1 // layout.cc -- lay out output file sections 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.
32 #include "libiberty.h"
36 #include "parameters.h"
40 #include "script-sections.h"
45 #include "compressed_output.h"
46 #include "reduced_debug_output.h"
48 #include "descriptors.h"
50 #include "incremental.h"
56 // Layout::Relaxation_debug_check methods.
58 // Check that sections and special data are in reset states.
59 // We do not save states for Output_sections and special Output_data.
60 // So we check that they have not assigned any addresses or offsets.
61 // clean_up_after_relaxation simply resets their addresses and offsets.
63 Layout::Relaxation_debug_check::check_output_data_for_reset_values(
64 const Layout::Section_list& sections,
65 const Layout::Data_list& special_outputs)
67 for(Layout::Section_list::const_iterator p = sections.begin();
70 gold_assert((*p)->address_and_file_offset_have_reset_values());
72 for(Layout::Data_list::const_iterator p = special_outputs.begin();
73 p != special_outputs.end();
75 gold_assert((*p)->address_and_file_offset_have_reset_values());
78 // Save information of SECTIONS for checking later.
81 Layout::Relaxation_debug_check::read_sections(
82 const Layout::Section_list& sections)
84 for(Layout::Section_list::const_iterator p = sections.begin();
88 Output_section* os = *p;
90 info.output_section = os;
91 info.address = os->is_address_valid() ? os->address() : 0;
92 info.data_size = os->is_data_size_valid() ? os->data_size() : -1;
93 info.offset = os->is_offset_valid()? os->offset() : -1 ;
94 this->section_infos_.push_back(info);
98 // Verify SECTIONS using previously recorded information.
101 Layout::Relaxation_debug_check::verify_sections(
102 const Layout::Section_list& sections)
105 for(Layout::Section_list::const_iterator p = sections.begin();
109 Output_section* os = *p;
110 uint64_t address = os->is_address_valid() ? os->address() : 0;
111 off_t data_size = os->is_data_size_valid() ? os->data_size() : -1;
112 off_t offset = os->is_offset_valid()? os->offset() : -1 ;
114 if (i >= this->section_infos_.size())
116 gold_fatal("Section_info of %s missing.\n", os->name());
118 const Section_info& info = this->section_infos_[i];
119 if (os != info.output_section)
120 gold_fatal("Section order changed. Expecting %s but see %s\n",
121 info.output_section->name(), os->name());
122 if (address != info.address
123 || data_size != info.data_size
124 || offset != info.offset)
125 gold_fatal("Section %s changed.\n", os->name());
129 // Layout_task_runner methods.
131 // Lay out the sections. This is called after all the input objects
135 Layout_task_runner::run(Workqueue* workqueue, const Task* task)
137 off_t file_size = this->layout_->finalize(this->input_objects_,
142 // Now we know the final size of the output file and we know where
143 // each piece of information goes.
145 if (this->mapfile_ != NULL)
147 this->mapfile_->print_discarded_sections(this->input_objects_);
148 this->layout_->print_to_mapfile(this->mapfile_);
151 Output_file* of = new Output_file(parameters->options().output_file_name());
152 if (this->options_.oformat_enum() != General_options::OBJECT_FORMAT_ELF)
153 of->set_is_temporary();
156 // Queue up the final set of tasks.
