1 // output.cc -- manage the output file for gold
3 // Copyright 2006, 2007, 2008, 2009, 2010 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.
33 #include "libiberty.h"
35 #include "parameters.h"
40 #include "descriptors.h"
43 // Some BSD systems still use MAP_ANON instead of MAP_ANONYMOUS
45 # define MAP_ANONYMOUS MAP_ANON
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.
54 posix_fallocate(int o, off_t offset, off_t len)
56 return ftruncate(o, offset + len);
58 #endif // !defined(HAVE_POSIX_FALLOCATE)
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.
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.
85 Output_data::default_alignment_for_size(int size)
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(
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)
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.
117 Output_section_headers::do_size() const
119 // Count all the sections. Start with 1 for the null section.
121 if (!parameters->options().relocatable())
123 for (Layout::Segment_list::const_iterator p =
124 this->segment_list_->begin();
125 p != this->segment_list_->end();
127 if ((*p)->type() == elfcpp::PT_LOAD)
128 count += (*p)->output_section_count();
132 for (Layout::Section_list::const_iterator p =
133 this->section_list_->begin();
134 p != this->section_list_->end();
136 if (((*p)->flags() & elfcpp::SHF_ALLOC) != 0)
139 count += this->unattached_section_list_->size();
141 const int size = parameters->target().get_size();
144 shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
146 shdr_size = elfcpp::Elf_sizes<64>::shdr_size;
150 return count * shdr_size;
153 // Write out the section headers.
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);
165 #ifdef HAVE_TARGET_32_BIG
166 case Parameters::TARGET_32_BIG:
167 this->do_sized_write<32, true>(of);
170 #ifdef HAVE_TARGET_64_LITTLE
171 case Parameters::TARGET_64_LITTLE:
172 this->do_sized_write<64, false>(of);
175 #ifdef HAVE_TARGET_64_BIG
176 case Parameters::TARGET_64_BIG:
177 this->do_sized_write<64, true>(of);
185 template<int size, bool big_endian>
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);
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);
214 oshdr.put_sh_link(shstrndx);
216 size_t segment_count = this->segment_list_->size();
217 oshdr.put_sh_info(segment_count >= elfcpp::PN_XNUM ? segment_count : 0);
219 oshdr.put_sh_addralign(0);
220 oshdr.put_sh_entsize(0);
225 unsigned int shndx = 1;
226 if (!parameters->options().relocatable())
228 for (Layout::Segment_list::const_iterator p =
229 this->segment_list_->begin();
230 p != this->segment_list_->end();
232 v = (*p)->write_section_headers<size, big_endian>(this->layout_,
239 for (Layout::Section_list::const_iterator p =
240 this->section_list_->begin();
241 p != this->section_list_->end();
244 // We do unallocated sections below, except that group
245 // sections have to come first.
246 if (((*p)->flags() & elfcpp::SHF_ALLOC) == 0
247 && (*p)->type() != elfcpp::SHT_GROUP)
249 gold_assert(shndx == (*p)->out_shndx());
250 elfcpp::Shdr_write<size, big_endian> oshdr(v);
251 (*p)->write_header(this->layout_, this->secnamepool_, &oshdr);
257 for (Layout::Section_list::const_iterator p =
258 this->unattached_section_list_->begin();
259 p != this->unattached_section_list_->end();
262 // For a relocatable link, we did unallocated group sections
263 // above, since they have to come first.
264 if ((*p)->type() == elfcpp::SHT_GROUP
265 && parameters->options().relocatable())
267 gold_assert(shndx == (*p)->out_shndx());
268 elfcpp::Shdr_write<size, big_endian> oshdr(v);
269 (*p)->write_header(this->layout_, this->secnamepool_, &oshdr);
274 of->write_output_view(this->offset(), all_shdrs_size, view);
277 // Output_segment_header methods.
279 Output_segment_headers::Output_segment_headers(
280 const Layout::Segment_list& segment_list)
281 : segment_list_(segment_list)
283 this->set_current_data_size_for_child(this->do_size());
287 Output_segment_headers::do_write(Output_file* of)
289 switch (parameters->size_and_endianness())
291 #ifdef HAVE_TARGET_32_LITTLE
292 case Parameters::TARGET_32_LITTLE:
293 this->do_sized_write<32, false>(of);
296 #ifdef HAVE_TARGET_32_BIG
297 case Parameters::TARGET_32_BIG:
298 this->do_sized_write<32, true>(of);
301 #ifdef HAVE_TARGET_64_LITTLE
302 case Parameters::TARGET_64_LITTLE:
303 this->do_sized_write<64, false>(of);
306 #ifdef HAVE_TARGET_64_BIG
307 case Parameters::TARGET_64_BIG:
308 this->do_sized_write<64, true>(of);
316 template<int size, bool big_endian>
318 Output_segment_headers::do_sized_write(Output_file* of)
320 const int phdr_size = elfcpp::Elf_sizes<size>::phdr_size;
321 off_t all_phdrs_size = this->segment_list_.size() * phdr_size;
322 gold_assert(all_phdrs_size == this->data_size());
323 unsigned char* view = of->get_output_view(this->offset(),
325 unsigned char* v = view;
326 for (Layout::Segment_list::const_iterator p = this->segment_list_.begin();
327 p != this->segment_list_.end();
330 elfcpp::Phdr_write<size, big_endian> ophdr(v);
331 (*p)->write_header(&ophdr);
335 gold_assert(v - view == all_phdrs_size);
337 of->write_output_view(this->offset(), all_phdrs_size, view);
341 Output_segment_headers::do_size() const
343 const int size = parameters->target().get_size();
346 phdr_size = elfcpp::Elf_sizes<32>::phdr_size;
348 phdr_size = elfcpp::Elf_sizes<64>::phdr_size;
352 return this->segment_list_.size() * phdr_size;
355 // Output_file_header methods.
357 Output_file_header::Output_file_header(const Target* target,
358 const Symbol_table* symtab,
359 const Output_segment_headers* osh,
363 segment_header_(osh),
364 section_header_(NULL),
368 this->set_data_size(this->do_size());
371 // Set the section table information for a file header.
374 Output_file_header::set_section_info(const Output_section_headers* shdrs,
375 const Output_section* shstrtab)
377 this->section_header_ = shdrs;
378 this->shstrtab_ = shstrtab;
381 // Write out the file header.
384 Output_file_header::do_write(Output_file* of)
386 gold_assert(this->offset() == 0);
388 switch (parameters->size_and_endianness())
390 #ifdef HAVE_TARGET_32_LITTLE
391 case Parameters::TARGET_32_LITTLE:
392 this->do_sized_write<32, false>(of);
395 #ifdef HAVE_TARGET_32_BIG
396 case Parameters::TARGET_32_BIG:
397 this->do_sized_write<32, true>(of);
400 #ifdef HAVE_TARGET_64_LITTLE
401 case Parameters::TARGET_64_LITTLE:
402 this->do_sized_write<64, false>(of);
405 #ifdef HAVE_TARGET_64_BIG
406 case Parameters::TARGET_64_BIG:
407 this->do_sized_write<64, true>(of);
415 // Write out the file header with appropriate size and endianess.
417 template<int size, bool big_endian>
419 Output_file_header::do_sized_write(Output_file* of)
421 gold_assert(this->offset() == 0);
423 int ehdr_size = elfcpp::Elf_sizes<size>::ehdr_size;
424 unsigned char* view = of->get_output_view(0, ehdr_size);
425 elfcpp::Ehdr_write<size, big_endian> oehdr(view);
427 unsigned char e_ident[elfcpp::EI_NIDENT];
428 memset(e_ident, 0, elfcpp::EI_NIDENT);
429 e_ident[elfcpp::EI_MAG0] = elfcpp::ELFMAG0;
430 e_ident[elfcpp::EI_MAG1] = elfcpp::ELFMAG1;
431 e_ident[elfcpp::EI_MAG2] = elfcpp::ELFMAG2;
432 e_ident[elfcpp::EI_MAG3] = elfcpp::ELFMAG3;
434 e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS32;
436 e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS64;
439 e_ident[elfcpp::EI_DATA] = (big_endian
440 ? elfcpp::ELFDATA2MSB
441 : elfcpp::ELFDATA2LSB);
442 e_ident[elfcpp::EI_VERSION] = elfcpp::EV_CURRENT;
443 oehdr.put_e_ident(e_ident);
446 if (parameters->options().relocatable())
447 e_type = elfcpp::ET_REL;
448 else if (parameters->options().output_is_position_independent())
449 e_type = elfcpp::ET_DYN;
451 e_type = elfcpp::ET_EXEC;
452 oehdr.put_e_type(e_type);
454 oehdr.put_e_machine(this->target_->machine_code());
455 oehdr.put_e_version(elfcpp::EV_CURRENT);
457 oehdr.put_e_entry(this->entry<size>());
459 if (this->segment_header_ == NULL)
460 oehdr.put_e_phoff(0);
462 oehdr.put_e_phoff(this->segment_header_->offset());
464 oehdr.put_e_shoff(this->section_header_->offset());
465 oehdr.put_e_flags(this->target_->processor_specific_flags());
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);
475 oehdr.put_e_phentsize(elfcpp::Elf_sizes<size>::phdr_size);
476 size_t phnum = (this->segment_header_->data_size()
477 / elfcpp::Elf_sizes<size>::phdr_size);
478 if (phnum > elfcpp::PN_XNUM)
479 phnum = elfcpp::PN_XNUM;
480 oehdr.put_e_phnum(phnum);
483 oehdr.put_e_shentsize(elfcpp::Elf_sizes<size>::shdr_size);
484 size_t section_count = (this->section_header_->data_size()
485 / elfcpp::Elf_sizes<size>::shdr_size);
487 if (section_count < elfcpp::SHN_LORESERVE)
488 oehdr.put_e_shnum(this->section_header_->data_size()
489 / elfcpp::Elf_sizes<size>::shdr_size);
491 oehdr.put_e_shnum(0);
493 unsigned int shstrndx = this->shstrtab_->out_shndx();
494 if (shstrndx < elfcpp::SHN_LORESERVE)
495 oehdr.put_e_shstrndx(this->shstrtab_->out_shndx());
497 oehdr.put_e_shstrndx(elfcpp::SHN_XINDEX);
499 // Let the target adjust the ELF header, e.g., to set EI_OSABI in
500 // the e_ident field.
501 parameters->target().adjust_elf_header(view, ehdr_size);
503 of->write_output_view(0, ehdr_size, view);
506 // Return the value to use for the entry address. THIS->ENTRY_ is the
507 // symbol specified on the command line, if any.
510 typename elfcpp::Elf_types<size>::Elf_Addr
511 Output_file_header::entry()
513 const bool should_issue_warning = (this->entry_ != NULL
514 && !parameters->options().relocatable()
515 && !parameters->options().shared());
517 // FIXME: Need to support target specific entry symbol.
518 const char* entry = this->entry_;
522 Symbol* sym = this->symtab_->lookup(entry);
524 typename Sized_symbol<size>::Value_type v;
527 Sized_symbol<size>* ssym;
528 ssym = this->symtab_->get_sized_symbol<size>(sym);
529 if (!ssym->is_defined() && should_issue_warning)
530 gold_warning("entry symbol '%s' exists but is not defined", entry);
535 // We couldn't find the entry symbol. See if we can parse it as
536 // a number. This supports, e.g., -e 0x1000.
538 v = strtoull(entry, &endptr, 0);
541 if (should_issue_warning)
542 gold_warning("cannot find entry symbol '%s'", entry);
550 // Compute the current data size.
553 Output_file_header::do_size() const
555 const int size = parameters->target().get_size();
557 return elfcpp::Elf_sizes<32>::ehdr_size;
559 return elfcpp::Elf_sizes<64>::ehdr_size;
564 // Output_data_const methods.
567 Output_data_const::do_write(Output_file* of)
569 of->write(this->offset(), this->data_.data(), this->data_.size());
572 // Output_data_const_buffer methods.
575 Output_data_const_buffer::do_write(Output_file* of)
577 of->write(this->offset(), this->p_, this->data_size());
580 // Output_section_data methods.
582 // Record the output section, and set the entry size and such.
585 Output_section_data::set_output_section(Output_section* os)
587 gold_assert(this->output_section_ == NULL);
588 this->output_section_ = os;
589 this->do_adjust_output_section(os);
592 // Return the section index of the output section.
595 Output_section_data::do_out_shndx() const
597 gold_assert(this->output_section_ != NULL);
598 return this->output_section_->out_shndx();
601 // Set the alignment, which means we may need to update the alignment
602 // of the output section.
605 Output_section_data::set_addralign(uint64_t addralign)
607 this->addralign_ = addralign;
608 if (this->output_section_ != NULL
609 && this->output_section_->addralign() < addralign)
610 this->output_section_->set_addralign(addralign);
613 // Output_data_strtab methods.
615 // Set the final data size.
618 Output_data_strtab::set_final_data_size()
620 this->strtab_->set_string_offsets();
621 this->set_data_size(this->strtab_->get_strtab_size());
624 // Write out a string table.
627 Output_data_strtab::do_write(Output_file* of)
629 this->strtab_->write(of, this->offset());
632 // Output_reloc methods.
634 // A reloc against a global symbol.
636 template<bool dynamic, int size, bool big_endian>
637 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
644 : address_(address), local_sym_index_(GSYM_CODE), type_(type),
645 is_relative_(is_relative), is_symbolless_(is_symbolless),
646 is_section_symbol_(false), shndx_(INVALID_CODE)
648 // this->type_ is a bitfield; make sure TYPE fits.
649 gold_assert(this->type_ == type);
650 this->u1_.gsym = gsym;
653 this->set_needs_dynsym_index();
656 template<bool dynamic, int size, bool big_endian>
657 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
660 Sized_relobj<size, big_endian>* relobj,
665 : address_(address), local_sym_index_(GSYM_CODE), type_(type),
666 is_relative_(is_relative), is_symbolless_(is_symbolless),
667 is_section_symbol_(false), shndx_(shndx)
669 gold_assert(shndx != INVALID_CODE);
670 // this->type_ is a bitfield; make sure TYPE fits.
671 gold_assert(this->type_ == type);
672 this->u1_.gsym = gsym;
673 this->u2_.relobj = relobj;
675 this->set_needs_dynsym_index();
678 // A reloc against a local symbol.
680 template<bool dynamic, int size, bool big_endian>
681 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
682 Sized_relobj<size, big_endian>* relobj,
683 unsigned int local_sym_index,
689 bool is_section_symbol)
690 : address_(address), local_sym_index_(local_sym_index), type_(type),
691 is_relative_(is_relative), is_symbolless_(is_symbolless),
692 is_section_symbol_(is_section_symbol), shndx_(INVALID_CODE)
694 gold_assert(local_sym_index != GSYM_CODE
695 && local_sym_index != INVALID_CODE);
696 // this->type_ is a bitfield; make sure TYPE fits.
697 gold_assert(this->type_ == type);
698 this->u1_.relobj = relobj;
701 this->set_needs_dynsym_index();
704 template<bool dynamic, int size, bool big_endian>
705 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
706 Sized_relobj<size, big_endian>* relobj,
707 unsigned int local_sym_index,
713 bool is_section_symbol)
714 : address_(address), local_sym_index_(local_sym_index), type_(type),
715 is_relative_(is_relative), is_symbolless_(is_symbolless),
716 is_section_symbol_(is_section_symbol), shndx_(shndx)
718 gold_assert(local_sym_index != GSYM_CODE
719 && local_sym_index != INVALID_CODE);
720 gold_assert(shndx != INVALID_CODE);
721 // this->type_ is a bitfield; make sure TYPE fits.
722 gold_assert(this->type_ == type);
723 this->u1_.relobj = relobj;
724 this->u2_.relobj = relobj;
726 this->set_needs_dynsym_index();
729 // A reloc against the STT_SECTION symbol of an output section.
731 template<bool dynamic, int size, bool big_endian>
732 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
737 : address_(address), local_sym_index_(SECTION_CODE), type_(type),
738 is_relative_(false), is_symbolless_(false),
739 is_section_symbol_(true), shndx_(INVALID_CODE)
741 // this->type_ is a bitfield; make sure TYPE fits.
742 gold_assert(this->type_ == type);
746 this->set_needs_dynsym_index();
748 os->set_needs_symtab_index();
751 template<bool dynamic, int size, bool big_endian>
752 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
755 Sized_relobj<size, big_endian>* relobj,
758 : address_(address), local_sym_index_(SECTION_CODE), type_(type),
759 is_relative_(false), is_symbolless_(false),
760 is_section_symbol_(true), shndx_(shndx)
762 gold_assert(shndx != INVALID_CODE);
763 // this->type_ is a bitfield; make sure TYPE fits.
