of the maps.
2511
2512 void
2513 Output_section::build_lookup_maps() const
2514 {
2515   this->lookup_maps_->clear();
2516   for (Input_section_list::const_iterator p = this->input_sections_.begin();
2517        p != this->input_sections_.end();
2518        ++p)
2519     {
2520       if (p->is_merge_section())
2521         {
2522           Output_merge_base* pomb = p->output_merge_base();
2523           Merge_section_properties msp(pomb->is_string(), pomb->entsize(),
2524                                        pomb->addralign());
2525           this->lookup_maps_->add_merge_section(msp, pomb);
2526           for (Output_merge_base::Input_sections::const_iterator is =
2527                  pomb->input_sections_begin();
2528                is != pomb->input_sections_end();
2529                ++is) 
2530             {
2531               const Const_section_id& csid = *is;
2532             this->lookup_maps_->add_merge_input_section(csid.first,
2533                                                         csid.second, pomb);
2534             }
2535             
2536         }
2537       else if (p->is_relaxed_input_section())
2538         {
2539           Output_relaxed_input_section* poris = p->relaxed_input_section();
2540           this->lookup_maps_->add_relaxed_input_section(poris->relobj(),
2541                                                         poris->shndx(), poris);
2542         }
2543     }
2544 }
2545
2546 // Find an relaxed input section corresponding to an input section
2547 // in OBJECT with index SHNDX.
2548
2549 const Output_relaxed_input_section*
2550 Output_section::find_relaxed_input_section(const Relobj* object,
2551                                            unsigned int shndx) const
2552 {
2553   if (!this->lookup_maps_->is_valid())
2554     this->build_lookup_maps();
2555   return this->lookup_maps_->find_relaxed_input_section(object, shndx);
2556 }
2557
2558 // Given an address OFFSET relative to the start of input section
2559 // SHNDX in OBJECT, return whether this address is being included in
2560 // the final link.  This should only be called if SHNDX in OBJECT has
2561 // a special mapping.
2562
2563 bool
2564 Output_section::is_input_address_mapped(const Relobj* object,
2565                                         unsigned int shndx,
2566                                         off_t offset) const
2567 {
2568   // Look at the Output_section_data_maps first.
2569   const Output_section_data* posd = this->find_merge_section(object, shndx);
2570   if (posd == NULL)
2571     posd = this->find_relaxed_input_section(object, shndx);
2572
2573   if (posd != NULL)
2574     {
2575       section_offset_type output_offset;
2576       bool found = posd->output_offset(object, shndx, offset, &output_offset);
2577       gold_assert(found);   
2578       return output_offset != -1;
2579     }
2580
2581   // Fall back to the slow look-up.
2582   for (Input_section_list::const_iterator p = this->input_sections_.begin();
2583        p != this->input_sections_.end();
2584        ++p)
2585     {
2586       section_offset_type output_offset;
2587       if (p->output_offset(object, shndx, offset, &output_offset))
2588         return output_offset != -1;
2589     }
2590
2591   // By default we assume that the address is mapped.  This should
2592   // only be called after we have passed all sections to Layout.  At
2593   // that point we should know what we are discarding.
2594   return true;
2595 }
2596
2597 // Given an address OFFSET relative to the start of input section
2598 // SHNDX in object OBJECT, return the output offset relative to the
2599 // start of the input section in the output section.  This should only
2600 // be called if SHNDX in OBJECT has a special mapping.
2601
2602 section_offset_type
2603 Output_section::output_offset(const Relobj* object, unsigned int shndx,
2604                               section_offset_type offset) const
2605 {
2606   // This can only be called meaningfully when we know the data size
2607   // of this.
2608   gold_assert(this->is_data_size_valid());
2609
2610   // Look at the Output_section_data_maps first.
2611   const Output_section_data* posd = this->find_merge_section(object, shndx);
2612   if (posd == NULL) 
2613     posd = this->find_relaxed_input_section(object, shndx);
2614   if (posd != NULL)
2615     {
2616       section_offset_type output_offset;
2617       bool found = posd->output_offset(object, shndx, offset, &output_offset);
2618       gold_assert(found);   
2619       return output_offset;
2620     }
2621
2622   // Fall back to the slow look-up.
2623   for (Input_section_list::const_iterator p = this->input_sections_.begin();
2624        p != this->input_sections_.end();
2625        ++p)
2626     {
2627       section_offset_type output_offset;
2628       if (p->output_offset(object, shndx, offset, &output_offset))
2629         return output_offset;
2630     }
2631   gold_unreachable();
2632 }
2633
2634 // Return the output virtual address of OFFSET relative to the start
2635 // of input section SHNDX in object OBJECT.
2636
2637 uint64_t
2638 Output_section::output_address(const Relobj* object, unsigned int shndx,
2639                                off_t offset) const
2640 {
2641   uint64_t addr = this->address() + this->first_input_offset_;
2642
2643   // Look at the Output_section_data_maps first.
2644   const Output_section_data* posd = this->find_merge_section(object, shndx);
2645   if (posd == NULL) 
2646     posd = this->find_relaxed_input_section(object, shndx);
2647   if (posd != NULL && posd->is_address_valid())
2648     {
2649       section_offset_type output_offset;
2650       bool found = posd->output_offset(object, shndx, offset, &output_offset);
2651       gold_assert(found);
2652       return posd->address() + output_offset;
2653     }
2654
2655   // Fall back to the slow look-up.
2656   for (Input_section_list::const_iterator p = this->input_sections_.begin();
2657        p != this->input_sections_.end();
2658        ++p)
2659     {
2660       addr = align_address(addr, p->addralign());
2661       section_offset_type output_offset;
2662       if (p->output_offset(object, shndx, offset, &output_offset))
2663         {
2664           if (output_offset == -1)
2665             return -1ULL;
2666           return addr + output_offset;
2667         }
2668       addr += p->data_size();
2669     }
2670
2671   // If we get here, it means that we don't know the mapping for this
2672   // input section.  This might happen in principle if
2673   // add_input_section were called before add_output_section_data.
2674   // But it should never actually happen.
2675
2676   gold_unreachable();
2677 }
2678
2679 // Find the output address of the start of the merged section for
2680 // input section SHNDX in object OBJECT.
2681
2682 bool
2683 Output_section::find_starting_output_address(const Relobj* object,
2684                                              unsigned int shndx,
2685                                              uint64_t* paddr) const
2686 {
2687   // FIXME: This becomes a bottle-neck if we have many relaxed sections.
2688   // Looking up the merge section map does not always work as we sometimes
2689   // find a merge section without its address set.
2690   uint64_t addr = this->address() + this->first_input_offset_;
2691   for (Input_section_list::const_iterator p = this->input_sections_.begin();
2692        p != this->input_sections_.end();
2693        ++p)
2694     {
2695       addr = align_address(addr, p->addralign());
2696
2697       // It would be nice if we could use the existing output_offset
2698       // method to get the output offset of input offset 0.
2699       // Unfortunately we don't know for sure that input offset 0 is
2700       // mapped at all.
2701       if (p->is_merge_section_for(object, shndx))
2702         {
2703           *paddr = addr;
2704           return true;
2705         }
2706
2707       addr += p->data_size();
2708     }
2709
2710   // We couldn't find a merge output section for this input section.
2711   return false;
2712 }
2713
2714 // Set the data size of an Output_section.  This is where we handle
2715 // setting the addresses of any Output_section_data objects.
2716
2717 void
2718 Output_section::set_final_data_size()
2719 {
2720   if (this->input_sections_.empty())
2721     {
2722       this->set_data_size(this->current_data_size_for_child());
2723       return;
2724     }
2725
2726   if (this->must_sort_attached_input_sections()
2727       || this->input_section_order_specified())
2728     this->sort_attached_input_sections();
2729
2730   uint64_t address = this->address();
2731   off_t startoff = this->offset();
2732   off_t off = startoff + this->first_input_offset_;
2733   for (Input_section_list::iterator p = this->input_sections_.begin();
2734        p != this->input_sections_.end();
2735        ++p)
2736     {
2737       off = align_address(off, p->addralign());
2738       p->set_address_and_file_offset(address + (off - startoff), off,
2739                                      startoff);
2740       off += p->data_size();
2741     }
2742
2743   this->set_data_size(off - startoff);
2744 }
2745
2746 // Reset the address and file offset.