157 gold::queue_final_tasks(this->options_, this->input_objects_,
158 this->symtab_, this->layout_, workqueue, of);
163 Layout::Layout(int number_of_input_files, Script_options* script_options)
164 : number_of_input_files_(number_of_input_files),
165 script_options_(script_options),
173 unattached_section_list_(),
174 special_output_list_(),
175 section_headers_(NULL),
177 relro_segment_(NULL),
179 symtab_section_(NULL),
180 symtab_xindex_(NULL),
181 dynsym_section_(NULL),
182 dynsym_xindex_(NULL),
183 dynamic_section_(NULL),
184 dynamic_symbol_(NULL),
186 eh_frame_section_(NULL),
187 eh_frame_data_(NULL),
188 added_eh_frame_data_(false),
189 eh_frame_hdr_section_(NULL),
190 build_id_note_(NULL),
194 output_file_size_(-1),
195 have_added_input_section_(false),
196 sections_are_attached_(false),
197 input_requires_executable_stack_(false),
198 input_with_gnu_stack_note_(false),
199 input_without_gnu_stack_note_(false),
200 has_static_tls_(false),
201 any_postprocessing_sections_(false),
202 resized_signatures_(false),
203 have_stabstr_section_(false),
204 incremental_inputs_(NULL),
205 record_output_section_data_from_script_(false),
206 script_output_section_data_list_(),
207 segment_states_(NULL),
208 relaxation_debug_check_(NULL)
210 // Make space for more than enough segments for a typical file.
211 // This is just for efficiency--it's OK if we wind up needing more.
212 this->segment_list_.reserve(12);
214 // We expect two unattached Output_data objects: the file header and
215 // the segment headers.
216 this->special_output_list_.reserve(2);
218 // Initialize structure needed for an incremental build.
219 if (parameters->options().incremental())
220 this->incremental_inputs_ = new Incremental_inputs;
222 // The section name pool is worth optimizing in all cases, because
223 // it is small, but there are often overlaps due to .rel sections.
224 this->namepool_.set_optimize();
227 // Hash a key we use to look up an output section mapping.
230 Layout::Hash_key::operator()(const Layout::Key& k) const
232 return k.first + k.second.first + k.second.second;
235 // Returns whether the given section is in the list of
236 // debug-sections-used-by-some-version-of-gdb. Currently,
237 // we've checked versions of gdb up to and including 6.7.1.
239 static const char* gdb_sections[] =
241 // ".debug_aranges", // not used by gdb as of 6.7.1
247 // ".debug_pubnames", // not used by gdb as of 6.7.1
252 static const char* lines_only_debug_sections[] =
254 // ".debug_aranges", // not used by gdb as of 6.7.1
260 // ".debug_pubnames", // not used by gdb as of 6.7.1
266 is_gdb_debug_section(const char* str)
268 // We can do this faster: binary search or a hashtable. But why bother?
269 for (size_t i = 0; i < sizeof(gdb_sections)/sizeof(*gdb_sections); ++i)
270 if (strcmp(str, gdb_sections[i]) == 0)
276 is_lines_only_debug_section(const char* str)
278 // We can do this faster: binary search or a hashtable. But why bother?
280 i < sizeof(lines_only_debug_sections)/sizeof(*lines_only_debug_sections);
282 if (strcmp(str, lines_only_debug_sections[i]) == 0)
287 // Whether to include this section in the link.
289 template<int size, bool big_endian>
291 Layout::include_section(Sized_relobj<size, big_endian>*, const char* name,
292 const elfcpp::Shdr<size, big_endian>& shdr)
294 if (shdr.get_sh_flags() & elfcpp::SHF_EXCLUDE)
297 switch (shdr.get_sh_type())
299 case elfcpp::SHT_NULL:
300 case elfcpp::SHT_SYMTAB:
301 case elfcpp::SHT_DYNSYM:
302 case elfcpp::SHT_HASH:
303 case elfcpp::SHT_DYNAMIC:
304 case elfcpp::SHT_SYMTAB_SHNDX:
307 case elfcpp::SHT_STRTAB:
308 // Discard the sections which have special meanings in the ELF
309 // ABI. Keep others (e.g., .stabstr). We could also do this by
310 // checking the sh_link fields of the appropriate sections.
311 return (strcmp(name, ".dynstr") != 0
312 && strcmp(name, ".strtab") != 0
313 && strcmp(name, ".shstrtab") != 0);
315 case elfcpp::SHT_RELA:
316 case elfcpp::SHT_REL:
317 case elfcpp::SHT_GROUP:
318 // If we are emitting relocations these should be handled
320 gold_assert(!parameters->options().relocatable()
321 && !parameters->options().emit_relocs());
324 case elfcpp::SHT_PROGBITS:
325 if (parameters->options().strip_debug()
326 && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
328 if (is_debug_info_section(name))
331 if (parameters->options().strip_debug_non_line()
332 && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
334 // Debugging sections can only be recognized by name.
