* Makefile.am: Remove spurious sanitization marker.
[binutils.git] / gold / output.cc
blob29dad2b60e49aa88ffd10f471d56cb7d2e527f7d
1 // output.cc -- manage the output file for gold
3 // Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
6 // This file is part of gold.
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.
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.
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.
23 #include "gold.h"
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"
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"
43 // Some BSD systems still use MAP_ANON instead of MAP_ANONYMOUS
44 #ifndef MAP_ANONYMOUS
45 # define MAP_ANONYMOUS MAP_ANON
46 #endif
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)
56 return ftruncate(o, offset + len);
58 #endif // !defined(HAVE_POSIX_FALLOCATE)
60 namespace gold
63 // Output_data variables.
65 bool Output_data::allocated_sizes_are_fixed;
67 // Output_data methods.
69 Output_data::~Output_data()
73 // Return the default alignment for the target size.
75 uint64_t
76 Output_data::default_alignment()
78 return Output_data::default_alignment_for_size(
79 parameters->target().get_size());
82 // Return the default alignment for a size--32 or 64.
84 uint64_t
85 Output_data::default_alignment_for_size(int size)
87 if (size == 32)
88 return 4;
89 else if (size == 64)
90 return 8;
91 else
92 gold_unreachable();
95 // Output_section_header methods. This currently assumes that the
96 // segment and section lists are complete at construction time.
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)
114 // Compute the current data size.
116 off_t
117 Output_section_headers::do_size() const
119 // Count all the sections. Start with 1 for the null section.
120 off_t count = 1;
121 if (!parameters->options().relocatable())
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();
130 else
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;
139 count += this->unattached_section_list_->size();
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();
150 return count * shdr_size;
153 // Write out the section headers.
155 void
156 Output_section_headers::do_write(Output_file* of)
158 switch (parameters->size_and_endianness())
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();
185 template<int size, bool big_endian>
186 void
187 Output_section_headers::do_sized_write(Output_file* of)
189 off_t all_shdrs_size = this->data_size();
190 unsigned char* view = of->get_output_view(this->offset(), all_shdrs_size);
192 const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
193 unsigned char* v = view;
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);
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);
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);
216 oshdr.put_sh_info(0);
217 oshdr.put_sh_addralign(0);
218 oshdr.put_sh_entsize(0);
221 v += shdr_size;
223 unsigned int shndx = 1;
224 if (!parameters->options().relocatable())
226 for (Layout::Segment_list::const_iterator p =
227 this->segment_list_->begin();
228 p != this->segment_list_->end();
229 ++p)
230 v = (*p)->write_section_headers<size, big_endian>(this->layout_,
231 this->secnamepool_,
233 &shndx);
235 else
237 for (Layout::Section_list::const_iterator p =
238 this->section_list_->begin();
239 p != this->section_list_->end();
240 ++p)
242 // We do unallocated sections below, except that group
243 // sections have to come first.
244 if (((*p)->flags() & elfcpp::SHF_ALLOC) == 0
245 && (*p)->type() != elfcpp::SHT_GROUP)
246 continue;
247 gold_assert(shndx == (*p)->out_shndx());
248 elfcpp::Shdr_write<size, big_endian> oshdr(v);
249 (*p)->write_header(this->layout_, this->secnamepool_, &oshdr);
250 v += shdr_size;
251 ++shndx;
255 for (Layout::Section_list::const_iterator p =
256 this->unattached_section_list_->begin();
257 p != this->unattached_section_list_->end();
258 ++p)
260 // For a relocatable link, we did unallocated group sections
261 // above, since they have to come first.
262 if ((*p)->type() == elfcpp::SHT_GROUP
263 && parameters->options().relocatable())
264 continue;
265 gold_assert(shndx == (*p)->out_shndx());
266 elfcpp::Shdr_write<size, big_endian> oshdr(v);
267 (*p)->write_header(this->layout_, this->secnamepool_, &oshdr);
268 v += shdr_size;
269 ++shndx;
272 of->write_output_view(this->offset(), all_shdrs_size, view);
275 // Output_segment_header methods.
277 Output_segment_headers::Output_segment_headers(
278 const Layout::Segment_list& segment_list)
279 : segment_list_(segment_list)
283 void
284 Output_segment_headers::do_write(Output_file* of)
286 switch (parameters->size_and_endianness())
288 #ifdef HAVE_TARGET_32_LITTLE
289 case Parameters::TARGET_32_LITTLE:
290 this->do_sized_write<32, false>(of);
291 break;
292 #endif
293 #ifdef HAVE_TARGET_32_BIG
294 case Parameters::TARGET_32_BIG:
295 this->do_sized_write<32, true>(of);
296 break;
297 #endif
298 #ifdef HAVE_TARGET_64_LITTLE
299 case Parameters::TARGET_64_LITTLE:
300 this->do_sized_write<64, false>(of);
301 break;
302 #endif
303 #ifdef HAVE_TARGET_64_BIG
304 case Parameters::TARGET_64_BIG:
305 this->do_sized_write<64, true>(of);
306 break;
307 #endif
308 default:
309 gold_unreachable();
313 template<int size, bool big_endian>
314 void
315 Output_segment_headers::do_sized_write(Output_file* of)
317 const int phdr_size = elfcpp::Elf_sizes<size>::phdr_size;
318 off_t all_phdrs_size = this->segment_list_.size() * phdr_size;
319 gold_assert(all_phdrs_size == this->data_size());
320 unsigned char* view = of->get_output_view(this->offset(),
321 all_phdrs_size);
322 unsigned char* v = view;
323 for (Layout::Segment_list::const_iterator p = this->segment_list_.begin();
324 p != this->segment_list_.end();
325 ++p)
327 elfcpp::Phdr_write<size, big_endian> ophdr(v);
328 (*p)->write_header(&ophdr);
329 v += phdr_size;
332 gold_assert(v - view == all_phdrs_size);
334 of->write_output_view(this->offset(), all_phdrs_size, view);
337 off_t
338 Output_segment_headers::do_size() const
340 const int size = parameters->target().get_size();
341 int phdr_size;
342 if (size == 32)
343 phdr_size = elfcpp::Elf_sizes<32>::phdr_size;
344 else if (size == 64)
345 phdr_size = elfcpp::Elf_sizes<64>::phdr_size;
346 else
347 gold_unreachable();
349 return this->segment_list_.size() * phdr_size;
352 // Output_file_header methods.
354 Output_file_header::Output_file_header(const Target* target,
355 const Symbol_table* symtab,
356 const Output_segment_headers* osh,
357 const char* entry)
358 : target_(target),
359 symtab_(symtab),
360 segment_header_(osh),
361 section_header_(NULL),
362 shstrtab_(NULL),
363 entry_(entry)
365 this->set_data_size(this->do_size());
368 // Set the section table information for a file header.
370 void
371 Output_file_header::set_section_info(const Output_section_headers* shdrs,
372 const Output_section* shstrtab)
374 this->section_header_ = shdrs;
375 this->shstrtab_ = shstrtab;
378 // Write out the file header.
380 void
381 Output_file_header::do_write(Output_file* of)
383 gold_assert(this->offset() == 0);
385 switch (parameters->size_and_endianness())
387 #ifdef HAVE_TARGET_32_LITTLE
388 case Parameters::TARGET_32_LITTLE:
389 this->do_sized_write<32, false>(of);
390 break;
391 #endif
392 #ifdef HAVE_TARGET_32_BIG
393 case Parameters::TARGET_32_BIG:
394 this->do_sized_write<32, true>(of);
395 break;
396 #endif
397 #ifdef HAVE_TARGET_64_LITTLE
398 case Parameters::TARGET_64_LITTLE:
399 this->do_sized_write<64, false>(of);
400 break;
401 #endif
402 #ifdef HAVE_TARGET_64_BIG
403 case Parameters::TARGET_64_BIG:
404 this->do_sized_write<64, true>(of);
405 break;
406 #endif
407 default:
408 gold_unreachable();
412 // Write out the file header with appropriate size and endianess.
414 template<int size, bool big_endian>
415 void
416 Output_file_header::do_sized_write(Output_file* of)
418 gold_assert(this->offset() == 0);
420 int ehdr_size = elfcpp::Elf_sizes<size>::ehdr_size;
421 unsigned char* view = of->get_output_view(0, ehdr_size);
422 elfcpp::Ehdr_write<size, big_endian> oehdr(view);
424 unsigned char e_ident[elfcpp::EI_NIDENT];
425 memset(e_ident, 0, elfcpp::EI_NIDENT);
426 e_ident[elfcpp::EI_MAG0] = elfcpp::ELFMAG0;
427 e_ident[elfcpp::EI_MAG1] = elfcpp::ELFMAG1;
428 e_ident[elfcpp::EI_MAG2] = elfcpp::ELFMAG2;
429 e_ident[elfcpp::EI_MAG3] = elfcpp::ELFMAG3;
430 if (size == 32)
431 e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS32;
432 else if (size == 64)
433 e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS64;
434 else
435 gold_unreachable();
436 e_ident[elfcpp::EI_DATA] = (big_endian
437 ? elfcpp::ELFDATA2MSB
438 : elfcpp::ELFDATA2LSB);
439 e_ident[elfcpp::EI_VERSION] = elfcpp::EV_CURRENT;
440 oehdr.put_e_ident(e_ident);
442 elfcpp::ET e_type;
443 if (parameters->options().relocatable())
444 e_type = elfcpp::ET_REL;
445 else if (parameters->options().output_is_position_independent())
446 e_type = elfcpp::ET_DYN;
447 else
448 e_type = elfcpp::ET_EXEC;
449 oehdr.put_e_type(e_type);
451 oehdr.put_e_machine(this->target_->machine_code());
452 oehdr.put_e_version(elfcpp::EV_CURRENT);
454 oehdr.put_e_entry(this->entry<size>());
456 if (this->segment_header_ == NULL)
457 oehdr.put_e_phoff(0);
458 else
459 oehdr.put_e_phoff(this->segment_header_->offset());
461 oehdr.put_e_shoff(this->section_header_->offset());
463 // FIXME: The target needs to set the flags.
464 oehdr.put_e_flags(0);
466 oehdr.put_e_ehsize(elfcpp::Elf_sizes<size>::ehdr_size);
468 if (this->segment_header_ == NULL)
470 oehdr.put_e_phentsize(0);
471 oehdr.put_e_phnum(0);
473 else
475 oehdr.put_e_phentsize(elfcpp::Elf_sizes<size>::phdr_size);
476 oehdr.put_e_phnum(this->segment_header_->data_size()
477 / elfcpp::Elf_sizes<size>::phdr_size);
480 oehdr.put_e_shentsize(elfcpp::Elf_sizes<size>::shdr_size);
481 size_t section_count = (this->section_header_->data_size()
482 / elfcpp::Elf_sizes<size>::shdr_size);
484 if (section_count < elfcpp::SHN_LORESERVE)
485 oehdr.put_e_shnum(this->section_header_->data_size()
486 / elfcpp::Elf_sizes<size>::shdr_size);
487 else
488 oehdr.put_e_shnum(0);
490 unsigned int shstrndx = this->shstrtab_->out_shndx();
491 if (shstrndx < elfcpp::SHN_LORESERVE)
492 oehdr.put_e_shstrndx(this->shstrtab_->out_shndx());
493 else
494 oehdr.put_e_shstrndx(elfcpp::SHN_XINDEX);
496 // Let the target adjust the ELF header, e.g., to set EI_OSABI in
497 // the e_ident field.
498 parameters->target().adjust_elf_header(view, ehdr_size);
500 of->write_output_view(0, ehdr_size, view);
503 // Return the value to use for the entry address. THIS->ENTRY_ is the
504 // symbol specified on the command line, if any.
506 template<int size>
507 typename elfcpp::Elf_types<size>::Elf_Addr
508 Output_file_header::entry()
510 const bool should_issue_warning = (this->entry_ != NULL
511 && !parameters->options().relocatable()
512 && !parameters->options().shared());
514 // FIXME: Need to support target specific entry symbol.
515 const char* entry = this->entry_;
516 if (entry == NULL)
517 entry = "_start";
519 Symbol* sym = this->symtab_->lookup(entry);
521 typename Sized_symbol<size>::Value_type v;
522 if (sym != NULL)
524 Sized_symbol<size>* ssym;
525 ssym = this->symtab_->get_sized_symbol<size>(sym);
526 if (!ssym->is_defined() && should_issue_warning)
527 gold_warning("entry symbol '%s' exists but is not defined", entry);
528 v = ssym->value();
530 else
532 // We couldn't find the entry symbol. See if we can parse it as
533 // a number. This supports, e.g., -e 0x1000.
534 char* endptr;
535 v = strtoull(entry, &endptr, 0);
536 if (*endptr != '\0')
538 if (should_issue_warning)
539 gold_warning("cannot find entry symbol '%s'", entry);
540 v = 0;
544 return v;
547 // Compute the current data size.
549 off_t
550 Output_file_header::do_size() const
552 const int size = parameters->target().get_size();
553 if (size == 32)
554 return elfcpp::Elf_sizes<32>::ehdr_size;
555 else if (size == 64)
556 return elfcpp::Elf_sizes<64>::ehdr_size;
557 else
558 gold_unreachable();
561 // Output_data_const methods.
563 void
564 Output_data_const::do_write(Output_file* of)
566 of->write(this->offset(), this->data_.data(), this->data_.size());
569 // Output_data_const_buffer methods.
571 void
572 Output_data_const_buffer::do_write(Output_file* of)
574 of->write(this->offset(), this->p_, this->data_size());
577 // Output_section_data methods.
579 // Record the output section, and set the entry size and such.
581 void
582 Output_section_data::set_output_section(Output_section* os)
584 gold_assert(this->output_section_ == NULL);
585 this->output_section_ = os;
586 this->do_adjust_output_section(os);
589 // Return the section index of the output section.
591 unsigned int
592 Output_section_data::do_out_shndx() const
594 gold_assert(this->output_section_ != NULL);
595 return this->output_section_->out_shndx();
598 // Set the alignment, which means we may need to update the alignment
599 // of the output section.
601 void
602 Output_section_data::set_addralign(uint64_t addralign)
604 this->addralign_ = addralign;
605 if (this->output_section_ != NULL
606 && this->output_section_->addralign() < addralign)
607 this->output_section_->set_addralign(addralign);
610 // Output_data_strtab methods.
612 // Set the final data size.
614 void
615 Output_data_strtab::set_final_data_size()
617 this->strtab_->set_string_offsets();
618 this->set_data_size(this->strtab_->get_strtab_size());
621 // Write out a string table.
623 void
624 Output_data_strtab::do_write(Output_file* of)
626 this->strtab_->write(of, this->offset());
629 // Output_reloc methods.
631 // A reloc against a global symbol.
633 template<bool dynamic, int size, bool big_endian>
634 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
635 Symbol* gsym,
636 unsigned int type,
637 Output_data* od,
638 Address address,
639 bool is_relative)
640 : address_(address), local_sym_index_(GSYM_CODE), type_(type),
641 is_relative_(is_relative), is_section_symbol_(false), shndx_(INVALID_CODE)
643 // this->type_ is a bitfield; make sure TYPE fits.
644 gold_assert(this->type_ == type);
645 this->u1_.gsym = gsym;
646 this->u2_.od = od;
647 if (dynamic)
648 this->set_needs_dynsym_index();
651 template<bool dynamic, int size, bool big_endian>
652 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
653 Symbol* gsym,
654 unsigned int type,
655 Sized_relobj<size, big_endian>* relobj,
656 unsigned int shndx,
657 Address address,
658 bool is_relative)
659 : address_(address), local_sym_index_(GSYM_CODE), type_(type),
660 is_relative_(is_relative), is_section_symbol_(false), shndx_(shndx)
662 gold_assert(shndx != INVALID_CODE);
663 // this->type_ is a bitfield; make sure TYPE fits.
664 gold_assert(this->type_ == type);
665 this->u1_.gsym = gsym;
666 this->u2_.relobj = relobj;
667 if (dynamic)
668 this->set_needs_dynsym_index();
671 // A reloc against a local symbol.
673 template<bool dynamic, int size, bool big_endian>
674 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
675 Sized_relobj<size, big_endian>* relobj,
676 unsigned int local_sym_index,
677 unsigned int type,
678 Output_data* od,
679 Address address,
680 bool is_relative,
681 bool is_section_symbol)
682 : address_(address), local_sym_index_(local_sym_index), type_(type),
683 is_relative_(is_relative), is_section_symbol_(is_section_symbol),
684 shndx_(INVALID_CODE)
686 gold_assert(local_sym_index != GSYM_CODE
687 && local_sym_index != INVALID_CODE);
688 // this->type_ is a bitfield; make sure TYPE fits.