764 gold_assert(this->type_ == type);
766 this->u2_.relobj = relobj;
768 this->set_needs_dynsym_index();
770 os->set_needs_symtab_index();
773 // An absolute relocation.
775 template<bool dynamic, int size, bool big_endian>
776 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
780 : address_(address), local_sym_index_(0), type_(type),
781 is_relative_(false), is_symbolless_(false),
782 is_section_symbol_(false), shndx_(INVALID_CODE)
784 // this->type_ is a bitfield; make sure TYPE fits.
785 gold_assert(this->type_ == type);
786 this->u1_.relobj = NULL;
790 template<bool dynamic, int size, bool big_endian>
791 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
793 Sized_relobj<size, big_endian>* relobj,
796 : address_(address), local_sym_index_(0), type_(type),
797 is_relative_(false), is_symbolless_(false),
798 is_section_symbol_(false), shndx_(shndx)
800 gold_assert(shndx != INVALID_CODE);
801 // this->type_ is a bitfield; make sure TYPE fits.
802 gold_assert(this->type_ == type);
803 this->u1_.relobj = NULL;
804 this->u2_.relobj = relobj;
807 // A target specific relocation.
809 template<bool dynamic, int size, bool big_endian>
810 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
815 : address_(address), local_sym_index_(TARGET_CODE), type_(type),
816 is_relative_(false), is_symbolless_(false),
817 is_section_symbol_(false), shndx_(INVALID_CODE)
819 // this->type_ is a bitfield; make sure TYPE fits.
820 gold_assert(this->type_ == type);
825 template<bool dynamic, int size, bool big_endian>
826 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
829 Sized_relobj<size, big_endian>* relobj,
832 : address_(address), local_sym_index_(TARGET_CODE), type_(type),
833 is_relative_(false), is_symbolless_(false),
834 is_section_symbol_(false), shndx_(shndx)
836 gold_assert(shndx != INVALID_CODE);
837 // this->type_ is a bitfield; make sure TYPE fits.
838 gold_assert(this->type_ == type);
840 this->u2_.relobj = relobj;
843 // Record that we need a dynamic symbol index for this relocation.
845 template<bool dynamic, int size, bool big_endian>
847 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::
848 set_needs_dynsym_index()
850 if (this->is_symbolless_)
852 switch (this->local_sym_index_)
858 this->u1_.gsym->set_needs_dynsym_entry();
862 this->u1_.os->set_needs_dynsym_index();
866 // The target must take care of this if necessary.
874 const unsigned int lsi = this->local_sym_index_;
875 if (!this->is_section_symbol_)
876 this->u1_.relobj->set_needs_output_dynsym_entry(lsi);
878 this->u1_.relobj->output_section(lsi)->set_needs_dynsym_index();
884 // Get the symbol index of a relocation.
886 template<bool dynamic, int size, bool big_endian>
888 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::get_symbol_index()
892 if (this->is_symbolless_)
894 switch (this->local_sym_index_)
900 if (this->u1_.gsym == NULL)
903 index = this->u1_.gsym->dynsym_index();
905 index = this->u1_.gsym->symtab_index();
910 index = this->u1_.os->dynsym_index();
912 index = this->u1_.os->symtab_index();
916 index = parameters->target().reloc_symbol_index(this->u1_.arg,
921 // Relocations without symbols use a symbol index of 0.
927 const unsigned int lsi = this->local_sym_index_;
928 if (!this->is_section_symbol_)
931 index = this->u1_.relobj->dynsym_index(lsi);
933 index = this->u1_.relobj->symtab_index(lsi);
937 Output_section* os = this->u1_.relobj->output_section(lsi);
938 gold_assert(os != NULL);
940 index = os->dynsym_index();
942 index = os->symtab_index();
947 gold_assert(index != -1U);
951 // For a local section symbol, get the address of the offset ADDEND
952 // within the input section.
954 template<bool dynamic, int size, bool big_endian>
955 typename elfcpp::Elf_types<size>::Elf_Addr
956 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::
957 local_section_offset(Addend addend) const
959 gold_assert(this->local_sym_index_ != GSYM_CODE
960 && this->local_sym_index_ != SECTION_CODE
961 && this->local_sym_index_ != TARGET_CODE
962 && this->local_sym_index_ != INVALID_CODE
963 && this->local_sym_index_ != 0
964 && this->is_section_symbol_);
965 const unsigned int lsi = this->local_sym_index_;
966 Output_section* os = this->u1_.relobj->output_section(lsi);
967 gold_assert(os != NULL);
968 Address offset = this->u1_.relobj->get_output_section_offset(lsi);
969 if (offset != invalid_address)
970 return offset + addend;
971 // This is a merge section.
972 offset = os->output_address(this->u1_.relobj, lsi, addend);
973 gold_assert(offset != invalid_address);
977 // Get the output address of a relocation.
979 template<bool dynamic, int size, bool big_endian>
980 typename elfcpp::Elf_types<size>::Elf_Addr
981 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::get_address() const
983 Address address = this->address_;
984 if (this->shndx_ != INVALID_CODE)
986 Output_section* os = this->u2_.relobj->output_section(this->shndx_);
987 gold_assert(os != NULL);
988 Address off = this->u2_.relobj->get_output_section_offset(this->shndx_);
989 if (off != invalid_address)
990 address += os->address() + off;
993 address = os->output_address(this->u2_.relobj, this->shndx_,
995 gold_assert(address != invalid_address);
998 else if (this->u2_.od != NULL)
999 address += this->u2_.od->address();
1003 // Write out the offset and info fields of a Rel or Rela relocation
1006 template<bool dynamic, int size, bool big_endian>
1007 template<typename Write_rel>
1009 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::write_rel(
1010 Write_rel* wr) const
1012 wr->put_r_offset(this->get_address());
1013 unsigned int sym_index = this->get_symbol_index();
1014 wr->put_r_info(elfcpp::elf_r_info<size>(sym_index, this->type_));
1017 // Write out a Rel relocation.
1019 template<bool dynamic, int size, bool big_endian>
1021 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::write(
1022 unsigned char* pov) const
1024 elfcpp::Rel_write<size, big_endian> orel(pov);
1025 this->write_rel(&orel);
1028 // Get the value of the symbol referred to by a Rel relocation.
1030 template<bool dynamic, int size, bool big_endian>
1031 typename elfcpp::Elf_types<size>::Elf_Addr
1032 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::symbol_value(
1033 Addend addend) const
1035 if (this->local_sym_index_ == GSYM_CODE)
1037 const Sized_symbol<size>* sym;
1038 sym = static_cast<const Sized_symbol<size>*>(this->u1_.gsym);
1039 return sym->value() + addend;
1041 gold_assert(this->local_sym_index_ != SECTION_CODE
1042 && this->local_sym_index_ != TARGET_CODE
1043 && this->local_sym_index_ != INVALID_CODE
1044 && this->local_sym_index_ != 0
1045 && !this->is_section_symbol_);
1046 const unsigned int lsi = this->local_sym_index_;
1047 const Symbol_value<size>* symval = this->u1_.relobj->local_symbol(lsi);
1048 return symval->value(this->u1_.relobj, addend);
1051 // Reloc comparison. This function sorts the dynamic relocs for the
1052 // benefit of the dynamic linker. First we sort all relative relocs
1053 // to the front. Among relative relocs, we sort by output address.
1054 // Among non-relative relocs, we sort by symbol index, then by output
1057 template<bool dynamic, int size, bool big_endian>
1059 Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::
1060 compare(const Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>& r2)
1063 if (this->is_relative_)
1065 if (!r2.is_relative_)
1067 // Otherwise sort by reloc address below.
1069 else if (r2.is_relative_)
1073 unsigned int sym1 = this->get_symbol_index();
1074 unsigned int sym2 = r2.get_symbol_index();
1077 else if (sym1 > sym2)
1079 // Otherwise sort by reloc address.
1082 section_offset_type addr1 = this->get_address();
1083 section_offset_type addr2 = r2.get_address();
1086 else if (addr1 > addr2)
1089 // Final tie breaker, in order to generate the same output on any
1090 // host: reloc type.
1091 unsigned int type1 = this->type_;
1092 unsigned int type2 = r2.type_;
1095 else if (type1 > type2)
1098 // These relocs appear to be exactly the same.
1102 // Write out a Rela relocation.
1104 template<bool dynamic, int size, bool big_endian>
1106 Output_reloc<elfcpp::SHT_RELA, dynamic, size, big_endian>::write(
1107 unsigned char* pov) const
1109 elfcpp::Rela_write<size, big_endian> orel(pov);
1110 this->rel_.write_rel(&orel);
1111 Addend addend = this->addend_;
1112 if (this->rel_.is_target_specific())
1113 addend = parameters->target().reloc_addend(this->rel_.target_arg(),
1114 this->rel_.type(), addend);
1115 else if (this->rel_.is_symbolless())
1116 addend = this->rel_.symbol_value(addend);
1117 else if (this->rel_.is_local_section_symbol())
1118 addend = this->rel_.local_section_offset(addend);
1119 orel.put_r_addend(addend);
1122 // Output_data_reloc_base methods.
1124 // Adjust the output section.
1126 template<int sh_type, bool dynamic, int size, bool big_endian>
1128 Output_data_reloc_base<sh_type, dynamic, size, big_endian>
1129 ::do_adjust_output_section(Output_section* os)
1131 if (sh_type == elfcpp::SHT_REL)
1132 os->set_entsize(elfcpp::Elf_sizes<size>::rel_size);
1133 else if (sh_type == elfcpp::SHT_RELA)
1134 os->set_entsize(elfcpp::Elf_sizes<size>::rela_size);
1138 // A STT_GNU_IFUNC symbol may require a IRELATIVE reloc when doing a
1139 // static link. The backends will generate a dynamic reloc section
1140 // to hold this. In that case we don't want to link to the dynsym
1141 // section, because there isn't one.
1143 os->set_should_link_to_symtab();
1144 else if (parameters->doing_static_link())
1147 os->set_should_link_to_dynsym();
1150 // Write out relocation data.
1152 template<int sh_type, bool dynamic, int size, bool big_endian>
1154 Output_data_reloc_base<sh_type, dynamic, size, big_endian>::do_write(
1157 const off_t off = this->offset();
1158 const off_t oview_size = this->data_size();
1159 unsigned char* const oview = of->get_output_view(off, oview_size);
1161 if (this->sort_relocs())
1163 gold_assert(dynamic);
1164 std::sort(this->relocs_.begin(), this->relocs_.end(),
1165 Sort_relocs_comparison());
1168 unsigned char* pov = oview;
1169 for (typename Relocs::const_iterator p = this->relocs_.begin();
1170 p != this->relocs_.end();
1177 gold_assert(pov - oview == oview_size);
1179 of->write_output_view(off, oview_size, oview);
1181 // We no longer need the relocation entries.
1182 this->relocs_.clear();
1185 // Class Output_relocatable_relocs.
1187 template<int sh_type, int size, bool big_endian>
1189 Output_relocatable_relocs<sh_type, size, big_endian>::set_final_data_size()
1191 this->set_data_size(this->rr_->output_reloc_count()
1192 * Reloc_types<sh_type, size, big_endian>::reloc_size);
1195 // class Output_data_group.
1197 template<int size, bool big_endian>
1198 Output_data_group<size, big_endian>::Output_data_group(
1199 Sized_relobj<size, big_endian>* relobj,
1200 section_size_type entry_count,
1201 elfcpp::Elf_Word flags,
1202 std::vector<unsigned int>* input_shndxes)
1203 : Output_section_data(entry_count * 4, 4, false),
1207 this->input_shndxes_.swap(*input_shndxes);
1210 // Write out the section group, which means translating the section
1211 // indexes to apply to the output file.
1213 template<int size, bool big_endian>
1215 Output_data_group<size, big_endian>::do_write(Output_file* of)
1217 const off_t off = this->offset();
1218 const section_size_type oview_size =
1219 convert_to_section_size_type(this->data_size());
1220 unsigned char* const oview = of->get_output_view(off, oview_size);
1222 elfcpp::Elf_Word* contents = reinterpret_cast<elfcpp::Elf_Word*>(oview);
1223 elfcpp::Swap<32, big_endian>::writeval(contents, this->flags_);
1226 for (std::vector<unsigned int>::const_iterator p =
1227 this->input_shndxes_.begin();
1228 p != this->input_shndxes_.end();
1231 Output_section* os = this->relobj_->output_section(*p);
1233 unsigned int output_shndx;
1235 output_shndx = os->out_shndx();
1238 this->relobj_->error(_("section group retained but "
1239 "group element discarded"));
1243 elfcpp::Swap<32, big_endian>::writeval(contents, output_shndx);
1246 size_t wrote = reinterpret_cast<unsigned char*>(contents) - oview;
1247 gold_assert(wrote == oview_size);
1249 of->write_output_view(off, oview_size, oview);
1251 // We no longer need this information.
1252 this->input_shndxes_.clear();
1255 // Output_data_got::Got_entry methods.
1257 // Write out the entry.
1259 template<int size, bool big_endian>
1261 Output_data_got<size, big_endian>::Got_entry::write(unsigned char* pov) const
1265 switch (this->local_sym_index_)
1269 // If the symbol is resolved locally, we need to write out the
1270 // link-time value, which will be relocated dynamically by a
1271 // RELATIVE relocation.
1272 Symbol* gsym = this->u_.gsym;
1273 if (this->use_plt_offset_ && gsym->has_plt_offset())
1274 val = (parameters->target().plt_section_for_global(gsym)->address()
1275 + gsym->plt_offset());
1278 Sized_symbol<size>* sgsym;
1279 // This cast is a bit ugly. We don't want to put a
1280 // virtual method in Symbol, because we want Symbol to be
1281 // as small as possible.
1282 sgsym = static_cast<Sized_symbol<size>*>(gsym);
1283 val = sgsym->value();
1289 val = this->u_.constant;
1294 const Sized_relobj<size, big_endian>* object = this->u_.object;
1295 const unsigned int lsi = this->local_sym_index_;
1296 const Symbol_value<size>* symval = object->local_symbol(lsi);
1297 if (!this->use_plt_offset_)
1298 val = symval->value(this->u_.object, 0);
1301 const Output_data* plt =
1302 parameters->target().plt_section_for_local(object, lsi);
1303 val = plt->address() + object->local_plt_offset(lsi);
1309 elfcpp::Swap<size, big_endian>::writeval(pov, val);
1312 // Output_data_got methods.
1314 // Add an entry for a global symbol to the GOT. This returns true if
1315 // this is a new GOT entry, false if the symbol already had a GOT
1318 template<int size, bool big_endian>
1320 Output_data_got<size, big_endian>::add_global(
1322 unsigned int got_type)
1324 if (gsym->has_got_offset(got_type))
1327 this->entries_.push_back(Got_entry(gsym, false));
1328 this->set_got_size();
1329 gsym->set_got_offset(got_type, this->last_got_offset());
1333 // Like add_global, but use the PLT offset.
1335 template<int size, bool big_endian>
1337 Output_data_got<size, big_endian>::add_global_plt(Symbol* gsym,
1338 unsigned int got_type)
1340 if (gsym->has_got_offset(got_type))
1343 this->entries_.push_back(Got_entry(gsym, true));
1344 this->set_got_size();
1345 gsym->set_got_offset(got_type, this->last_got_offset());
1349 // Add an entry for a global symbol to the GOT, and add a dynamic
1350 // relocation of type R_TYPE for the GOT entry.
1352 template<int size, bool big_endian>
1354 Output_data_got<size, big_endian>::add_global_with_rel(
1356 unsigned int got_type,
1358 unsigned int r_type)
1360 if (gsym->has_got_offset(got_type))
1363 this->entries_.push_back(Got_entry());
1364 this->set_got_size();
1365 unsigned int got_offset = this->last_got_offset();
1366 gsym->set_got_offset(got_type, got_offset);
1367 rel_dyn->add_global(gsym, r_type, this, got_offset);
1370 template<int size, bool big_endian>
1372 Output_data_got<size, big_endian>::add_global_with_rela(
1374 unsigned int got_type,
1376 unsigned int r_type)
1378 if (gsym->has_got_offset(got_type))
1381 this->entries_.push_back(Got_entry());
1382 this->set_got_size();
1383 unsigned int got_offset = this->last_got_offset();
1384 gsym->set_got_offset(got_type, got_offset);
1385 rela_dyn->add_global(gsym, r_type, this, got_offset, 0);
1388 // Add a pair of entries for a global symbol to the GOT, and add
1389 // dynamic relocations of type R_TYPE_1 and R_TYPE_2, respectively.
1390 // If R_TYPE_2 == 0, add the second entry with no relocation.