335 if (is_prefix_of(".debug", name)
336 && !is_lines_only_debug_section(name))
339 if (parameters->options().strip_debug_gdb()
340 && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
342 // Debugging sections can only be recognized by name.
343 if (is_prefix_of(".debug", name)
344 && !is_gdb_debug_section(name))
347 if (parameters->options().strip_lto_sections()
348 && !parameters->options().relocatable()
349 && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
351 // Ignore LTO sections containing intermediate code.
352 if (is_prefix_of(".gnu.lto_", name))
355 // The GNU linker strips .gnu_debuglink sections, so we do too.
356 // This is a feature used to keep debugging information in
358 if (strcmp(name, ".gnu_debuglink") == 0)
367 // Return an output section named NAME, or NULL if there is none.
370 Layout::find_output_section(const char* name) const
372 for (Section_list::const_iterator p = this->section_list_.begin();
373 p != this->section_list_.end();
375 if (strcmp((*p)->name(), name) == 0)
380 // Return an output segment of type TYPE, with segment flags SET set
381 // and segment flags CLEAR clear. Return NULL if there is none.
384 Layout::find_output_segment(elfcpp::PT type, elfcpp::Elf_Word set,
385 elfcpp::Elf_Word clear) const
387 for (Segment_list::const_iterator p = this->segment_list_.begin();
388 p != this->segment_list_.end();
390 if (static_cast<elfcpp::PT>((*p)->type()) == type
391 && ((*p)->flags() & set) == set
392 && ((*p)->flags() & clear) == 0)
397 // Return the output section to use for section NAME with type TYPE
398 // and section flags FLAGS. NAME must be canonicalized in the string
399 // pool, and NAME_KEY is the key. IS_INTERP is true if this is the
400 // .interp section. IS_DYNAMIC_LINKER_SECTION is true if this section
401 // is used by the dynamic linker. IS_RELRO is true for a relro
402 // section. IS_LAST_RELRO is true for the last relro section.
403 // IS_FIRST_NON_RELRO is true for the first non-relro section.
406 Layout::get_output_section(const char* name, Stringpool::Key name_key,
407 elfcpp::Elf_Word type, elfcpp::Elf_Xword flags,
408 bool is_interp, bool is_dynamic_linker_section,
409 bool is_relro, bool is_last_relro,
410 bool is_first_non_relro)
412 elfcpp::Elf_Xword lookup_flags = flags;
414 // Ignoring SHF_WRITE and SHF_EXECINSTR here means that we combine
415 // read-write with read-only sections. Some other ELF linkers do
416 // not do this. FIXME: Perhaps there should be an option
418 lookup_flags &= ~(elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR);
420 const Key key(name_key, std::make_pair(type, lookup_flags));
421 const std::pair<Key, Output_section*> v(key, NULL);
422 std::pair<Section_name_map::iterator, bool> ins(
423 this->section_name_map_.insert(v));
426 return ins.first->second;
429 // This is the first time we've seen this name/type/flags
430 // combination. For compatibility with the GNU linker, we
431 // combine sections with contents and zero flags with sections
432 // with non-zero flags. This is a workaround for cases where
433 // assembler code forgets to set section flags. FIXME: Perhaps
434 // there should be an option to control this.