2747
2748 void
2749 Output_section::do_reset_address_and_file_offset()
2750 {
2751   // An unallocated section has no address.  Forcing this means that
2752   // we don't need special treatment for symbols defined in debug
2753   // sections.  We do the same in the constructor.  This does not
2754   // apply to NOLOAD sections though.
2755   if (((this->flags_ & elfcpp::SHF_ALLOC) == 0) && !this->is_noload_)
2756      this->set_address(0);
2757
2758   for (Input_section_list::iterator p = this->input_sections_.begin();
2759        p != this->input_sections_.end();
2760        ++p)
2761     p->reset_address_and_file_offset();
2762 }
2763   
2764 // Return true if address and file offset have the values after reset.
2765
2766 bool
2767 Output_section::do_address_and_file_offset_have_reset_values() const
2768 {
2769   if (this->is_offset_valid())
2770     return false;
2771
2772   // An unallocated section has address 0 after its construction or a reset.
2773   if ((this->flags_ & elfcpp::SHF_ALLOC) == 0)
2774     return this->is_address_valid() && this->address() == 0;
2775   else
2776     return !this->is_address_valid();
2777 }
2778
2779 // Set the TLS offset.  Called only for SHT_TLS sections.
2780
2781 void
2782 Output_section::do_set_tls_offset(uint64_t tls_base)
2783 {
2784   this->tls_offset_ = this->address() - tls_base;
2785 }
2786
2787 // In a few cases we need to sort the input sections attached to an
2788 // output section.  This is used to implement the type of constructor
2789 // priority ordering implemented by the GNU linker, in which the
2790 // priority becomes part of the section name and the sections are
2791 // sorted by name.  We only do this for an output section if we see an
2792 // attached input section matching ".ctor.*", ".dtor.*",
2793 // ".init_array.*" or ".fini_array.*".
2794
2795 class Output_section::Input_section_sort_entry
2796 {
2797  public:
2798   Input_section_sort_entry()
2799     : input_section_(), index_(-1U), section_has_name_(false),
2800       section_name_()
2801   { }
2802
2803   Input_section_sort_entry(const Input_section& input_section,
2804                            unsigned int index,
2805                            bool must_sort_attached_input_sections)
2806     : input_section_(input_section), index_(index),
2807       section_has_name_(input_section.is_input_section()
2808                         || input_section.is_relaxed_input_section())
2809   {
2810     if (this->section_has_name_
2811         && must_sort_attached_input_sections)
2812       {
2813         // This is only called single-threaded from Layout::finalize,
2814         // so it is OK to lock.  Unfortunately we have no way to pass
2815         // in a Task token.
2816         const Task* dummy_task = reinterpret_cast<const Task*>(-1);
2817         Object* obj = (input_section.is_input_section()
2818                        ? input_section.relobj()
2819                        : input_section.relaxed_input_section()->relobj());
2820         Task_lock_obj<Object> tl(dummy_task, obj);
2821
2822         // This is a slow operation, which should be cached in
2823         // Layout::layout if this becomes a speed problem.
2824         this->section_name_ = obj->section_name(input_section.shndx());
2825       }
2826   }
2827
2828   // Return the Input_section.
2829   const Input_section&
2830   input_section() const
2831   {
2832     gold_assert(this->index_ != -1U);
2833     return this->input_section_;
2834   }
2835
2836   // The index of this entry in the original list.  This is used to
2837   // make the sort stable.
2838   unsigned int
2839   index() const
2840   {
2841     gold_assert(this->index_ != -1U);
2842     return this->index_;
2843   }
2844
2845   // Whether there is a section name.
2846   bool
2847   section_has_name() const
2848   { return this->section_has_name_; }
2849
2850   // The section name.
2851   const std::string&
2852   section_name() const
2853   {
2854     gold_assert(this->section_has_name_);
2855     return this->section_name_;
2856   }
2857
2858   // Return true if the section name has a priority.  This is assumed
2859   // to be true if it has a dot after the initial dot.
2860   bool
2861   has_priority() const
2862   {
2863     gold_assert(this->section_has_name_);
2864     return this->section_name_.find('.', 1) != std::string::npos;
2865   }
2866
2867   // Return true if this an input file whose base name matches
2868   // FILE_NAME.  The base name must have an extension of ".o", and
2869   // must be exactly FILE_NAME.o or FILE_NAME, one character, ".o".
2870   // This is to match crtbegin.o as well as crtbeginS.o without
2871   // getting confused by other possibilities.  Overall matching the
2872   // file name this way is a dreadful hack, but the GNU linker does it
2873   // in order to better support gcc, and we need to be compatible.
2874   bool
2875   match_file_name(const char* match_file_name) const
2876   {
2877     const std::string& file_name(this->input_section_.relobj()->name());
2878     const char* base_name = lbasename(file_name.c_str());
2879     size_t match_len = strlen(match_file_name);
2880     if (strncmp(base_name, match_file_name, match_len) != 0)
2881       return false;
2882     size_t base_len = strlen(base_name);
2883     if (base_len != match_len + 2 && base_len != match_len + 3)
2884       return false;
2885     return memcmp(base_name + base_len - 2, ".o", 2) == 0;
2886   }
2887
2888   // Returns 1 if THIS should appear before S in section order, -1 if S
2889   // appears before THIS and 0 if they are not comparable.
2890   int
2891   compare_section_ordering(const Input_section_sort_entry& s) const
2892   {
2893     unsigned int this_secn_index = this->input_section_.section_order_index();
2894     unsigned int s_secn_index = s.input_section().section_order_index();
2895     if (this_secn_index > 0 && s_secn_index > 0)
2896       {
2897         if (this_secn_index < s_secn_index)
2898           return 1;
2899         else if (this_secn_index > s_secn_index)
2900           return -1;
2901       }
2902     return 0;
2903   }
2904
2905  private:
2906   // The Input_section we are sorting.
2907   Input_section input_section_;
2908   // The index of this Input_section in the original list.
2909   unsigned int index_;
2910   // Whether this Input_section has a section name--it won't if this
2911   // is some random Output_section_data.
2912   bool section_has_name_;
2913   // The section name if there is one.
2914   std::string section_name_;
2915 };
2916
2917 // Return true if S1 should come before S2 in the output section.
2918
2919 bool
2920 Output_section::Input_section_sort_compare::operator()(
2921     const Output_section::Input_section_sort_entry& s1,
2922     const Output_section::Input_section_sort_entry& s2) const
2923 {
2924   // crtbegin.o must come first.
2925   bool s1_begin = s1.match_file_name("crtbegin");
2926   bool s2_begin = s2.match_file_name("crtbegin");
2927   if (s1_begin || s2_begin)
2928     {
2929       if (!s1_begin)
2930         return false;
2931       if (!s2_begin)
2932         return true;
2933       return s1.index() < s2.index();
2934     }
2935
2936   // crtend.o must come last.
2937   bool s1_end = s1.match_file_name("crtend");
2938   bool s2_end = s2.match_file_name("crtend");
2939   if (s1_end || s2_end)
2940     {
2941       if (!s1_end)
2942         return true;
2943       if (!s2_end)
2944         return false;
2945       return s1.index() < s2.index();
2946     }
2947
2948   // We sort all the sections with no names to the end.
2949   if (!s1.section_has_name() || !s2.section_has_name())
2950     {
2951       if (s1.section_has_name())
2952         return true;
2953       if (s2.section_has_name())
2954         return false;
2955       return s1.index() < s2.index();
2956     }
2957
2958   // A section with a priority follows a section without a priority.
2959   bool s1_has_priority = s1.has_priority();
2960   bool s2_has_priority = s2.has_priority();
2961   if (s1_has_priority && !s2_has_priority)
2962     return false;
2963   if (!s1_has_priority && s2_has_priority)
2964     return true;
2965
2966   // Check if a section order exists for these sections through a section
2967   // ordering file.  If sequence_num is 0, an order does not exist.
2968   int sequence_num = s1.compare_section_ordering(s2);
2969   if (sequence_num != 0)
2970     return sequence_num == 1;
2971
2972   // Otherwise we sort by name.
2973   int compare = s1.section_name().compare(s2.section_name());
2974   if (compare != 0)
2975     return compare < 0;
2976
2977   // Otherwise we keep the input order.
2978   return s1.index() < s2.index();
2979 }
2980
2981 // Return true if S1 should come before S2 in an .init_array or .fini_array
2982 // output section.
2983
2984 bool
2985 Output_section::Input_section_sort_init_fini_compare::operator()(
2986     const Output_section::Input_section_sort_entry& s1,
2987     const Output_section::Input_section_sort_entry& s2) const
2988 {
2989   // We sort all the sections with no names to the end.