1391 template<int size, bool big_endian>
1393 Output_data_got<size, big_endian>::add_global_pair_with_rel(
1395 unsigned int got_type,
1397 unsigned int r_type_1,
1398 unsigned int r_type_2)
1400 if (gsym->has_got_offset(got_type))
1403 this->entries_.push_back(Got_entry());
1404 unsigned int got_offset = this->last_got_offset();
1405 gsym->set_got_offset(got_type, got_offset);
1406 rel_dyn->add_global(gsym, r_type_1, this, got_offset);
1408 this->entries_.push_back(Got_entry());
1411 got_offset = this->last_got_offset();
1412 rel_dyn->add_global(gsym, r_type_2, this, got_offset);
1415 this->set_got_size();
1418 template<int size, bool big_endian>
1420 Output_data_got<size, big_endian>::add_global_pair_with_rela(
1422 unsigned int got_type,
1424 unsigned int r_type_1,
1425 unsigned int r_type_2)
1427 if (gsym->has_got_offset(got_type))
1430 this->entries_.push_back(Got_entry());
1431 unsigned int got_offset = this->last_got_offset();
1432 gsym->set_got_offset(got_type, got_offset);
1433 rela_dyn->add_global(gsym, r_type_1, this, got_offset, 0);
1435 this->entries_.push_back(Got_entry());
1438 got_offset = this->last_got_offset();
1439 rela_dyn->add_global(gsym, r_type_2, this, got_offset, 0);
1442 this->set_got_size();
1445 // Add an entry for a local symbol to the GOT. This returns true if
1446 // this is a new GOT entry, false if the symbol already has a GOT
1449 template<int size, bool big_endian>
1451 Output_data_got<size, big_endian>::add_local(
1452 Sized_relobj<size, big_endian>* object,
1453 unsigned int symndx,
1454 unsigned int got_type)
1456 if (object->local_has_got_offset(symndx, got_type))
1459 this->entries_.push_back(Got_entry(object, symndx, false));
1460 this->set_got_size();
1461 object->set_local_got_offset(symndx, got_type, this->last_got_offset());
1465 // Like add_local, but use the PLT offset.
1467 template<int size, bool big_endian>
1469 Output_data_got<size, big_endian>::add_local_plt(
1470 Sized_relobj<size, big_endian>* object,
1471 unsigned int symndx,
1472 unsigned int got_type)
1474 if (object->local_has_got_offset(symndx, got_type))
1477 this->entries_.push_back(Got_entry(object, symndx, true));
1478 this->set_got_size();
1479 object->set_local_got_offset(symndx, got_type, this->last_got_offset());
1483 // Add an entry for a local symbol to the GOT, and add a dynamic
1484 // relocation of type R_TYPE for the GOT entry.
1486 template<int size, bool big_endian>
1488 Output_data_got<size, big_endian>::add_local_with_rel(
1489 Sized_relobj<size, big_endian>* object,
1490 unsigned int symndx,
1491 unsigned int got_type,
1493 unsigned int r_type)
1495 if (object->local_has_got_offset(symndx, got_type))
1498 this->entries_.push_back(Got_entry());
1499 this->set_got_size();
1500 unsigned int got_offset = this->last_got_offset();
1501 object->set_local_got_offset(symndx, got_type, got_offset);
1502 rel_dyn->add_local(object, symndx, r_type, this, got_offset);
1505 template<int size, bool big_endian>
1507 Output_data_got<size, big_endian>::add_local_with_rela(
1508 Sized_relobj<size, big_endian>* object,
1509 unsigned int symndx,
1510 unsigned int got_type,
1512 unsigned int r_type)
1514 if (object->local_has_got_offset(symndx, got_type))
1517 this->entries_.push_back(Got_entry());
1518 this->set_got_size();
1519 unsigned int got_offset = this->last_got_offset();
1520 object->set_local_got_offset(symndx, got_type, got_offset);
1521 rela_dyn->add_local(object, symndx, r_type, this, got_offset, 0);
1524 // Add a pair of entries for a local symbol to the GOT, and add
1525 // dynamic relocations of type R_TYPE_1 and R_TYPE_2, respectively.
1526 // If R_TYPE_2 == 0, add the second entry with no relocation.
1527 template<int size, bool big_endian>
1529 Output_data_got<size, big_endian>::add_local_pair_with_rel(
1530 Sized_relobj<size, big_endian>* object,
1531 unsigned int symndx,
1533 unsigned int got_type,
1535 unsigned int r_type_1,
1536 unsigned int r_type_2)
1538 if (object->local_has_got_offset(symndx, got_type))
1541 this->entries_.push_back(Got_entry());
1542 unsigned int got_offset = this->last_got_offset();
1543 object->set_local_got_offset(symndx, got_type, got_offset);
1544 Output_section* os = object->output_section(shndx);
1545 rel_dyn->add_output_section(os, r_type_1, this, got_offset);
1547 this->entries_.push_back(Got_entry(object, symndx, false));
1550 got_offset = this->last_got_offset();
1551 rel_dyn->add_output_section(os, r_type_2, this, got_offset);
1554 this->set_got_size();
1557 template<int size, bool big_endian>
1559 Output_data_got<size, big_endian>::add_local_pair_with_rela(
1560 Sized_relobj<size, big_endian>* object,
1561 unsigned int symndx,
1563 unsigned int got_type,
1565 unsigned int r_type_1,
1566 unsigned int r_type_2)
1568 if (object->local_has_got_offset(symndx, got_type))
1571 this->entries_.push_back(Got_entry());
1572 unsigned int got_offset = this->last_got_offset();
1573 object->set_local_got_offset(symndx, got_type, got_offset);
1574 Output_section* os = object->output_section(shndx);
1575 rela_dyn->add_output_section(os, r_type_1, this, got_offset, 0);
1577 this->entries_.push_back(Got_entry(object, symndx, false));
1580 got_offset = this->last_got_offset();
1581 rela_dyn->add_output_section(os, r_type_2, this, got_offset, 0);
1584 this->set_got_size();
1587 // Write out the GOT.
1589 template<int size, bool big_endian>
1591 Output_data_got<size, big_endian>::do_write(Output_file* of)
1593 const int add = size / 8;
1595 const off_t off = this->offset();
1596 const off_t oview_size = this->data_size();
1597 unsigned char* const oview = of->get_output_view(off, oview_size);
1599 unsigned char* pov = oview;
1600 for (typename Got_entries::const_iterator p = this->entries_.begin();
1601 p != this->entries_.end();
1608 gold_assert(pov - oview == oview_size);
1610 of->write_output_view(off, oview_size, oview);
1612 // We no longer need the GOT entries.
1613 this->entries_.clear();
1616 // Output_data_dynamic::Dynamic_entry methods.
1618 // Write out the entry.
1620 template<int size, bool big_endian>
1622 Output_data_dynamic::Dynamic_entry::write(
1624 const Stringpool* pool) const
1626 typename elfcpp::Elf_types<size>::Elf_WXword val;
1627 switch (this->offset_)
1629 case DYNAMIC_NUMBER:
1633 case DYNAMIC_SECTION_SIZE:
1634 val = this->u_.od->data_size();
1635 if (this->od2 != NULL)
1636 val += this->od2->data_size();
1639 case DYNAMIC_SYMBOL:
1641 const Sized_symbol<size>* s =
1642 static_cast<const Sized_symbol<size>*>(this->u_.sym);
1647 case DYNAMIC_STRING:
1648 val = pool->get_offset(this->u_.str);
1652 val = this->u_.od->address() + this->offset_;
1656 elfcpp::Dyn_write<size, big_endian> dw(pov);
1657 dw.put_d_tag(this->tag_);
1661 // Output_data_dynamic methods.
1663 // Adjust the output section to set the entry size.
1666 Output_data_dynamic::do_adjust_output_section(Output_section* os)
1668 if (parameters->target().get_size() == 32)
1669 os->set_entsize(elfcpp::Elf_sizes<32>::dyn_size);
1670 else if (parameters->target().get_size() == 64)
1671 os->set_entsize(elfcpp::Elf_sizes<64>::dyn_size);
1676 // Set the final data size.
1679 Output_data_dynamic::set_final_data_size()
1681 // Add the terminating entry if it hasn't been added.
1682 // Because of relaxation, we can run this multiple times.
1683 if (this->entries_.empty() || this->entries_.back().tag() != elfcpp::DT_NULL)
1685 int extra = parameters->options().spare_dynamic_tags();
1686 for (int i = 0; i < extra; ++i)
1687 this->add_constant(elfcpp::DT_NULL, 0);
1688 this->add_constant(elfcpp::DT_NULL, 0);
1692 if (parameters->target().get_size() == 32)
1693 dyn_size = elfcpp::Elf_sizes<32>::dyn_size;
1694 else if (parameters->target().get_size() == 64)
1695 dyn_size = elfcpp::Elf_sizes<64>::dyn_size;
1698 this->set_data_size(this->entries_.size() * dyn_size);
1701 // Write out the dynamic entries.
1704 Output_data_dynamic::do_write(Output_file* of)
1706 switch (parameters->size_and_endianness())
1708 #ifdef HAVE_TARGET_32_LITTLE
1709 case Parameters::TARGET_32_LITTLE:
1710 this->sized_write<32, false>(of);
1713 #ifdef HAVE_TARGET_32_BIG
1714 case Parameters::TARGET_32_BIG:
1715 this->sized_write<32, true>(of);
1718 #ifdef HAVE_TARGET_64_LITTLE
1719 case Parameters::TARGET_64_LITTLE:
1720 this->sized_write<64, false>(of);
1723 #ifdef HAVE_TARGET_64_BIG
1724 case Parameters::TARGET_64_BIG:
1725 this->sized_write<64, true>(of);
1733 template<int size, bool big_endian>
1735 Output_data_dynamic::sized_write(Output_file* of)
1737 const int dyn_size = elfcpp::Elf_sizes<size>::dyn_size;
1739 const off_t offset = this->offset();
1740 const off_t oview_size = this->data_size();
1741 unsigned char* const oview = of->get_output_view(offset, oview_size);
1743 unsigned char* pov = oview;
1744 for (typename Dynamic_entries::const_iterator p = this->entries_.begin();
1745 p != this->entries_.end();
1748 p->write<size, big_endian>(pov, this->pool_);
1752 gold_assert(pov - oview == oview_size);
1754 of->write_output_view(offset, oview_size, oview);
1756 // We no longer need the dynamic entries.
1757 this->entries_.clear();
1760 // Class Output_symtab_xindex.
1763 Output_symtab_xindex::do_write(Output_file* of)
1765 const off_t offset = this->offset();
1766 const off_t oview_size = this->data_size();
1767 unsigned char* const oview = of->get_output_view(offset, oview_size);
1769 memset(oview, 0, oview_size);
1771 if (parameters->target().is_big_endian())
1772 this->endian_do_write<true>(oview);
1774 this->endian_do_write<false>(oview);
1776 of->write_output_view(offset, oview_size, oview);
1778 // We no longer need the data.
1779 this->entries_.clear();
1782 template<bool big_endian>
1784 Output_symtab_xindex::endian_do_write(unsigned char* const oview)
1786 for (Xindex_entries::const_iterator p = this->entries_.begin();
1787 p != this->entries_.end();
1790 unsigned int symndx = p->first;
1791 gold_assert(symndx * 4 < this->data_size());
1792 elfcpp::Swap<32, big_endian>::writeval(oview + symndx * 4, p->second);
1796 // Output_section::Input_section methods.
1798 // Return the current data size. For an input section we store the size here.
1799 // For an Output_section_data, we have to ask it for the size.
1802 Output_section::Input_section::current_data_size() const
1804 if (this->is_input_section())
1805 return this->u1_.data_size;
1808 this->u2_.posd->pre_finalize_data_size();
1809 return this->u2_.posd->current_data_size();
1813 // Return the data size. For an input section we store the size here.
1814 // For an Output_section_data, we have to ask it for the size.
1817 Output_section::Input_section::data_size() const
1819 if (this->is_input_section())
1820 return this->u1_.data_size;
1822 return this->u2_.posd->data_size();
1825 // Return the object for an input section.
1828 Output_section::Input_section::relobj() const
1830 if (this->is_input_section())
1831 return this->u2_.object;
1832 else if (this->is_merge_section())
1834 gold_assert(this->u2_.pomb->first_relobj() != NULL);
1835 return this->u2_.pomb->first_relobj();
1837 else if (this->is_relaxed_input_section())
1838 return this->u2_.poris->relobj();
1843 // Return the input section index for an input section.
1846 Output_section::Input_section::shndx() const
1848 if (this->is_input_section())
1849 return this->shndx_;
1850 else if (this->is_merge_section())
1852 gold_assert(this->u2_.pomb->first_relobj() != NULL);
1853 return this->u2_.pomb->first_shndx();
1855 else if (this->is_relaxed_input_section())
1856 return this->u2_.poris->shndx();
1861 // Set the address and file offset.
1864 Output_section::Input_section::set_address_and_file_offset(
1867 off_t section_file_offset)
1869 if (this->is_input_section())
1870 this->u2_.object->set_section_offset(this->shndx_,
1871 file_offset - section_file_offset);
1873 this->u2_.posd->set_address_and_file_offset(address, file_offset);
1876 // Reset the address and file offset.
1879 Output_section::Input_section::reset_address_and_file_offset()
1881 if (!this->is_input_section())
1882 this->u2_.posd->reset_address_and_file_offset();
1885 // Finalize the data size.
1888 Output_section::Input_section::finalize_data_size()
1890 if (!this->is_input_section())
1891 this->u2_.posd->finalize_data_size();
1894 // Try to turn an input offset into an output offset. We want to
1895 // return the output offset relative to the start of this
1896 // Input_section in the output section.
1899 Output_section::Input_section::output_offset(
1900 const Relobj* object,
1902 section_offset_type offset,
1903 section_offset_type* poutput) const
1905 if (!this->is_input_section())
1906 return this->u2_.posd->output_offset(object, shndx, offset, poutput);
1909 if (this->shndx_ != shndx || this->u2_.object != object)
1916 // Return whether this is the merge section for the input section
1920 Output_section::Input_section::is_merge_section_for(const Relobj* object,
1921 unsigned int shndx) const
1923 if (this->is_input_section())
1925 return this->u2_.posd->is_merge_section_for(object, shndx);
1928 // Write out the data. We don't have to do anything for an input
1929 // section--they are handled via Object::relocate--but this is where
1930 // we write out the data for an Output_section_data.
1933 Output_section::Input_section::write(Output_file* of)
1935 if (!this->is_input_section())
1936 this->u2_.posd->write(of);
1939 // Write the data to a buffer. As for write(), we don't have to do
1940 // anything for an input section.
1943 Output_section::Input_section::write_to_buffer(unsigned char* buffer)
1945 if (!this->is_input_section())
1946 this->u2_.posd->write_to_buffer(buffer);
1949 // Print to a map file.
1952 Output_section::Input_section::print_to_mapfile(Mapfile* mapfile) const
1954 switch (this->shndx_)
1956 case OUTPUT_SECTION_CODE:
1957 case MERGE_DATA_SECTION_CODE:
1958 case MERGE_STRING_SECTION_CODE:
1959 this->u2_.posd->print_to_mapfile(mapfile);
1962 case RELAXED_INPUT_SECTION_CODE:
1964 Output_relaxed_input_section* relaxed_section =
1965 this->relaxed_input_section();
1966 mapfile->print_input_section(relaxed_section->relobj(),
1967 relaxed_section->shndx());
1971 mapfile->print_input_section(this->u2_.object, this->shndx_);
1976 // Output_section methods.
1978 // Construct an Output_section. NAME will point into a Stringpool.
1980 Output_section::Output_section(const char* name, elfcpp::Elf_Word type,
1981 elfcpp::Elf_Xword flags)
1986 link_section_(NULL),
1988 info_section_(NULL),
1993 order_(ORDER_INVALID),
1998 first_input_offset_(0),
2000 postprocessing_buffer_(NULL),
2001 needs_symtab_index_(false),
2002 needs_dynsym_index_(false),
2003 should_link_to_symtab_(false),
2004 should_link_to_dynsym_(false),
2005 after_input_sections_(false),
2006 requires_postprocessing_(false),
2007 found_in_sections_clause_(false),
2008 has_load_address_(false),
2009 info_uses_section_index_(false),
2010 input_section_order_specified_(false),
2011 may_sort_attached_input_sections_(false),
2012 must_sort_attached_input_sections_(false),
2013 attached_input_sections_are_sorted_(false),
2015 is_small_section_(false),
2016 is_large_section_(false),
2017 generate_code_fills_at_write_(false),
2018 is_entsize_zero_(false),
2019 section_offsets_need_adjustment_(false),
2021 always_keeps_input_sections_(false),
2022 has_fixed_layout_(false),
2025 lookup_maps_(new Output_section_lookup_maps),
2028 // An unallocated section has no address. Forcing this means that
2029 // we don't need special treatment for symbols defined in debug
2031 if ((flags & elfcpp::SHF_ALLOC) == 0)
2032 this->set_address(0);
2035 Output_section::~Output_section()
2037 delete this->checkpoint_;
2040 // Set the entry size.