435 Output_section* os = NULL;
437 if (type == elfcpp::SHT_PROGBITS)
441 Output_section* same_name = this->find_output_section(name);
442 if (same_name != NULL
443 && same_name->type() == elfcpp::SHT_PROGBITS
444 && (same_name->flags() & elfcpp::SHF_TLS) == 0)
447 else if ((flags & elfcpp::SHF_TLS) == 0)
449 elfcpp::Elf_Xword zero_flags = 0;
450 const Key zero_key(name_key, std::make_pair(type, zero_flags));
451 Section_name_map::iterator p =
452 this->section_name_map_.find(zero_key);
453 if (p != this->section_name_map_.end())
459 os = this->make_output_section(name, type, flags, is_interp,
460 is_dynamic_linker_section, is_relro,
461 is_last_relro, is_first_non_relro);
462 ins.first->second = os;
467 // Pick the output section to use for section NAME, in input file
468 // RELOBJ, with type TYPE and flags FLAGS. RELOBJ may be NULL for a
469 // linker created section. IS_INPUT_SECTION is true if we are
470 // choosing an output section for an input section found in a input
471 // file. IS_INTERP is true if this is the .interp section.
472 // IS_DYNAMIC_LINKER_SECTION is true if this section is used by the
473 // dynamic linker. IS_RELRO is true for a relro section.
474 // IS_LAST_RELRO is true for the last relro section.
475 // IS_FIRST_NON_RELRO is true for the first non-relro section. This
476 // will return NULL if the input section should be discarded.
479 Layout::choose_output_section(const Relobj* relobj, const char* name,
480 elfcpp::Elf_Word type, elfcpp::Elf_Xword flags,
481 bool is_input_section, bool is_interp,
482 bool is_dynamic_linker_section, bool is_relro,
483 bool is_last_relro, bool is_first_non_relro)
485 // We should not see any input sections after we have attached
486 // sections to segments.
487 gold_assert(!is_input_section || !this->sections_are_attached_);
489 // Some flags in the input section should not be automatically
490 // copied to the output section.
491 flags &= ~ (elfcpp::SHF_INFO_LINK
492 | elfcpp::SHF_LINK_ORDER
495 | elfcpp::SHF_STRINGS);
497 if (this->script_options_->saw_sections_clause())
499 // We are using a SECTIONS clause, so the output section is
500 // chosen based only on the name.
502 Script_sections* ss = this->script_options_->script_sections();
503 const char* file_name = relobj == NULL ? NULL : relobj->name().c_str();
504 Output_section** output_section_slot;
505 name = ss->output_section_name(file_name, name, &output_section_slot);
508 // The SECTIONS clause says to discard this input section.
512 // If this is an orphan section--one not mentioned in the linker
513 // script--then OUTPUT_SECTION_SLOT will be NULL, and we do the
514 // default processing below.
516 if (output_section_slot != NULL)
518 if (*output_section_slot != NULL)
520 (*output_section_slot)->update_flags_for_input_section(flags);
521 return *output_section_slot;
524 // We don't put sections found in the linker script into
525 // SECTION_NAME_MAP_. That keeps us from getting confused
526 // if an orphan section is mapped to a section with the same
527 // name as one in the linker script.
529 name = this->namepool_.add(name, false, NULL);
532 this->make_output_section(name, type, flags, is_interp,
533 is_dynamic_linker_section, is_relro,
534 is_last_relro, is_first_non_relro);
535 os->set_found_in_sections_clause();
536 *output_section_slot = os;
541 // FIXME: Handle SHF_OS_NONCONFORMING somewhere.
543 // Turn NAME from the name of the input section into the name of the
546 size_t len = strlen(name);
548 && !this->script_options_->saw_sections_clause()
549 && !parameters->options().relocatable())
550 name = Layout::output_section_name(name, &len);
552 Stringpool::Key name_key;
553 name = this->namepool_.add_with_length(name, len, true, &name_key);
555 // Find or make the output section. The output section is selected
556 // based on the section name, type, and flags.