2990   if (!s1.section_has_name() || !s2.section_has_name())
2991     {
2992       if (s1.section_has_name())
2993         return true;
2994       if (s2.section_has_name())
2995         return false;
2996       return s1.index() < s2.index();
2997     }
2998
2999   // A section without a priority follows a section with a priority.
3000   // This is the reverse of .ctors and .dtors sections.
3001   bool s1_has_priority = s1.has_priority();
3002   bool s2_has_priority = s2.has_priority();
3003   if (s1_has_priority && !s2_has_priority)
3004     return true;
3005   if (!s1_has_priority && s2_has_priority)
3006     return false;
3007
3008   // Check if a section order exists for these sections through a section
3009   // ordering file.  If sequence_num is 0, an order does not exist.
3010   int sequence_num = s1.compare_section_ordering(s2);
3011   if (sequence_num != 0)
3012     return sequence_num == 1;
3013
3014   // Otherwise we sort by name.
3015   int compare = s1.section_name().compare(s2.section_name());
3016   if (compare != 0)
3017     return compare < 0;
3018
3019   // Otherwise we keep the input order.
3020   return s1.index() < s2.index();
3021 }
3022
3023 // Return true if S1 should come before S2.  Sections that do not match
3024 // any pattern in the section ordering file are placed ahead of the sections
3025 // that match some pattern.
3026
3027 bool
3028 Output_section::Input_section_sort_section_order_index_compare::operator()(
3029     const Output_section::Input_section_sort_entry& s1,
3030     const Output_section::Input_section_sort_entry& s2) const
3031 {
3032   unsigned int s1_secn_index = s1.input_section().section_order_index();
3033   unsigned int s2_secn_index = s2.input_section().section_order_index();
3034
3035   // Keep input order if section ordering cannot determine order.
3036   if (s1_secn_index == s2_secn_index)
3037     return s1.index() < s2.index();
3038   
3039   return s1_secn_index < s2_secn_index;
3040 }
3041
3042 // Sort the input sections attached to an output section.
3043
3044 void
3045 Output_section::sort_attached_input_sections()
3046 {
3047   if (this->attached_input_sections_are_sorted_)
3048     return;
3049
3050   if (this->checkpoint_ != NULL
3051       && !this->checkpoint_->input_sections_saved())
3052     this->checkpoint_->save_input_sections();
3053
3054   // The only thing we know about an input section is the object and
3055   // the section index.  We need the section name.  Recomputing this
3056   // is slow but this is an unusual case.  If this becomes a speed
3057   // problem we can cache the names as required in Layout::layout.
3058
3059   // We start by building a larger vector holding a copy of each
3060   // Input_section, plus its current index in the list and its name.
3061   std::vector<Input_section_sort_entry> sort_list;
3062
3063   unsigned int i = 0;
3064   for (Input_section_list::iterator p = this->input_sections_.begin();
3065        p != this->input_sections_.end();
3066        ++p, ++i)
3067       sort_list.push_back(Input_section_sort_entry(*p, i,
3068                             this->must_sort_attached_input_sections()));
3069
3070   // Sort the input sections.
3071   if (this->must_sort_attached_input_sections())
3072     {
3073       if (this->type() == elfcpp::SHT_PREINIT_ARRAY
3074           || this->type() == elfcpp::SHT_INIT_ARRAY
3075           || this->type() == elfcpp::SHT_FINI_ARRAY)
3076         std::sort(sort_list.begin(), sort_list.end(),
3077                   Input_section_sort_init_fini_compare());
3078       else
3079         std::sort(sort_list.begin(), sort_list.end(),
3080                   Input_section_sort_compare());
3081     }
3082   else
3083     {
3084       gold_assert(parameters->options().section_ordering_file());
3085       std::sort(sort_list.begin(), sort_list.end(),
3086                 Input_section_sort_section_order_index_compare());
3087     }
3088
3089   // Copy the sorted input sections back to our list.
3090   this->input_sections_.clear();
3091   for (std::vector<Input_section_sort_entry>::iterator p = sort_list.begin();
3092        p != sort_list.end();
3093        ++p)
3094     this->input_sections_.push_back(p->input_section());
3095   sort_list.clear();
3096
3097   // Remember that we sorted the input sections, since we might get
3098   // called again.
3099   this->attached_input_sections_are_sorted_ = true;
3100 }
3101
3102 // Write the section header to *OSHDR.
3103
3104 template<int size, bool big_endian>
3105 void
3106 Output_section::write_header(const Layout* layout,
3107                              const Stringpool* secnamepool,
3108                              elfcpp::Shdr_write<size, big_endian>* oshdr) const
3109 {
3110   oshdr->put_sh_name(secnamepool->get_offset(this->name_));
3111   oshdr->put_sh_type(this->type_);
3112
3113   elfcpp::Elf_Xword flags = this->flags_;
3114   if (this->info_section_ != NULL && this->info_uses_section_index_)
3115     flags |= elfcpp::SHF_INFO_LINK;
3116   oshdr->put_sh_flags(flags);
3117
3118   oshdr->put_sh_addr(this->address());
3119   oshdr->put_sh_offset(this->offset());
3120   oshdr->put_sh_size(this->data_size());
3121   if (this->link_section_ != NULL)
3122     oshdr->put_sh_link(this->link_section_->out_shndx());
3123   else if (this->should_link_to_symtab_)
3124     oshdr->put_sh_link(layout->symtab_section()->out_shndx());
3125   else if (this->should_link_to_dynsym_)
3126     oshdr->put_sh_link(layout->dynsym_section()->out_shndx());
3127   else
3128     oshdr->put_sh_link(this->link_);
3129
3130   elfcpp::Elf_Word info;
3131   if (this->info_section_ != NULL)
3132     {
3133       if (this->info_uses_section_index_)
3134         info = this->info_section_->out_shndx();
3135       else
3136         info = this->info_section_->symtab_index();
3137     }
3138   else if (this->info_symndx_ != NULL)
3139     info = this->info_symndx_->symtab_index();
3140   else
3141     info = this->info_;
3142   oshdr->put_sh_info(info);
3143
3144   oshdr->put_sh_addralign(this->addralign_);
3145   oshdr->put_sh_entsize(this->entsize_);
3146 }
3147
3148 // Write out the data.  For input sections the data is written out by
3149 // Object::relocate, but we have to handle Output_section_data objects
3150 // here.
3151
3152 void
3153 Output_section::do_write(Output_file* of)
3154 {
3155   gold_assert(!this->requires_postprocessing());
3156
3157   // If the target performs relaxation, we delay filler generation until now.
3158   gold_assert(!this->generate_code_fills_at_write_ || this->fills_.empty());
3159
3160   off_t output_section_file_offset = this->offset();
3161   for (Fill_list::iterator p = this->fills_.begin();
3162        p != this->fills_.end();
3163        ++p)
3164     {
3165       std::string fill_data(parameters->target().code_fill(p->length()));
3166       of->write(output_section_file_offset + p->section_offset(),
3167                 fill_data.data(), fill_data.size());
3168     }
3169
3170   off_t off = this->offset() + this->first_input_offset_;
3171   for (Input_section_list::iterator p = this->input_sections_.begin();
3172        p != this->input_sections_.end();
3173        ++p)
3174     {
3175       off_t aligned_off = align_address(off, p->addralign());
3176       if (this->generate_code_fills_at_write_ && (off != aligned_off))
3177         {
3178           size_t fill_len = aligned_off - off;
3179           std::string fill_data(parameters->target().code_fill(fill_len));
3180           of->write(off, fill_data.data(), fill_data.size());
3181         }
3182
3183       p->write(of);
3184       off = aligned_off + p->data_size();
3185     }
3186 }
3187
3188 // If a section requires postprocessing, create the buffer to use.
3189
3190 void
3191 Output_section::create_postprocessing_buffer()
3192 {
3193   gold_assert(this->requires_postprocessing());
3194
3195   if (this->postprocessing_buffer_ != NULL)
3196     return;
3197
3198   if (!this->input_sections_.empty())
3199     {
3200       off_t off = this->first_input_offset_;
3201       for (Input_section_list::iterator p = this->input_sections_.begin();
3202            p != this->input_sections_.end();
3203            ++p)
3204         {
3205           off = align_address(off, p->addralign());
3206           p->finalize_data_size();
3207           off += p->data_size();
3208         }
3209       this->set_current_data_size_for_child(off);
3210     }
3211
3212   off_t buffer_size = this->current_data_size_for_child();
3213   this->postprocessing_buffer_ = new unsigned char[buffer_size];
3214 }
3215
3216 // Write all the data of an Output_section into the postprocessing
3217 // buffer.  This is used for sections which require postprocessing,
3218 // such as compression.  Input sections are handled by
3219 // Object::Relocate.