2043 Output_section::set_entsize(uint64_t v)
2045 if (this->is_entsize_zero_)
2047 else if (this->entsize_ == 0)
2049 else if (this->entsize_ != v)
2052 this->is_entsize_zero_ = 1;
2056 // Add the input section SHNDX, with header SHDR, named SECNAME, in
2057 // OBJECT, to the Output_section. RELOC_SHNDX is the index of a
2058 // relocation section which applies to this section, or 0 if none, or
2059 // -1U if more than one. Return the offset of the input section
2060 // within the output section. Return -1 if the input section will
2061 // receive special handling. In the normal case we don't always keep
2062 // track of input sections for an Output_section. Instead, each
2063 // Object keeps track of the Output_section for each of its input
2064 // sections. However, if HAVE_SECTIONS_SCRIPT is true, we do keep
2065 // track of input sections here; this is used when SECTIONS appears in
2068 template<int size, bool big_endian>
2070 Output_section::add_input_section(Layout* layout,
2071 Sized_relobj<size, big_endian>* object,
2073 const char* secname,
2074 const elfcpp::Shdr<size, big_endian>& shdr,
2075 unsigned int reloc_shndx,
2076 bool have_sections_script)
2078 elfcpp::Elf_Xword addralign = shdr.get_sh_addralign();
2079 if ((addralign & (addralign - 1)) != 0)
2081 object->error(_("invalid alignment %lu for section \"%s\""),
2082 static_cast<unsigned long>(addralign), secname);
2086 if (addralign > this->addralign_)
2087 this->addralign_ = addralign;
2089 typename elfcpp::Elf_types<size>::Elf_WXword sh_flags = shdr.get_sh_flags();
2090 uint64_t entsize = shdr.get_sh_entsize();
2092 // .debug_str is a mergeable string section, but is not always so
2093 // marked by compilers. Mark manually here so we can optimize.
2094 if (strcmp(secname, ".debug_str") == 0)
2096 sh_flags |= (elfcpp::SHF_MERGE | elfcpp::SHF_STRINGS);
2100 this->update_flags_for_input_section(sh_flags);
2101 this->set_entsize(entsize);
2103 // If this is a SHF_MERGE section, we pass all the input sections to
2104 // a Output_data_merge. We don't try to handle relocations for such
2105 // a section. We don't try to handle empty merge sections--they
2106 // mess up the mappings, and are useless anyhow.
2107 // FIXME: Need to handle merge sections during incremental update.
2108 if ((sh_flags & elfcpp::SHF_MERGE) != 0
2110 && shdr.get_sh_size() > 0
2111 && !parameters->incremental())
2113 // Keep information about merged input sections for rebuilding fast
2114 // lookup maps if we have sections-script or we do relaxation.
2115 bool keeps_input_sections = (this->always_keeps_input_sections_
2116 || have_sections_script
2117 || parameters->target().may_relax());
2119 if (this->add_merge_input_section(object, shndx, sh_flags, entsize,
2120 addralign, keeps_input_sections))
2122 // Tell the relocation routines that they need to call the
2123 // output_offset method to determine the final address.
2128 section_size_type input_section_size = shdr.get_sh_size();
2129 section_size_type uncompressed_size;
2130 if (object->section_is_compressed(shndx, &uncompressed_size))
2131 input_section_size = uncompressed_size;
2133 off_t offset_in_section;
2134 off_t aligned_offset_in_section;
2135 if (this->has_fixed_layout())
2137 // For incremental updates, find a chunk of unused space in the section.
2138 offset_in_section = this->free_list_.allocate(input_section_size,
2140 if (offset_in_section == -1)
2141 gold_fatal(_("out of patch space; relink with --incremental-full"));
2142 aligned_offset_in_section = offset_in_section;
2146 offset_in_section = this->current_data_size_for_child();
2147 aligned_offset_in_section = align_address(offset_in_section,
2149 this->set_current_data_size_for_child(aligned_offset_in_section
2150 + input_section_size);
2153 // Determine if we want to delay code-fill generation until the output
2154 // section is written. When the target is relaxing, we want to delay fill
2155 // generating to avoid adjusting them during relaxation. Also, if we are
2156 // sorting input sections we must delay fill generation.
2157 if (!this->generate_code_fills_at_write_
2158 && !have_sections_script
2159 && (sh_flags & elfcpp::SHF_EXECINSTR) != 0
2160 && parameters->target().has_code_fill()
2161 && (parameters->target().may_relax()
2162 || parameters->options().section_ordering_file()))
2164 gold_assert(this->fills_.empty());
2165 this->generate_code_fills_at_write_ = true;
2168 if (aligned_offset_in_section > offset_in_section
2169 && !this->generate_code_fills_at_write_
2170 && !have_sections_script
2171 && (sh_flags & elfcpp::SHF_EXECINSTR) != 0
2172 && parameters->target().has_code_fill())
2174 // We need to add some fill data. Using fill_list_ when
2175 // possible is an optimization, since we will often have fill
2176 // sections without input sections.
2177 off_t fill_len = aligned_offset_in_section - offset_in_section;
2178 if (this->input_sections_.empty())
2179 this->fills_.push_back(Fill(offset_in_section, fill_len));
2182 std::string fill_data(parameters->target().code_fill(fill_len));
2183 Output_data_const* odc = new Output_data_const(fill_data, 1);
2184 this->input_sections_.push_back(Input_section(odc));
2188 // We need to keep track of this section if we are already keeping
2189 // track of sections, or if we are relaxing. Also, if this is a
2190 // section which requires sorting, or which may require sorting in
2191 // the future, we keep track of the sections. If the
2192 // --section-ordering-file option is used to specify the order of
2193 // sections, we need to keep track of sections.
2194 if (this->always_keeps_input_sections_
2195 || have_sections_script
2196 || !this->input_sections_.empty()
2197 || this->may_sort_attached_input_sections()
2198 || this->must_sort_attached_input_sections()
2199 || parameters->options().user_set_Map()
2200 || parameters->target().may_relax()
2201 || parameters->options().section_ordering_file())
2203 Input_section isecn(object, shndx, input_section_size, addralign);
2204 if (parameters->options().section_ordering_file())
2206 unsigned int section_order_index =
2207 layout->find_section_order_index(std::string(secname));
2208 if (section_order_index != 0)
2210 isecn.set_section_order_index(section_order_index);
2211 this->set_input_section_order_specified();
2214 if (this->has_fixed_layout())
2216 // For incremental updates, finalize the address and offset now.
2217 uint64_t addr = this->address();
2218 isecn.set_address_and_file_offset(addr + aligned_offset_in_section,
2219 aligned_offset_in_section,
2222 this->input_sections_.push_back(isecn);
2225 return aligned_offset_in_section;
2228 // Add arbitrary data to an output section.
2231 Output_section::add_output_section_data(Output_section_data* posd)
2233 Input_section inp(posd);
2234 this->add_output_section_data(&inp);
2236 if (posd->is_data_size_valid())
2238 off_t offset_in_section;
2239 if (this->has_fixed_layout())
2241 // For incremental updates, find a chunk of unused space.
2242 offset_in_section = this->free_list_.allocate(posd->data_size(),
2243 posd->addralign(), 0);
2244 if (offset_in_section == -1)
2245 gold_fatal(_("out of patch space; relink with --incremental-full"));
2246 // Finalize the address and offset now.
2247 uint64_t addr = this->address();
2248 off_t offset = this->offset();
2249 posd->set_address_and_file_offset(addr + offset_in_section,
2250 offset + offset_in_section);
2254 offset_in_section = this->current_data_size_for_child();
2255 off_t aligned_offset_in_section = align_address(offset_in_section,
2257 this->set_current_data_size_for_child(aligned_offset_in_section
2258 + posd->data_size());
2261 else if (this->has_fixed_layout())
2263 // For incremental updates, arrange for the data to have a fixed layout.
2264 // This will mean that additions to the data must be allocated from
2265 // free space within the containing output section.
2266 uint64_t addr = this->address();
2267 posd->set_address(addr);
2268 posd->set_file_offset(0);
2269 // FIXME: Mark *POSD as part of a fixed-layout section.
2273 // Add a relaxed input section.
2276 Output_section::add_relaxed_input_section(Layout* layout,
2277 Output_relaxed_input_section* poris,
2278 const std::string& name)
2280 Input_section inp(poris);
2282 // If the --section-ordering-file option is used to specify the order of
2283 // sections, we need to keep track of sections.
2284 if (parameters->options().section_ordering_file())
2286 unsigned int section_order_index =
2287 layout->find_section_order_index(name);
2288 if (section_order_index != 0)
2290 inp.set_section_order_index(section_order_index);
2291 this->set_input_section_order_specified();
2295 this->add_output_section_data(&inp);
2296 if (this->lookup_maps_->is_valid())
2297 this->lookup_maps_->add_relaxed_input_section(poris->relobj(),
2298 poris->shndx(), poris);
2300 // For a relaxed section, we use the current data size. Linker scripts
2301 // get all the input sections, including relaxed one from an output
2302 // section and add them back to them same output section to compute the
2303 // output section size. If we do not account for sizes of relaxed input
2304 // sections, an output section would be incorrectly sized.
2305 off_t offset_in_section = this->current_data_size_for_child();
2306 off_t aligned_offset_in_section = align_address(offset_in_section,
2307 poris->addralign());
2308 this->set_current_data_size_for_child(aligned_offset_in_section
2309 + poris->current_data_size());
2312 // Add arbitrary data to an output section by Input_section.
2315 Output_section::add_output_section_data(Input_section* inp)
2317 if (this->input_sections_.empty())
2318 this->first_input_offset_ = this->current_data_size_for_child();
2320 this->input_sections_.push_back(*inp);
2322 uint64_t addralign = inp->addralign();
2323 if (addralign > this->addralign_)
2324 this->addralign_ = addralign;
2326 inp->set_output_section(this);
2329 // Add a merge section to an output section.
2332 Output_section::add_output_merge_section(Output_section_data* posd,
2333 bool is_string, uint64_t entsize)
2335 Input_section inp(posd, is_string, entsize);
2336 this->add_output_section_data(&inp);
2339 // Add an input section to a SHF_MERGE section.
2342 Output_section::add_merge_input_section(Relobj* object, unsigned int shndx,
2343 uint64_t flags, uint64_t entsize,
2345 bool keeps_input_sections)
2347 bool is_string = (flags & elfcpp::SHF_STRINGS) != 0;
2349 // We only merge strings if the alignment is not more than the
2350 // character size. This could be handled, but it's unusual.
2351 if (is_string && addralign > entsize)
2354 // We cannot restore merged input section states.
2355 gold_assert(this->checkpoint_ == NULL);
2357 // Look up merge sections by required properties.
2358 // Currently, we only invalidate the lookup maps in script processing
2359 // and relaxation. We should not have done either when we reach here.
2360 // So we assume that the lookup maps are valid to simply code.
2361 gold_assert(this->lookup_maps_->is_valid());
2362 Merge_section_properties msp(is_string, entsize, addralign);
2363 Output_merge_base* pomb = this->lookup_maps_->find_merge_section(msp);
2364 bool is_new = false;
2367 gold_assert(pomb->is_string() == is_string
2368 && pomb->entsize() == entsize
2369 && pomb->addralign() == addralign);
2373 // Create a new Output_merge_data or Output_merge_string_data.
2375 pomb = new Output_merge_data(entsize, addralign);
2381 pomb = new Output_merge_string<char>(addralign);
2384 pomb = new Output_merge_string<uint16_t>(addralign);
2387 pomb = new Output_merge_string<uint32_t>(addralign);
2393 // If we need to do script processing or relaxation, we need to keep
2394 // the original input sections to rebuild the fast lookup maps.
2395 if (keeps_input_sections)
2396 pomb->set_keeps_input_sections();
2400 if (pomb->add_input_section(object, shndx))
2402 // Add new merge section to this output section and link merge
2403 // section properties to new merge section in map.
2406 this->add_output_merge_section(pomb, is_string, entsize);
2407 this->lookup_maps_->add_merge_section(msp, pomb);
2410 // Add input section to new merge section and link input section to new
2411 // merge section in map.
2412 this->lookup_maps_->add_merge_input_section(object, shndx, pomb);
2417 // If add_input_section failed, delete new merge section to avoid
2418 // exporting empty merge sections in Output_section::get_input_section.
2425 // Build a relaxation map to speed up relaxation of existing input sections.
2426 // Look up to the first LIMIT elements in INPUT_SECTIONS.
2429 Output_section::build_relaxation_map(
2430 const Input_section_list& input_sections,
2432 Relaxation_map* relaxation_map) const
2434 for (size_t i = 0; i < limit; ++i)
2436 const Input_section& is(input_sections[i]);
2437 if (is.is_input_section() || is.is_relaxed_input_section())
2439 Section_id sid(is.relobj(), is.shndx());
2440 (*relaxation_map)[sid] = i;
2445 // Convert regular input sections in INPUT_SECTIONS into relaxed input
2446 // sections in RELAXED_SECTIONS. MAP is a prebuilt map from section id
2447 // indices of INPUT_SECTIONS.
2450 Output_section::convert_input_sections_in_list_to_relaxed_sections(
2451 const std::vector<Output_relaxed_input_section*>& relaxed_sections,
2452 const Relaxation_map& map,
2453 Input_section_list* input_sections)
2455 for (size_t i = 0; i < relaxed_sections.size(); ++i)
2457 Output_relaxed_input_section* poris = relaxed_sections[i];
2458 Section_id sid(poris->relobj(), poris->shndx());
2459 Relaxation_map::const_iterator p = map.find(sid);
2460 gold_assert(p != map.end());
2461 gold_assert((*input_sections)[p->second].is_input_section());
2463 // Remember section order index of original input section
2464 // if it is set. Copy it to the relaxed input section.
2466 (*input_sections)[p->second].section_order_index();
2467 (*input_sections)[p->second] = Input_section(poris);
2468 (*input_sections)[p->second].set_section_order_index(soi);
2472 // Convert regular input sections into relaxed input sections. RELAXED_SECTIONS
2473 // is a vector of pointers to Output_relaxed_input_section or its derived
2474 // classes. The relaxed sections must correspond to existing input sections.
2477 Output_section::convert_input_sections_to_relaxed_sections(
2478 const std::vector<Output_relaxed_input_section*>& relaxed_sections)
2480 gold_assert(parameters->target().may_relax());
2482 // We want to make sure that restore_states does not undo the effect of
2483 // this. If there is no checkpoint active, just search the current
2484 // input section list and replace the sections there. If there is
2485 // a checkpoint, also replace the sections there.
2487 // By default, we look at the whole list.
2488 size_t limit = this->input_sections_.size();
2490 if (this->checkpoint_ != NULL)
2492 // Replace input sections with relaxed input section in the saved
2493 // copy of the input section list.
2494 if (this->checkpoint_->input_sections_saved())
2497 this->build_relaxation_map(
2498 *(this->checkpoint_->input_sections()),
2499 this->checkpoint_->input_sections()->size(),
2501 this->convert_input_sections_in_list_to_relaxed_sections(
2504 this->checkpoint_->input_sections());
2508 // We have not copied the input section list yet. Instead, just
2509 // look at the portion that would be saved.
2510 limit = this->checkpoint_->input_sections_size();
2514 // Convert input sections in input_section_list.
2516 this->build_relaxation_map(this->input_sections_, limit, &map);
2517 this->convert_input_sections_in_list_to_relaxed_sections(
2520 &this->input_sections_);
2522 // Update fast look-up map.
2523 if (this->lookup_maps_->is_valid())
2524 for (size_t i = 0; i < relaxed_sections.size(); ++i)
2526 Output_relaxed_input_section* poris = relaxed_sections[i];
2527 this->lookup_maps_->add_relaxed_input_section(poris->relobj(),
2528 poris->shndx(), poris);
2532 // Update the output section flags based on input section flags.
2535 Output_section::update_flags_for_input_section(elfcpp::Elf_Xword flags)
2537 // If we created the section with SHF_ALLOC clear, we set the
2538 // address. If we are now setting the SHF_ALLOC flag, we need to
2540 if ((this->flags_ & elfcpp::SHF_ALLOC) == 0
2541 && (flags & elfcpp::SHF_ALLOC) != 0)
2542 this->mark_address_invalid();
2544 this->flags_ |= (flags
2545 & (elfcpp::SHF_WRITE
2547 | elfcpp::SHF_EXECINSTR));
2549 if ((flags & elfcpp::SHF_MERGE) == 0)
2550 this->flags_ &=~ elfcpp::SHF_MERGE;
2553 if (this->current_data_size_for_child() == 0)
2554 this->flags_ |= elfcpp::SHF_MERGE;
2557 if ((flags & elfcpp::SHF_STRINGS) == 0)
2558 this->flags_ &=~ elfcpp::SHF_STRINGS;
2561 if (this->current_data_size_for_child() == 0)
2562 this->flags_ |= elfcpp::SHF_STRINGS;
2566 // Find the merge section into which an input section with index SHNDX in
2567 // OBJECT has been added. Return NULL if none found.