689 gold_assert(this->type_ == type);
690 this->u1_.relobj = relobj;
691 this->u2_.od = od;
692 if (dynamic)
693 this->set_needs_dynsym_index();
696 template<bool dynamic, int size, bool big_endian>
697 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
698 Sized_relobj<size, big_endian>* relobj,
699 unsigned int local_sym_index,
700 unsigned int type,
701 unsigned int shndx,
702 Address address,
703 bool is_relative,
704 bool is_section_symbol)
705 : address_(address), local_sym_index_(local_sym_index), type_(type),
706 is_relative_(is_relative), is_section_symbol_(is_section_symbol),
707 shndx_(shndx)
709 gold_assert(local_sym_index != GSYM_CODE
710 && local_sym_index != INVALID_CODE);
711 gold_assert(shndx != INVALID_CODE);
712 // this->type_ is a bitfield; make sure TYPE fits.
713 gold_assert(this->type_ == type);
714 this->u1_.relobj = relobj;
715 this->u2_.relobj = relobj;
716 if (dynamic)
717 this->set_needs_dynsym_index();
720 // A reloc against the STT_SECTION symbol of an output section.
722 template<bool dynamic, int size, bool big_endian>
723 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
724 Output_section* os,
725 unsigned int type,
726 Output_data* od,
727 Address address)
728 : address_(address), local_sym_index_(SECTION_CODE), type_(type),
729 is_relative_(false), is_section_symbol_(true), shndx_(INVALID_CODE)
731 // this->type_ is a bitfield; make sure TYPE fits.
732 gold_assert(this->type_ == type);
733 this->u1_.os = os;
734 this->u2_.od = od;
735 if (dynamic)
736 this->set_needs_dynsym_index();
737 else
738 os->set_needs_symtab_index();
741 template<bool dynamic, int size, bool big_endian>
742 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
743 Output_section* os,
744 unsigned int type,
745 Sized_relobj<size, big_endian>* relobj,
746 unsigned int shndx,
747 Address address)
748 : address_(address), local_sym_index_(SECTION_CODE), type_(type),
749 is_relative_(false), is_section_symbol_(true), shndx_(shndx)
751 gold_assert(shndx != INVALID_CODE);
752 // this->type_ is a bitfield; make sure TYPE fits.
753 gold_assert(this->type_ == type);
754 this->u1_.os = os;
755 this->u2_.relobj = relobj;
756 if (dynamic)
757 this->set_needs_dynsym_index();
758 else
759 os->set_needs_symtab_index();
762 // Record that we need a dynamic symbol index for this relocation.
764 template<bool dynamic, int size, bool big_endian>
765 void
766 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::
767 set_needs_dynsym_index()
769 if (this->is_relative_)
770 return;
771 switch (this->local_sym_index_)
773 case INVALID_CODE:
774 gold_unreachable();
776 case GSYM_CODE:
777 this->u1_.gsym->set_needs_dynsym_entry();
778 break;
780 case SECTION_CODE:
781 this->u1_.os->set_needs_dynsym_index();
782 break;
784 case 0:
785 break;
787 default:
789 const unsigned int lsi = this->local_sym_index_;
790 if (!this->is_section_symbol_)
791 this->u1_.relobj->set_needs_output_dynsym_entry(lsi);
792 else
793 this->u1_.relobj->output_section(lsi)->set_needs_dynsym_index();
795 break;
799 // Get the symbol index of a relocation.
801 template<bool dynamic, int size, bool big_endian>
802 unsigned int
803 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::get_symbol_index()
804 const
806 unsigned int index;
807 switch (this->local_sym_index_)
809 case INVALID_CODE:
810 gold_unreachable();
812 case GSYM_CODE:
813 if (this->u1_.gsym == NULL)
814 index = 0;
815 else if (dynamic)
816 index = this->u1_.gsym->dynsym_index();
817 else
818 index = this->u1_.gsym->symtab_index();
819 break;
821 case SECTION_CODE:
822 if (dynamic)
823 index = this->u1_.os->dynsym_index();
824 else
825 index = this->u1_.os->symtab_index();
826 break;
828 case 0:
829 // Relocations without symbols use a symbol index of 0.
830 index = 0;
831 break;
833 default:
835 const unsigned int lsi = this->local_sym_index_;
836 if (!this->is_section_symbol_)
838 if (dynamic)
839 index = this->u1_.relobj->dynsym_index(lsi);
840 else
841 index = this->u1_.relobj->symtab_index(lsi);
843 else
845 Output_section* os = this->u1_.relobj->output_section(lsi);
846 gold_assert(os != NULL);
847 if (dynamic)
848 index = os->dynsym_index();
849 else
850 index = os->symtab_index();
853 break;
855 gold_assert(index != -1U);
856 return index;
859 // For a local section symbol, get the address of the offset ADDEND
860 // within the input section.
862 template<bool dynamic, int size, bool big_endian>
863 typename elfcpp::Elf_types<size>::Elf_Addr
864 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::
865 local_section_offset(Addend addend) const
867 gold_assert(this->local_sym_index_ != GSYM_CODE
868 && this->local_sym_index_ != SECTION_CODE
869 && this->local_sym_index_ != INVALID_CODE
870 && this->is_section_symbol_);
871 const unsigned int lsi = this->local_sym_index_;
872 Output_section* os = this->u1_.relobj->output_section(lsi);
873 gold_assert(os != NULL);
874 Address offset = this->u1_.relobj->get_output_section_offset(lsi);
875 if (offset != invalid_address)
876 return offset + addend;
877 // This is a merge section.
878 offset = os->output_address(this->u1_.relobj, lsi, addend);
879 gold_assert(offset != invalid_address);
880 return offset;
883 // Get the output address of a relocation.
885 template<bool dynamic, int size, bool big_endian>
886 typename elfcpp::Elf_types<size>::Elf_Addr
887 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::get_address() const
889 Address address = this->address_;
890 if (this->shndx_ != INVALID_CODE)
892 Output_section* os = this->u2_.relobj->output_section(this->shndx_);
893 gold_assert(os != NULL);
894 Address off = this->u2_.relobj->get_output_section_offset(this->shndx_);
895 if (off != invalid_address)
896 address += os->address() + off;
897 else
899 address = os->output_address(this->u2_.relobj, this->shndx_,
900 address);
901 gold_assert(address != invalid_address);
904 else if (this->u2_.od != NULL)
905 address += this->u2_.od->address();
906 return address;
909 // Write out the offset and info fields of a Rel or Rela relocation
910 // entry.
912 template<bool dynamic, int size, bool big_endian>
913 template<typename Write_rel>
914 void
915 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::write_rel(
916 Write_rel* wr) const
918 wr->put_r_offset(this->get_address());
919 unsigned int sym_index = this->is_relative_ ? 0 : this->get_symbol_index();
920 wr->put_r_info(elfcpp::elf_r_info<size>(sym_index, this->type_));
923 // Write out a Rel relocation.
925 template<bool dynamic, int size, bool big_endian>
926 void
927 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::write(
928 unsigned char* pov) const
930 elfcpp::Rel_write<size, big_endian> orel(pov);
931 this->write_rel(&orel);
934 // Get the value of the symbol referred to by a Rel relocation.
936 template<bool dynamic, int size, bool big_endian>
937 typename elfcpp::Elf_types<size>::Elf_Addr
938 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::symbol_value(
939 Addend addend) const
941 if (this->local_sym_index_ == GSYM_CODE)
943 const Sized_symbol<size>* sym;
944 sym = static_cast<const Sized_symbol<size>*>(this->u1_.gsym);
945 return sym->value() + addend;
947 gold_assert(this->local_sym_index_ != SECTION_CODE
948 && this->local_sym_index_ != INVALID_CODE
949 && !this->is_section_symbol_);
950 const unsigned int lsi = this->local_sym_index_;
951 const Symbol_value<size>* symval = this->u1_.relobj->local_symbol(lsi);
952 return symval->value(this->u1_.relobj, addend);
955 // Reloc comparison. This function sorts the dynamic relocs for the
956 // benefit of the dynamic linker. First we sort all relative relocs
957 // to the front. Among relative relocs, we sort by output address.
958 // Among non-relative relocs, we sort by symbol index, then by output
959 // address.
961 template<bool dynamic, int size, bool big_endian>
963 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::
964 compare(const Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>& r2)
965 const
967 if (this->is_relative_)
969 if (!r2.is_relative_)
970 return -1;
971 // Otherwise sort by reloc address below.
973 else if (r2.is_relative_)
974 return 1;
975 else
977 unsigned int sym1 = this->get_symbol_index();
978 unsigned int sym2 = r2.get_symbol_index();
979 if (sym1 < sym2)
980 return -1;
981 else if (sym1 > sym2)
982 return 1;
983 // Otherwise sort by reloc address.
986 section_offset_type addr1 = this->get_address();
987 section_offset_type addr2 = r2.get_address();
988 if (addr1 < addr2)
989 return -1;
990 else if (addr1 > addr2)
991 return 1;
993 // Final tie breaker, in order to generate the same output on any
994 // host: reloc type.
995 unsigned int type1 = this->type_;
996 unsigned int type2 = r2.type_;
997 if (type1 < type2)
998 return -1;
999 else if (type1 > type2)
1000 return 1;
1002 // These relocs appear to be exactly the same.
1003 return 0;
1006 // Write out a Rela relocation.
1008 template<bool dynamic, int size, bool big_endian>
1009 void
1010 Output_reloc<elfcpp::SHT_RELA, dynamic, size, big_endian>::write(
1011 unsigned char* pov) const
1013 elfcpp::Rela_write<size, big_endian> orel(pov);
1014 this->rel_.write_rel(&orel);
1015 Addend addend = this->addend_;
1016 if (this->rel_.is_relative())
1017 addend = this->rel_.symbol_value(addend);
1018 else if (this->rel_.is_local_section_symbol())
1019 addend = this->rel_.local_section_offset(addend);
1020 orel.put_r_addend(addend);
1023 // Output_data_reloc_base methods.
1025 // Adjust the output section.
1027 template<int sh_type, bool dynamic, int size, bool big_endian>
1028 void
1029 Output_data_reloc_base<sh_type, dynamic, size, big_endian>
1030 ::do_adjust_output_section(Output_section* os)
1032 if (sh_type == elfcpp::SHT_REL)
1033 os->set_entsize(elfcpp::Elf_sizes<size>::rel_size);
1034 else if (sh_type == elfcpp::SHT_RELA)
1035 os->set_entsize(elfcpp::Elf_sizes<size>::rela_size);
1036 else
1037 gold_unreachable();
1038 if (dynamic)
1039 os->set_should_link_to_dynsym();
1040 else
1041 os->set_should_link_to_symtab();
1044 // Write out relocation data.
1046 template<int sh_type, bool dynamic, int size, bool big_endian>
1047 void
1048 Output_data_reloc_base<sh_type, dynamic, size, big_endian>::do_write(
1049 Output_file* of)
1051 const off_t off = this->offset();
1052 const off_t oview_size = this->data_size();
1053 unsigned char* const oview = of->get_output_view(off, oview_size);
1055 if (this->sort_relocs_)
1057 gold_assert(dynamic);
1058 std::sort(this->relocs_.begin(), this->relocs_.end(),
1059 Sort_relocs_comparison());
1062 unsigned char* pov = oview;
1063 for (typename Relocs::const_iterator p = this->relocs_.begin();
1064 p != this->relocs_.end();
1065 ++p)
1067 p->write(pov);
1068 pov += reloc_size;
1071 gold_assert(pov - oview == oview_size);
1073 of->write_output_view(off, oview_size, oview);
1075 // We no longer need the relocation entries.
1076 this->relocs_.clear();
1079 // Class Output_relocatable_relocs.
1081 template<int sh_type, int size, bool big_endian>
1082 void
1083 Output_relocatable_relocs<sh_type, size, big_endian>::set_final_data_size()
1085 this->set_data_size(this->rr_->output_reloc_count()
1086 * Reloc_types<sh_type, size, big_endian>::reloc_size);
1089 // class Output_data_group.
1091 template<int size, bool big_endian>
1092 Output_data_group<size, big_endian>::Output_data_group(
1093 Sized_relobj<size, big_endian>* relobj,
1094 section_size_type entry_count,
1095 elfcpp::Elf_Word flags,
1096 std::vector<unsigned int>* input_shndxes)
1097 : Output_section_data(entry_count * 4, 4, false),
1098 relobj_(relobj),
1099 flags_(flags)
1101 this->input_shndxes_.swap(*input_shndxes);
1104 // Write out the section group, which means translating the section
1105 // indexes to apply to the output file.
1107 template<int size, bool big_endian>
1108 void
1109 Output_data_group<size, big_endian>::do_write(Output_file* of)
1111 const off_t off = this->offset();
1112 const section_size_type oview_size =
1113 convert_to_section_size_type(this->data_size());
1114 unsigned char* const oview = of->get_output_view(off, oview_size);
1116 elfcpp::Elf_Word* contents = reinterpret_cast<elfcpp::Elf_Word*>(oview);
1117 elfcpp::Swap<32, big_endian>::writeval(contents, this->flags_);
1118 ++contents;
1120 for (std::vector<unsigned int>::const_iterator p =
1121 this->input_shndxes_.begin();
1122 p != this->input_shndxes_.end();
1123 ++p, ++contents)
1125 Output_section* os = this->relobj_->output_section(*p);
1127 unsigned int output_shndx;
1128 if (os != NULL)
1129 output_shndx = os->out_shndx();
1130 else
1132 this->relobj_->error(_("section group retained but "
1133 "group element discarded"));
1134 output_shndx = 0;
1137 elfcpp::Swap<32, big_endian>::writeval(contents, output_shndx);
1140 size_t wrote = reinterpret_cast<unsigned char*>(contents) - oview;
1141 gold_assert(wrote == oview_size);
1143 of->write_output_view(off, oview_size, oview);
1145 // We no longer need this information.
1146 this->input_shndxes_.clear();
1149 // Output_data_got::Got_entry methods.
1151 // Write out the entry.
1153 template<int size, bool big_endian>
1154 void
1155 Output_data_got<size, big_endian>::Got_entry::write(unsigned char* pov) const
1157 Valtype val = 0;
1159 switch (this->local_sym_index_)
1161 case GSYM_CODE:
1163 // If the symbol is resolved locally, we need to write out the
1164 // link-time value, which will be relocated dynamically by a
1165 // RELATIVE relocation.
1166 Symbol* gsym = this->u_.gsym;
1167 Sized_symbol<size>* sgsym;
1168 // This cast is a bit ugly. We don't want to put a
1169 // virtual method in Symbol, because we want Symbol to be
1170 // as small as possible.
1171 sgsym = static_cast<Sized_symbol<size>*>(gsym);
1172 val = sgsym->value();
1174 break;
1176 case CONSTANT_CODE:
1177 val = this->u_.constant;
1178 break;
1180 default:
1182 const unsigned int lsi = this->local_sym_index_;
1183 const Symbol_value<size>* symval = this->u_.object->local_symbol(lsi);
1184 val = symval->value(this->u_.object, 0);
1186 break;
1189 elfcpp::Swap<size, big_endian>::writeval(pov, val);
1192 // Output_data_got methods.
1194 // Add an entry for a global symbol to the GOT. This returns true if
1195 // this is a new GOT entry, false if the symbol already had a GOT
1196 // entry.
1198 template<int size, bool big_endian>
1199 bool
1200 Output_data_got<size, big_endian>::add_global(
1201 Symbol* gsym,
1202 unsigned int got_type)
1204 if (gsym->has_got_offset(got_type))
1205 return false;
1207 this->entries_.push_back(Got_entry(gsym));
1208 this->set_got_size();
1209 gsym->set_got_offset(got_type, this->last_got_offset());
1210 return true;
1213 // Add an entry for a global symbol to the GOT, and add a dynamic
1214 // relocation of type R_TYPE for the GOT entry.
1215 template<int size, bool big_endian>
1216 void
1217 Output_data_got<size, big_endian>::add_global_with_rel(
1218 Symbol* gsym,
1219 unsigned int got_type,
1220 Rel_dyn* rel_dyn,
1221 unsigned int r_type)
1223 if (gsym->has_got_offset(got_type))
1224 return;
1226 this->entries_.push_back(Got_entry());
1227 this->set_got_size();
1228 unsigned int got_offset = this->last_got_offset();
1229 gsym->set_got_offset(got_type, got_offset);
1230 rel_dyn->add_global(gsym, r_type, this, got_offset);
1233 template<int size, bool big_endian>
1234 void
1235 Output_data_got<size, big_endian>::add_global_with_rela(
1236 Symbol* gsym,
1237 unsigned int got_type,
1238 Rela_dyn* rela_dyn,
1239 unsigned int r_type)
1241 if (gsym->has_got_offset(got_type))
1242 return;
1244 this->entries_.push_back(Got_entry());
1245 this->set_got_size();
1246 unsigned int got_offset = this->last_got_offset();
1247 gsym->set_got_offset(got_type, got_offset);
1248 rela_dyn->add_global(gsym, r_type, this, got_offset, 0);
1251 // Add a pair of entries for a global symbol to the GOT, and add
1252 // dynamic relocations of type R_TYPE_1 and R_TYPE_2, respectively.