3220
3221 void
3222 Output_section::write_to_postprocessing_buffer()
3223 {
3224   gold_assert(this->requires_postprocessing());
3225
3226   // If the target performs relaxation, we delay filler generation until now.
3227   gold_assert(!this->generate_code_fills_at_write_ || this->fills_.empty());
3228
3229   unsigned char* buffer = this->postprocessing_buffer();
3230   for (Fill_list::iterator p = this->fills_.begin();
3231        p != this->fills_.end();
3232        ++p)
3233     {
3234       std::string fill_data(parameters->target().code_fill(p->length()));
3235       memcpy(buffer + p->section_offset(), fill_data.data(),
3236              fill_data.size());
3237     }
3238
3239   off_t off = this->first_input_offset_;
3240   for (Input_section_list::iterator p = this->input_sections_.begin();
3241        p != this->input_sections_.end();
3242        ++p)
3243     {
3244       off_t aligned_off = align_address(off, p->addralign());
3245       if (this->generate_code_fills_at_write_ && (off != aligned_off))
3246         {
3247           size_t fill_len = aligned_off - off;
3248           std::string fill_data(parameters->target().code_fill(fill_len));
3249           memcpy(buffer + off, fill_data.data(), fill_data.size());
3250         }
3251
3252       p->write_to_buffer(buffer + aligned_off);
3253       off = aligned_off + p->data_size();
3254     }
3255 }
3256
3257 // Get the input sections for linker script processing.  We leave
3258 // behind the Output_section_data entries.  Note that this may be
3259 // slightly incorrect for merge sections.  We will leave them behind,
3260 // but it is possible that the script says that they should follow
3261 // some other input sections, as in:
3262 //    .rodata { *(.rodata) *(.rodata.cst*) }
3263 // For that matter, we don't handle this correctly:
3264 //    .rodata { foo.o(.rodata.cst*) *(.rodata.cst*) }
3265 // With luck this will never matter.
3266
3267 uint64_t
3268 Output_section::get_input_sections(
3269     uint64_t address,
3270     const std::string& fill,
3271     std::list<Input_section>* input_sections)
3272 {
3273   if (this->checkpoint_ != NULL
3274       && !this->checkpoint_->input_sections_saved())
3275     this->checkpoint_->save_input_sections();
3276
3277   // Invalidate fast look-up maps.
3278   this->lookup_maps_->invalidate();
3279
3280   uint64_t orig_address = address;
3281
3282   address = align_address(address, this->addralign());
3283
3284   Input_section_list remaining;
3285   for (Input_section_list::iterator p = this->input_sections_.begin();
3286        p != this->input_sections_.end();
3287        ++p)
3288     {
3289       if (p->is_input_section()
3290           || p->is_relaxed_input_section()
3291           || p->is_merge_section())
3292         input_sections->push_back(*p);
3293       else
3294         {
3295           uint64_t aligned_address = align_address(address, p->addralign());
3296           if (aligned_address != address && !fill.empty())
3297             {
3298               section_size_type length =
3299                 convert_to_section_size_type(aligned_address - address);
3300               std::string this_fill;
3301               this_fill.reserve(length);
3302               while (this_fill.length() + fill.length() <= length)
3303                 this_fill += fill;
3304               if (this_fill.length() < length)
3305                 this_fill.append(fill, 0, length - this_fill.length());
3306
3307               Output_section_data* posd = new Output_data_const(this_fill, 0);
3308               remaining.push_back(Input_section(posd));
3309             }
3310           address = aligned_address;
3311
3312           remaining.push_back(*p);
3313
3314           p->finalize_data_size();
3315           address += p->data_size();
3316         }
3317     }
3318
3319   this->input_sections_.swap(remaining);
3320   this->first_input_offset_ = 0;
3321
3322   uint64_t data_size = address - orig_address;
3323   this->set_current_data_size_for_child(data_size);
3324   return data_size;
3325 }
3326
3327 // Add a script input section.  SIS is an Output_section::Input_section,
3328 // which can be either a plain input section or a special input section like
3329 // a relaxed input section.  For a special input section, its size must be
3330 // finalized.
3331
3332 void
3333 Output_section::add_script_input_section(const Input_section& sis)
3334 {
3335   uint64_t data_size = sis.data_size();
3336   uint64_t addralign = sis.addralign();
3337   if (addralign > this->addralign_)
3338     this->addralign_ = addralign;
3339
3340   off_t offset_in_section = this->current_data_size_for_child();
3341   off_t aligned_offset_in_section = align_address(offset_in_section,
3342                                                   addralign);
3343
3344   this->set_current_data_size_for_child(aligned_offset_in_section
3345                                         + data_size);
3346
3347   this->input_sections_.push_back(sis);
3348
3349   // Update fast lookup maps if necessary. 
3350   if (this->lookup_maps_->is_valid())
3351     {
3352       if (sis.is_merge_section())
3353         {
3354           Output_merge_base* pomb = sis.output_merge_base();
3355           Merge_section_properties msp(pomb->is_string(), pomb->entsize(),
3356                                        pomb->addralign());
3357           this->lookup_maps_->add_merge_section(msp, pomb);
3358           for (Output_merge_base::Input_sections::const_iterator p =
3359                  pomb->input_sections_begin();
3360                p != pomb->input_sections_end();
3361                ++p)
3362             this->lookup_maps_->add_merge_input_section(p->first, p->second,
3363                                                         pomb);
3364         }
3365       else if (sis.is_relaxed_input_section())
3366         {
3367           Output_relaxed_input_section* poris = sis.relaxed_input_section();
3368           this->lookup_maps_->add_relaxed_input_section(poris->relobj(),
3369                                                         poris->shndx(), poris);
3370         }
3371     }
3372 }
3373
3374 // Save states for relaxation.
3375
3376 void
3377 Output_section::save_states()
3378 {
3379   gold_assert(this->checkpoint_ == NULL);
3380   Checkpoint_output_section* checkpoint =
3381     new Checkpoint_output_section(this->addralign_, this->flags_,
3382                                   this->input_sections_,
3383                                   this->first_input_offset_,
3384                                   this->attached_input_sections_are_sorted_);
3385   this->checkpoint_ = checkpoint;
3386   gold_assert(this->fills_.empty());
3387 }
3388
3389 void
3390 Output_section::discard_states()
3391 {
3392   gold_assert(this->checkpoint_ != NULL);
3393   delete this->checkpoint_;
3394   this->checkpoint_ = NULL;
3395   gold_assert(this->fills_.empty());
3396
3397   // Simply invalidate the fast lookup maps since we do not keep
3398   // track of them.
3399   this->lookup_maps_->invalidate();
3400 }
3401
3402 void
3403 Output_section::restore_states()
3404 {
3405   gold_assert(this->checkpoint_ != NULL);
3406   Checkpoint_output_section* checkpoint = this->checkpoint_;
3407
3408   this->addralign_ = checkpoint->addralign();
3409   this->flags_ = checkpoint->flags();
3410   this->first_input_offset_ = checkpoint->first_input_offset();
3411
3412   if (!checkpoint->input_sections_saved())
3413     {
3414       // If we have not copied the input sections, just resize it.
3415       size_t old_size = checkpoint->input_sections_size();
3416       gold_assert(this->input_sections_.size() >= old_size);
3417       this->input_sections_.resize(old_size);
3418     }
3419   else
3420     {
3421       // We need to copy the whole list.  This is not efficient for
3422       // extremely large output with hundreads of thousands of input
3423       // objects.  We may need to re-think how we should pass sections
3424       // to scripts.
3425       this->input_sections_ = *checkpoint->input_sections();
3426     }
3427
3428   this->attached_input_sections_are_sorted_ =
3429     checkpoint->attached_input_sections_are_sorted();
3430
3431   // Simply invalidate the fast lookup maps since we do not keep
3432   // track of them.
3433   this->lookup_maps_->invalidate();
3434 }
3435
3436 // Update the section offsets of input sections in this.  This is required if
3437 // relaxation causes some input sections to change sizes.