2569 Output_section_data*
2570 Output_section::find_merge_section(const Relobj* object,
2571 unsigned int shndx) const
2573 if (!this->lookup_maps_->is_valid())
2574 this->build_lookup_maps();
2575 return this->lookup_maps_->find_merge_section(object, shndx);
2578 // Build the lookup maps for merge and relaxed sections. This is needs
2579 // to be declared as a const methods so that it is callable with a const
2580 // Output_section pointer. The method only updates states of the maps.
2583 Output_section::build_lookup_maps() const
2585 this->lookup_maps_->clear();
2586 for (Input_section_list::const_iterator p = this->input_sections_.begin();
2587 p != this->input_sections_.end();
2590 if (p->is_merge_section())
2592 Output_merge_base* pomb = p->output_merge_base();
2593 Merge_section_properties msp(pomb->is_string(), pomb->entsize(),
2595 this->lookup_maps_->add_merge_section(msp, pomb);
2596 for (Output_merge_base::Input_sections::const_iterator is =
2597 pomb->input_sections_begin();
2598 is != pomb->input_sections_end();
2601 const Const_section_id& csid = *is;
2602 this->lookup_maps_->add_merge_input_section(csid.first,
2607 else if (p->is_relaxed_input_section())
2609 Output_relaxed_input_section* poris = p->relaxed_input_section();
2610 this->lookup_maps_->add_relaxed_input_section(poris->relobj(),
2611 poris->shndx(), poris);
2616 // Find an relaxed input section corresponding to an input section
2617 // in OBJECT with index SHNDX.
2619 const Output_relaxed_input_section*
2620 Output_section::find_relaxed_input_section(const Relobj* object,
2621 unsigned int shndx) const
2623 if (!this->lookup_maps_->is_valid())
2624 this->build_lookup_maps();
2625 return this->lookup_maps_->find_relaxed_input_section(object, shndx);
2628 // Given an address OFFSET relative to the start of input section
2629 // SHNDX in OBJECT, return whether this address is being included in
2630 // the final link. This should only be called if SHNDX in OBJECT has
2631 // a special mapping.
2634 Output_section::is_input_address_mapped(const Relobj* object,
2638 // Look at the Output_section_data_maps first.
2639 const Output_section_data* posd = this->find_merge_section(object, shndx);
2641 posd = this->find_relaxed_input_section(object, shndx);
2645 section_offset_type output_offset;
2646 bool found = posd->output_offset(object, shndx, offset, &output_offset);
2648 return output_offset != -1;
2651 // Fall back to the slow look-up.
2652 for (Input_section_list::const_iterator p = this->input_sections_.begin();
2653 p != this->input_sections_.end();
2656 section_offset_type output_offset;
2657 if (p->output_offset(object, shndx, offset, &output_offset))
2658 return output_offset != -1;
2661 // By default we assume that the address is mapped. This should
2662 // only be called after we have passed all sections to Layout. At
2663 // that point we should know what we are discarding.
2667 // Given an address OFFSET relative to the start of input section
2668 // SHNDX in object OBJECT, return the output offset relative to the
2669 // start of the input section in the output section. This should only
2670 // be called if SHNDX in OBJECT has a special mapping.
2673 Output_section::output_offset(const Relobj* object, unsigned int shndx,
2674 section_offset_type offset) const
2676 // This can only be called meaningfully when we know the data size
2678 gold_assert(this->is_data_size_valid());
2680 // Look at the Output_section_data_maps first.
2681 const Output_section_data* posd = this->find_merge_section(object, shndx);
2683 posd = this->find_relaxed_input_section(object, shndx);
2686 section_offset_type output_offset;
2687 bool found = posd->output_offset(object, shndx, offset, &output_offset);
2689 return output_offset;
2692 // Fall back to the slow look-up.
2693 for (Input_section_list::const_iterator p = this->input_sections_.begin();
2694 p != this->input_sections_.end();
2697 section_offset_type output_offset;
2698 if (p->output_offset(object, shndx, offset, &output_offset))
2699 return output_offset;
2704 // Return the output virtual address of OFFSET relative to the start
2705 // of input section SHNDX in object OBJECT.
2708 Output_section::output_address(const Relobj* object, unsigned int shndx,
2711 uint64_t addr = this->address() + this->first_input_offset_;
2713 // Look at the Output_section_data_maps first.
2714 const Output_section_data* posd = this->find_merge_section(object, shndx);
2716 posd = this->find_relaxed_input_section(object, shndx);
2717 if (posd != NULL && posd->is_address_valid())
2719 section_offset_type output_offset;
2720 bool found = posd->output_offset(object, shndx, offset, &output_offset);
2722 return posd->address() + output_offset;
2725 // Fall back to the slow look-up.
2726 for (Input_section_list::const_iterator p = this->input_sections_.begin();
2727 p != this->input_sections_.end();
2730 addr = align_address(addr, p->addralign());
2731 section_offset_type output_offset;
2732 if (p->output_offset(object, shndx, offset, &output_offset))
2734 if (output_offset == -1)
2736 return addr + output_offset;
2738 addr += p->data_size();
2741 // If we get here, it means that we don't know the mapping for this
2742 // input section. This might happen in principle if
2743 // add_input_section were called before add_output_section_data.
2744 // But it should never actually happen.
2749 // Find the output address of the start of the merged section for
2750 // input section SHNDX in object OBJECT.
2753 Output_section::find_starting_output_address(const Relobj* object,
2755 uint64_t* paddr) const
2757 // FIXME: This becomes a bottle-neck if we have many relaxed sections.
2758 // Looking up the merge section map does not always work as we sometimes
2759 // find a merge section without its address set.
2760 uint64_t addr = this->address() + this->first_input_offset_;
2761 for (Input_section_list::const_iterator p = this->input_sections_.begin();
2762 p != this->input_sections_.end();
2765 addr = align_address(addr, p->addralign());
2767 // It would be nice if we could use the existing output_offset
2768 // method to get the output offset of input offset 0.
2769 // Unfortunately we don't know for sure that input offset 0 is
2771 if (p->is_merge_section_for(object, shndx))
2777 addr += p->data_size();
2780 // We couldn't find a merge output section for this input section.
2784 // Update the data size of an Output_section.
2787 Output_section::update_data_size()
2789 if (this->input_sections_.empty())
2792 if (this->must_sort_attached_input_sections()
2793 || this->input_section_order_specified())
2794 this->sort_attached_input_sections();
2796 off_t off = this->first_input_offset_;
2797 for (Input_section_list::iterator p = this->input_sections_.begin();
2798 p != this->input_sections_.end();
2801 off = align_address(off, p->addralign());
2802 off += p->current_data_size();
2805 this->set_current_data_size_for_child(off);
2808 // Set the data size of an Output_section. This is where we handle
2809 // setting the addresses of any Output_section_data objects.
2812 Output_section::set_final_data_size()
2814 if (this->input_sections_.empty())
2816 this->set_data_size(this->current_data_size_for_child());
2820 if (this->must_sort_attached_input_sections()
2821 || this->input_section_order_specified())
2822 this->sort_attached_input_sections();
2824 uint64_t address = this->address();
2825 off_t startoff = this->offset();
2826 off_t off = startoff + this->first_input_offset_;
2827 for (Input_section_list::iterator p = this->input_sections_.begin();
2828 p != this->input_sections_.end();
2831 off = align_address(off, p->addralign());
2832 p->set_address_and_file_offset(address + (off - startoff), off,
2834 off += p->data_size();
2837 this->set_data_size(off - startoff);
2840 // Reset the address and file offset.
2843 Output_section::do_reset_address_and_file_offset()
2845 // An unallocated section has no address. Forcing this means that
2846 // we don't need special treatment for symbols defined in debug
2847 // sections. We do the same in the constructor. This does not
2848 // apply to NOLOAD sections though.
2849 if (((this->flags_ & elfcpp::SHF_ALLOC) == 0) && !this->is_noload_)
2850 this->set_address(0);
2852 for (Input_section_list::iterator p = this->input_sections_.begin();
2853 p != this->input_sections_.end();
2855 p->reset_address_and_file_offset();
2858 // Return true if address and file offset have the values after reset.
2861 Output_section::do_address_and_file_offset_have_reset_values() const
2863 if (this->is_offset_valid())
2866 // An unallocated section has address 0 after its construction or a reset.
2867 if ((this->flags_ & elfcpp::SHF_ALLOC) == 0)
2868 return this->is_address_valid() && this->address() == 0;
2870 return !this->is_address_valid();
2873 // Set the TLS offset. Called only for SHT_TLS sections.
2876 Output_section::do_set_tls_offset(uint64_t tls_base)
2878 this->tls_offset_ = this->address() - tls_base;
2881 // In a few cases we need to sort the input sections attached to an
2882 // output section. This is used to implement the type of constructor
2883 // priority ordering implemented by the GNU linker, in which the
2884 // priority becomes part of the section name and the sections are
2885 // sorted by name. We only do this for an output section if we see an
2886 // attached input section matching ".ctor.*", ".dtor.*",
2887 // ".init_array.*" or ".fini_array.*".
2889 class Output_section::Input_section_sort_entry
2892 Input_section_sort_entry()
2893 : input_section_(), index_(-1U), section_has_name_(false),
2897 Input_section_sort_entry(const Input_section& input_section,
2899 bool must_sort_attached_input_sections)
2900 : input_section_(input_section), index_(index),
2901 section_has_name_(input_section.is_input_section()
2902 || input_section.is_relaxed_input_section())
2904 if (this->section_has_name_
2905 && must_sort_attached_input_sections)
2907 // This is only called single-threaded from Layout::finalize,
2908 // so it is OK to lock. Unfortunately we have no way to pass
2910 const Task* dummy_task = reinterpret_cast<const Task*>(-1);
2911 Object* obj = (input_section.is_input_section()
2912 ? input_section.relobj()
2913 : input_section.relaxed_input_section()->relobj());
2914 Task_lock_obj<Object> tl(dummy_task, obj);
2916 // This is a slow operation, which should be cached in
2917 // Layout::layout if this becomes a speed problem.
2918 this->section_name_ = obj->section_name(input_section.shndx());
2922 // Return the Input_section.
2923 const Input_section&
2924 input_section() const
2926 gold_assert(this->index_ != -1U);
2927 return this->input_section_;
2930 // The index of this entry in the original list. This is used to
2931 // make the sort stable.
2935 gold_assert(this->index_ != -1U);
2936 return this->index_;
2939 // Whether there is a section name.
2941 section_has_name() const
2942 { return this->section_has_name_; }
2944 // The section name.
2946 section_name() const
2948 gold_assert(this->section_has_name_);
2949 return this->section_name_;
2952 // Return true if the section name has a priority. This is assumed
2953 // to be true if it has a dot after the initial dot.
2955 has_priority() const
2957 gold_assert(this->section_has_name_);
2958 return this->section_name_.find('.', 1) != std::string::npos;
2961 // Return true if this an input file whose base name matches
2962 // FILE_NAME. The base name must have an extension of ".o", and
2963 // must be exactly FILE_NAME.o or FILE_NAME, one character, ".o".
2964 // This is to match crtbegin.o as well as crtbeginS.o without
2965 // getting confused by other possibilities. Overall matching the
2966 // file name this way is a dreadful hack, but the GNU linker does it
2967 // in order to better support gcc, and we need to be compatible.
2969 match_file_name(const char* match_file_name) const
2971 const std::string& file_name(this->input_section_.relobj()->name());
2972 const char* base_name = lbasename(file_name.c_str());
2973 size_t match_len = strlen(match_file_name);
2974 if (strncmp(base_name, match_file_name, match_len) != 0)
2976 size_t base_len = strlen(base_name);
2977 if (base_len != match_len + 2 && base_len != match_len + 3)
2979 return memcmp(base_name + base_len - 2, ".o", 2) == 0;
2982 // Returns 1 if THIS should appear before S in section order, -1 if S
2983 // appears before THIS and 0 if they are not comparable.
2985 compare_section_ordering(const Input_section_sort_entry& s) const
2987 unsigned int this_secn_index = this->input_section_.section_order_index();
2988 unsigned int s_secn_index = s.input_section().section_order_index();
2989 if (this_secn_index > 0 && s_secn_index > 0)
2991 if (this_secn_index < s_secn_index)
2993 else if (this_secn_index > s_secn_index)
3000 // The Input_section we are sorting.
3001 Input_section input_section_;
3002 // The index of this Input_section in the original list.
3003 unsigned int index_;
3004 // Whether this Input_section has a section name--it won't if this
3005 // is some random Output_section_data.
3006 bool section_has_name_;
3007 // The section name if there is one.
3008 std::string section_name_;
3011 // Return true if S1 should come before S2 in the output section.
3014 Output_section::Input_section_sort_compare::operator()(
3015 const Output_section::Input_section_sort_entry& s1,
3016 const Output_section::Input_section_sort_entry& s2) const
3018 // crtbegin.o must come first.
3019 bool s1_begin = s1.match_file_name("crtbegin");
3020 bool s2_begin = s2.match_file_name("crtbegin");
3021 if (s1_begin || s2_begin)
3027 return s1.index() < s2.index();
3030 // crtend.o must come last.
3031 bool s1_end = s1.match_file_name("crtend");
3032 bool s2_end = s2.match_file_name("crtend");
3033 if (s1_end || s2_end)
3039 return s1.index() < s2.index();
3042 // We sort all the sections with no names to the end.
3043 if (!s1.section_has_name() || !s2.section_has_name())
3045 if (s1.section_has_name())
3047 if (s2.section_has_name())
3049 return s1.index() < s2.index();
3052 // A section with a priority follows a section without a priority.
3053 bool s1_has_priority = s1.has_priority();
3054 bool s2_has_priority = s2.has_priority();
3055 if (s1_has_priority && !s2_has_priority)
3057 if (!s1_has_priority && s2_has_priority)
3060 // Check if a section order exists for these sections through a section
3061 // ordering file. If sequence_num is 0, an order does not exist.
3062 int sequence_num = s1.compare_section_ordering(s2);
3063 if (sequence_num != 0)
3064 return sequence_num == 1;
3066 // Otherwise we sort by name.
3067 int compare = s1.section_name().compare(s2.section_name());
3071 // Otherwise we keep the input order.
3072 return s1.index() < s2.index();
3075 // Return true if S1 should come before S2 in an .init_array or .fini_array
3079 Output_section::Input_section_sort_init_fini_compare::operator()(
3080 const Output_section::Input_section_sort_entry& s1,
3081 const Output_section::Input_section_sort_entry& s2) const
3083 // We sort all the sections with no names to the end.
3084 if (!s1.section_has_name() || !s2.section_has_name())
3086 if (s1.section_has_name())
3088 if (s2.section_has_name())
3090 return s1.index() < s2.index();
3093 // A section without a priority follows a section with a priority.
3094 // This is the reverse of .ctors and .dtors sections.
3095 bool s1_has_priority = s1.has_priority();
3096 bool s2_has_priority = s2.has_priority();
3097 if (s1_has_priority && !s2_has_priority)
3099 if (!s1_has_priority && s2_has_priority)
3102 // Check if a section order exists for these sections through a section
3103 // ordering file. If sequence_num is 0, an order does not exist.
3104 int sequence_num = s1.compare_section_ordering(s2);
3105 if (sequence_num != 0)
3106 return sequence_num == 1;
3108 // Otherwise we sort by name.
3109 int compare = s1.section_name().compare(s2.section_name());
3113 // Otherwise we keep the input order.
3114 return s1.index() < s2.index();
3117 // Return true if S1 should come before S2. Sections that do not match
3118 // any pattern in the section ordering file are placed ahead of the sections
3119 // that match some pattern.
3122 Output_section::Input_section_sort_section_order_index_compare::operator()(
3123 const Output_section::Input_section_sort_entry& s1,
3124 const Output_section::Input_section_sort_entry& s2) const
3126 unsigned int s1_secn_index = s1.input_section().section_order_index();
3127 unsigned int s2_secn_index = s2.input_section().section_order_index();
3129 // Keep input order if section ordering cannot determine order.
3130 if (s1_secn_index == s2_secn_index)
3131 return s1.index() < s2.index();
3133 return s1_secn_index < s2_secn_index;
3136 // Sort the input sections attached to an output section.