1253 // If R_TYPE_2 == 0, add the second entry with no relocation.
1254 template<int size, bool big_endian>
1255 void
1256 Output_data_got<size, big_endian>::add_global_pair_with_rel(
1257 Symbol* gsym,
1258 unsigned int got_type,
1259 Rel_dyn* rel_dyn,
1260 unsigned int r_type_1,
1261 unsigned int r_type_2)
1263 if (gsym->has_got_offset(got_type))
1264 return;
1266 this->entries_.push_back(Got_entry());
1267 unsigned int got_offset = this->last_got_offset();
1268 gsym->set_got_offset(got_type, got_offset);
1269 rel_dyn->add_global(gsym, r_type_1, this, got_offset);
1271 this->entries_.push_back(Got_entry());
1272 if (r_type_2 != 0)
1274 got_offset = this->last_got_offset();
1275 rel_dyn->add_global(gsym, r_type_2, this, got_offset);
1278 this->set_got_size();
1281 template<int size, bool big_endian>
1282 void
1283 Output_data_got<size, big_endian>::add_global_pair_with_rela(
1284 Symbol* gsym,
1285 unsigned int got_type,
1286 Rela_dyn* rela_dyn,
1287 unsigned int r_type_1,
1288 unsigned int r_type_2)
1290 if (gsym->has_got_offset(got_type))
1291 return;
1293 this->entries_.push_back(Got_entry());
1294 unsigned int got_offset = this->last_got_offset();
1295 gsym->set_got_offset(got_type, got_offset);
1296 rela_dyn->add_global(gsym, r_type_1, this, got_offset, 0);
1298 this->entries_.push_back(Got_entry());
1299 if (r_type_2 != 0)
1301 got_offset = this->last_got_offset();
1302 rela_dyn->add_global(gsym, r_type_2, this, got_offset, 0);
1305 this->set_got_size();
1308 // Add an entry for a local symbol to the GOT. This returns true if
1309 // this is a new GOT entry, false if the symbol already has a GOT
1310 // entry.
1312 template<int size, bool big_endian>
1313 bool
1314 Output_data_got<size, big_endian>::add_local(
1315 Sized_relobj<size, big_endian>* object,
1316 unsigned int symndx,
1317 unsigned int got_type)
1319 if (object->local_has_got_offset(symndx, got_type))
1320 return false;
1322 this->entries_.push_back(Got_entry(object, symndx));
1323 this->set_got_size();
1324 object->set_local_got_offset(symndx, got_type, this->last_got_offset());
1325 return true;
1328 // Add an entry for a local symbol to the GOT, and add a dynamic
1329 // relocation of type R_TYPE for the GOT entry.
1330 template<int size, bool big_endian>
1331 void
1332 Output_data_got<size, big_endian>::add_local_with_rel(
1333 Sized_relobj<size, big_endian>* object,
1334 unsigned int symndx,
1335 unsigned int got_type,
1336 Rel_dyn* rel_dyn,
1337 unsigned int r_type)
1339 if (object->local_has_got_offset(symndx, got_type))
1340 return;
1342 this->entries_.push_back(Got_entry());
1343 this->set_got_size();
1344 unsigned int got_offset = this->last_got_offset();
1345 object->set_local_got_offset(symndx, got_type, got_offset);
1346 rel_dyn->add_local(object, symndx, r_type, this, got_offset);
1349 template<int size, bool big_endian>
1350 void
1351 Output_data_got<size, big_endian>::add_local_with_rela(
1352 Sized_relobj<size, big_endian>* object,
1353 unsigned int symndx,
1354 unsigned int got_type,
1355 Rela_dyn* rela_dyn,
1356 unsigned int r_type)
1358 if (object->local_has_got_offset(symndx, got_type))
1359 return;
1361 this->entries_.push_back(Got_entry());
1362 this->set_got_size();
1363 unsigned int got_offset = this->last_got_offset();
1364 object->set_local_got_offset(symndx, got_type, got_offset);
1365 rela_dyn->add_local(object, symndx, r_type, this, got_offset, 0);
1368 // Add a pair of entries for a local symbol to the GOT, and add
1369 // dynamic relocations of type R_TYPE_1 and R_TYPE_2, respectively.
1370 // If R_TYPE_2 == 0, add the second entry with no relocation.
1371 template<int size, bool big_endian>
1372 void
1373 Output_data_got<size, big_endian>::add_local_pair_with_rel(
1374 Sized_relobj<size, big_endian>* object,
1375 unsigned int symndx,
1376 unsigned int shndx,
1377 unsigned int got_type,
1378 Rel_dyn* rel_dyn,
1379 unsigned int r_type_1,
1380 unsigned int r_type_2)
1382 if (object->local_has_got_offset(symndx, got_type))
1383 return;
1385 this->entries_.push_back(Got_entry());
1386 unsigned int got_offset = this->last_got_offset();
1387 object->set_local_got_offset(symndx, got_type, got_offset);
1388 Output_section* os = object->output_section(shndx);
1389 rel_dyn->add_output_section(os, r_type_1, this, got_offset);
1391 this->entries_.push_back(Got_entry(object, symndx));
1392 if (r_type_2 != 0)
1394 got_offset = this->last_got_offset();
1395 rel_dyn->add_output_section(os, r_type_2, this, got_offset);
1398 this->set_got_size();
1401 template<int size, bool big_endian>
1402 void
1403 Output_data_got<size, big_endian>::add_local_pair_with_rela(
1404 Sized_relobj<size, big_endian>* object,
1405 unsigned int symndx,
1406 unsigned int shndx,
1407 unsigned int got_type,
1408 Rela_dyn* rela_dyn,
1409 unsigned int r_type_1,
1410 unsigned int r_type_2)
1412 if (object->local_has_got_offset(symndx, got_type))
1413 return;
1415 this->entries_.push_back(Got_entry());
1416 unsigned int got_offset = this->last_got_offset();
1417 object->set_local_got_offset(symndx, got_type, got_offset);
1418 Output_section* os = object->output_section(shndx);
1419 rela_dyn->add_output_section(os, r_type_1, this, got_offset, 0);
1421 this->entries_.push_back(Got_entry(object, symndx));
1422 if (r_type_2 != 0)
1424 got_offset = this->last_got_offset();
1425 rela_dyn->add_output_section(os, r_type_2, this, got_offset, 0);
1428 this->set_got_size();
1431 // Write out the GOT.
1433 template<int size, bool big_endian>
1434 void
1435 Output_data_got<size, big_endian>::do_write(Output_file* of)
1437 const int add = size / 8;
1439 const off_t off = this->offset();
1440 const off_t oview_size = this->data_size();
1441 unsigned char* const oview = of->get_output_view(off, oview_size);
1443 unsigned char* pov = oview;
1444 for (typename Got_entries::const_iterator p = this->entries_.begin();
1445 p != this->entries_.end();
1446 ++p)
1448 p->write(pov);
1449 pov += add;
1452 gold_assert(pov - oview == oview_size);
1454 of->write_output_view(off, oview_size, oview);
1456 // We no longer need the GOT entries.
1457 this->entries_.clear();
1460 // Output_data_dynamic::Dynamic_entry methods.
1462 // Write out the entry.
1464 template<int size, bool big_endian>
1465 void
1466 Output_data_dynamic::Dynamic_entry::write(
1467 unsigned char* pov,
1468 const Stringpool* pool) const
1470 typename elfcpp::Elf_types<size>::Elf_WXword val;
1471 switch (this->offset_)
1473 case DYNAMIC_NUMBER:
1474 val = this->u_.val;
1475 break;
1477 case DYNAMIC_SECTION_SIZE:
1478 val = this->u_.od->data_size();
1479 break;
1481 case DYNAMIC_SYMBOL:
1483 const Sized_symbol<size>* s =
1484 static_cast<const Sized_symbol<size>*>(this->u_.sym);
1485 val = s->value();
1487 break;
1489 case DYNAMIC_STRING:
1490 val = pool->get_offset(this->u_.str);
1491 break;
1493 default:
1494 val = this->u_.od->address() + this->offset_;
1495 break;
1498 elfcpp::Dyn_write<size, big_endian> dw(pov);
1499 dw.put_d_tag(this->tag_);
1500 dw.put_d_val(val);
1503 // Output_data_dynamic methods.
1505 // Adjust the output section to set the entry size.
1507 void
1508 Output_data_dynamic::do_adjust_output_section(Output_section* os)
1510 if (parameters->target().get_size() == 32)
1511 os->set_entsize(elfcpp::Elf_sizes<32>::dyn_size);
1512 else if (parameters->target().get_size() == 64)
1513 os->set_entsize(elfcpp::Elf_sizes<64>::dyn_size);
1514 else
1515 gold_unreachable();
1518 // Set the final data size.
1520 void
1521 Output_data_dynamic::set_final_data_size()
1523 // Add the terminating entry if it hasn't been added.
1524 // Because of relaxation, we can run this multiple times.
1525 if (this->entries_.empty()
1526 || this->entries_.rbegin()->tag() != elfcpp::DT_NULL)
1527 this->add_constant(elfcpp::DT_NULL, 0);
1529 int dyn_size;
1530 if (parameters->target().get_size() == 32)
1531 dyn_size = elfcpp::Elf_sizes<32>::dyn_size;
1532 else if (parameters->target().get_size() == 64)
1533 dyn_size = elfcpp::Elf_sizes<64>::dyn_size;
1534 else
1535 gold_unreachable();
1536 this->set_data_size(this->entries_.size() * dyn_size);
1539 // Write out the dynamic entries.
1541 void
1542 Output_data_dynamic::do_write(Output_file* of)
1544 switch (parameters->size_and_endianness())
1546 #ifdef HAVE_TARGET_32_LITTLE
1547 case Parameters::TARGET_32_LITTLE:
1548 this->sized_write<32, false>(of);
1549 break;
1550 #endif
1551 #ifdef HAVE_TARGET_32_BIG
1552 case Parameters::TARGET_32_BIG:
1553 this->sized_write<32, true>(of);
1554 break;
1555 #endif
1556 #ifdef HAVE_TARGET_64_LITTLE
1557 case Parameters::TARGET_64_LITTLE:
1558 this->sized_write<64, false>(of);
1559 break;
1560 #endif
1561 #ifdef HAVE_TARGET_64_BIG
1562 case Parameters::TARGET_64_BIG:
1563 this->sized_write<64, true>(of);
1564 break;
1565 #endif
1566 default:
1567 gold_unreachable();
1571 template<int size, bool big_endian>
1572 void
1573 Output_data_dynamic::sized_write(Output_file* of)
1575 const int dyn_size = elfcpp::Elf_sizes<size>::dyn_size;
1577 const off_t offset = this->offset();
1578 const off_t oview_size = this->data_size();
1579 unsigned char* const oview = of->get_output_view(offset, oview_size);
1581 unsigned char* pov = oview;
1582 for (typename Dynamic_entries::const_iterator p = this->entries_.begin();
1583 p != this->entries_.end();
1584 ++p)
1586 p->write<size, big_endian>(pov, this->pool_);
1587 pov += dyn_size;
1590 gold_assert(pov - oview == oview_size);
1592 of->write_output_view(offset, oview_size, oview);
1594 // We no longer need the dynamic entries.
1595 this->entries_.clear();
1598 // Class Output_symtab_xindex.
1600 void
1601 Output_symtab_xindex::do_write(Output_file* of)
1603 const off_t offset = this->offset();
1604 const off_t oview_size = this->data_size();
1605 unsigned char* const oview = of->get_output_view(offset, oview_size);
1607 memset(oview, 0, oview_size);
1609 if (parameters->target().is_big_endian())
1610 this->endian_do_write<true>(oview);
1611 else
1612 this->endian_do_write<false>(oview);
1614 of->write_output_view(offset, oview_size, oview);
1616 // We no longer need the data.
1617 this->entries_.clear();
1620 template<bool big_endian>
1621 void
1622 Output_symtab_xindex::endian_do_write(unsigned char* const oview)
1624 for (Xindex_entries::const_iterator p = this->entries_.begin();
1625 p != this->entries_.end();
1626 ++p)
1628 unsigned int symndx = p->first;
1629 gold_assert(symndx * 4 < this->data_size());
1630 elfcpp::Swap<32, big_endian>::writeval(oview + symndx * 4, p->second);
1634 // Output_section::Input_section methods.
1636 // Return the data size. For an input section we store the size here.
1637 // For an Output_section_data, we have to ask it for the size.
1639 off_t
1640 Output_section::Input_section::data_size() const
1642 if (this->is_input_section())
1643 return this->u1_.data_size;
1644 else
1645 return this->u2_.posd->data_size();
1648 // Set the address and file offset.
1650 void
1651 Output_section::Input_section::set_address_and_file_offset(
1652 uint64_t address,
1653 off_t file_offset,
1654 off_t section_file_offset)
1656 if (this->is_input_section())
1657 this->u2_.object->set_section_offset(this->shndx_,
1658 file_offset - section_file_offset);
1659 else
1660 this->u2_.posd->set_address_and_file_offset(address, file_offset);
1663 // Reset the address and file offset.
1665 void
1666 Output_section::Input_section::reset_address_and_file_offset()
1668 if (!this->is_input_section())
1669 this->u2_.posd->reset_address_and_file_offset();
1672 // Finalize the data size.
1674 void
1675 Output_section::Input_section::finalize_data_size()
1677 if (!this->is_input_section())
1678 this->u2_.posd->finalize_data_size();
1681 // Try to turn an input offset into an output offset. We want to
1682 // return the output offset relative to the start of this
1683 // Input_section in the output section.
1685 inline bool
1686 Output_section::Input_section::output_offset(
1687 const Relobj* object,
1688 unsigned int shndx,
1689 section_offset_type offset,
1690 section_offset_type *poutput) const
1692 if (!this->is_input_section())
1693 return this->u2_.posd->output_offset(object, shndx, offset, poutput);
1694 else
1696 if (this->shndx_ != shndx || this->u2_.object != object)
1697 return false;
1698 *poutput = offset;
1699 return true;
1703 // Return whether this is the merge section for the input section
1704 // SHNDX in OBJECT.
1706 inline bool
1707 Output_section::Input_section::is_merge_section_for(const Relobj* object,
1708 unsigned int shndx) const
1710 if (this->is_input_section())
1711 return false;
1712 return this->u2_.posd->is_merge_section_for(object, shndx);
1715 // Write out the data. We don't have to do anything for an input
1716 // section--they are handled via Object::relocate--but this is where
1717 // we write out the data for an Output_section_data.
1719 void
1720 Output_section::Input_section::write(Output_file* of)
1722 if (!this->is_input_section())
1723 this->u2_.posd->write(of);
1726 // Write the data to a buffer. As for write(), we don't have to do
1727 // anything for an input section.
1729 void
1730 Output_section::Input_section::write_to_buffer(unsigned char* buffer)
1732 if (!this->is_input_section())
1733 this->u2_.posd->write_to_buffer(buffer);
1736 // Print to a map file.
1738 void
1739 Output_section::Input_section::print_to_mapfile(Mapfile* mapfile) const
1741 switch (this->shndx_)
1743 case OUTPUT_SECTION_CODE:
1744 case MERGE_DATA_SECTION_CODE:
1745 case MERGE_STRING_SECTION_CODE:
1746 this->u2_.posd->print_to_mapfile(mapfile);
1747 break;
1749 case RELAXED_INPUT_SECTION_CODE:
1751 Output_relaxed_input_section* relaxed_section =
1752 this->relaxed_input_section();
1753 mapfile->print_input_section(relaxed_section->relobj(),
1754 relaxed_section->shndx());
1756 break;
1757 default:
1758 mapfile->print_input_section(this->u2_.object, this->shndx_);
1759 break;
1763 // Output_section methods.
1765 // Construct an Output_section. NAME will point into a Stringpool.