3438
3439 void
3440 Output_section::adjust_section_offsets()
3441 {
3442   if (!this->section_offsets_need_adjustment_)
3443     return;
3444
3445   off_t off = 0;
3446   for (Input_section_list::iterator p = this->input_sections_.begin();
3447        p != this->input_sections_.end();
3448        ++p)
3449     {
3450       off = align_address(off, p->addralign());
3451       if (p->is_input_section())
3452         p->relobj()->set_section_offset(p->shndx(), off);
3453       off += p->data_size();
3454     }
3455
3456   this->section_offsets_need_adjustment_ = false;
3457 }
3458
3459 // Print to the map file.
3460
3461 void
3462 Output_section::do_print_to_mapfile(Mapfile* mapfile) const
3463 {
3464   mapfile->print_output_section(this);
3465
3466   for (Input_section_list::const_iterator p = this->input_sections_.begin();
3467        p != this->input_sections_.end();
3468        ++p)
3469     p->print_to_mapfile(mapfile);
3470 }
3471
3472 // Print stats for merge sections to stderr.
3473
3474 void
3475 Output_section::print_merge_stats()
3476 {
3477   Input_section_list::iterator p;
3478   for (p = this->input_sections_.begin();
3479        p != this->input_sections_.end();
3480        ++p)
3481     p->print_merge_stats(this->name_);
3482 }
3483
3484 // Output segment methods.
3485
3486 Output_segment::Output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags)
3487   : vaddr_(0),
3488     paddr_(0),
3489     memsz_(0),
3490     max_align_(0),
3491     min_p_align_(0),
3492     offset_(0),
3493     filesz_(0),
3494     type_(type),
3495     flags_(flags),
3496     is_max_align_known_(false),
3497     are_addresses_set_(false),
3498     is_large_data_segment_(false)
3499 {
3500   // The ELF ABI specifies that a PT_TLS segment always has PF_R as
3501   // the flags.
3502   if (type == elfcpp::PT_TLS)
3503     this->flags_ = elfcpp::PF_R;
3504 }
3505
3506 // Add an Output_section to a PT_LOAD Output_segment.
3507
3508 void
3509 Output_segment::add_output_section_to_load(Layout* layout,
3510                                            Output_section* os,
3511                                            elfcpp::Elf_Word seg_flags)
3512 {
3513   gold_assert(this->type() == elfcpp::PT_LOAD);
3514   gold_assert((os->flags() & elfcpp::SHF_ALLOC) != 0);
3515   gold_assert(!this->is_max_align_known_);
3516   gold_assert(os->is_large_data_section() == this->is_large_data_segment());
3517
3518   this->update_flags_for_output_section(seg_flags);
3519
3520   // We don't want to change the ordering if we have a linker script
3521   // with a SECTIONS clause.
3522   Output_section_order order = os->order();
3523   if (layout->script_options()->saw_sections_clause())
3524     order = static_cast<Output_section_order>(0);
3525   else
3526     gold_assert(order != ORDER_INVALID);
3527
3528   this->output_lists_[order].push_back(os);
3529 }
3530
3531 // Add an Output_section to a non-PT_LOAD Output_segment.
3532
3533 void
3534 Output_segment::add_output_section_to_nonload(Output_section* os,
3535                                               elfcpp::Elf_Word seg_flags)
3536 {
3537   gold_assert(this->type() != elfcpp::PT_LOAD);
3538   gold_assert((os->flags() & elfcpp::SHF_ALLOC) != 0);
3539   gold_assert(!this->is_max_align_known_);
3540
3541   this->update_flags_for_output_section(seg_flags);
3542
3543   this->output_lists_[0].push_back(os);
3544 }
3545
3546 // Remove an Output_section from this segment.  It is an error if it
3547 // is not present.
3548
3549 void
3550 Output_segment::remove_output_section(Output_section* os)
3551 {
3552   for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
3553     {
3554       Output_data_list* pdl = &this->output_lists_[i];
3555       for (Output_data_list::iterator p = pdl->begin(); p != pdl->end(); ++p)
3556         {
3557           if (*p == os)
3558             {
3559               pdl->erase(p);
3560               return;
3561             }
3562         }
3563     }
3564   gold_unreachable();
3565 }
3566
3567 // Add an Output_data (which need not be an Output_section) to the
3568 // start of a segment.
3569
3570 void
3571 Output_segment::add_initial_output_data(Output_data* od)
3572 {
3573   gold_assert(!this->is_max_align_known_);
3574   Output_data_list::iterator p = this->output_lists_[0].begin();
3575   this->output_lists_[0].insert(p, od);
3576 }
3577
3578 // Return true if this segment has any sections which hold actual
3579 // data, rather than being a BSS section.
3580
3581 bool
3582 Output_segment::has_any_data_sections() const
3583 {
3584   for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
3585     {
3586       const Output_data_list* pdl = &this->output_lists_[i];
3587       for (Output_data_list::const_iterator p = pdl->begin();
3588            p != pdl->end();
3589            ++p)
3590         {
3591           if (!(*p)->is_section())
3592             return true;
3593           if ((*p)->output_section()->type() != elfcpp::SHT_NOBITS)
3594             return true;
3595         }
3596     }
3597   return false;
3598 }
3599
3600 // Return whether the first data section (not counting TLS sections)
3601 // is a relro section.
3602
3603 bool
3604 Output_segment::is_first_section_relro() const
3605 {
3606   for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
3607     {
3608       if (i == static_cast<int>(ORDER_TLS_DATA)
3609           || i == static_cast<int>(ORDER_TLS_BSS))
3610         continue;
3611       const Output_data_list* pdl = &this->output_lists_[i];
3612       if (!pdl->empty())
3613         {
3614           Output_data* p = pdl->front();
3615           return p->is_section() && p->output_section()->is_relro();
3616         }
3617     }
3618   return false;
3619 }
3620
3621 // Return the maximum alignment of the Output_data in Output_segment.
3622
3623 uint64_t
3624 Output_segment::maximum_alignment()
3625 {
3626   if (!this->is_max_align_known_)
3627     {
3628       for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
3629         {       
3630           const Output_data_list* pdl = &this->output_lists_[i];
3631           uint64_t addralign = Output_segment::maximum_alignment_list(pdl);
3632           if (addralign > this->max_align_)
3633             this->max_align_ = addralign;
3634         }
3635       this->is_max_align_known_ = true;
3636     }
3637
3638   return this->max_align_;
3639 }
3640
3641 // Return the maximum alignment of a list of Output_data.
3642
3643 uint64_t
3644 Output_segment::maximum_alignment_list(const Output_data_list* pdl)
3645 {
3646   uint64_t ret = 0;
3647   for (Output_data_list::const_iterator p = pdl->begin();
3648        p != pdl->end();
3649        ++p)
3650     {
3651       uint64_t addralign = (*p)->addralign();
3652       if (addralign > ret)
3653         ret = addralign;
3654     }
3655   return ret;
3656 }
3657
3658 // Return whether this segment has any dynamic relocs.
3659
3660 bool
3661 Output_segment::has_dynamic_reloc() const
3662 {
3663   for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
3664     if (this->has_dynamic_reloc_list(&this->output_lists_[i]))
3665       return true;
3666   return false;
3667 }
3668
3669 // Return whether this Output_data_list has any dynamic relocs.
3670
3671 bool
3672 Output_segment::has_dynamic_reloc_list(const Output_data_list* pdl) const
3673 {
3674   for (Output_data_list::const_iterator p = pdl->begin();
3675        p != pdl->end();
3676        ++p)
3677     if ((*p)->has_dynamic_reloc())
3678       return true;
3679   return false;
3680 }
3681
3682 // Set the section addresses for an Output_segment.  If RESET is true,
3683 // reset the addresses first.  ADDR is the address and *POFF is the
3684 // file offset.  Set the section indexes starting with *PSHNDX.
3685 // INCREASE_RELRO is the size of the portion of the first non-relro
3686 // section that should be included in the PT_GNU_RELRO segment.
3687 // If this segment has relro sections, and has been aligned for
3688 // that purpose, set *HAS_RELRO to TRUE.  Return the address of
3689 // the immediately following segment.  Update *HAS_RELRO, *POFF,
3690 // and *PSHNDX.