3139 Output_section::sort_attached_input_sections()
3141 if (this->attached_input_sections_are_sorted_)
3144 if (this->checkpoint_ != NULL
3145 && !this->checkpoint_->input_sections_saved())
3146 this->checkpoint_->save_input_sections();
3148 // The only thing we know about an input section is the object and
3149 // the section index. We need the section name. Recomputing this
3150 // is slow but this is an unusual case. If this becomes a speed
3151 // problem we can cache the names as required in Layout::layout.
3153 // We start by building a larger vector holding a copy of each
3154 // Input_section, plus its current index in the list and its name.
3155 std::vector<Input_section_sort_entry> sort_list;
3158 for (Input_section_list::iterator p = this->input_sections_.begin();
3159 p != this->input_sections_.end();
3161 sort_list.push_back(Input_section_sort_entry(*p, i,
3162 this->must_sort_attached_input_sections()));
3164 // Sort the input sections.
3165 if (this->must_sort_attached_input_sections())
3167 if (this->type() == elfcpp::SHT_PREINIT_ARRAY
3168 || this->type() == elfcpp::SHT_INIT_ARRAY
3169 || this->type() == elfcpp::SHT_FINI_ARRAY)
3170 std::sort(sort_list.begin(), sort_list.end(),
3171 Input_section_sort_init_fini_compare());
3173 std::sort(sort_list.begin(), sort_list.end(),
3174 Input_section_sort_compare());
3178 gold_assert(parameters->options().section_ordering_file());
3179 std::sort(sort_list.begin(), sort_list.end(),
3180 Input_section_sort_section_order_index_compare());
3183 // Copy the sorted input sections back to our list.
3184 this->input_sections_.clear();
3185 for (std::vector<Input_section_sort_entry>::iterator p = sort_list.begin();
3186 p != sort_list.end();
3188 this->input_sections_.push_back(p->input_section());
3191 // Remember that we sorted the input sections, since we might get
3193 this->attached_input_sections_are_sorted_ = true;
3196 // Write the section header to *OSHDR.
3198 template<int size, bool big_endian>
3200 Output_section::write_header(const Layout* layout,
3201 const Stringpool* secnamepool,
3202 elfcpp::Shdr_write<size, big_endian>* oshdr) const
3204 oshdr->put_sh_name(secnamepool->get_offset(this->name_));
3205 oshdr->put_sh_type(this->type_);
3207 elfcpp::Elf_Xword flags = this->flags_;
3208 if (this->info_section_ != NULL && this->info_uses_section_index_)
3209 flags |= elfcpp::SHF_INFO_LINK;
3210 oshdr->put_sh_flags(flags);
3212 oshdr->put_sh_addr(this->address());
3213 oshdr->put_sh_offset(this->offset());
3214 oshdr->put_sh_size(this->data_size());
3215 if (this->link_section_ != NULL)
3216 oshdr->put_sh_link(this->link_section_->out_shndx());
3217 else if (this->should_link_to_symtab_)
3218 oshdr->put_sh_link(layout->symtab_section()->out_shndx());
3219 else if (this->should_link_to_dynsym_)
3220 oshdr->put_sh_link(layout->dynsym_section()->out_shndx());
3222 oshdr->put_sh_link(this->link_);
3224 elfcpp::Elf_Word info;
3225 if (this->info_section_ != NULL)
3227 if (this->info_uses_section_index_)
3228 info = this->info_section_->out_shndx();
3230 info = this->info_section_->symtab_index();
3232 else if (this->info_symndx_ != NULL)
3233 info = this->info_symndx_->symtab_index();
3236 oshdr->put_sh_info(info);
3238 oshdr->put_sh_addralign(this->addralign_);
3239 oshdr->put_sh_entsize(this->entsize_);
3242 // Write out the data. For input sections the data is written out by
3243 // Object::relocate, but we have to handle Output_section_data objects
3247 Output_section::do_write(Output_file* of)
3249 gold_assert(!this->requires_postprocessing());
3251 // If the target performs relaxation, we delay filler generation until now.
3252 gold_assert(!this->generate_code_fills_at_write_ || this->fills_.empty());
3254 off_t output_section_file_offset = this->offset();
3255 for (Fill_list::iterator p = this->fills_.begin();
3256 p != this->fills_.end();
3259 std::string fill_data(parameters->target().code_fill(p->length()));
3260 of->write(output_section_file_offset + p->section_offset(),
3261 fill_data.data(), fill_data.size());
3264 off_t off = this->offset() + this->first_input_offset_;
3265 for (Input_section_list::iterator p = this->input_sections_.begin();
3266 p != this->input_sections_.end();
3269 off_t aligned_off = align_address(off, p->addralign());
3270 if (this->generate_code_fills_at_write_ && (off != aligned_off))
3272 size_t fill_len = aligned_off - off;
3273 std::string fill_data(parameters->target().code_fill(fill_len));
3274 of->write(off, fill_data.data(), fill_data.size());
3278 off = aligned_off + p->data_size();
3282 // If a section requires postprocessing, create the buffer to use.
3285 Output_section::create_postprocessing_buffer()
3287 gold_assert(this->requires_postprocessing());
3289 if (this->postprocessing_buffer_ != NULL)
3292 if (!this->input_sections_.empty())
3294 off_t off = this->first_input_offset_;
3295 for (Input_section_list::iterator p = this->input_sections_.begin();
3296 p != this->input_sections_.end();
3299 off = align_address(off, p->addralign());
3300 p->finalize_data_size();
3301 off += p->data_size();
3303 this->set_current_data_size_for_child(off);
3306 off_t buffer_size = this->current_data_size_for_child();
3307 this->postprocessing_buffer_ = new unsigned char[buffer_size];
3310 // Write all the data of an Output_section into the postprocessing
3311 // buffer. This is used for sections which require postprocessing,
3312 // such as compression. Input sections are handled by
3313 // Object::Relocate.
3316 Output_section::write_to_postprocessing_buffer()
3318 gold_assert(this->requires_postprocessing());
3320 // If the target performs relaxation, we delay filler generation until now.
3321 gold_assert(!this->generate_code_fills_at_write_ || this->fills_.empty());
3323 unsigned char* buffer = this->postprocessing_buffer();
3324 for (Fill_list::iterator p = this->fills_.begin();
3325 p != this->fills_.end();
3328 std::string fill_data(parameters->target().code_fill(p->length()));
3329 memcpy(buffer + p->section_offset(), fill_data.data(),
3333 off_t off = this->first_input_offset_;
3334 for (Input_section_list::iterator p = this->input_sections_.begin();
3335 p != this->input_sections_.end();
3338 off_t aligned_off = align_address(off, p->addralign());
3339 if (this->generate_code_fills_at_write_ && (off != aligned_off))
3341 size_t fill_len = aligned_off - off;
3342 std::string fill_data(parameters->target().code_fill(fill_len));
3343 memcpy(buffer + off, fill_data.data(), fill_data.size());
3346 p->write_to_buffer(buffer + aligned_off);
3347 off = aligned_off + p->data_size();
3351 // Get the input sections for linker script processing. We leave
3352 // behind the Output_section_data entries. Note that this may be
3353 // slightly incorrect for merge sections. We will leave them behind,
3354 // but it is possible that the script says that they should follow
3355 // some other input sections, as in:
3356 // .rodata { *(.rodata) *(.rodata.cst*) }
3357 // For that matter, we don't handle this correctly:
3358 // .rodata { foo.o(.rodata.cst*) *(.rodata.cst*) }
3359 // With luck this will never matter.
3362 Output_section::get_input_sections(
3364 const std::string& fill,
3365 std::list<Input_section>* input_sections)
3367 if (this->checkpoint_ != NULL
3368 && !this->checkpoint_->input_sections_saved())
3369 this->checkpoint_->save_input_sections();
3371 // Invalidate fast look-up maps.
3372 this->lookup_maps_->invalidate();
3374 uint64_t orig_address = address;
3376 address = align_address(address, this->addralign());
3378 Input_section_list remaining;
3379 for (Input_section_list::iterator p = this->input_sections_.begin();
3380 p != this->input_sections_.end();
3383 if (p->is_input_section()
3384 || p->is_relaxed_input_section()
3385 || p->is_merge_section())
3386 input_sections->push_back(*p);
3389 uint64_t aligned_address = align_address(address, p->addralign());
3390 if (aligned_address != address && !fill.empty())
3392 section_size_type length =
3393 convert_to_section_size_type(aligned_address - address);
3394 std::string this_fill;
3395 this_fill.reserve(length);
3396 while (this_fill.length() + fill.length() <= length)
3398 if (this_fill.length() < length)
3399 this_fill.append(fill, 0, length - this_fill.length());
3401 Output_section_data* posd = new Output_data_const(this_fill, 0);
3402 remaining.push_back(Input_section(posd));
3404 address = aligned_address;
3406 remaining.push_back(*p);
3408 p->finalize_data_size();
3409 address += p->data_size();
3413 this->input_sections_.swap(remaining);
3414 this->first_input_offset_ = 0;
3416 uint64_t data_size = address - orig_address;
3417 this->set_current_data_size_for_child(data_size);
3421 // Add a script input section. SIS is an Output_section::Input_section,
3422 // which can be either a plain input section or a special input section like
3423 // a relaxed input section. For a special input section, its size must be
3427 Output_section::add_script_input_section(const Input_section& sis)
3429 uint64_t data_size = sis.data_size();
3430 uint64_t addralign = sis.addralign();
3431 if (addralign > this->addralign_)
3432 this->addralign_ = addralign;
3434 off_t offset_in_section = this->current_data_size_for_child();
3435 off_t aligned_offset_in_section = align_address(offset_in_section,
3438 this->set_current_data_size_for_child(aligned_offset_in_section
3441 this->input_sections_.push_back(sis);
3443 // Update fast lookup maps if necessary.
3444 if (this->lookup_maps_->is_valid())
3446 if (sis.is_merge_section())
3448 Output_merge_base* pomb = sis.output_merge_base();
3449 Merge_section_properties msp(pomb->is_string(), pomb->entsize(),
3451 this->lookup_maps_->add_merge_section(msp, pomb);
3452 for (Output_merge_base::Input_sections::const_iterator p =
3453 pomb->input_sections_begin();
3454 p != pomb->input_sections_end();
3456 this->lookup_maps_->add_merge_input_section(p->first, p->second,
3459 else if (sis.is_relaxed_input_section())
3461 Output_relaxed_input_section* poris = sis.relaxed_input_section();
3462 this->lookup_maps_->add_relaxed_input_section(poris->relobj(),
3463 poris->shndx(), poris);
3468 // Save states for relaxation.
3471 Output_section::save_states()
3473 gold_assert(this->checkpoint_ == NULL);
3474 Checkpoint_output_section* checkpoint =
3475 new Checkpoint_output_section(this->addralign_, this->flags_,
3476 this->input_sections_,
3477 this->first_input_offset_,
3478 this->attached_input_sections_are_sorted_);
3479 this->checkpoint_ = checkpoint;
3480 gold_assert(this->fills_.empty());
3484 Output_section::discard_states()
3486 gold_assert(this->checkpoint_ != NULL);
3487 delete this->checkpoint_;
3488 this->checkpoint_ = NULL;
3489 gold_assert(this->fills_.empty());
3491 // Simply invalidate the fast lookup maps since we do not keep
3493 this->lookup_maps_->invalidate();
3497 Output_section::restore_states()
3499 gold_assert(this->checkpoint_ != NULL);
3500 Checkpoint_output_section* checkpoint = this->checkpoint_;
3502 this->addralign_ = checkpoint->addralign();
3503 this->flags_ = checkpoint->flags();
3504 this->first_input_offset_ = checkpoint->first_input_offset();
3506 if (!checkpoint->input_sections_saved())
3508 // If we have not copied the input sections, just resize it.
3509 size_t old_size = checkpoint->input_sections_size();
3510 gold_assert(this->input_sections_.size() >= old_size);
3511 this->input_sections_.resize(old_size);
3515 // We need to copy the whole list. This is not efficient for
3516 // extremely large output with hundreads of thousands of input
3517 // objects. We may need to re-think how we should pass sections
3519 this->input_sections_ = *checkpoint->input_sections();
3522 this->attached_input_sections_are_sorted_ =
3523 checkpoint->attached_input_sections_are_sorted();
3525 // Simply invalidate the fast lookup maps since we do not keep
3527 this->lookup_maps_->invalidate();
3530 // Update the section offsets of input sections in this. This is required if
3531 // relaxation causes some input sections to change sizes.
3534 Output_section::adjust_section_offsets()
3536 if (!this->section_offsets_need_adjustment_)
3540 for (Input_section_list::iterator p = this->input_sections_.begin();
3541 p != this->input_sections_.end();
3544 off = align_address(off, p->addralign());
3545 if (p->is_input_section())
3546 p->relobj()->set_section_offset(p->shndx(), off);
3547 off += p->data_size();
3550 this->section_offsets_need_adjustment_ = false;
3553 // Print to the map file.
3556 Output_section::do_print_to_mapfile(Mapfile* mapfile) const
3558 mapfile->print_output_section(this);
3560 for (Input_section_list::const_iterator p = this->input_sections_.begin();
3561 p != this->input_sections_.end();
3563 p->print_to_mapfile(mapfile);
3566 // Print stats for merge sections to stderr.
3569 Output_section::print_merge_stats()
3571 Input_section_list::iterator p;
3572 for (p = this->input_sections_.begin();
3573 p != this->input_sections_.end();
3575 p->print_merge_stats(this->name_);
3578 // Set a fixed layout for the section. Used for incremental update links.
3581 Output_section::set_fixed_layout(uint64_t sh_addr, off_t sh_offset,
3582 off_t sh_size, uint64_t sh_addralign)
3584 this->addralign_ = sh_addralign;
3585 this->set_current_data_size(sh_size);
3586 if ((this->flags_ & elfcpp::SHF_ALLOC) != 0)
3587 this->set_address(sh_addr);
3588 this->set_file_offset(sh_offset);
3589 this->finalize_data_size();
3590 this->free_list_.init(sh_size, false);
3591 this->has_fixed_layout_ = true;
3594 // Reserve space within the fixed layout for the section. Used for
3595 // incremental update links.
3597 Output_section::reserve(uint64_t sh_offset, uint64_t sh_size)
3599 this->free_list_.remove(sh_offset, sh_offset + sh_size);
3602 // Output segment methods.
3604 Output_segment::Output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags)
3614 is_max_align_known_(false),
3615 are_addresses_set_(false),
3616 is_large_data_segment_(false)
3618 // The ELF ABI specifies that a PT_TLS segment always has PF_R as
3620 if (type == elfcpp::PT_TLS)
3621 this->flags_ = elfcpp::PF_R;
3624 // Add an Output_section to a PT_LOAD Output_segment.
3627 Output_segment::add_output_section_to_load(Layout* layout,
3629 elfcpp::Elf_Word seg_flags)
3631 gold_assert(this->type() == elfcpp::PT_LOAD);
3632 gold_assert((os->flags() & elfcpp::SHF_ALLOC) != 0);
3633 gold_assert(!this->is_max_align_known_);
3634 gold_assert(os->is_large_data_section() == this->is_large_data_segment());
3636 this->update_flags_for_output_section(seg_flags);
3638 // We don't want to change the ordering if we have a linker script
3639 // with a SECTIONS clause.
3640 Output_section_order order = os->order();
3641 if (layout->script_options()->saw_sections_clause())
3642 order = static_cast<Output_section_order>(0);
3644 gold_assert(order != ORDER_INVALID);
3646 this->output_lists_[order].push_back(os);
3649 // Add an Output_section to a non-PT_LOAD Output_segment.
3652 Output_segment::add_output_section_to_nonload(Output_section* os,
3653 elfcpp::Elf_Word seg_flags)
3655 gold_assert(this->type() != elfcpp::PT_LOAD);
3656 gold_assert((os->flags() & elfcpp::SHF_ALLOC) != 0);
3657 gold_assert(!this->is_max_align_known_);
3659 this->update_flags_for_output_section(seg_flags);
3661 this->output_lists_[0].push_back(os);
3664 // Remove an Output_section from this segment. It is an error if it
3668 Output_segment::remove_output_section(Output_section* os)
3670 for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
3672 Output_data_list* pdl = &this->output_lists_[i];
3673 for (Output_data_list::iterator p = pdl->begin(); p != pdl->end(); ++p)
3685 // Add an Output_data (which need not be an Output_section) to the
3686 // start of a segment.
3689 Output_segment::add_initial_output_data(Output_data* od)
3691 gold_assert(!this->is_max_align_known_);
3692 Output_data_list::iterator p = this->output_lists_[0].begin();
3693 this->output_lists_[0].insert(p, od);
3696 // Return true if this segment has any sections which hold actual
3697 // data, rather than being a BSS section.