1767 Output_section::Output_section(const char* name, elfcpp::Elf_Word type,
1768 elfcpp::Elf_Xword flags)
1769 : name_(name),
1770 addralign_(0),
1771 entsize_(0),
1772 load_address_(0),
1773 link_section_(NULL),
1774 link_(0),
1775 info_section_(NULL),
1776 info_symndx_(NULL),
1777 info_(0),
1778 type_(type),
1779 flags_(flags),
1780 out_shndx_(-1U),
1781 symtab_index_(0),
1782 dynsym_index_(0),
1783 input_sections_(),
1784 first_input_offset_(0),
1785 fills_(),
1786 postprocessing_buffer_(NULL),
1787 needs_symtab_index_(false),
1788 needs_dynsym_index_(false),
1789 should_link_to_symtab_(false),
1790 should_link_to_dynsym_(false),
1791 after_input_sections_(false),
1792 requires_postprocessing_(false),
1793 found_in_sections_clause_(false),
1794 has_load_address_(false),
1795 info_uses_section_index_(false),
1796 may_sort_attached_input_sections_(false),
1797 must_sort_attached_input_sections_(false),
1798 attached_input_sections_are_sorted_(false),
1799 is_relro_(false),
1800 is_relro_local_(false),
1801 is_small_section_(false),
1802 is_large_section_(false),
1803 tls_offset_(0),
1804 checkpoint_(NULL),
1805 merge_section_map_(),
1806 merge_section_by_properties_map_(),
1807 relaxed_input_section_map_(),
1808 is_relaxed_input_section_map_valid_(true),
1809 generate_code_fills_at_write_(false)
1811 // An unallocated section has no address. Forcing this means that
1812 // we don't need special treatment for symbols defined in debug
1813 // sections.
1814 if ((flags & elfcpp::SHF_ALLOC) == 0)
1815 this->set_address(0);
1818 Output_section::~Output_section()
1820 delete this->checkpoint_;
1823 // Set the entry size.
1825 void
1826 Output_section::set_entsize(uint64_t v)
1828 if (this->entsize_ == 0)
1829 this->entsize_ = v;
1830 else
1831 gold_assert(this->entsize_ == v);
1834 // Add the input section SHNDX, with header SHDR, named SECNAME, in
1835 // OBJECT, to the Output_section. RELOC_SHNDX is the index of a
1836 // relocation section which applies to this section, or 0 if none, or
1837 // -1U if more than one. Return the offset of the input section
1838 // within the output section. Return -1 if the input section will
1839 // receive special handling. In the normal case we don't always keep
1840 // track of input sections for an Output_section. Instead, each
1841 // Object keeps track of the Output_section for each of its input
1842 // sections. However, if HAVE_SECTIONS_SCRIPT is true, we do keep
1843 // track of input sections here; this is used when SECTIONS appears in
1844 // a linker script.
1846 template<int size, bool big_endian>
1847 off_t
1848 Output_section::add_input_section(Sized_relobj<size, big_endian>* object,
1849 unsigned int shndx,
1850 const char* secname,
1851 const elfcpp::Shdr<size, big_endian>& shdr,
1852 unsigned int reloc_shndx,
1853 bool have_sections_script)
1855 elfcpp::Elf_Xword addralign = shdr.get_sh_addralign();
1856 if ((addralign & (addralign - 1)) != 0)
1858 object->error(_("invalid alignment %lu for section \"%s\""),
1859 static_cast<unsigned long>(addralign), secname);
1860 addralign = 1;
1863 if (addralign > this->addralign_)
1864 this->addralign_ = addralign;
1866 typename elfcpp::Elf_types<size>::Elf_WXword sh_flags = shdr.get_sh_flags();
1867 this->update_flags_for_input_section(sh_flags);
1869 uint64_t entsize = shdr.get_sh_entsize();
1871 // .debug_str is a mergeable string section, but is not always so
1872 // marked by compilers. Mark manually here so we can optimize.
1873 if (strcmp(secname, ".debug_str") == 0)
1875 sh_flags |= (elfcpp::SHF_MERGE | elfcpp::SHF_STRINGS);
1876 entsize = 1;
1879 // If this is a SHF_MERGE section, we pass all the input sections to
1880 // a Output_data_merge. We don't try to handle relocations for such
1881 // a section. We don't try to handle empty merge sections--they
1882 // mess up the mappings, and are useless anyhow.
1883 if ((sh_flags & elfcpp::SHF_MERGE) != 0
1884 && reloc_shndx == 0
1885 && shdr.get_sh_size() > 0)
1887 if (this->add_merge_input_section(object, shndx, sh_flags,
1888 entsize, addralign))
1890 // Tell the relocation routines that they need to call the
1891 // output_offset method to determine the final address.
1892 return -1;
1896 off_t offset_in_section = this->current_data_size_for_child();
1897 off_t aligned_offset_in_section = align_address(offset_in_section,
1898 addralign);
1900 // Determine if we want to delay code-fill generation until the output
1901 // section is written. When the target is relaxing, we want to delay fill
1902 // generating to avoid adjusting them during relaxation.
1903 if (!this->generate_code_fills_at_write_
1904 && !have_sections_script
1905 && (sh_flags & elfcpp::SHF_EXECINSTR) != 0
1906 && parameters->target().has_code_fill()
1907 && parameters->target().may_relax())
1909 gold_assert(this->fills_.empty());
1910 this->generate_code_fills_at_write_ = true;
1913 if (aligned_offset_in_section > offset_in_section
1914 && !this->generate_code_fills_at_write_
1915 && !have_sections_script
1916 && (sh_flags & elfcpp::SHF_EXECINSTR) != 0
1917 && parameters->target().has_code_fill())
1919 // We need to add some fill data. Using fill_list_ when
1920 // possible is an optimization, since we will often have fill
1921 // sections without input sections.
1922 off_t fill_len = aligned_offset_in_section - offset_in_section;
1923 if (this->input_sections_.empty())
1924 this->fills_.push_back(Fill(offset_in_section, fill_len));
1925 else
1927 std::string fill_data(parameters->target().code_fill(fill_len));
1928 Output_data_const* odc = new Output_data_const(fill_data, 1);
1929 this->input_sections_.push_back(Input_section(odc));
1933 this->set_current_data_size_for_child(aligned_offset_in_section
1934 + shdr.get_sh_size());
1936 // We need to keep track of this section if we are already keeping
1937 // track of sections, or if we are relaxing. Also, if this is a
1938 // section which requires sorting, or which may require sorting in
1939 // the future, we keep track of the sections.
1940 if (have_sections_script
1941 || !this->input_sections_.empty()
1942 || this->may_sort_attached_input_sections()
1943 || this->must_sort_attached_input_sections()
1944 || parameters->options().user_set_Map()
1945 || parameters->target().may_relax())
1946 this->input_sections_.push_back(Input_section(object, shndx,
1947 shdr.get_sh_size(),
1948 addralign));
1950 return aligned_offset_in_section;
1953 // Add arbitrary data to an output section.
1955 void
1956 Output_section::add_output_section_data(Output_section_data* posd)
1958 Input_section inp(posd);
1959 this->add_output_section_data(&inp);
1961 if (posd->is_data_size_valid())
1963 off_t offset_in_section = this->current_data_size_for_child();
1964 off_t aligned_offset_in_section = align_address(offset_in_section,
1965 posd->addralign());
1966 this->set_current_data_size_for_child(aligned_offset_in_section
1967 + posd->data_size());
1971 // Add a relaxed input section.
1973 void
1974 Output_section::add_relaxed_input_section(Output_relaxed_input_section* poris)
1976 Input_section inp(poris);
1977 this->add_output_section_data(&inp);
1978 if (this->is_relaxed_input_section_map_valid_)
1980 Input_section_specifier iss(poris->relobj(), poris->shndx());
1981 this->relaxed_input_section_map_[iss] = poris;
1984 // For a relaxed section, we use the current data size. Linker scripts
1985 // get all the input sections, including relaxed one from an output
1986 // section and add them back to them same output section to compute the
1987 // output section size. If we do not account for sizes of relaxed input
1988 // sections, an output section would be incorrectly sized.
1989 off_t offset_in_section = this->current_data_size_for_child();
1990 off_t aligned_offset_in_section = align_address(offset_in_section,
1991 poris->addralign());
1992 this->set_current_data_size_for_child(aligned_offset_in_section
1993 + poris->current_data_size());
1996 // Add arbitrary data to an output section by Input_section.
1998 void
1999 Output_section::add_output_section_data(Input_section* inp)
2001 if (this->input_sections_.empty())
2002 this->first_input_offset_ = this->current_data_size_for_child();
2004 this->input_sections_.push_back(*inp);
2006 uint64_t addralign = inp->addralign();
2007 if (addralign > this->addralign_)
2008 this->addralign_ = addralign;
2010 inp->set_output_section(this);
2013 // Add a merge section to an output section.
2015 void
2016 Output_section::add_output_merge_section(Output_section_data* posd,
2017 bool is_string, uint64_t entsize)
2019 Input_section inp(posd, is_string, entsize);
2020 this->add_output_section_data(&inp);
2023 // Add an input section to a SHF_MERGE section.
2025 bool
2026 Output_section::add_merge_input_section(Relobj* object, unsigned int shndx,
2027 uint64_t flags, uint64_t entsize,
2028 uint64_t addralign)
2030 bool is_string = (flags & elfcpp::SHF_STRINGS) != 0;
2032 // We only merge strings if the alignment is not more than the
2033 // character size. This could be handled, but it's unusual.
2034 if (is_string && addralign > entsize)
2035 return false;
2037 // We cannot restore merged input section states.
2038 gold_assert(this->checkpoint_ == NULL);
2040 // Look up merge sections by required properties.
2041 Merge_section_properties msp(is_string, entsize, addralign);
2042 Merge_section_by_properties_map::const_iterator p =
2043 this->merge_section_by_properties_map_.find(msp);
2044 if (p != this->merge_section_by_properties_map_.end())
2046 Output_merge_base* merge_section = p->second;
2047 merge_section->add_input_section(object, shndx);
2048 gold_assert(merge_section->is_string() == is_string
2049 && merge_section->entsize() == entsize
2050 && merge_section->addralign() == addralign);
2052 // Link input section to found merge section.
2053 Input_section_specifier iss(object, shndx);
2054 this->merge_section_map_[iss] = merge_section;
2055 return true;
2058 // We handle the actual constant merging in Output_merge_data or
2059 // Output_merge_string_data.
2060 Output_merge_base* pomb;
2061 if (!is_string)
2062 pomb = new Output_merge_data(entsize, addralign);
2063 else
2065 switch (entsize)
2067 case 1:
2068 pomb = new Output_merge_string<char>(addralign);
2069 break;
2070 case 2:
2071 pomb = new Output_merge_string<uint16_t>(addralign);
2072 break;
2073 case 4:
2074 pomb = new Output_merge_string<uint32_t>(addralign);
2075 break;
2076 default:
2077 return false;
2081 // Add new merge section to this output section and link merge section
2082 // properties to new merge section in map.
2083 this->add_output_merge_section(pomb, is_string, entsize);
2084 this->merge_section_by_properties_map_[msp] = pomb;
2086 // Add input section to new merge section and link input section to new
2087 // merge section in map.
2088 pomb->add_input_section(object, shndx);
2089 Input_section_specifier iss(object, shndx);
2090 this->merge_section_map_[iss] = pomb;
2092 return true;
2095 // Build a relaxation map to speed up relaxation of existing input sections.
2096 // Look up to the first LIMIT elements in INPUT_SECTIONS.
2098 void
2099 Output_section::build_relaxation_map(
2100 const Input_section_list& input_sections,
2101 size_t limit,
2102 Relaxation_map* relaxation_map) const
2104 for (size_t i = 0; i < limit; ++i)
2106 const Input_section& is(input_sections[i]);
2107 if (is.is_input_section() || is.is_relaxed_input_section())
2109 Input_section_specifier iss(is.relobj(), is.shndx());
2110 (*relaxation_map)[iss] = i;
2115 // Convert regular input sections in INPUT_SECTIONS into relaxed input
2116 // sections in RELAXED_SECTIONS. MAP is a prebuilt map from input section
2117 // specifier to indices of INPUT_SECTIONS.
2119 void
2120 Output_section::convert_input_sections_in_list_to_relaxed_sections(
2121 const std::vector<Output_relaxed_input_section*>& relaxed_sections,
2122 const Relaxation_map& map,
2123 Input_section_list* input_sections)
2125 for (size_t i = 0; i < relaxed_sections.size(); ++i)
2127 Output_relaxed_input_section* poris = relaxed_sections[i];
2128 Input_section_specifier iss(poris->relobj(), poris->shndx());
2129 Relaxation_map::const_iterator p = map.find(iss);
2130 gold_assert(p != map.end());
2131 gold_assert((*input_sections)[p->second].is_input_section());
2132 (*input_sections)[p->second] = Input_section(poris);
2136 // Convert regular input sections into relaxed input sections. RELAXED_SECTIONS
2137 // is a vector of pointers to Output_relaxed_input_section or its derived
2138 // classes. The relaxed sections must correspond to existing input sections.
2140 void
2141 Output_section::convert_input_sections_to_relaxed_sections(
2142 const std::vector<Output_relaxed_input_section*>& relaxed_sections)
2144 gold_assert(parameters->target().may_relax());
2146 // We want to make sure that restore_states does not undo the effect of
2147 // this. If there is no checkpoint active, just search the current
2148 // input section list and replace the sections there. If there is
2149 // a checkpoint, also replace the sections there.
2151 // By default, we look at the whole list.
2152 size_t limit = this->input_sections_.size();
2154 if (this->checkpoint_ != NULL)
2156 // Replace input sections with relaxed input section in the saved
2157 // copy of the input section list.
2158 if (this->checkpoint_->input_sections_saved())
2160 Relaxation_map map;
2161 this->build_relaxation_map(
2162 *(this->checkpoint_->input_sections()),
2163 this->checkpoint_->input_sections()->size(),
2164 &map);
2165 this->convert_input_sections_in_list_to_relaxed_sections(
2166 relaxed_sections,
2167 map,
2168 this->checkpoint_->input_sections());
2170 else
2172 // We have not copied the input section list yet. Instead, just
2173 // look at the portion that would be saved.
2174 limit = this->checkpoint_->input_sections_size();
2178 // Convert input sections in input_section_list.
2179 Relaxation_map map;
2180 this->build_relaxation_map(this->input_sections_, limit, &map);
2181 this->convert_input_sections_in_list_to_relaxed_sections(
2182 relaxed_sections,
2183 map,
2184 &this->input_sections_);
2187 // Update the output section flags based on input section flags.
2189 void
2190 Output_section::update_flags_for_input_section(elfcpp::Elf_Xword flags)
2192 // If we created the section with SHF_ALLOC clear, we set the
2193 // address. If we are now setting the SHF_ALLOC flag, we need to
2194 // undo that.
2195 if ((this->flags_ & elfcpp::SHF_ALLOC) == 0
2196 && (flags & elfcpp::SHF_ALLOC) != 0)
2197 this->mark_address_invalid();
2199 this->flags_ |= (flags
2200 & (elfcpp::SHF_WRITE
2201 | elfcpp::SHF_ALLOC
2202 | elfcpp::SHF_EXECINSTR));
2205 // Find the merge section into which an input section with index SHNDX in
2206 // OBJECT has been added. Return NULL if none found.
2208 Output_section_data*
2209 Output_section::find_merge_section(const Relobj* object,
2210 unsigned int shndx) const
2212 Input_section_specifier iss(object, shndx);
2213 Output_section_data_by_input_section_map::const_iterator p =
2214 this->merge_section_map_.find(iss);
2215 if (p != this->merge_section_map_.end())
2217 Output_section_data* posd = p->second;
2218 gold_assert(posd->is_merge_section_for(object, shndx));
2219 return posd;
2221 else
2222 return NULL;
2225 // Find an relaxed input section corresponding to an input section
2226 // in OBJECT with index SHNDX.
2228 const Output_section_data*
2229 Output_section::find_relaxed_input_section(const Relobj* object,
2230 unsigned int shndx) const
2232 // Be careful that the map may not be valid due to input section export
2233 // to scripts or a check-point restore.
2234 if (!this->is_relaxed_input_section_map_valid_)
2236 // Rebuild the map as needed.
2237 this->relaxed_input_section_map_.clear();
2238 for (Input_section_list::const_iterator p = this->input_sections_.begin();
2239 p != this->input_sections_.end();
2240 ++p)
2241 if (p->is_relaxed_input_section())
2243 Input_section_specifier iss(p->relobj(), p->shndx());
2244 this->relaxed_input_section_map_[iss] =
2245 p->relaxed_input_section();
2247 this->is_relaxed_input_section_map_valid_ = true;
2250 Input_section_specifier iss(object, shndx);
2251 Output_section_data_by_input_section_map::const_iterator p =
2252 this->relaxed_input_section_map_.find(iss);
2253 if (p != this->relaxed_input_section_map_.end())
2254 return p->second;
2255 else
2256 return NULL;
2259 // Given an address OFFSET relative to the start of input section
2260 // SHNDX in OBJECT, return whether this address is being included in
2261 // the final link. This should only be called if SHNDX in OBJECT has
2262 // a special mapping.