3691
3692 uint64_t
3693 Output_segment::set_section_addresses(const Layout* layout, bool reset,
3694                                       uint64_t addr,
3695                                       unsigned int* increase_relro,
3696                                       bool* has_relro,
3697                                       off_t* poff,
3698                                       unsigned int* pshndx)
3699 {
3700   gold_assert(this->type_ == elfcpp::PT_LOAD);
3701
3702   uint64_t last_relro_pad = 0;
3703   off_t orig_off = *poff;
3704
3705   bool in_tls = false;
3706
3707   // If we have relro sections, we need to pad forward now so that the
3708   // relro sections plus INCREASE_RELRO end on a common page boundary.
3709   if (parameters->options().relro()
3710       && this->is_first_section_relro()
3711       && (!this->are_addresses_set_ || reset))
3712     {
3713       uint64_t relro_size = 0;
3714       off_t off = *poff;
3715       uint64_t max_align = 0;
3716       for (int i = 0; i <= static_cast<int>(ORDER_RELRO_LAST); ++i)
3717         {
3718           Output_data_list* pdl = &this->output_lists_[i];
3719           Output_data_list::iterator p;
3720           for (p = pdl->begin(); p != pdl->end(); ++p)
3721             {
3722               if (!(*p)->is_section())
3723                 break;
3724               uint64_t align = (*p)->addralign();
3725               if (align > max_align)
3726                 max_align = align;
3727               if ((*p)->is_section_flag_set(elfcpp::SHF_TLS))
3728                 in_tls = true;
3729               else if (in_tls)
3730                 {
3731                   // Align the first non-TLS section to the alignment
3732                   // of the TLS segment.
3733                   align = max_align;
3734                   in_tls = false;
3735                 }
3736               relro_size = align_address(relro_size, align);
3737               // Ignore the size of the .tbss section.
3738               if ((*p)->is_section_flag_set(elfcpp::SHF_TLS)
3739                   && (*p)->is_section_type(elfcpp::SHT_NOBITS))
3740                 continue;
3741               if ((*p)->is_address_valid())
3742                 relro_size += (*p)->data_size();
3743               else
3744                 {
3745                   // FIXME: This could be faster.
3746                   (*p)->set_address_and_file_offset(addr + relro_size,
3747                                                     off + relro_size);
3748                   relro_size += (*p)->data_size();
3749                   (*p)->reset_address_and_file_offset();
3750                 }
3751             }
3752           if (p != pdl->end())
3753             break;
3754         }
3755       relro_size += *increase_relro;
3756       // Pad the total relro size to a multiple of the maximum
3757       // section alignment seen.
3758       uint64_t aligned_size = align_address(relro_size, max_align);
3759       // Note the amount of padding added after the last relro section.
3760       last_relro_pad = aligned_size - relro_size;
3761       *has_relro = true;
3762
3763       uint64_t page_align = parameters->target().common_pagesize();
3764
3765       // Align to offset N such that (N + RELRO_SIZE) % PAGE_ALIGN == 0.
3766       uint64_t desired_align = page_align - (aligned_size % page_align);
3767       if (desired_align < *poff % page_align)
3768         *poff += page_align - *poff % page_align;
3769       *poff += desired_align - *poff % page_align;
3770       addr += *poff - orig_off;
3771       orig_off = *poff;
3772     }
3773
3774   if (!reset && this->are_addresses_set_)
3775     {
3776       gold_assert(this->paddr_ == addr);
3777       addr = this->vaddr_;
3778     }
3779   else
3780     {
3781       this->vaddr_ = addr;
3782       this->paddr_ = addr;
3783       this->are_addresses_set_ = true;
3784     }
3785
3786   in_tls = false;
3787
3788   this->offset_ = orig_off;
3789
3790   off_t off = 0;
3791   uint64_t ret;
3792   for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
3793     {
3794       if (i == static_cast<int>(ORDER_RELRO_LAST))
3795         {
3796           *poff += last_relro_pad;
3797           addr += last_relro_pad;
3798           if (this->output_lists_[i].empty())
3799             {
3800               // If there is nothing in the ORDER_RELRO_LAST list,
3801               // the padding will occur at the end of the relro
3802               // segment, and we need to add it to *INCREASE_RELRO.
3803               *increase_relro += last_relro_pad;
3804             }
3805         }
3806       addr = this->set_section_list_addresses(layout, reset,
3807                                               &this->output_lists_[i],
3808                                               addr, poff, pshndx, &in_tls);
3809       if (i < static_cast<int>(ORDER_SMALL_BSS))
3810         {
3811           this->filesz_ = *poff - orig_off;
3812           off = *poff;
3813         }
3814
3815       ret = addr;
3816     }
3817
3818   // If the last section was a TLS section, align upward to the
3819   // alignment of the TLS segment, so that the overall size of the TLS
3820   // segment is aligned.
3821   if (in_tls)
3822     {
3823       uint64_t segment_align = layout->tls_segment()->maximum_alignment();
3824       *poff = align_address(*poff, segment_align);
3825     }
3826
3827   this->memsz_ = *poff - orig_off;
3828
3829   // Ignore the file offset adjustments made by the BSS Output_data
3830   // objects.
3831   *poff = off;
3832
3833   return ret;
3834 }
3835
3836 // Set the addresses and file offsets in a list of Output_data
3837 // structures.
3838
3839 uint64_t
3840 Output_segment::set_section_list_addresses(const Layout* layout, bool reset,
3841                                            Output_data_list* pdl,
3842                                            uint64_t addr, off_t* poff,
3843                                            unsigned int* pshndx,
3844                                            bool* in_tls)
3845 {
3846   off_t startoff = *poff;
3847
3848   off_t off = startoff;
3849   for (Output_data_list::iterator p = pdl->begin();
3850        p != pdl->end();
3851        ++p)
3852     {
3853       if (reset)
3854         (*p)->reset_address_and_file_offset();
3855
3856       // When using a linker script the section will most likely
3857       // already have an address.
3858       if (!(*p)->is_address_valid())
3859         {
3860           uint64_t align = (*p)->addralign();
3861
3862           if ((*p)->is_section_flag_set(elfcpp::SHF_TLS))
3863             {
3864               // Give the first TLS section the alignment of the
3865               // entire TLS segment.  Otherwise the TLS segment as a
3866               // whole may be misaligned.
3867               if (!*in_tls)
3868                 {
3869                   Output_segment* tls_segment = layout->tls_segment();
3870                   gold_assert(tls_segment != NULL);
3871                   uint64_t segment_align = tls_segment->maximum_alignment();
3872                   gold_assert(segment_align >= align);
3873                   align = segment_align;
3874
3875                   *in_tls = true;
3876                 }
3877             }
3878           else
3879             {
3880               // If this is the first section after the TLS segment,
3881               // align it to at least the alignment of the TLS
3882               // segment, so that the size of the overall TLS segment
3883               // is aligned.
3884               if (*in_tls)
3885                 {
3886                   uint64_t segment_align =
3887                       layout->tls_segment()->maximum_alignment();
3888                   if (segment_align > align)
3889                     align = segment_align;
3890
3891                   *in_tls = false;
3892                 }
3893             }
3894
3895           off = align_address(off, align);
3896           (*p)->set_address_and_file_offset(addr + (off - startoff), off);
3897         }
3898       else
3899         {
3900           // The script may have inserted a skip forward, but it
3901           // better not have moved backward.
3902           if ((*p)->address() >= addr + (off - startoff))
3903             off += (*p)->address() - (addr + (off - startoff));
3904           else
3905             {
3906               if (!layout->script_options()->saw_sections_clause())
3907                 gold_unreachable();
3908               else
3909                 {
3910                   Output_section* os = (*p)->output_section();
3911
3912                   // Cast to unsigned long long to avoid format warnings.
3913                   unsigned long long previous_dot =
3914                     static_cast<unsigned long long>(addr + (off - startoff));
3915                   unsigned long long dot =
3916                     static_cast<unsigned long long>((*p)->address());
3917
3918                   if (os == NULL)
3919                     gold_error(_("dot moves backward in linker script "
3920                                  "from 0x%llx to 0x%llx"), previous_dot, dot);
3921                   else
3922                     gold_error(_("address of section '%s' moves backward "
3923                                  "from 0x%llx to 0x%llx"),
3924                                os->name(), previous_dot, dot);
3925                 }
3926             }
3927           (*p)->set_file_offset(off);
3928           (*p)->finalize_data_size();
3929         }
3930
3931       // We want to ignore the size of a SHF_TLS or SHT_NOBITS
3932       // section.  Such a section does not affect the size of a
3933       // PT_LOAD segment.