3700 Output_segment::has_any_data_sections() const
3702 for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
3704 const Output_data_list* pdl = &this->output_lists_[i];
3705 for (Output_data_list::const_iterator p = pdl->begin();
3709 if (!(*p)->is_section())
3711 if ((*p)->output_section()->type() != elfcpp::SHT_NOBITS)
3718 // Return whether the first data section (not counting TLS sections)
3719 // is a relro section.
3722 Output_segment::is_first_section_relro() const
3724 for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
3726 if (i == static_cast<int>(ORDER_TLS_DATA)
3727 || i == static_cast<int>(ORDER_TLS_BSS))
3729 const Output_data_list* pdl = &this->output_lists_[i];
3732 Output_data* p = pdl->front();
3733 return p->is_section() && p->output_section()->is_relro();
3739 // Return the maximum alignment of the Output_data in Output_segment.
3742 Output_segment::maximum_alignment()
3744 if (!this->is_max_align_known_)
3746 for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
3748 const Output_data_list* pdl = &this->output_lists_[i];
3749 uint64_t addralign = Output_segment::maximum_alignment_list(pdl);
3750 if (addralign > this->max_align_)
3751 this->max_align_ = addralign;
3753 this->is_max_align_known_ = true;
3756 return this->max_align_;
3759 // Return the maximum alignment of a list of Output_data.
3762 Output_segment::maximum_alignment_list(const Output_data_list* pdl)
3765 for (Output_data_list::const_iterator p = pdl->begin();
3769 uint64_t addralign = (*p)->addralign();
3770 if (addralign > ret)
3776 // Return whether this segment has any dynamic relocs.
3779 Output_segment::has_dynamic_reloc() const
3781 for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
3782 if (this->has_dynamic_reloc_list(&this->output_lists_[i]))
3787 // Return whether this Output_data_list has any dynamic relocs.
3790 Output_segment::has_dynamic_reloc_list(const Output_data_list* pdl) const
3792 for (Output_data_list::const_iterator p = pdl->begin();
3795 if ((*p)->has_dynamic_reloc())
3800 // Set the section addresses for an Output_segment. If RESET is true,
3801 // reset the addresses first. ADDR is the address and *POFF is the
3802 // file offset. Set the section indexes starting with *PSHNDX.
3803 // INCREASE_RELRO is the size of the portion of the first non-relro
3804 // section that should be included in the PT_GNU_RELRO segment.
3805 // If this segment has relro sections, and has been aligned for
3806 // that purpose, set *HAS_RELRO to TRUE. Return the address of
3807 // the immediately following segment. Update *HAS_RELRO, *POFF,
3811 Output_segment::set_section_addresses(Layout* layout, bool reset,
3813 unsigned int* increase_relro,
3816 unsigned int* pshndx)
3818 gold_assert(this->type_ == elfcpp::PT_LOAD);
3820 uint64_t last_relro_pad = 0;
3821 off_t orig_off = *poff;
3823 bool in_tls = false;
3825 // If we have relro sections, we need to pad forward now so that the
3826 // relro sections plus INCREASE_RELRO end on a common page boundary.
3827 if (parameters->options().relro()
3828 && this->is_first_section_relro()
3829 && (!this->are_addresses_set_ || reset))
3831 uint64_t relro_size = 0;
3833 uint64_t max_align = 0;
3834 for (int i = 0; i <= static_cast<int>(ORDER_RELRO_LAST); ++i)
3836 Output_data_list* pdl = &this->output_lists_[i];
3837 Output_data_list::iterator p;
3838 for (p = pdl->begin(); p != pdl->end(); ++p)
3840 if (!(*p)->is_section())
3842 uint64_t align = (*p)->addralign();
3843 if (align > max_align)
3845 if ((*p)->is_section_flag_set(elfcpp::SHF_TLS))
3849 // Align the first non-TLS section to the alignment
3850 // of the TLS segment.
3854 relro_size = align_address(relro_size, align);
3855 // Ignore the size of the .tbss section.
3856 if ((*p)->is_section_flag_set(elfcpp::SHF_TLS)
3857 && (*p)->is_section_type(elfcpp::SHT_NOBITS))
3859 if ((*p)->is_address_valid())
3860 relro_size += (*p)->data_size();
3863 // FIXME: This could be faster.
3864 (*p)->set_address_and_file_offset(addr + relro_size,
3866 relro_size += (*p)->data_size();
3867 (*p)->reset_address_and_file_offset();
3870 if (p != pdl->end())
3873 relro_size += *increase_relro;
3874 // Pad the total relro size to a multiple of the maximum
3875 // section alignment seen.
3876 uint64_t aligned_size = align_address(relro_size, max_align);
3877 // Note the amount of padding added after the last relro section.
3878 last_relro_pad = aligned_size - relro_size;
3881 uint64_t page_align = parameters->target().common_pagesize();
3883 // Align to offset N such that (N + RELRO_SIZE) % PAGE_ALIGN == 0.
3884 uint64_t desired_align = page_align - (aligned_size % page_align);
3885 if (desired_align < *poff % page_align)
3886 *poff += page_align - *poff % page_align;
3887 *poff += desired_align - *poff % page_align;
3888 addr += *poff - orig_off;
3892 if (!reset && this->are_addresses_set_)
3894 gold_assert(this->paddr_ == addr);
3895 addr = this->vaddr_;
3899 this->vaddr_ = addr;
3900 this->paddr_ = addr;
3901 this->are_addresses_set_ = true;
3906 this->offset_ = orig_off;
3910 for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
3912 if (i == static_cast<int>(ORDER_RELRO_LAST))
3914 *poff += last_relro_pad;
3915 addr += last_relro_pad;
3916 if (this->output_lists_[i].empty())
3918 // If there is nothing in the ORDER_RELRO_LAST list,
3919 // the padding will occur at the end of the relro
3920 // segment, and we need to add it to *INCREASE_RELRO.
3921 *increase_relro += last_relro_pad;
3924 addr = this->set_section_list_addresses(layout, reset,
3925 &this->output_lists_[i],
3926 addr, poff, pshndx, &in_tls);
3927 if (i < static_cast<int>(ORDER_SMALL_BSS))
3929 this->filesz_ = *poff - orig_off;
3936 // If the last section was a TLS section, align upward to the
3937 // alignment of the TLS segment, so that the overall size of the TLS
3938 // segment is aligned.
3941 uint64_t segment_align = layout->tls_segment()->maximum_alignment();
3942 *poff = align_address(*poff, segment_align);
3945 this->memsz_ = *poff - orig_off;
3947 // Ignore the file offset adjustments made by the BSS Output_data
3954 // Set the addresses and file offsets in a list of Output_data
3958 Output_segment::set_section_list_addresses(Layout* layout, bool reset,
3959 Output_data_list* pdl,
3960 uint64_t addr, off_t* poff,
3961 unsigned int* pshndx,
3964 off_t startoff = *poff;
3965 // For incremental updates, we may allocate non-fixed sections from
3966 // free space in the file. This keeps track of the high-water mark.
3967 off_t maxoff = startoff;
3969 off_t off = startoff;
3970 for (Output_data_list::iterator p = pdl->begin();
3975 (*p)->reset_address_and_file_offset();
3977 // When doing an incremental update or when using a linker script,
3978 // the section will most likely already have an address.
3979 if (!(*p)->is_address_valid())
3981 uint64_t align = (*p)->addralign();
3983 if ((*p)->is_section_flag_set(elfcpp::SHF_TLS))
3985 // Give the first TLS section the alignment of the
3986 // entire TLS segment. Otherwise the TLS segment as a
3987 // whole may be misaligned.
3990 Output_segment* tls_segment = layout->tls_segment();
3991 gold_assert(tls_segment != NULL);
3992 uint64_t segment_align = tls_segment->maximum_alignment();
3993 gold_assert(segment_align >= align);
3994 align = segment_align;
4001 // If this is the first section after the TLS segment,
4002 // align it to at least the alignment of the TLS
4003 // segment, so that the size of the overall TLS segment
4007 uint64_t segment_align =
4008 layout->tls_segment()->maximum_alignment();
4009 if (segment_align > align)
4010 align = segment_align;
4016 // FIXME: Need to handle TLS and .bss with incremental update.
4017 if (!parameters->incremental_update()
4018 || (*p)->is_section_flag_set(elfcpp::SHF_TLS)
4019 || (*p)->is_section_type(elfcpp::SHT_NOBITS))
4021 off = align_address(off, align);
4022 (*p)->set_address_and_file_offset(addr + (off - startoff), off);
4026 // Incremental update: allocate file space from free list.
4027 (*p)->pre_finalize_data_size();
4028 off_t current_size = (*p)->current_data_size();
4029 off = layout->allocate(current_size, align, startoff);
4032 gold_assert((*p)->output_section() != NULL);
4033 gold_fatal(_("out of patch space for section %s; "
4034 "relink with --incremental-full"),
4035 (*p)->output_section()->name());
4037 (*p)->set_address_and_file_offset(addr + (off - startoff), off);
4038 if ((*p)->data_size() > current_size)
4040 gold_assert((*p)->output_section() != NULL);
4041 gold_fatal(_("%s: section changed size; "
4042 "relink with --incremental-full"),
4043 (*p)->output_section()->name());
4047 else if (parameters->incremental_update())
4049 // For incremental updates, use the fixed offset for the
4050 // high-water mark computation.
4051 off = (*p)->offset();
4055 // The script may have inserted a skip forward, but it
4056 // better not have moved backward.
4057 if ((*p)->address() >= addr + (off - startoff))
4058 off += (*p)->address() - (addr + (off - startoff));
4061 if (!layout->script_options()->saw_sections_clause())
4065 Output_section* os = (*p)->output_section();
4067 // Cast to unsigned long long to avoid format warnings.
4068 unsigned long long previous_dot =
4069 static_cast<unsigned long long>(addr + (off - startoff));
4070 unsigned long long dot =
4071 static_cast<unsigned long long>((*p)->address());
4074 gold_error(_("dot moves backward in linker script "
4075 "from 0x%llx to 0x%llx"), previous_dot, dot);
4077 gold_error(_("address of section '%s' moves backward "
4078 "from 0x%llx to 0x%llx"),
4079 os->name(), previous_dot, dot);
4082 (*p)->set_file_offset(off);
4083 (*p)->finalize_data_size();
4086 gold_debug(DEBUG_INCREMENTAL,
4087 "set_section_list_addresses: %08lx %08lx %s",
4088 static_cast<long>(off),
4089 static_cast<long>((*p)->data_size()),
4090 ((*p)->output_section() != NULL
4091 ? (*p)->output_section()->name() : "(special)"));
4093 // We want to ignore the size of a SHF_TLS or SHT_NOBITS
4094 // section. Such a section does not affect the size of a
4096 if (!(*p)->is_section_flag_set(elfcpp::SHF_TLS)
4097 || !(*p)->is_section_type(elfcpp::SHT_NOBITS))
4098 off += (*p)->data_size();
4103 if ((*p)->is_section())
4105 (*p)->set_out_shndx(*pshndx);
4111 return addr + (maxoff - startoff);
4114 // For a non-PT_LOAD segment, set the offset from the sections, if
4115 // any. Add INCREASE to the file size and the memory size.
4118 Output_segment::set_offset(unsigned int increase)
4120 gold_assert(this->type_ != elfcpp::PT_LOAD);
4122 gold_assert(!this->are_addresses_set_);
4124 // A non-load section only uses output_lists_[0].
4126 Output_data_list* pdl = &this->output_lists_[0];
4130 gold_assert(increase == 0);
4133 this->are_addresses_set_ = true;
4135 this->min_p_align_ = 0;
4141 // Find the first and last section by address.
4142 const Output_data* first = NULL;
4143 const Output_data* last_data = NULL;
4144 const Output_data* last_bss = NULL;
4145 for (Output_data_list::const_iterator p = pdl->begin();
4150 || (*p)->address() < first->address()
4151 || ((*p)->address() == first->address()
4152 && (*p)->data_size() < first->data_size()))
4154 const Output_data** plast;
4155 if ((*p)->is_section()
4156 && (*p)->output_section()->type() == elfcpp::SHT_NOBITS)
4161 || (*p)->address() > (*plast)->address()
4162 || ((*p)->address() == (*plast)->address()
4163 && (*p)->data_size() > (*plast)->data_size()))
4167 this->vaddr_ = first->address();
4168 this->paddr_ = (first->has_load_address()
4169 ? first->load_address()
4171 this->are_addresses_set_ = true;
4172 this->offset_ = first->offset();
4174 if (last_data == NULL)
4177 this->filesz_ = (last_data->address()
4178 + last_data->data_size()
4181 const Output_data* last = last_bss != NULL ? last_bss : last_data;
4182 this->memsz_ = (last->address()
4186 this->filesz_ += increase;
4187 this->memsz_ += increase;
4189 // If this is a RELRO segment, verify that the segment ends at a
4191 if (this->type_ == elfcpp::PT_GNU_RELRO)
4193 uint64_t page_align = parameters->target().common_pagesize();
4194 uint64_t segment_end = this->vaddr_ + this->memsz_;
4195 if (parameters->incremental_update())
4197 // The INCREASE_RELRO calculation is bypassed for an incremental
4198 // update, so we need to adjust the segment size manually here.
4199 segment_end = align_address(segment_end, page_align);
4200 this->memsz_ = segment_end - this->vaddr_;
4203 gold_assert(segment_end == align_address(segment_end, page_align));
4206 // If this is a TLS segment, align the memory size. The code in
4207 // set_section_list ensures that the section after the TLS segment
4208 // is aligned to give us room.
4209 if (this->type_ == elfcpp::PT_TLS)
4211 uint64_t segment_align = this->maximum_alignment();
4212 gold_assert(this->vaddr_ == align_address(this->vaddr_, segment_align));
4213 this->memsz_ = align_address(this->memsz_, segment_align);
4217 // Set the TLS offsets of the sections in the PT_TLS segment.
4220 Output_segment::set_tls_offsets()
4222 gold_assert(this->type_ == elfcpp::PT_TLS);
4224 for (Output_data_list::iterator p = this->output_lists_[0].begin();
4225 p != this->output_lists_[0].end();
4227 (*p)->set_tls_offset(this->vaddr_);
4230 // Return the load address of the first section.
4233 Output_segment::first_section_load_address() const
4235 for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
4237 const Output_data_list* pdl = &this->output_lists_[i];
4238 for (Output_data_list::const_iterator p = pdl->begin();
4242 if ((*p)->is_section())
4243 return ((*p)->has_load_address()
4244 ? (*p)->load_address()
4251 // Return the number of Output_sections in an Output_segment.
4254 Output_segment::output_section_count() const
4256 unsigned int ret = 0;
4257 for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
4258 ret += this->output_section_count_list(&this->output_lists_[i]);
4262 // Return the number of Output_sections in an Output_data_list.
4265 Output_segment::output_section_count_list(const Output_data_list* pdl) const
4267 unsigned int count = 0;
4268 for (Output_data_list::const_iterator p = pdl->begin();
4272 if ((*p)->is_section())
4278 // Return the section attached to the list segment with the lowest
4279 // load address. This is used when handling a PHDRS clause in a
4283 Output_segment::section_with_lowest_load_address() const
4285 Output_section* found = NULL;
4286 uint64_t found_lma = 0;
4287 for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
4288 this->lowest_load_address_in_list(&this->output_lists_[i], &found,
4293 // Look through a list for a section with a lower load address.
4296 Output_segment::lowest_load_address_in_list(const Output_data_list* pdl,
4297 Output_section** found,
4298 uint64_t* found_lma) const
4300 for (Output_data_list::const_iterator p = pdl->begin();
4304 if (!(*p)->is_section())
4306 Output_section* os = static_cast<Output_section*>(*p);
4307 uint64_t lma = (os->has_load_address()
4308 ? os->load_address()
4310 if (*found == NULL || lma < *found_lma)
4318 // Write the segment data into *OPHDR.
4320 template<int size, bool big_endian>
4322 Output_segment::write_header(elfcpp::Phdr_write<size, big_endian>* ophdr)
4324 ophdr->put_p_type(this->type_);
4325 ophdr->put_p_offset(this->offset_);
4326 ophdr->put_p_vaddr(this->vaddr_);
4327 ophdr->put_p_paddr(this->paddr_);
4328 ophdr->put_p_filesz(this->filesz_);
4329 ophdr->put_p_memsz(this->memsz_);
4330 ophdr->put_p_flags(this->flags_);
4331 ophdr->put_p_align(std::max(this->min_p_align_, this->maximum_alignment()));
4334 // Write the section headers into V.