2264 bool
2265 Output_section::is_input_address_mapped(const Relobj* object,
2266 unsigned int shndx,
2267 off_t offset) const
2269 // Look at the Output_section_data_maps first.
2270 const Output_section_data* posd = this->find_merge_section(object, shndx);
2271 if (posd == NULL)
2272 posd = this->find_relaxed_input_section(object, shndx);
2274 if (posd != NULL)
2276 section_offset_type output_offset;
2277 bool found = posd->output_offset(object, shndx, offset, &output_offset);
2278 gold_assert(found);
2279 return output_offset != -1;
2282 // Fall back to the slow look-up.
2283 for (Input_section_list::const_iterator p = this->input_sections_.begin();
2284 p != this->input_sections_.end();
2285 ++p)
2287 section_offset_type output_offset;
2288 if (p->output_offset(object, shndx, offset, &output_offset))
2289 return output_offset != -1;
2292 // By default we assume that the address is mapped. This should
2293 // only be called after we have passed all sections to Layout. At
2294 // that point we should know what we are discarding.
2295 return true;
2298 // Given an address OFFSET relative to the start of input section
2299 // SHNDX in object OBJECT, return the output offset relative to the
2300 // start of the input section in the output section. This should only
2301 // be called if SHNDX in OBJECT has a special mapping.
2303 section_offset_type
2304 Output_section::output_offset(const Relobj* object, unsigned int shndx,
2305 section_offset_type offset) const
2307 // This can only be called meaningfully when we know the data size
2308 // of this.
2309 gold_assert(this->is_data_size_valid());
2311 // Look at the Output_section_data_maps first.
2312 const Output_section_data* posd = this->find_merge_section(object, shndx);
2313 if (posd == NULL)
2314 posd = this->find_relaxed_input_section(object, shndx);
2315 if (posd != NULL)
2317 section_offset_type output_offset;
2318 bool found = posd->output_offset(object, shndx, offset, &output_offset);
2319 gold_assert(found);
2320 return output_offset;
2323 // Fall back to the slow look-up.
2324 for (Input_section_list::const_iterator p = this->input_sections_.begin();
2325 p != this->input_sections_.end();
2326 ++p)
2328 section_offset_type output_offset;
2329 if (p->output_offset(object, shndx, offset, &output_offset))
2330 return output_offset;
2332 gold_unreachable();
2335 // Return the output virtual address of OFFSET relative to the start
2336 // of input section SHNDX in object OBJECT.
2338 uint64_t
2339 Output_section::output_address(const Relobj* object, unsigned int shndx,
2340 off_t offset) const
2342 uint64_t addr = this->address() + this->first_input_offset_;
2344 // Look at the Output_section_data_maps first.
2345 const Output_section_data* posd = this->find_merge_section(object, shndx);
2346 if (posd == NULL)
2347 posd = this->find_relaxed_input_section(object, shndx);
2348 if (posd != NULL && posd->is_address_valid())
2350 section_offset_type output_offset;
2351 bool found = posd->output_offset(object, shndx, offset, &output_offset);
2352 gold_assert(found);
2353 return posd->address() + output_offset;
2356 // Fall back to the slow look-up.
2357 for (Input_section_list::const_iterator p = this->input_sections_.begin();
2358 p != this->input_sections_.end();
2359 ++p)
2361 addr = align_address(addr, p->addralign());
2362 section_offset_type output_offset;
2363 if (p->output_offset(object, shndx, offset, &output_offset))
2365 if (output_offset == -1)
2366 return -1ULL;
2367 return addr + output_offset;
2369 addr += p->data_size();
2372 // If we get here, it means that we don't know the mapping for this
2373 // input section. This might happen in principle if
2374 // add_input_section were called before add_output_section_data.
2375 // But it should never actually happen.
2377 gold_unreachable();
2380 // Find the output address of the start of the merged section for
2381 // input section SHNDX in object OBJECT.
2383 bool
2384 Output_section::find_starting_output_address(const Relobj* object,
2385 unsigned int shndx,
2386 uint64_t* paddr) const
2388 // FIXME: This becomes a bottle-neck if we have many relaxed sections.
2389 // Looking up the merge section map does not always work as we sometimes
2390 // find a merge section without its address set.
2391 uint64_t addr = this->address() + this->first_input_offset_;
2392 for (Input_section_list::const_iterator p = this->input_sections_.begin();
2393 p != this->input_sections_.end();
2394 ++p)
2396 addr = align_address(addr, p->addralign());
2398 // It would be nice if we could use the existing output_offset
2399 // method to get the output offset of input offset 0.
2400 // Unfortunately we don't know for sure that input offset 0 is
2401 // mapped at all.
2402 if (p->is_merge_section_for(object, shndx))
2404 *paddr = addr;
2405 return true;
2408 addr += p->data_size();
2411 // We couldn't find a merge output section for this input section.
2412 return false;
2415 // Set the data size of an Output_section. This is where we handle
2416 // setting the addresses of any Output_section_data objects.
2418 void
2419 Output_section::set_final_data_size()
2421 if (this->input_sections_.empty())
2423 this->set_data_size(this->current_data_size_for_child());
2424 return;
2427 if (this->must_sort_attached_input_sections())
2428 this->sort_attached_input_sections();
2430 uint64_t address = this->address();
2431 off_t startoff = this->offset();
2432 off_t off = startoff + this->first_input_offset_;
2433 for (Input_section_list::iterator p = this->input_sections_.begin();
2434 p != this->input_sections_.end();
2435 ++p)
2437 off = align_address(off, p->addralign());
2438 p->set_address_and_file_offset(address + (off - startoff), off,
2439 startoff);
2440 off += p->data_size();
2443 this->set_data_size(off - startoff);
2446 // Reset the address and file offset.
2448 void
2449 Output_section::do_reset_address_and_file_offset()
2451 // An unallocated section has no address. Forcing this means that
2452 // we don't need special treatment for symbols defined in debug
2453 // sections. We do the same in the constructor.
2454 if ((this->flags_ & elfcpp::SHF_ALLOC) == 0)
2455 this->set_address(0);
2457 for (Input_section_list::iterator p = this->input_sections_.begin();
2458 p != this->input_sections_.end();
2459 ++p)
2460 p->reset_address_and_file_offset();
2463 // Return true if address and file offset have the values after reset.
2465 bool
2466 Output_section::do_address_and_file_offset_have_reset_values() const
2468 if (this->is_offset_valid())
2469 return false;
2471 // An unallocated section has address 0 after its construction or a reset.
2472 if ((this->flags_ & elfcpp::SHF_ALLOC) == 0)
2473 return this->is_address_valid() && this->address() == 0;
2474 else
2475 return !this->is_address_valid();
2478 // Set the TLS offset. Called only for SHT_TLS sections.
2480 void
2481 Output_section::do_set_tls_offset(uint64_t tls_base)
2483 this->tls_offset_ = this->address() - tls_base;
2486 // In a few cases we need to sort the input sections attached to an
2487 // output section. This is used to implement the type of constructor
2488 // priority ordering implemented by the GNU linker, in which the
2489 // priority becomes part of the section name and the sections are
2490 // sorted by name. We only do this for an output section if we see an
2491 // attached input section matching ".ctor.*", ".dtor.*",
2492 // ".init_array.*" or ".fini_array.*".
2494 class Output_section::Input_section_sort_entry
2496 public:
2497 Input_section_sort_entry()
2498 : input_section_(), index_(-1U), section_has_name_(false),
2499 section_name_()
2502 Input_section_sort_entry(const Input_section& input_section,
2503 unsigned int index)
2504 : input_section_(input_section), index_(index),
2505 section_has_name_(input_section.is_input_section()
2506 || input_section.is_relaxed_input_section())
2508 if (this->section_has_name_)
2510 // This is only called single-threaded from Layout::finalize,
2511 // so it is OK to lock. Unfortunately we have no way to pass
2512 // in a Task token.
2513 const Task* dummy_task = reinterpret_cast<const Task*>(-1);
2514 Object* obj = (input_section.is_input_section()
2515 ? input_section.relobj()
2516 : input_section.relaxed_input_section()->relobj());
2517 Task_lock_obj<Object> tl(dummy_task, obj);
2519 // This is a slow operation, which should be cached in
2520 // Layout::layout if this becomes a speed problem.
2521 this->section_name_ = obj->section_name(input_section.shndx());
2525 // Return the Input_section.
2526 const Input_section&
2527 input_section() const
2529 gold_assert(this->index_ != -1U);
2530 return this->input_section_;
2533 // The index of this entry in the original list. This is used to
2534 // make the sort stable.
2535 unsigned int
2536 index() const
2538 gold_assert(this->index_ != -1U);
2539 return this->index_;
2542 // Whether there is a section name.
2543 bool
2544 section_has_name() const
2545 { return this->section_has_name_; }
2547 // The section name.
2548 const std::string&
2549 section_name() const
2551 gold_assert(this->section_has_name_);
2552 return this->section_name_;
2555 // Return true if the section name has a priority. This is assumed
2556 // to be true if it has a dot after the initial dot.
2557 bool
2558 has_priority() const
2560 gold_assert(this->section_has_name_);
2561 return this->section_name_.find('.', 1);
2564 // Return true if this an input file whose base name matches
2565 // FILE_NAME. The base name must have an extension of ".o", and
2566 // must be exactly FILE_NAME.o or FILE_NAME, one character, ".o".
2567 // This is to match crtbegin.o as well as crtbeginS.o without
2568 // getting confused by other possibilities. Overall matching the
2569 // file name this way is a dreadful hack, but the GNU linker does it
2570 // in order to better support gcc, and we need to be compatible.
2571 bool
2572 match_file_name(const char* match_file_name) const
2574 const std::string& file_name(this->input_section_.relobj()->name());
2575 const char* base_name = lbasename(file_name.c_str());
2576 size_t match_len = strlen(match_file_name);
2577 if (strncmp(base_name, match_file_name, match_len) != 0)
2578 return false;
2579 size_t base_len = strlen(base_name);
2580 if (base_len != match_len + 2 && base_len != match_len + 3)
2581 return false;
2582 return memcmp(base_name + base_len - 2, ".o", 2) == 0;
2585 private:
2586 // The Input_section we are sorting.
2587 Input_section input_section_;
2588 // The index of this Input_section in the original list.
2589 unsigned int index_;
2590 // Whether this Input_section has a section name--it won't if this
2591 // is some random Output_section_data.
2592 bool section_has_name_;
2593 // The section name if there is one.
2594 std::string section_name_;
2597 // Return true if S1 should come before S2 in the output section.
2599 bool
2600 Output_section::Input_section_sort_compare::operator()(
2601 const Output_section::Input_section_sort_entry& s1,
2602 const Output_section::Input_section_sort_entry& s2) const
2604 // crtbegin.o must come first.
2605 bool s1_begin = s1.match_file_name("crtbegin");
2606 bool s2_begin = s2.match_file_name("crtbegin");
2607 if (s1_begin || s2_begin)
2609 if (!s1_begin)
2610 return false;
2611 if (!s2_begin)
2612 return true;
2613 return s1.index() < s2.index();
2616 // crtend.o must come last.
2617 bool s1_end = s1.match_file_name("crtend");
2618 bool s2_end = s2.match_file_name("crtend");
2619 if (s1_end || s2_end)
2621 if (!s1_end)
2622 return true;
2623 if (!s2_end)
2624 return false;
2625 return s1.index() < s2.index();
2628 // We sort all the sections with no names to the end.
2629 if (!s1.section_has_name() || !s2.section_has_name())
2631 if (s1.section_has_name())
2632 return true;
2633 if (s2.section_has_name())
2634 return false;
2635 return s1.index() < s2.index();
2638 // A section with a priority follows a section without a priority.
2639 // The GNU linker does this for all but .init_array sections; until
2640 // further notice we'll assume that that is an mistake.
2641 bool s1_has_priority = s1.has_priority();
2642 bool s2_has_priority = s2.has_priority();
2643 if (s1_has_priority && !s2_has_priority)
2644 return false;
2645 if (!s1_has_priority && s2_has_priority)
2646 return true;
2648 // Otherwise we sort by name.
2649 int compare = s1.section_name().compare(s2.section_name());
2650 if (compare != 0)
2651 return compare < 0;
2653 // Otherwise we keep the input order.
2654 return s1.index() < s2.index();
2657 // Sort the input sections attached to an output section.
2659 void
2660 Output_section::sort_attached_input_sections()
2662 if (this->attached_input_sections_are_sorted_)
2663 return;
2665 if (this->checkpoint_ != NULL
2666 && !this->checkpoint_->input_sections_saved())
2667 this->checkpoint_->save_input_sections();
2669 // The only thing we know about an input section is the object and
2670 // the section index. We need the section name. Recomputing this
2671 // is slow but this is an unusual case. If this becomes a speed
2672 // problem we can cache the names as required in Layout::layout.
2674 // We start by building a larger vector holding a copy of each
2675 // Input_section, plus its current index in the list and its name.
2676 std::vector<Input_section_sort_entry> sort_list;
2678 unsigned int i = 0;
2679 for (Input_section_list::iterator p = this->input_sections_.begin();
2680 p != this->input_sections_.end();
2681 ++p, ++i)
2682 sort_list.push_back(Input_section_sort_entry(*p, i));
2684 // Sort the input sections.
2685 std::sort(sort_list.begin(), sort_list.end(), Input_section_sort_compare());
2687 // Copy the sorted input sections back to our list.
2688 this->input_sections_.clear();
2689 for (std::vector<Input_section_sort_entry>::iterator p = sort_list.begin();
2690 p != sort_list.end();
2691 ++p)
2692 this->input_sections_.push_back(p->input_section());
2694 // Remember that we sorted the input sections, since we might get
2695 // called again.
2696 this->attached_input_sections_are_sorted_ = true;
2699 // Write the section header to *OSHDR.
2701 template<int size, bool big_endian>
2702 void
2703 Output_section::write_header(const Layout* layout,
2704 const Stringpool* secnamepool,
2705 elfcpp::Shdr_write<size, big_endian>* oshdr) const
2707 oshdr->put_sh_name(secnamepool->get_offset(this->name_));
2708 oshdr->put_sh_type(this->type_);
2710 elfcpp::Elf_Xword flags = this->flags_;
2711 if (this->info_section_ != NULL && this->info_uses_section_index_)
2712 flags |= elfcpp::SHF_INFO_LINK;
2713 oshdr->put_sh_flags(flags);
2715 oshdr->put_sh_addr(this->address());
2716 oshdr->put_sh_offset(this->offset());
2717 oshdr->put_sh_size(this->data_size());
2718 if (this->link_section_ != NULL)
2719 oshdr->put_sh_link(this->link_section_->out_shndx());
2720 else if (this->should_link_to_symtab_)
2721 oshdr->put_sh_link(layout->symtab_section()->out_shndx());
2722 else if (this->should_link_to_dynsym_)
2723 oshdr->put_sh_link(layout->dynsym_section()->out_shndx());
2724 else
2725 oshdr->put_sh_link(this->link_);
2727 elfcpp::Elf_Word info;
2728 if (this->info_section_ != NULL)
2730 if (this->info_uses_section_index_)
2731 info = this->info_section_->out_shndx();
2732 else
2733 info = this->info_section_->symtab_index();
2735 else if (this->info_symndx_ != NULL)
2736 info = this->info_symndx_->symtab_index();
2737 else
2738 info = this->info_;
2739 oshdr->put_sh_info(info);
2741 oshdr->put_sh_addralign(this->addralign_);
2742 oshdr->put_sh_entsize(this->entsize_);
2745 // Write out the data. For input sections the data is written out by
2746 // Object::relocate, but we have to handle Output_section_data objects
2747 // here.
2749 void
2750 Output_section::do_write(Output_file* of)
2752 gold_assert(!this->requires_postprocessing());
2754 // If the target performs relaxation, we delay filler generation until now.
2755 gold_assert(!this->generate_code_fills_at_write_ || this->fills_.empty());
2757 off_t output_section_file_offset = this->offset();
2758 for (Fill_list::iterator p = this->fills_.begin();
2759 p != this->fills_.end();
2760 ++p)
2762 std::string fill_data(parameters->target().code_fill(p->length()));
2763 of->write(output_section_file_offset + p->section_offset(),
2764 fill_data.data(), fill_data.size());
2767 off_t off = this->offset() + this->first_input_offset_;
2768 for (Input_section_list::iterator p = this->input_sections_.begin();
2769 p != this->input_sections_.end();
2770 ++p)
2772 off_t aligned_off = align_address(off, p->addralign());
2773 if (this->generate_code_fills_at_write_ && (off != aligned_off))
2775 size_t fill_len = aligned_off - off;
2776 std::string fill_data(parameters->target().code_fill(fill_len));
2777 of->write(off, fill_data.data(), fill_data.size());
2780 p->write(of);
2781 off = aligned_off + p->data_size();
2785 // If a section requires postprocessing, create the buffer to use.