3934       if (!(*p)->is_section_flag_set(elfcpp::SHF_TLS)
3935           || !(*p)->is_section_type(elfcpp::SHT_NOBITS))
3936         off += (*p)->data_size();
3937
3938       if ((*p)->is_section())
3939         {
3940           (*p)->set_out_shndx(*pshndx);
3941           ++*pshndx;
3942         }
3943     }
3944
3945   *poff = off;
3946   return addr + (off - startoff);
3947 }
3948
3949 // For a non-PT_LOAD segment, set the offset from the sections, if
3950 // any.  Add INCREASE to the file size and the memory size.
3951
3952 void
3953 Output_segment::set_offset(unsigned int increase)
3954 {
3955   gold_assert(this->type_ != elfcpp::PT_LOAD);
3956
3957   gold_assert(!this->are_addresses_set_);
3958
3959   // A non-load section only uses output_lists_[0].
3960
3961   Output_data_list* pdl = &this->output_lists_[0];
3962
3963   if (pdl->empty())
3964     {
3965       gold_assert(increase == 0);
3966       this->vaddr_ = 0;
3967       this->paddr_ = 0;
3968       this->are_addresses_set_ = true;
3969       this->memsz_ = 0;
3970       this->min_p_align_ = 0;
3971       this->offset_ = 0;
3972       this->filesz_ = 0;
3973       return;
3974     }
3975
3976   // Find the first and last section by address.
3977   const Output_data* first = NULL;
3978   const Output_data* last_data = NULL;
3979   const Output_data* last_bss = NULL;
3980   for (Output_data_list::const_iterator p = pdl->begin();
3981        p != pdl->end();
3982        ++p)
3983     {
3984       if (first == NULL
3985           || (*p)->address() < first->address()
3986           || ((*p)->address() == first->address()
3987               && (*p)->data_size() < first->data_size()))
3988         first = *p;
3989       const Output_data** plast;
3990       if ((*p)->is_section()
3991           && (*p)->output_section()->type() == elfcpp::SHT_NOBITS)
3992         plast = &last_bss;
3993       else
3994         plast = &last_data;
3995       if (*plast == NULL
3996           || (*p)->address() > (*plast)->address()
3997           || ((*p)->address() == (*plast)->address()
3998               && (*p)->data_size() > (*plast)->data_size()))
3999         *plast = *p;
4000     }
4001
4002   this->vaddr_ = first->address();
4003   this->paddr_ = (first->has_load_address()
4004                   ? first->load_address()
4005                   : this->vaddr_);
4006   this->are_addresses_set_ = true;
4007   this->offset_ = first->offset();
4008
4009   if (last_data == NULL)
4010     this->filesz_ = 0;
4011   else
4012     this->filesz_ = (last_data->address()
4013                      + last_data->data_size()
4014                      - this->vaddr_);
4015
4016   const Output_data* last = last_bss != NULL ? last_bss : last_data;
4017   this->memsz_ = (last->address()
4018                   + last->data_size()
4019                   - this->vaddr_);
4020
4021   this->filesz_ += increase;
4022   this->memsz_ += increase;
4023
4024   // If this is a RELRO segment, verify that the segment ends at a
4025   // page boundary.
4026   if (this->type_ == elfcpp::PT_GNU_RELRO)
4027     {
4028       uint64_t page_align = parameters->target().common_pagesize();
4029       uint64_t segment_end = this->vaddr_ + this->memsz_;
4030       gold_assert(segment_end == align_address(segment_end, page_align));
4031     }
4032
4033   // If this is a TLS segment, align the memory size.  The code in
4034   // set_section_list ensures that the section after the TLS segment
4035   // is aligned to give us room.
4036   if (this->type_ == elfcpp::PT_TLS)
4037     {
4038       uint64_t segment_align = this->maximum_alignment();
4039       gold_assert(this->vaddr_ == align_address(this->vaddr_, segment_align));
4040       this->memsz_ = align_address(this->memsz_, segment_align);
4041     }
4042 }
4043
4044 // Set the TLS offsets of the sections in the PT_TLS segment.
4045
4046 void
4047 Output_segment::set_tls_offsets()
4048 {
4049   gold_assert(this->type_ == elfcpp::PT_TLS);
4050
4051   for (Output_data_list::iterator p = this->output_lists_[0].begin();
4052        p != this->output_lists_[0].end();
4053        ++p)
4054     (*p)->set_tls_offset(this->vaddr_);
4055 }
4056
4057 // Return the load address of the first section.
4058
4059 uint64_t
4060 Output_segment::first_section_load_address() const
4061 {
4062   for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
4063     {
4064       const Output_data_list* pdl = &this->output_lists_[i];
4065       for (Output_data_list::const_iterator p = pdl->begin();
4066            p != pdl->end();
4067            ++p)
4068         {
4069           if ((*p)->is_section())
4070             return ((*p)->has_load_address()
4071                     ? (*p)->load_address()
4072                     : (*p)->address());
4073         }
4074     }
4075   gold_unreachable();
4076 }
4077
4078 // Return the number of Output_sections in an Output_segment.
4079
4080 unsigned int
4081 Output_segment::output_section_count() const
4082 {
4083   unsigned int ret = 0;
4084   for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
4085     ret += this->output_section_count_list(&this->output_lists_[i]);
4086   return ret;
4087 }
4088
4089 // Return the number of Output_sections in an Output_data_list.
4090
4091 unsigned int
4092 Output_segment::output_section_count_list(const Output_data_list* pdl) const
4093 {
4094   unsigned int count = 0;
4095   for (Output_data_list::const_iterator p = pdl->begin();
4096        p != pdl->end();
4097        ++p)
4098     {
4099       if ((*p)->is_section())
4100         ++count;
4101     }
4102   return count;
4103 }
4104
4105 // Return the section attached to the list segment with the lowest
4106 // load address.  This is used when handling a PHDRS clause in a
4107 // linker script.
4108
4109 Output_section*
4110 Output_segment::section_with_lowest_load_address() const
4111 {
4112   Output_section* found = NULL;
4113   uint64_t found_lma = 0;
4114   for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
4115     this->lowest_load_address_in_list(&this->output_lists_[i], &found,
4116                                       &found_lma);
4117   return found;
4118 }
4119
4120 // Look through a list for a section with a lower load address.
4121
4122 void
4123 Output_segment::lowest_load_address_in_list(const Output_data_list* pdl,
4124                                             Output_section** found,
4125                                             uint64_t* found_lma) const
4126 {
4127   for (Output_data_list::const_iterator p = pdl->begin();
4128        p != pdl->end();
4129        ++p)
4130     {
4131       if (!(*p)->is_section())
4132         continue;
4133       Output_section* os = static_cast<Output_section*>(*p);
4134       uint64_t lma = (os->has_load_address()
4135                       ? os->load_address()
4136                       : os->address());
4137       if (*found == NULL || lma < *found_lma)
4138         {
4139           *found = os;
4140           *found_lma = lma;
4141         }
4142     }
4143 }
4144
4145 // Write the segment data into *OPHDR.
4146
4147 template<int size, bool big_endian>
4148 void
4149 Output_segment::write_header(elfcpp::Phdr_write<size, big_endian>* ophdr)
4150 {
4151   ophdr->put_p_type(this->type_);
4152   ophdr->put_p_offset(this->offset_);
4153   ophdr->put_p_vaddr(this->vaddr_);
4154   ophdr->put_p_paddr(this->paddr_);
4155   ophdr->put_p_filesz(this->filesz_);
4156   ophdr->put_p_memsz(this->memsz_);
4157   ophdr->put_p_flags(this->flags_);
4158   ophdr->put_p_align(std::max(this->min_p_align_, this->maximum_alignment()));
4159 }
4160
4161 // Write the section headers into V.
4162
4163 template<int size, bool big_endian>
4164 unsigned char*
4165 Output_segment::write_section_headers(const Layout* layout,
4166                                       const Stringpool* secnamepool,
4167                                       unsigned char* v,
4168                                       unsigned int* pshndx) const
4169 {
4170   // Every section that is attached to a segment must be attached to a
4171   // PT_LOAD segment, so we only write out section headers for PT_LOAD
4172   // segments.