4336 template<int size, bool big_endian>
4338 Output_segment::write_section_headers(const Layout* layout,
4339 const Stringpool* secnamepool,
4341 unsigned int* pshndx) const
4343 // Every section that is attached to a segment must be attached to a
4344 // PT_LOAD segment, so we only write out section headers for PT_LOAD
4346 if (this->type_ != elfcpp::PT_LOAD)
4349 for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
4351 const Output_data_list* pdl = &this->output_lists_[i];
4352 v = this->write_section_headers_list<size, big_endian>(layout,
4361 template<int size, bool big_endian>
4363 Output_segment::write_section_headers_list(const Layout* layout,
4364 const Stringpool* secnamepool,
4365 const Output_data_list* pdl,
4367 unsigned int* pshndx) const
4369 const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
4370 for (Output_data_list::const_iterator p = pdl->begin();
4374 if ((*p)->is_section())
4376 const Output_section* ps = static_cast<const Output_section*>(*p);
4377 gold_assert(*pshndx == ps->out_shndx());
4378 elfcpp::Shdr_write<size, big_endian> oshdr(v);
4379 ps->write_header(layout, secnamepool, &oshdr);
4387 // Print the output sections to the map file.
4390 Output_segment::print_sections_to_mapfile(Mapfile* mapfile) const
4392 if (this->type() != elfcpp::PT_LOAD)
4394 for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
4395 this->print_section_list_to_mapfile(mapfile, &this->output_lists_[i]);
4398 // Print an output section list to the map file.
4401 Output_segment::print_section_list_to_mapfile(Mapfile* mapfile,
4402 const Output_data_list* pdl) const
4404 for (Output_data_list::const_iterator p = pdl->begin();
4407 (*p)->print_to_mapfile(mapfile);
4410 // Output_file methods.
4412 Output_file::Output_file(const char* name)
4417 map_is_anonymous_(false),
4418 is_temporary_(false)
4422 // Try to open an existing file. Returns false if the file doesn't
4423 // exist, has a size of 0 or can't be mmapped.
4426 Output_file::open_for_modification()
4428 // The name "-" means "stdout".
4429 if (strcmp(this->name_, "-") == 0)
4432 // Don't bother opening files with a size of zero.
4434 if (::stat(this->name_, &s) != 0 || s.st_size == 0)
4437 int o = open_descriptor(-1, this->name_, O_RDWR, 0);
4439 gold_fatal(_("%s: open: %s"), this->name_, strerror(errno));
4441 this->file_size_ = s.st_size;
4443 // If the file can't be mmapped, copying the content to an anonymous
4444 // map will probably negate the performance benefits of incremental
4445 // linking. This could be helped by using views and loading only
4446 // the necessary parts, but this is not supported as of now.
4447 if (!this->map_no_anonymous())
4449 release_descriptor(o, true);
4451 this->file_size_ = 0;
4458 // Open the output file.
4461 Output_file::open(off_t file_size)
4463 this->file_size_ = file_size;
4465 // Unlink the file first; otherwise the open() may fail if the file
4466 // is busy (e.g. it's an executable that's currently being executed).
4468 // However, the linker may be part of a system where a zero-length
4469 // file is created for it to write to, with tight permissions (gcc
4470 // 2.95 did something like this). Unlinking the file would work
4471 // around those permission controls, so we only unlink if the file
4472 // has a non-zero size. We also unlink only regular files to avoid
4473 // trouble with directories/etc.
4475 // If we fail, continue; this command is merely a best-effort attempt
4476 // to improve the odds for open().
4478 // We let the name "-" mean "stdout"
4479 if (!this->is_temporary_)
4481 if (strcmp(this->name_, "-") == 0)
4482 this->o_ = STDOUT_FILENO;
4486 if (::stat(this->name_, &s) == 0
4487 && (S_ISREG (s.st_mode) || S_ISLNK (s.st_mode)))
4490 ::unlink(this->name_);
4491 else if (!parameters->options().relocatable())
4493 // If we don't unlink the existing file, add execute
4494 // permission where read permissions already exist
4495 // and where the umask permits.
4496 int mask = ::umask(0);
4498 s.st_mode |= (s.st_mode & 0444) >> 2;
4499 ::chmod(this->name_, s.st_mode & ~mask);
4503 int mode = parameters->options().relocatable() ? 0666 : 0777;
4504 int o = open_descriptor(-1, this->name_, O_RDWR | O_CREAT | O_TRUNC,
4507 gold_fatal(_("%s: open: %s"), this->name_, strerror(errno));
4515 // Resize the output file.
4518 Output_file::resize(off_t file_size)
4520 // If the mmap is mapping an anonymous memory buffer, this is easy:
4521 // just mremap to the new size. If it's mapping to a file, we want
4522 // to unmap to flush to the file, then remap after growing the file.
4523 if (this->map_is_anonymous_)
4525 void* base = ::mremap(this->base_, this->file_size_, file_size,
4527 if (base == MAP_FAILED)
4528 gold_fatal(_("%s: mremap: %s"), this->name_, strerror(errno));
4529 this->base_ = static_cast<unsigned char*>(base);
4530 this->file_size_ = file_size;
4535 this->file_size_ = file_size;
4536 if (!this->map_no_anonymous())
4537 gold_fatal(_("%s: mmap: %s"), this->name_, strerror(errno));
4541 // Map an anonymous block of memory which will later be written to the
4542 // file. Return whether the map succeeded.
4545 Output_file::map_anonymous()
4547 void* base = ::mmap(NULL, this->file_size_, PROT_READ | PROT_WRITE,
4548 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
4549 if (base != MAP_FAILED)
4551 this->map_is_anonymous_ = true;
4552 this->base_ = static_cast<unsigned char*>(base);
4558 // Map the file into memory. Return whether the mapping succeeded.
4561 Output_file::map_no_anonymous()
4563 const int o = this->o_;
4565 // If the output file is not a regular file, don't try to mmap it;
4566 // instead, we'll mmap a block of memory (an anonymous buffer), and
4567 // then later write the buffer to the file.
4569 struct stat statbuf;
4570 if (o == STDOUT_FILENO || o == STDERR_FILENO
4571 || ::fstat(o, &statbuf) != 0
4572 || !S_ISREG(statbuf.st_mode)
4573 || this->is_temporary_)
4576 // Ensure that we have disk space available for the file. If we
4577 // don't do this, it is possible that we will call munmap, close,
4578 // and exit with dirty buffers still in the cache with no assigned
4579 // disk blocks. If the disk is out of space at that point, the
4580 // output file will wind up incomplete, but we will have already
4581 // exited. The alternative to fallocate would be to use fdatasync,
4582 // but that would be a more significant performance hit.
4583 if (::posix_fallocate(o, 0, this->file_size_) < 0)
4584 gold_fatal(_("%s: %s"), this->name_, strerror(errno));
4586 // Map the file into memory.
4587 base = ::mmap(NULL, this->file_size_, PROT_READ | PROT_WRITE,
4590 // The mmap call might fail because of file system issues: the file
4591 // system might not support mmap at all, or it might not support
4592 // mmap with PROT_WRITE.
4593 if (base == MAP_FAILED)
4596 this->map_is_anonymous_ = false;
4597 this->base_ = static_cast<unsigned char*>(base);
4601 // Map the file into memory.
4606 if (this->map_no_anonymous())
4609 // The mmap call might fail because of file system issues: the file
4610 // system might not support mmap at all, or it might not support
4611 // mmap with PROT_WRITE. I'm not sure which errno values we will
4612 // see in all cases, so if the mmap fails for any reason and we
4613 // don't care about file contents, try for an anonymous map.
4614 if (this->map_anonymous())
4617 gold_fatal(_("%s: mmap: failed to allocate %lu bytes for output file: %s"),
4618 this->name_, static_cast<unsigned long>(this->file_size_),
4622 // Unmap the file from memory.
4625 Output_file::unmap()
4627 if (::munmap(this->base_, this->file_size_) < 0)
4628 gold_error(_("%s: munmap: %s"), this->name_, strerror(errno));
4632 // Close the output file.
4635 Output_file::close()
4637 // If the map isn't file-backed, we need to write it now.
4638 if (this->map_is_anonymous_ && !this->is_temporary_)
4640 size_t bytes_to_write = this->file_size_;
4642 while (bytes_to_write > 0)
4644 ssize_t bytes_written = ::write(this->o_, this->base_ + offset,
4646 if (bytes_written == 0)
4647 gold_error(_("%s: write: unexpected 0 return-value"), this->name_);
4648 else if (bytes_written < 0)
4649 gold_error(_("%s: write: %s"), this->name_, strerror(errno));
4652 bytes_to_write -= bytes_written;
4653 offset += bytes_written;
4659 // We don't close stdout or stderr
4660 if (this->o_ != STDOUT_FILENO
4661 && this->o_ != STDERR_FILENO
4662 && !this->is_temporary_)
4663 if (::close(this->o_) < 0)
4664 gold_error(_("%s: close: %s"), this->name_, strerror(errno));
4668 // Instantiate the templates we need. We could use the configure
4669 // script to restrict this to only the ones for implemented targets.
4671 #ifdef HAVE_TARGET_32_LITTLE
4674 Output_section::add_input_section<32, false>(
4676 Sized_relobj<32, false>* object,
4678 const char* secname,
4679 const elfcpp::Shdr<32, false>& shdr,
4680 unsigned int reloc_shndx,
4681 bool have_sections_script);
4684 #ifdef HAVE_TARGET_32_BIG
4687 Output_section::add_input_section<32, true>(
4689 Sized_relobj<32, true>* object,
4691 const char* secname,
4692 const elfcpp::Shdr<32, true>& shdr,
4693 unsigned int reloc_shndx,
4694 bool have_sections_script);
4697 #ifdef HAVE_TARGET_64_LITTLE
4700 Output_section::add_input_section<64, false>(
4702 Sized_relobj<64, false>* object,
4704 const char* secname,
4705 const elfcpp::Shdr<64, false>& shdr,
4706 unsigned int reloc_shndx,
4707 bool have_sections_script);
4710 #ifdef HAVE_TARGET_64_BIG
4713 Output_section::add_input_section<64, true>(
4715 Sized_relobj<64, true>* object,
4717 const char* secname,
4718 const elfcpp::Shdr<64, true>& shdr,
4719 unsigned int reloc_shndx,
4720 bool have_sections_script);
4723 #ifdef HAVE_TARGET_32_LITTLE
4725 class Output_reloc<elfcpp::SHT_REL, false, 32, false>;
4728 #ifdef HAVE_TARGET_32_BIG
4730 class Output_reloc<elfcpp::SHT_REL, false, 32, true>;
4733 #ifdef HAVE_TARGET_64_LITTLE
4735 class Output_reloc<elfcpp::SHT_REL, false, 64, false>;
4738 #ifdef HAVE_TARGET_64_BIG
4740 class Output_reloc<elfcpp::SHT_REL, false, 64, true>;
4743 #ifdef HAVE_TARGET_32_LITTLE
4745 class Output_reloc<elfcpp::SHT_REL, true, 32, false>;
4748 #ifdef HAVE_TARGET_32_BIG
4750 class Output_reloc<elfcpp::SHT_REL, true, 32, true>;
4753 #ifdef HAVE_TARGET_64_LITTLE
4755 class Output_reloc<elfcpp::SHT_REL, true, 64, false>;
4758 #ifdef HAVE_TARGET_64_BIG
4760 class Output_reloc<elfcpp::SHT_REL, true, 64, true>;
4763 #ifdef HAVE_TARGET_32_LITTLE
4765 class Output_reloc<elfcpp::SHT_RELA, false, 32, false>;
4768 #ifdef HAVE_TARGET_32_BIG
4770 class Output_reloc<elfcpp::SHT_RELA, false, 32, true>;
4773 #ifdef HAVE_TARGET_64_LITTLE
4775 class Output_reloc<elfcpp::SHT_RELA, false, 64, false>;
4778 #ifdef HAVE_TARGET_64_BIG
4780 class Output_reloc<elfcpp::SHT_RELA, false, 64, true>;
4783 #ifdef HAVE_TARGET_32_LITTLE
4785 class Output_reloc<elfcpp::SHT_RELA, true, 32, false>;
4788 #ifdef HAVE_TARGET_32_BIG
4790 class Output_reloc<elfcpp::SHT_RELA, true, 32, true>;
4793 #ifdef HAVE_TARGET_64_LITTLE
4795 class Output_reloc<elfcpp::SHT_RELA, true, 64, false>;
4798 #ifdef HAVE_TARGET_64_BIG
4800 class Output_reloc<elfcpp::SHT_RELA, true, 64, true>;
4803 #ifdef HAVE_TARGET_32_LITTLE
4805 class Output_data_reloc<elfcpp::SHT_REL, false, 32, false>;
4808 #ifdef HAVE_TARGET_32_BIG
4810 class Output_data_reloc<elfcpp::SHT_REL, false, 32, true>;
4813 #ifdef HAVE_TARGET_64_LITTLE
4815 class Output_data_reloc<elfcpp::SHT_REL, false, 64, false>;
4818 #ifdef HAVE_TARGET_64_BIG
4820 class Output_data_reloc<elfcpp::SHT_REL, false, 64, true>;
4823 #ifdef HAVE_TARGET_32_LITTLE
4825 class Output_data_reloc<elfcpp::SHT_REL, true, 32, false>;
4828 #ifdef HAVE_TARGET_32_BIG
4830 class Output_data_reloc<elfcpp::SHT_REL, true, 32, true>;
4833 #ifdef HAVE_TARGET_64_LITTLE
4835 class Output_data_reloc<elfcpp::SHT_REL, true, 64, false>;
4838 #ifdef HAVE_TARGET_64_BIG
4840 class Output_data_reloc<elfcpp::SHT_REL, true, 64, true>;
4843 #ifdef HAVE_TARGET_32_LITTLE
4845 class Output_data_reloc<elfcpp::SHT_RELA, false, 32, false>;
4848 #ifdef HAVE_TARGET_32_BIG
4850 class Output_data_reloc<elfcpp::SHT_RELA, false, 32, true>;
4853 #ifdef HAVE_TARGET_64_LITTLE
4855 class Output_data_reloc<elfcpp::SHT_RELA, false, 64, false>;
4858 #ifdef HAVE_TARGET_64_BIG
4860 class Output_data_reloc<elfcpp::SHT_RELA, false, 64, true>;
4863 #ifdef HAVE_TARGET_32_LITTLE
4865 class Output_data_reloc<elfcpp::SHT_RELA, true, 32, false>;
4868 #ifdef HAVE_TARGET_32_BIG
4870 class Output_data_reloc<elfcpp::SHT_RELA, true, 32, true>;
4873 #ifdef HAVE_TARGET_64_LITTLE
4875 class Output_data_reloc<elfcpp::SHT_RELA, true, 64, false>;
4878 #ifdef HAVE_TARGET_64_BIG
4880 class Output_data_reloc<elfcpp::SHT_RELA, true, 64, true>;
4883 #ifdef HAVE_TARGET_32_LITTLE
4885 class Output_relocatable_relocs<elfcpp::SHT_REL, 32, false>;
4888 #ifdef HAVE_TARGET_32_BIG
4890 class Output_relocatable_relocs<elfcpp::SHT_REL, 32, true>;
4893 #ifdef HAVE_TARGET_64_LITTLE
4895 class Output_relocatable_relocs<elfcpp::SHT_REL, 64, false>;
4898 #ifdef HAVE_TARGET_64_BIG
4900 class Output_relocatable_relocs<elfcpp::SHT_REL, 64, true>;
4903 #ifdef HAVE_TARGET_32_LITTLE
4905 class Output_relocatable_relocs<elfcpp::SHT_RELA, 32, false>;
4908 #ifdef HAVE_TARGET_32_BIG
4910 class Output_relocatable_relocs<elfcpp::SHT_RELA, 32, true>;
4913 #ifdef HAVE_TARGET_64_LITTLE
4915 class Output_relocatable_relocs<elfcpp::SHT_RELA, 64, false>;
4918 #ifdef HAVE_TARGET_64_BIG
4920 class Output_relocatable_relocs<elfcpp::SHT_RELA, 64, true>;
4923 #ifdef HAVE_TARGET_32_LITTLE
4925 class Output_data_group<32, false>;
4928 #ifdef HAVE_TARGET_32_BIG
4930 class Output_data_group<32, true>;
4933 #ifdef HAVE_TARGET_64_LITTLE
4935 class Output_data_group<64, false>;
4938 #ifdef HAVE_TARGET_64_BIG
4940 class Output_data_group<64, true>;
4943 #ifdef HAVE_TARGET_32_LITTLE
4945 class Output_data_got<32, false>;
4948 #ifdef HAVE_TARGET_32_BIG
4950 class Output_data_got<32, true>;
4953 #ifdef HAVE_TARGET_64_LITTLE
4955 class Output_data_got<64, false>;
4958 #ifdef HAVE_TARGET_64_BIG
4960 class Output_data_got<64, true>;
4963 } // End namespace gold.