2787 void
2788 Output_section::create_postprocessing_buffer()
2790 gold_assert(this->requires_postprocessing());
2792 if (this->postprocessing_buffer_ != NULL)
2793 return;
2795 if (!this->input_sections_.empty())
2797 off_t off = this->first_input_offset_;
2798 for (Input_section_list::iterator p = this->input_sections_.begin();
2799 p != this->input_sections_.end();
2800 ++p)
2802 off = align_address(off, p->addralign());
2803 p->finalize_data_size();
2804 off += p->data_size();
2806 this->set_current_data_size_for_child(off);
2809 off_t buffer_size = this->current_data_size_for_child();
2810 this->postprocessing_buffer_ = new unsigned char[buffer_size];
2813 // Write all the data of an Output_section into the postprocessing
2814 // buffer. This is used for sections which require postprocessing,
2815 // such as compression. Input sections are handled by
2816 // Object::Relocate.
2818 void
2819 Output_section::write_to_postprocessing_buffer()
2821 gold_assert(this->requires_postprocessing());
2823 // If the target performs relaxation, we delay filler generation until now.
2824 gold_assert(!this->generate_code_fills_at_write_ || this->fills_.empty());
2826 unsigned char* buffer = this->postprocessing_buffer();
2827 for (Fill_list::iterator p = this->fills_.begin();
2828 p != this->fills_.end();
2829 ++p)
2831 std::string fill_data(parameters->target().code_fill(p->length()));
2832 memcpy(buffer + p->section_offset(), fill_data.data(),
2833 fill_data.size());
2836 off_t off = this->first_input_offset_;
2837 for (Input_section_list::iterator p = this->input_sections_.begin();
2838 p != this->input_sections_.end();
2839 ++p)
2841 off_t aligned_off = align_address(off, p->addralign());
2842 if (this->generate_code_fills_at_write_ && (off != aligned_off))
2844 size_t fill_len = aligned_off - off;
2845 std::string fill_data(parameters->target().code_fill(fill_len));
2846 memcpy(buffer + off, fill_data.data(), fill_data.size());
2849 p->write_to_buffer(buffer + aligned_off);
2850 off = aligned_off + p->data_size();
2854 // Get the input sections for linker script processing. We leave
2855 // behind the Output_section_data entries. Note that this may be
2856 // slightly incorrect for merge sections. We will leave them behind,
2857 // but it is possible that the script says that they should follow
2858 // some other input sections, as in:
2859 // .rodata { *(.rodata) *(.rodata.cst*) }
2860 // For that matter, we don't handle this correctly:
2861 // .rodata { foo.o(.rodata.cst*) *(.rodata.cst*) }
2862 // With luck this will never matter.
2864 uint64_t
2865 Output_section::get_input_sections(
2866 uint64_t address,
2867 const std::string& fill,
2868 std::list<Simple_input_section>* input_sections)
2870 if (this->checkpoint_ != NULL
2871 && !this->checkpoint_->input_sections_saved())
2872 this->checkpoint_->save_input_sections();
2874 // Invalidate the relaxed input section map.
2875 this->is_relaxed_input_section_map_valid_ = false;
2877 uint64_t orig_address = address;
2879 address = align_address(address, this->addralign());
2881 Input_section_list remaining;
2882 for (Input_section_list::iterator p = this->input_sections_.begin();
2883 p != this->input_sections_.end();
2884 ++p)
2886 if (p->is_input_section())
2887 input_sections->push_back(Simple_input_section(p->relobj(),
2888 p->shndx()));
2889 else if (p->is_relaxed_input_section())
2890 input_sections->push_back(
2891 Simple_input_section(p->relaxed_input_section()));
2892 else
2894 uint64_t aligned_address = align_address(address, p->addralign());
2895 if (aligned_address != address && !fill.empty())
2897 section_size_type length =
2898 convert_to_section_size_type(aligned_address - address);
2899 std::string this_fill;
2900 this_fill.reserve(length);
2901 while (this_fill.length() + fill.length() <= length)
2902 this_fill += fill;
2903 if (this_fill.length() < length)
2904 this_fill.append(fill, 0, length - this_fill.length());
2906 Output_section_data* posd = new Output_data_const(this_fill, 0);
2907 remaining.push_back(Input_section(posd));
2909 address = aligned_address;
2911 remaining.push_back(*p);
2913 p->finalize_data_size();
2914 address += p->data_size();
2918 this->input_sections_.swap(remaining);
2919 this->first_input_offset_ = 0;
2921 uint64_t data_size = address - orig_address;
2922 this->set_current_data_size_for_child(data_size);
2923 return data_size;
2926 // Add an input section from a script.
2928 void
2929 Output_section::add_input_section_for_script(const Simple_input_section& sis,
2930 off_t data_size,
2931 uint64_t addralign)
2933 if (addralign > this->addralign_)
2934 this->addralign_ = addralign;
2936 off_t offset_in_section = this->current_data_size_for_child();
2937 off_t aligned_offset_in_section = align_address(offset_in_section,
2938 addralign);
2940 this->set_current_data_size_for_child(aligned_offset_in_section
2941 + data_size);
2943 Input_section is =
2944 (sis.is_relaxed_input_section()
2945 ? Input_section(sis.relaxed_input_section())
2946 : Input_section(sis.relobj(), sis.shndx(), data_size, addralign));
2947 this->input_sections_.push_back(is);
2952 void
2953 Output_section::save_states()
2955 gold_assert(this->checkpoint_ == NULL);
2956 Checkpoint_output_section* checkpoint =
2957 new Checkpoint_output_section(this->addralign_, this->flags_,
2958 this->input_sections_,
2959 this->first_input_offset_,
2960 this->attached_input_sections_are_sorted_);
2961 this->checkpoint_ = checkpoint;
2962 gold_assert(this->fills_.empty());
2965 void
2966 Output_section::restore_states()
2968 gold_assert(this->checkpoint_ != NULL);
2969 Checkpoint_output_section* checkpoint = this->checkpoint_;
2971 this->addralign_ = checkpoint->addralign();
2972 this->flags_ = checkpoint->flags();
2973 this->first_input_offset_ = checkpoint->first_input_offset();
2975 if (!checkpoint->input_sections_saved())
2977 // If we have not copied the input sections, just resize it.
2978 size_t old_size = checkpoint->input_sections_size();
2979 gold_assert(this->input_sections_.size() >= old_size);
2980 this->input_sections_.resize(old_size);
2982 else
2984 // We need to copy the whole list. This is not efficient for
2985 // extremely large output with hundreads of thousands of input
2986 // objects. We may need to re-think how we should pass sections
2987 // to scripts.
2988 this->input_sections_ = *checkpoint->input_sections();
2991 this->attached_input_sections_are_sorted_ =
2992 checkpoint->attached_input_sections_are_sorted();
2994 // Simply invalidate the relaxed input section map since we do not keep
2995 // track of it.
2996 this->is_relaxed_input_section_map_valid_ = false;
2999 // Print to the map file.
3001 void
3002 Output_section::do_print_to_mapfile(Mapfile* mapfile) const
3004 mapfile->print_output_section(this);
3006 for (Input_section_list::const_iterator p = this->input_sections_.begin();
3007 p != this->input_sections_.end();
3008 ++p)
3009 p->print_to_mapfile(mapfile);
3012 // Print stats for merge sections to stderr.
3014 void
3015 Output_section::print_merge_stats()
3017 Input_section_list::iterator p;
3018 for (p = this->input_sections_.begin();
3019 p != this->input_sections_.end();
3020 ++p)
3021 p->print_merge_stats(this->name_);
3024 // Output segment methods.
3026 Output_segment::Output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags)
3027 : output_data_(),
3028 output_bss_(),
3029 vaddr_(0),
3030 paddr_(0),
3031 memsz_(0),
3032 max_align_(0),
3033 min_p_align_(0),
3034 offset_(0),
3035 filesz_(0),
3036 type_(type),
3037 flags_(flags),
3038 is_max_align_known_(false),
3039 are_addresses_set_(false),
3040 is_large_data_segment_(false)
3044 // Add an Output_section to an Output_segment.
3046 void
3047 Output_segment::add_output_section(Output_section* os,
3048 elfcpp::Elf_Word seg_flags)
3050 gold_assert((os->flags() & elfcpp::SHF_ALLOC) != 0);
3051 gold_assert(!this->is_max_align_known_);
3052 gold_assert(os->is_large_data_section() == this->is_large_data_segment());
3054 // Update the segment flags.
3055 this->flags_ |= seg_flags;
3057 Output_segment::Output_data_list* pdl;
3058 if (os->type() == elfcpp::SHT_NOBITS)
3059 pdl = &this->output_bss_;
3060 else
3061 pdl = &this->output_data_;
3063 // So that PT_NOTE segments will work correctly, we need to ensure
3064 // that all SHT_NOTE sections are adjacent. This will normally
3065 // happen automatically, because all the SHT_NOTE input sections
3066 // will wind up in the same output section. However, it is possible
3067 // for multiple SHT_NOTE input sections to have different section
3068 // flags, and thus be in different output sections, but for the
3069 // different section flags to map into the same segment flags and
3070 // thus the same output segment.
3072 // Note that while there may be many input sections in an output
3073 // section, there are normally only a few output sections in an
3074 // output segment. This loop is expected to be fast.
3076 if (os->type() == elfcpp::SHT_NOTE && !pdl->empty())
3078 Output_segment::Output_data_list::iterator p = pdl->end();
3081 --p;
3082 if ((*p)->is_section_type(elfcpp::SHT_NOTE))
3084 ++p;
3085 pdl->insert(p, os);
3086 return;
3089 while (p != pdl->begin());
3092 // Similarly, so that PT_TLS segments will work, we need to group
3093 // SHF_TLS sections. An SHF_TLS/SHT_NOBITS section is a special
3094 // case: we group the SHF_TLS/SHT_NOBITS sections right after the
3095 // SHF_TLS/SHT_PROGBITS sections. This lets us set up PT_TLS
3096 // correctly. SHF_TLS sections get added to both a PT_LOAD segment
3097 // and the PT_TLS segment -- we do this grouping only for the
3098 // PT_LOAD segment.
3099 if (this->type_ != elfcpp::PT_TLS
3100 && (os->flags() & elfcpp::SHF_TLS) != 0)
3102 pdl = &this->output_data_;
3103 if (!pdl->empty())
3105 bool nobits = os->type() == elfcpp::SHT_NOBITS;
3106 bool sawtls = false;
3107 Output_segment::Output_data_list::iterator p = pdl->end();
3108 gold_assert(p != pdl->begin());
3111 --p;
3112 bool insert;
3113 if ((*p)->is_section_flag_set(elfcpp::SHF_TLS))
3115 sawtls = true;
3116 // Put a NOBITS section after the first TLS section.
3117 // Put a PROGBITS section after the first
3118 // TLS/PROGBITS section.
3119 insert = nobits || !(*p)->is_section_type(elfcpp::SHT_NOBITS);
3121 else
3123 // If we've gone past the TLS sections, but we've
3124 // seen a TLS section, then we need to insert this
3125 // section now.
3126 insert = sawtls;
3129 if (insert)
3131 ++p;
3132 pdl->insert(p, os);
3133 return;
3136 while (p != pdl->begin());
3139 // There are no TLS sections yet; put this one at the requested
3140 // location in the section list.
3143 // For the PT_GNU_RELRO segment, we need to group relro sections,
3144 // and we need to put them before any non-relro sections. Also,
3145 // relro local sections go before relro non-local sections.
3146 if (parameters->options().relro() && os->is_relro())
3148 gold_assert(pdl == &this->output_data_);
3149 Output_segment::Output_data_list::iterator p;
3150 for (p = pdl->begin(); p != pdl->end(); ++p)
3152 if (!(*p)->is_section())
3153 break;
3155 Output_section* pos = (*p)->output_section();
3156 if (!pos->is_relro()
3157 || (os->is_relro_local() && !pos->is_relro_local()))
3158 break;
3161 pdl->insert(p, os);
3162 return;
3165 // Small data sections go at the end of the list of data sections.
3166 // If OS is not small, and there are small sections, we have to
3167 // insert it before the first small section.
3168 if (os->type() != elfcpp::SHT_NOBITS
3169 && !os->is_small_section()
3170 && !pdl->empty()
3171 && pdl->back()->is_section()
3172 && pdl->back()->output_section()->is_small_section())
3174 for (Output_segment::Output_data_list::iterator p = pdl->begin();
3175 p != pdl->end();
3176 ++p)
3178 if ((*p)->is_section()
3179 && (*p)->output_section()->is_small_section())
3181 pdl->insert(p, os);
3182 return;
3185 gold_unreachable();
3188 // A small BSS section goes at the start of the BSS sections, after
3189 // other small BSS sections.
3190 if (os->type() == elfcpp::SHT_NOBITS && os->is_small_section())
3192 for (Output_segment::Output_data_list::iterator p = pdl->begin();
3193 p != pdl->end();
3194 ++p)
3196 if (!(*p)->is_section()
3197 || !(*p)->output_section()->is_small_section())
3199 pdl->insert(p, os);
3200 return;
3205 // A large BSS section goes at the end of the BSS sections, which
3206 // means that one that is not large must come before the first large
3207 // one.
3208 if (os->type() == elfcpp::SHT_NOBITS
3209 && !os->is_large_section()
3210 && !pdl->empty()
3211 && pdl->back()->is_section()
3212 && pdl->back()->output_section()->is_large_section())
3214 for (Output_segment::Output_data_list::iterator p = pdl->begin();
3215 p != pdl->end();
3216 ++p)
3218 if ((*p)->is_section()
3219 && (*p)->output_section()->is_large_section())
3221 pdl->insert(p, os);
3222 return;
3225 gold_unreachable();
3228 pdl->push_back(os);
3231 // Remove an Output_section from this segment. It is an error if it
3232 // is not present.
3234 void
3235 Output_segment::remove_output_section(Output_section* os)
3237 // We only need this for SHT_PROGBITS.
3238 gold_assert(os->type() == elfcpp::SHT_PROGBITS);
3239 for (Output_data_list::iterator p = this->output_data_.begin();
3240 p != this->output_data_.end();
3241 ++p)
3243 if (*p == os)
3245 this->output_data_.erase(p);
3246 return;
3249 gold_unreachable();
3252 // Add an Output_data (which is not an Output_section) to the start of
3253 // a segment.
3255 void
3256 Output_segment::add_initial_output_data(Output_data* od)
3258 gold_assert(!this->is_max_align_known_);
3259 this->output_data_.push_front(od);
3262 // Return whether the first data section is a relro section.
3264 bool
3265 Output_segment::is_first_section_relro() const
3267 return (!this->output_data_.empty()
3268 && this->output_data_.front()->is_section()
3269 && this->output_data_.front()->output_section()->is_relro());
3272 // Return the maximum alignment of the Output_data in Output_segment.
3274 uint64_t
3275 Output_segment::maximum_alignment()
3277 if (!this->is_max_align_known_)
3279 uint64_t addralign;
3281 addralign = Output_segment::maximum_alignment_list(&this->output_data_);
3282 if (addralign > this->max_align_)
3283 this->max_align_ = addralign;
3285 addralign = Output_segment::maximum_alignment_list(&this->output_bss_);
3286 if (addralign > this->max_align_)
3287 this->max_align_ = addralign;
3289 // If -z relro is in effect, and the first section in this
3290 // segment is a relro section, then the segment must be aligned
3291 // to at least the common page size. This ensures that the
3292 // PT_GNU_RELRO segment will start at a page boundary.
3293 if (this->type_ == elfcpp::PT_LOAD
3294 && parameters->options().relro()
3295 && this->is_first_section_relro())
3297 addralign = parameters->target().common_pagesize();
3298 if (addralign > this->max_align_)
3299 this->max_align_ = addralign;
3302 this->is_max_align_known_ = true;
3305 return this->max_align_;
3308 // Return the maximum alignment of a list of Output_data.
3310 uint64_t
3311 Output_segment::maximum_alignment_list(const Output_data_list* pdl)
3313 uint64_t ret = 0;
3314 for (Output_data_list::const_iterator p = pdl->begin();
3315 p != pdl->end();
3316 ++p)
3318 uint64_t addralign = (*p)->addralign();
3319 if (addralign > ret)
3320 ret = addralign;
3322 return ret;
3325 // Return the number of dynamic relocs applied to this segment.