4173   if (this->type_ != elfcpp::PT_LOAD)
4174     return v;
4175
4176   for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
4177     {
4178       const Output_data_list* pdl = &this->output_lists_[i];
4179       v = this->write_section_headers_list<size, big_endian>(layout,
4180                                                              secnamepool,
4181                                                              pdl,
4182                                                              v, pshndx);
4183     }
4184
4185   return v;
4186 }
4187
4188 template<int size, bool big_endian>
4189 unsigned char*
4190 Output_segment::write_section_headers_list(const Layout* layout,
4191                                            const Stringpool* secnamepool,
4192                                            const Output_data_list* pdl,
4193                                            unsigned char* v,
4194                                            unsigned int* pshndx) const
4195 {
4196   const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
4197   for (Output_data_list::const_iterator p = pdl->begin();
4198        p != pdl->end();
4199        ++p)
4200     {
4201       if ((*p)->is_section())
4202         {
4203           const Output_section* ps = static_cast<const Output_section*>(*p);
4204           gold_assert(*pshndx == ps->out_shndx());
4205           elfcpp::Shdr_write<size, big_endian> oshdr(v);
4206           ps->write_header(layout, secnamepool, &oshdr);
4207           v += shdr_size;
4208           ++*pshndx;
4209         }
4210     }
4211   return v;
4212 }
4213
4214 // Print the output sections to the map file.
4215
4216 void
4217 Output_segment::print_sections_to_mapfile(Mapfile* mapfile) const
4218 {
4219   if (this->type() != elfcpp::PT_LOAD)
4220     return;
4221   for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
4222     this->print_section_list_to_mapfile(mapfile, &this->output_lists_[i]);
4223 }
4224
4225 // Print an output section list to the map file.
4226
4227 void
4228 Output_segment::print_section_list_to_mapfile(Mapfile* mapfile,
4229                                               const Output_data_list* pdl) const
4230 {
4231   for (Output_data_list::const_iterator p = pdl->begin();
4232        p != pdl->end();
4233        ++p)
4234     (*p)->print_to_mapfile(mapfile);
4235 }
4236
4237 // Output_file methods.
4238
4239 Output_file::Output_file(const char* name)
4240   : name_(name),
4241     o_(-1),
4242     file_size_(0),
4243     base_(NULL),
4244     map_is_anonymous_(false),
4245     is_temporary_(false)
4246 {
4247 }
4248
4249 // Try to open an existing file.  Returns false if the file doesn't
4250 // exist, has a size of 0 or can't be mmapped.
4251
4252 bool
4253 Output_file::open_for_modification()
4254 {
4255   // The name "-" means "stdout".
4256   if (strcmp(this->name_, "-") == 0)
4257     return false;
4258
4259   // Don't bother opening files with a size of zero.
4260   struct stat s;
4261   if (::stat(this->name_, &s) != 0 || s.st_size == 0)
4262     return false;
4263
4264   int o = open_descriptor(-1, this->name_, O_RDWR, 0);
4265   if (o < 0)
4266     gold_fatal(_("%s: open: %s"), this->name_, strerror(errno));
4267   this->o_ = o;
4268   this->file_size_ = s.st_size;
4269
4270   // If the file can't be mmapped, copying the content to an anonymous
4271   // map will probably negate the performance benefits of incremental
4272   // linking.  This could be helped by using views and loading only
4273   // the necessary parts, but this is not supported as of now.
4274   if (!this->map_no_anonymous())
4275     {
4276       release_descriptor(o, true);
4277       this->o_ = -1;
4278       this->file_size_ = 0;
4279       return false;
4280     }
4281
4282   return true;
4283 }
4284
4285 // Open the output file.
4286
4287 void
4288 Output_file::open(off_t file_size)
4289 {
4290   this->file_size_ = file_size;
4291
4292   // Unlink the file first; otherwise the open() may fail if the file
4293   // is busy (e.g. it's an executable that's currently being executed).
4294   //
4295   // However, the linker may be part of a system where a zero-length
4296   // file is created for it to write to, with tight permissions (gcc
4297   // 2.95 did something like this).  Unlinking the file would work
4298   // around those permission controls, so we only unlink if the file
4299   // has a non-zero size.  We also unlink only regular files to avoid
4300   // trouble with directories/etc.
4301   //
4302   // If we fail, continue; this command is merely a best-effort attempt
4303   // to improve the odds for open().
4304
4305   // We let the name "-" mean "stdout"
4306   if (!this->is_temporary_)
4307     {
4308       if (strcmp(this->name_, "-") == 0)
4309         this->o_ = STDOUT_FILENO;
4310       else
4311         {
4312           struct stat s;
4313           if (::stat(this->name_, &s) == 0
4314               && (S_ISREG (s.st_mode) || S_ISLNK (s.st_mode)))
4315             {
4316               if (s.st_size != 0)
4317                 ::unlink(this->name_);
4318               else if (!parameters->options().relocatable())
4319                 {
4320                   // If we don't unlink the existing file, add execute
4321                   // permission where read permissions already exist
4322                   // and where the umask permits.
4323                   int mask = ::umask(0);
4324                   ::umask(mask);
4325                   s.st_mode |= (s.st_mode & 0444) >> 2;
4326                   ::chmod(this->name_, s.st_mode & ~mask);
4327                 }
4328             }
4329
4330           int mode = parameters->options().relocatable() ? 0666 : 0777;
4331           int o = open_descriptor(-1, this->name_, O_RDWR | O_CREAT | O_TRUNC,
4332                                   mode);
4333           if (o < 0)
4334             gold_fatal(_("%s: open: %s"), this->name_, strerror(errno));
4335           this->o_ = o;
4336         }
4337     }
4338
4339   this->map();
4340 }
4341
4342 // Resize the output file.
4343
4344 void
4345 Output_file::resize(off_t file_size)
4346 {
4347   // If the mmap is mapping an anonymous memory buffer, this is easy:
4348   // just mremap to the new size.  If it's mapping to a file, we want
4349   // to unmap to flush to the file, then remap after growing the file.
4350   if (this->map_is_anonymous_)
4351     {
4352       void* base = ::mremap(this->base_, this->file_size_, file_size,
4353                             MREMAP_MAYMOVE);
4354       if (base == MAP_FAILED)
4355         gold_fatal(_("%s: mremap: %s"), this->name_, strerror(errno));
4356       this->base_ = static_cast<unsigned char*>(base);
4357       this->file_size_ = file_size;
4358     }
4359   else
4360     {
4361       this->unmap();
4362       this->file_size_ = file_size;
4363       if (!this->map_no_anonymous())
4364         gold_fatal(_("%s: mmap: %s"), this->name_, strerror(errno));
4365     }
4366 }
4367
4368 // Map an anonymous block of memory which will later be written to the
4369 // file.  Return whether the map succeeded.
4370
4371 bool
4372 Output_file::map_anonymous()
4373 {
4374   void* base = ::mmap(NULL, this->file_size_, PROT_READ | PROT_WRITE,
4375                       MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
4376   if (base != MAP_FAILED)
4377     {
4378       this->map_is_anonymous_ = true;
4379       this->base_ = static_cast<unsigned char*>(base);
4380       return true;
4381     }
4382   return false;
4383 }
4384
4385 // Map the file into memory.  Return whether the mapping succeeded.
4386
4387 bool
4388 Output_file::map_no_anonymous()
4389 {
4390   const int o = this->o_;
4391
4392   // If the output file is not a regular file, don't try to mmap it;
4393   // instead, we'll mmap a block of memory (an anonymous buffer), and
4394   // then later write the buffer to the file.
4395   void* base;
4396   struct stat statbuf;
4397   if (o == STDOUT_FILENO || o == STDERR_FILENO
4398       || ::fstat(o, &statbuf) != 0
4399       || !S_ISREG(statbuf.st_mode)
4400       || this->is_temporary_)
4401     return false;
4402
4403   // Ensure that we have disk space available for the file.  If we
4404   // don't do this, it is possible that we will call munmap, close,
4405   // and exit with dirty buffers still in the cache with no assigned
4406   // disk blocks.  If the disk is out of space at that point, the
4407   // output file will wind up incomplete, but we will have already
4408   // exited.  The alternative to fallocate would be to use fdatasync,
4409   // but that would be a more significant performance hit.
4410   if (::posix_fallocate(o, 0, this->file_size_) < 0)
4411     gold_fatal(_("%s: %s"), this->name_, strerror(errno));
4412
4413   // Map the file into memory.
4414   base = ::mmap(NULL, this->file_size_, PROT_READ | PROT_WRITE,
4415                 MAP_SHARED, o, 0);
4416
4417   // The mmap call might fail because of file system issues: the file
4418   // system might not support mmap at all, or it might not support