3327 unsigned int
3328 Output_segment::dynamic_reloc_count() const
3330 return (this->dynamic_reloc_count_list(&this->output_data_)
3331 + this->dynamic_reloc_count_list(&this->output_bss_));
3334 // Return the number of dynamic relocs applied to an Output_data_list.
3336 unsigned int
3337 Output_segment::dynamic_reloc_count_list(const Output_data_list* pdl) const
3339 unsigned int count = 0;
3340 for (Output_data_list::const_iterator p = pdl->begin();
3341 p != pdl->end();
3342 ++p)
3343 count += (*p)->dynamic_reloc_count();
3344 return count;
3347 // Set the section addresses for an Output_segment. If RESET is true,
3348 // reset the addresses first. ADDR is the address and *POFF is the
3349 // file offset. Set the section indexes starting with *PSHNDX.
3350 // Return the address of the immediately following segment. Update
3351 // *POFF and *PSHNDX.
3353 uint64_t
3354 Output_segment::set_section_addresses(const Layout* layout, bool reset,
3355 uint64_t addr, off_t* poff,
3356 unsigned int* pshndx)
3358 gold_assert(this->type_ == elfcpp::PT_LOAD);
3360 if (!reset && this->are_addresses_set_)
3362 gold_assert(this->paddr_ == addr);
3363 addr = this->vaddr_;
3365 else
3367 this->vaddr_ = addr;
3368 this->paddr_ = addr;
3369 this->are_addresses_set_ = true;
3372 bool in_tls = false;
3374 bool in_relro = (parameters->options().relro()
3375 && this->is_first_section_relro());
3377 off_t orig_off = *poff;
3378 this->offset_ = orig_off;
3380 addr = this->set_section_list_addresses(layout, reset, &this->output_data_,
3381 addr, poff, pshndx, &in_tls,
3382 &in_relro);
3383 this->filesz_ = *poff - orig_off;
3385 off_t off = *poff;
3387 uint64_t ret = this->set_section_list_addresses(layout, reset,
3388 &this->output_bss_,
3389 addr, poff, pshndx,
3390 &in_tls, &in_relro);
3392 // If the last section was a TLS section, align upward to the
3393 // alignment of the TLS segment, so that the overall size of the TLS
3394 // segment is aligned.
3395 if (in_tls)
3397 uint64_t segment_align = layout->tls_segment()->maximum_alignment();
3398 *poff = align_address(*poff, segment_align);
3401 // If all the sections were relro sections, align upward to the
3402 // common page size.
3403 if (in_relro)
3405 uint64_t page_align = parameters->target().common_pagesize();
3406 *poff = align_address(*poff, page_align);
3409 this->memsz_ = *poff - orig_off;
3411 // Ignore the file offset adjustments made by the BSS Output_data
3412 // objects.
3413 *poff = off;
3415 return ret;
3418 // Set the addresses and file offsets in a list of Output_data
3419 // structures.
3421 uint64_t
3422 Output_segment::set_section_list_addresses(const Layout* layout, bool reset,
3423 Output_data_list* pdl,
3424 uint64_t addr, off_t* poff,
3425 unsigned int* pshndx,
3426 bool* in_tls, bool* in_relro)
3428 off_t startoff = *poff;
3430 off_t off = startoff;
3431 for (Output_data_list::iterator p = pdl->begin();
3432 p != pdl->end();
3433 ++p)
3435 if (reset)
3436 (*p)->reset_address_and_file_offset();
3438 // When using a linker script the section will most likely
3439 // already have an address.
3440 if (!(*p)->is_address_valid())
3442 uint64_t align = (*p)->addralign();
3444 if ((*p)->is_section_flag_set(elfcpp::SHF_TLS))
3446 // Give the first TLS section the alignment of the
3447 // entire TLS segment. Otherwise the TLS segment as a
3448 // whole may be misaligned.
3449 if (!*in_tls)
3451 Output_segment* tls_segment = layout->tls_segment();
3452 gold_assert(tls_segment != NULL);
3453 uint64_t segment_align = tls_segment->maximum_alignment();
3454 gold_assert(segment_align >= align);
3455 align = segment_align;
3457 *in_tls = true;
3460 else
3462 // If this is the first section after the TLS segment,
3463 // align it to at least the alignment of the TLS
3464 // segment, so that the size of the overall TLS segment
3465 // is aligned.
3466 if (*in_tls)
3468 uint64_t segment_align =
3469 layout->tls_segment()->maximum_alignment();
3470 if (segment_align > align)
3471 align = segment_align;
3473 *in_tls = false;
3477 // If this is a non-relro section after a relro section,
3478 // align it to a common page boundary so that the dynamic
3479 // linker has a page to mark as read-only.
3480 if (*in_relro
3481 && (!(*p)->is_section()
3482 || !(*p)->output_section()->is_relro()))
3484 uint64_t page_align = parameters->target().common_pagesize();
3485 if (page_align > align)
3486 align = page_align;
3487 *in_relro = false;
3490 off = align_address(off, align);
3491 (*p)->set_address_and_file_offset(addr + (off - startoff), off);
3493 else
3495 // The script may have inserted a skip forward, but it
3496 // better not have moved backward.
3497 if ((*p)->address() >= addr + (off - startoff))
3498 off += (*p)->address() - (addr + (off - startoff));
3499 else
3501 if (!layout->script_options()->saw_sections_clause())
3502 gold_unreachable();
3503 else
3505 Output_section* os = (*p)->output_section();
3507 // Cast to unsigned long long to avoid format warnings.
3508 unsigned long long previous_dot =
3509 static_cast<unsigned long long>(addr + (off - startoff));
3510 unsigned long long dot =
3511 static_cast<unsigned long long>((*p)->address());
3513 if (os == NULL)
3514 gold_error(_("dot moves backward in linker script "
3515 "from 0x%llx to 0x%llx"), previous_dot, dot);
3516 else
3517 gold_error(_("address of section '%s' moves backward "
3518 "from 0x%llx to 0x%llx"),
3519 os->name(), previous_dot, dot);
3522 (*p)->set_file_offset(off);
3523 (*p)->finalize_data_size();
3526 // We want to ignore the size of a SHF_TLS or SHT_NOBITS
3527 // section. Such a section does not affect the size of a
3528 // PT_LOAD segment.
3529 if (!(*p)->is_section_flag_set(elfcpp::SHF_TLS)
3530 || !(*p)->is_section_type(elfcpp::SHT_NOBITS))
3531 off += (*p)->data_size();
3533 if ((*p)->is_section())
3535 (*p)->set_out_shndx(*pshndx);
3536 ++*pshndx;
3540 *poff = off;
3541 return addr + (off - startoff);
3544 // For a non-PT_LOAD segment, set the offset from the sections, if
3545 // any.
3547 void
3548 Output_segment::set_offset()
3550 gold_assert(this->type_ != elfcpp::PT_LOAD);
3552 gold_assert(!this->are_addresses_set_);
3554 if (this->output_data_.empty() && this->output_bss_.empty())
3556 this->vaddr_ = 0;
3557 this->paddr_ = 0;
3558 this->are_addresses_set_ = true;
3559 this->memsz_ = 0;
3560 this->min_p_align_ = 0;
3561 this->offset_ = 0;
3562 this->filesz_ = 0;
3563 return;
3566 const Output_data* first;
3567 if (this->output_data_.empty())
3568 first = this->output_bss_.front();
3569 else
3570 first = this->output_data_.front();
3571 this->vaddr_ = first->address();
3572 this->paddr_ = (first->has_load_address()
3573 ? first->load_address()
3574 : this->vaddr_);
3575 this->are_addresses_set_ = true;
3576 this->offset_ = first->offset();
3578 if (this->output_data_.empty())
3579 this->filesz_ = 0;
3580 else
3582 const Output_data* last_data = this->output_data_.back();
3583 this->filesz_ = (last_data->address()
3584 + last_data->data_size()
3585 - this->vaddr_);
3588 const Output_data* last;
3589 if (this->output_bss_.empty())
3590 last = this->output_data_.back();
3591 else
3592 last = this->output_bss_.back();
3593 this->memsz_ = (last->address()
3594 + last->data_size()
3595 - this->vaddr_);
3597 // If this is a TLS segment, align the memory size. The code in
3598 // set_section_list ensures that the section after the TLS segment
3599 // is aligned to give us room.
3600 if (this->type_ == elfcpp::PT_TLS)
3602 uint64_t segment_align = this->maximum_alignment();
3603 gold_assert(this->vaddr_ == align_address(this->vaddr_, segment_align));
3604 this->memsz_ = align_address(this->memsz_, segment_align);
3607 // If this is a RELRO segment, align the memory size. The code in
3608 // set_section_list ensures that the section after the RELRO segment
3609 // is aligned to give us room.
3610 if (this->type_ == elfcpp::PT_GNU_RELRO)
3612 uint64_t page_align = parameters->target().common_pagesize();
3613 gold_assert(this->vaddr_ == align_address(this->vaddr_, page_align));
3614 this->memsz_ = align_address(this->memsz_, page_align);
3618 // Set the TLS offsets of the sections in the PT_TLS segment.
3620 void
3621 Output_segment::set_tls_offsets()
3623 gold_assert(this->type_ == elfcpp::PT_TLS);
3625 for (Output_data_list::iterator p = this->output_data_.begin();
3626 p != this->output_data_.end();
3627 ++p)
3628 (*p)->set_tls_offset(this->vaddr_);
3630 for (Output_data_list::iterator p = this->output_bss_.begin();
3631 p != this->output_bss_.end();
3632 ++p)
3633 (*p)->set_tls_offset(this->vaddr_);
3636 // Return the address of the first section.
3638 uint64_t
3639 Output_segment::first_section_load_address() const
3641 for (Output_data_list::const_iterator p = this->output_data_.begin();
3642 p != this->output_data_.end();
3643 ++p)
3644 if ((*p)->is_section())
3645 return (*p)->has_load_address() ? (*p)->load_address() : (*p)->address();
3647 for (Output_data_list::const_iterator p = this->output_bss_.begin();
3648 p != this->output_bss_.end();
3649 ++p)
3650 if ((*p)->is_section())
3651 return (*p)->has_load_address() ? (*p)->load_address() : (*p)->address();
3653 gold_unreachable();
3656 // Return the number of Output_sections in an Output_segment.
3658 unsigned int
3659 Output_segment::output_section_count() const
3661 return (this->output_section_count_list(&this->output_data_)
3662 + this->output_section_count_list(&this->output_bss_));
3665 // Return the number of Output_sections in an Output_data_list.
3667 unsigned int
3668 Output_segment::output_section_count_list(const Output_data_list* pdl) const
3670 unsigned int count = 0;
3671 for (Output_data_list::const_iterator p = pdl->begin();
3672 p != pdl->end();
3673 ++p)
3675 if ((*p)->is_section())
3676 ++count;
3678 return count;
3681 // Return the section attached to the list segment with the lowest
3682 // load address. This is used when handling a PHDRS clause in a
3683 // linker script.
3685 Output_section*
3686 Output_segment::section_with_lowest_load_address() const
3688 Output_section* found = NULL;
3689 uint64_t found_lma = 0;
3690 this->lowest_load_address_in_list(&this->output_data_, &found, &found_lma);
3692 Output_section* found_data = found;
3693 this->lowest_load_address_in_list(&this->output_bss_, &found, &found_lma);
3694 if (found != found_data && found_data != NULL)
3696 gold_error(_("nobits section %s may not precede progbits section %s "
3697 "in same segment"),
3698 found->name(), found_data->name());
3699 return NULL;
3702 return found;
3705 // Look through a list for a section with a lower load address.
3707 void
3708 Output_segment::lowest_load_address_in_list(const Output_data_list* pdl,
3709 Output_section** found,
3710 uint64_t* found_lma) const
3712 for (Output_data_list::const_iterator p = pdl->begin();
3713 p != pdl->end();
3714 ++p)
3716 if (!(*p)->is_section())
3717 continue;
3718 Output_section* os = static_cast<Output_section*>(*p);
3719 uint64_t lma = (os->has_load_address()
3720 ? os->load_address()
3721 : os->address());
3722 if (*found == NULL || lma < *found_lma)
3724 *found = os;
3725 *found_lma = lma;
3730 // Write the segment data into *OPHDR.
3732 template<int size, bool big_endian>
3733 void
3734 Output_segment::write_header(elfcpp::Phdr_write<size, big_endian>* ophdr)
3736 ophdr->put_p_type(this->type_);
3737 ophdr->put_p_offset(this->offset_);
3738 ophdr->put_p_vaddr(this->vaddr_);
3739 ophdr->put_p_paddr(this->paddr_);
3740 ophdr->put_p_filesz(this->filesz_);
3741 ophdr->put_p_memsz(this->memsz_);
3742 ophdr->put_p_flags(this->flags_);
3743 ophdr->put_p_align(std::max(this->min_p_align_, this->maximum_alignment()));
3746 // Write the section headers into V.
3748 template<int size, bool big_endian>
3749 unsigned char*
3750 Output_segment::write_section_headers(const Layout* layout,
3751 const Stringpool* secnamepool,
3752 unsigned char* v,
3753 unsigned int *pshndx) const
3755 // Every section that is attached to a segment must be attached to a
3756 // PT_LOAD segment, so we only write out section headers for PT_LOAD
3757 // segments.
3758 if (this->type_ != elfcpp::PT_LOAD)
3759 return v;
3761 v = this->write_section_headers_list<size, big_endian>(layout, secnamepool,
3762 &this->output_data_,
3763 v, pshndx);
3764 v = this->write_section_headers_list<size, big_endian>(layout, secnamepool,
3765 &this->output_bss_,
3766 v, pshndx);
3767 return v;
3770 template<int size, bool big_endian>
3771 unsigned char*
3772 Output_segment::write_section_headers_list(const Layout* layout,
3773 const Stringpool* secnamepool,
3774 const Output_data_list* pdl,
3775 unsigned char* v,
3776 unsigned int* pshndx) const
3778 const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
3779 for (Output_data_list::const_iterator p = pdl->begin();
3780 p != pdl->end();
3781 ++p)
3783 if ((*p)->is_section())
3785 const Output_section* ps = static_cast<const Output_section*>(*p);
3786 gold_assert(*pshndx == ps->out_shndx());
3787 elfcpp::Shdr_write<size, big_endian> oshdr(v);
3788 ps->write_header(layout, secnamepool, &oshdr);
3789 v += shdr_size;
3790 ++*pshndx;
3793 return v;
3796 // Print the output sections to the map file.
3798 void
3799 Output_segment::print_sections_to_mapfile(Mapfile* mapfile) const
3801 if (this->type() != elfcpp::PT_LOAD)
3802 return;
3803 this->print_section_list_to_mapfile(mapfile, &this->output_data_);
3804 this->print_section_list_to_mapfile(mapfile, &this->output_bss_);
3807 // Print an output section list to the map file.
3809 void
3810 Output_segment::print_section_list_to_mapfile(Mapfile* mapfile,
3811 const Output_data_list* pdl) const
3813 for (Output_data_list::const_iterator p = pdl->begin();
3814 p != pdl->end();
3815 ++p)
3816 (*p)->print_to_mapfile(mapfile);
3819 // Output_file methods.
3821 Output_file::Output_file(const char* name)
3822 : name_(name),
3823 o_(-1),
3824 file_size_(0),
3825 base_(NULL),
3826 map_is_anonymous_(false),
3827 is_temporary_(false)
3831 // Try to open an existing file. Returns false if the file doesn't
3832 // exist, has a size of 0 or can't be mmapped.
3834 bool
3835 Output_file::open_for_modification()
3837 // The name "-" means "stdout".
3838 if (strcmp(this->name_, "-") == 0)
3839 return false;
3841 // Don't bother opening files with a size of zero.
3842 struct stat s;
3843 if (::stat(this->name_, &s) != 0 || s.st_size == 0)
3844 return false;
3846 int o = open_descriptor(-1, this->name_, O_RDWR, 0);
3847 if (o < 0)
3848 gold_fatal(_("%s: open: %s"), this->name_, strerror(errno));
3849 this->o_ = o;
3850 this->file_size_ = s.st_size;
3852 // If the file can't be mmapped, copying the content to an anonymous
3853 // map will probably negate the performance benefits of incremental
3854 // linking. This could be helped by using views and loading only
3855 // the necessary parts, but this is not supported as of now.
3856 if (!this->map_no_anonymous())
3858 release_descriptor(o, true);
3859 this->o_ = -1;
3860 this->file_size_ = 0;
3861 return false;
3864 return true;
3867 // Open the output file.
3869 void
3870 Output_file::open(off_t file_size)
3872 this->file_size_ = file_size;
3874 // Unlink the file first; otherwise the open() may fail if the file
3875 // is busy (e.g. it's an executable that's currently being executed).
3877 // However, the linker may be part of a system where a zero-length
3878 // file is created for it to write to, with tight permissions (gcc
3879 // 2.95 did something like this). Unlinking the file would work
3880 // around those permission controls, so we only unlink if the file
3881 // has a non-zero size. We also unlink only regular files to avoid
3882 // trouble with directories/etc.
3884 // If we fail, continue; this command is merely a best-effort attempt
3885 // to improve the odds for open().
3887 // We let the name "-" mean "stdout"
3888 if (!this->is_temporary_)
3890 if (strcmp(this->name_, "-") == 0)
3891 this->o_ = STDOUT_FILENO;
3892 else
3894 struct stat s;
3895 if (::stat(this->name_, &s) == 0
3896 && (S_ISREG (s.st_mode) || S_ISLNK (s.st_mode)))
3898 if (s.st_size != 0)
3899 ::unlink(this->name_);
3900 else if (!parameters->options().relocatable())
3902 // If we don't unlink the existing file, add execute
3903 // permission where read permissions already exist
3904 // and where the umask permits.
3905 int mask = ::umask(0);
3906 ::umask(mask);
3907 s.st_mode |= (s.st_mode & 0444) >> 2;
3908 ::chmod(this->name_, s.st_mode & ~mask);
3912 int mode = parameters->options().relocatable() ? 0666 : 0777;
3913 int o = open_descriptor(-1, this->name_, O_RDWR | O_CREAT | O_TRUNC,
3914 mode);
3915 if (o < 0)
3916 gold_fatal(_("%s: open: %s"), this->name_, strerror(errno));
3917 this->o_ = o;
3921 this->map();
3924 // Resize the output file.
3926 void
3927 Output_file::resize(off_t file_size)
3929 // If the mmap is mapping an anonymous memory buffer, this is easy:
3930 // just mremap to the new size. If it's mapping to a file, we want
3931 // to unmap to flush to the file, then remap after growing the file.
3932 if (this->map_is_anonymous_)
3934 void* base = ::mremap(this->base_, this->file_size_, file_size,
3935 MREMAP_MAYMOVE);
3936 if (base == MAP_FAILED)
3937 gold_fatal(_("%s: mremap: %s"), this->name_, strerror(errno));
3938 this->base_ = static_cast<unsigned char*>(base);
3939 this->file_size_ = file_size;
3941 else
3943 this->unmap();
3944 this->file_size_ = file_size;
3945 if (!this->map_no_anonymous())
3946 gold_fatal(_("%s: mmap: %s"), this->name_, strerror(errno));
3950 // Map an anonymous block of memory which will later be written to the
3951 // file. Return whether the map succeeded.
3953 bool
3954 Output_file::map_anonymous()
3956 void* base = ::mmap(NULL, this->file_size_, PROT_READ | PROT_WRITE,
3957 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
3958 if (base != MAP_FAILED)
3960 this->map_is_anonymous_ = true;
3961 this->base_ = static_cast<unsigned char*>(base);
3962 return true;
3964 return false;
3967 // Map the file into memory. Return whether the mapping succeeded.
3969 bool
3970 Output_file::map_no_anonymous()
3972 const int o = this->o_;
3974 // If the output file is not a regular file, don't try to mmap it;
3975 // instead, we'll mmap a block of memory (an anonymous buffer), and
3976 // then later write the buffer to the file.
3977 void* base;
3978 struct stat statbuf;
3979 if (o == STDOUT_FILENO || o == STDERR_FILENO
3980 || ::fstat(o, &statbuf) != 0
3981 || !S_ISREG(statbuf.st_mode)
3982 || this->is_temporary_)
3983 return false;
3985 // Ensure that we have disk space available for the file. If we
3986 // don't do this, it is possible that we will call munmap, close,
3987 // and exit with dirty buffers still in the cache with no assigned
3988 // disk blocks. If the disk is out of space at that point, the
3989 // output file will wind up incomplete, but we will have already
3990 // exited. The alternative to fallocate would be to use fdatasync,
3991 // but that would be a more significant performance hit.
3992 if (::posix_fallocate(o, 0, this->file_size_) < 0)
3993 gold_fatal(_("%s: %s"), this->name_, strerror(errno));
3995 // Map the file into memory.
3996 base = ::mmap(NULL, this->file_size_, PROT_READ | PROT_WRITE,
3997 MAP_SHARED, o, 0);
3999 // The mmap call might fail because of file system issues: the file
4000 // system might not support mmap at all, or it might not support
4001 // mmap with PROT_WRITE.
4002 if (base == MAP_FAILED)
4003 return false;
4005 this->map_is_anonymous_ = false;
4006 this->base_ = static_cast<unsigned char*>(base);
4007 return true;
4010 // Map the file into memory.
4012 void
4013 Output_file::map()
4015 if (this->map_no_anonymous())
4016 return;
4018 // The mmap call might fail because of file system issues: the file
4019 // system might not support mmap at all, or it might not support
4020 // mmap with PROT_WRITE. I'm not sure which errno values we will
4021 // see in all cases, so if the mmap fails for any reason and we
4022 // don't care about file contents, try for an anonymous map.
4023 if (this->map_anonymous())
4024 return;
4026 gold_fatal(_("%s: mmap: failed to allocate %lu bytes for output file: %s"),
4027 this->name_, static_cast<unsigned long>(this->file_size_),
4028 strerror(errno));
4031 // Unmap the file from memory.
4033 void
4034 Output_file::unmap()
4036 if (::munmap(this->base_, this->file_size_) < 0)
4037 gold_error(_("%s: munmap: %s"), this->name_, strerror(errno));
4038 this->base_ = NULL;
4041 // Close the output file.
4043 void
4044 Output_file::close()
4046 // If the map isn't file-backed, we need to write it now.
4047 if (this->map_is_anonymous_ && !this->is_temporary_)
4049 size_t bytes_to_write = this->file_size_;
4050 size_t offset = 0;
4051 while (bytes_to_write > 0)
4053 ssize_t bytes_written = ::write(this->o_, this->base_ + offset,
4054 bytes_to_write);
4055 if (bytes_written == 0)
4056 gold_error(_("%s: write: unexpected 0 return-value"), this->name_);
4057 else if (bytes_written < 0)
4058 gold_error(_("%s: write: %s"), this->name_, strerror(errno));
4059 else
4061 bytes_to_write -= bytes_written;
4062 offset += bytes_written;
4066 this->unmap();
4068 // We don't close stdout or stderr
4069 if (this->o_ != STDOUT_FILENO
4070 && this->o_ != STDERR_FILENO
4071 && !this->is_temporary_)
4072 if (::close(this->o_) < 0)
4073 gold_error(_("%s: close: %s"), this->name_, strerror(errno));
4074 this->o_ = -1;
4077 // Instantiate the templates we need. We could use the configure
4078 // script to restrict this to only the ones for implemented targets.
4080 #ifdef HAVE_TARGET_32_LITTLE
4081 template
4082 off_t
4083 Output_section::add_input_section<32, false>(
4084 Sized_relobj<32, false>* object,
4085 unsigned int shndx,
4086 const char* secname,
4087 const elfcpp::Shdr<32, false>& shdr,
4088 unsigned int reloc_shndx,
4089 bool have_sections_script);
4090 #endif
4092 #ifdef HAVE_TARGET_32_BIG
4093 template
4094 off_t
4095 Output_section::add_input_section<32, true>(
4096 Sized_relobj<32, true>* object,
4097 unsigned int shndx,
4098 const char* secname,
4099 const elfcpp::Shdr<32, true>& shdr,
4100 unsigned int reloc_shndx,
4101 bool have_sections_script);
4102 #endif
4104 #ifdef HAVE_TARGET_64_LITTLE
4105 template
4106 off_t
4107 Output_section::add_input_section<64, false>(
4108 Sized_relobj<64, false>* object,
4109 unsigned int shndx,
4110 const char* secname,
4111 const elfcpp::Shdr<64, false>& shdr,
4112 unsigned int reloc_shndx,
4113 bool have_sections_script);
4114 #endif
4116 #ifdef HAVE_TARGET_64_BIG
4117 template
4118 off_t
4119 Output_section::add_input_section<64, true>(
4120 Sized_relobj<64, true>* object,
4121 unsigned int shndx,
4122 const char* secname,
4123 const elfcpp::Shdr<64, true>& shdr,
4124 unsigned int reloc_shndx,
4125 bool have_sections_script);
4126 #endif
4128 #ifdef HAVE_TARGET_32_LITTLE
4129 template
4130 class Output_reloc<elfcpp::SHT_REL, false, 32, false>;
4131 #endif
4133 #ifdef HAVE_TARGET_32_BIG
4134 template
4135 class Output_reloc<elfcpp::SHT_REL, false, 32, true>;
4136 #endif
4138 #ifdef HAVE_TARGET_64_LITTLE
4139 template
4140 class Output_reloc<elfcpp::SHT_REL, false, 64, false>;
4141 #endif
4143 #ifdef HAVE_TARGET_64_BIG
4144 template
4145 class Output_reloc<elfcpp::SHT_REL, false, 64, true>;
4146 #endif
4148 #ifdef HAVE_TARGET_32_LITTLE
4149 template
4150 class Output_reloc<elfcpp::SHT_REL, true, 32, false>;
4151 #endif
4153 #ifdef HAVE_TARGET_32_BIG
4154 template
4155 class Output_reloc<elfcpp::SHT_REL, true, 32, true>;
4156 #endif
4158 #ifdef HAVE_TARGET_64_LITTLE
4159 template
4160 class Output_reloc<elfcpp::SHT_REL, true, 64, false>;
4161 #endif
4163 #ifdef HAVE_TARGET_64_BIG
4164 template
4165 class Output_reloc<elfcpp::SHT_REL, true, 64, true>;
4166 #endif
4168 #ifdef HAVE_TARGET_32_LITTLE
4169 template
4170 class Output_reloc<elfcpp::SHT_RELA, false, 32, false>;
4171 #endif
4173 #ifdef HAVE_TARGET_32_BIG
4174 template
4175 class Output_reloc<elfcpp::SHT_RELA, false, 32, true>;
4176 #endif
4178 #ifdef HAVE_TARGET_64_LITTLE
4179 template
4180 class Output_reloc<elfcpp::SHT_RELA, false, 64, false>;
4181 #endif
4183 #ifdef HAVE_TARGET_64_BIG
4184 template
4185 class Output_reloc<elfcpp::SHT_RELA, false, 64, true>;
4186 #endif
4188 #ifdef HAVE_TARGET_32_LITTLE
4189 template
4190 class Output_reloc<elfcpp::SHT_RELA, true, 32, false>;
4191 #endif
4193 #ifdef HAVE_TARGET_32_BIG
4194 template
4195 class Output_reloc<elfcpp::SHT_RELA, true, 32, true>;
4196 #endif
4198 #ifdef HAVE_TARGET_64_LITTLE
4199 template
4200 class Output_reloc<elfcpp::SHT_RELA, true, 64, false>;
4201 #endif
4203 #ifdef HAVE_TARGET_64_BIG
4204 template
4205 class Output_reloc<elfcpp::SHT_RELA, true, 64, true>;
4206 #endif
4208 #ifdef HAVE_TARGET_32_LITTLE
4209 template
4210 class Output_data_reloc<elfcpp::SHT_REL, false, 32, false>;
4211 #endif
4213 #ifdef HAVE_TARGET_32_BIG
4214 template
4215 class Output_data_reloc<elfcpp::SHT_REL, false, 32, true>;
4216 #endif
4218 #ifdef HAVE_TARGET_64_LITTLE
4219 template
4220 class Output_data_reloc<elfcpp::SHT_REL, false, 64, false>;
4221 #endif
4223 #ifdef HAVE_TARGET_64_BIG
4224 template
4225 class Output_data_reloc<elfcpp::SHT_REL, false, 64, true>;
4226 #endif
4228 #ifdef HAVE_TARGET_32_LITTLE
4229 template
4230 class Output_data_reloc<elfcpp::SHT_REL, true, 32, false>;
4231 #endif
4233 #ifdef HAVE_TARGET_32_BIG
4234 template
4235 class Output_data_reloc<elfcpp::SHT_REL, true, 32, true>;
4236 #endif
4238 #ifdef HAVE_TARGET_64_LITTLE
4239 template
4240 class Output_data_reloc<elfcpp::SHT_REL, true, 64, false>;
4241 #endif
4243 #ifdef HAVE_TARGET_64_BIG
4244 template
4245 class Output_data_reloc<elfcpp::SHT_REL, true, 64, true>;
4246 #endif
4248 #ifdef HAVE_TARGET_32_LITTLE
4249 template
4250 class Output_data_reloc<elfcpp::SHT_RELA, false, 32, false>;
4251 #endif
4253 #ifdef HAVE_TARGET_32_BIG
4254 template
4255 class Output_data_reloc<elfcpp::SHT_RELA, false, 32, true>;
4256 #endif
4258 #ifdef HAVE_TARGET_64_LITTLE
4259 template
4260 class Output_data_reloc<elfcpp::SHT_RELA, false, 64, false>;
4261 #endif
4263 #ifdef HAVE_TARGET_64_BIG
4264 template
4265 class Output_data_reloc<elfcpp::SHT_RELA, false, 64, true>;
4266 #endif
4268 #ifdef HAVE_TARGET_32_LITTLE
4269 template
4270 class Output_data_reloc<elfcpp::SHT_RELA, true, 32, false>;
4271 #endif
4273 #ifdef HAVE_TARGET_32_BIG
4274 template
4275 class Output_data_reloc<elfcpp::SHT_RELA, true, 32, true>;
4276 #endif
4278 #ifdef HAVE_TARGET_64_LITTLE
4279 template
4280 class Output_data_reloc<elfcpp::SHT_RELA, true, 64, false>;
4281 #endif
4283 #ifdef HAVE_TARGET_64_BIG
4284 template
4285 class Output_data_reloc<elfcpp::SHT_RELA, true, 64, true>;
4286 #endif
4288 #ifdef HAVE_TARGET_32_LITTLE
4289 template
4290 class Output_relocatable_relocs<elfcpp::SHT_REL, 32, false>;
4291 #endif
4293 #ifdef HAVE_TARGET_32_BIG
4294 template
4295 class Output_relocatable_relocs<elfcpp::SHT_REL, 32, true>;
4296 #endif
4298 #ifdef HAVE_TARGET_64_LITTLE
4299 template
4300 class Output_relocatable_relocs<elfcpp::SHT_REL, 64, false>;
4301 #endif
4303 #ifdef HAVE_TARGET_64_BIG
4304 template
4305 class Output_relocatable_relocs<elfcpp::SHT_REL, 64, true>;
4306 #endif
4308 #ifdef HAVE_TARGET_32_LITTLE
4309 template
4310 class Output_relocatable_relocs<elfcpp::SHT_RELA, 32, false>;
4311 #endif
4313 #ifdef HAVE_TARGET_32_BIG
4314 template
4315 class Output_relocatable_relocs<elfcpp::SHT_RELA, 32, true>;
4316 #endif
4318 #ifdef HAVE_TARGET_64_LITTLE
4319 template
4320 class Output_relocatable_relocs<elfcpp::SHT_RELA, 64, false>;
4321 #endif
4323 #ifdef HAVE_TARGET_64_BIG
4324 template
4325 class Output_relocatable_relocs<elfcpp::SHT_RELA, 64, true>;
4326 #endif
4328 #ifdef HAVE_TARGET_32_LITTLE
4329 template
4330 class Output_data_group<32, false>;
4331 #endif
4333 #ifdef HAVE_TARGET_32_BIG
4334 template
4335 class Output_data_group<32, true>;
4336 #endif
4338 #ifdef HAVE_TARGET_64_LITTLE
4339 template
4340 class Output_data_group<64, false>;
4341 #endif
4343 #ifdef HAVE_TARGET_64_BIG
4344 template
4345 class Output_data_group<64, true>;
4346 #endif
4348 #ifdef HAVE_TARGET_32_LITTLE
4349 template
4350 class Output_data_got<32, false>;
4351 #endif
4353 #ifdef HAVE_TARGET_32_BIG
4354 template
4355 class Output_data_got<32, true>;
4356 #endif
4358 #ifdef HAVE_TARGET_64_LITTLE
4359 template
4360 class Output_data_got<64, false>;
4361 #endif
4363 #ifdef HAVE_TARGET_64_BIG
4364 template
4365 class Output_data_got<64, true>;
4366 #endif
4368 } // End namespace gold.