557 return this->get_output_section(name, name_key, type, flags, is_interp,
558 is_dynamic_linker_section, is_relro,
559 is_last_relro, is_first_non_relro);
562 // Return the output section to use for input section SHNDX, with name
563 // NAME, with header HEADER, from object OBJECT. RELOC_SHNDX is the
564 // index of a relocation section which applies to this section, or 0
565 // if none, or -1U if more than one. RELOC_TYPE is the type of the
566 // relocation section if there is one. Set *OFF to the offset of this
567 // input section without the output section. Return NULL if the
568 // section should be discarded. Set *OFF to -1 if the section
569 // contents should not be written directly to the output file, but
570 // will instead receive special handling.
572 template<int size, bool big_endian>
574 Layout::layout(Sized_relobj<size, big_endian>* object, unsigned int shndx,
575 const char* name, const elfcpp::Shdr<size, big_endian>& shdr,
576 unsigned int reloc_shndx, unsigned int, off_t* off)
580 if (!this->include_section(object, name, shdr))
585 // In a relocatable link a grouped section must not be combined with
586 // any other sections.
587 if (parameters->options().relocatable()
588 && (shdr.get_sh_flags() & elfcpp::SHF_GROUP) != 0)
590 name = this->namepool_.add(name, true, NULL);
591 os = this->make_output_section(name, shdr.get_sh_type(),
592 shdr.get_sh_flags(), false, false,
593 false, false, false);
597 os = this->choose_output_section(object, name, shdr.get_sh_type(),
598 shdr.get_sh_flags(), true, false,
599 false, false, false, false);
604 // By default the GNU linker sorts input sections whose names match
605 // .ctor.*, .dtor.*, .init_array.*, or .fini_array.*. The sections
606 // are sorted by name. This is used to implement constructor
607 // priority ordering. We are compatible.
608 if (!this->script_options_->saw_sections_clause()
609 && (is_prefix_of(".ctors.", name)
610 || is_prefix_of(".dtors.", name)
611 || is_prefix_of(".init_array.", name)
612 || is_prefix_of(".fini_array.", name)))
613 os->set_must_sort_attached_input_sections();
615 // FIXME: Handle SHF_LINK_ORDER somewhere.
617 *off = os->add_input_section(object, shndx, name, shdr, reloc_shndx,
618 this->script_options_->saw_sections_clause());
619 this->have_added_input_section_ = true;
624 // Handle a relocation section when doing a relocatable link.
626 template<int size, bool big_endian>
628 Layout::layout_reloc(Sized_relobj<size, big_endian>* object,
630 const elfcpp::Shdr<size, big_endian>& shdr,
631 Output_section* data_section,
632 Relocatable_relocs* rr)
634 gold_assert(parameters->options().relocatable()
635 || parameters->options().emit_relocs());
637 int sh_type = shdr.get_sh_type();
640 if (sh_type == elfcpp::SHT_REL)
642 else if (sh_type == elfcpp::SHT_RELA)
646 name += data_section->name();
648 Output_section* os = this->choose_output_section(object, name.c_str(),
652 false, false, false);
654 os->set_should_link_to_symtab();
655 os->set_info_section(data_section);
657 Output_section_data* posd;
658 if (sh_type == elfcpp::SHT_REL)
660 os->set_entsize(elfcpp::Elf_sizes<size>::rel_size);
661 posd = new Output_relocatable_relocs<elfcpp::SHT_REL,
665 else if (sh_type == elfcpp::SHT_RELA)
667 os->set_entsize(elfcpp::Elf_sizes<size>::rela_size);
668 posd = new Output_relocatable_relocs<elfcpp::SHT_RELA,
675 os->add_output_section_data(posd);
676 rr->set_output_data(posd);
681 // Handle a group section when doing a relocatable link.
683 template<int size, bool big_endian>
685 Layout::layout_group(Symbol_table* symtab,
686 Sized_relobj<size, big_endian>* object,
688 const char* group_section_name,
689 const char* signature,
690 const elfcpp::Shdr<size, big_endian>& shdr,
691 elfcpp::Elf_Word flags,
692 std::vector<unsigned int>* shndxes)
694 gold_assert(parameters->options().relocatable());
695 gold_assert(shdr.get_sh_type() == elfcpp::SHT_GROUP);
696 group_section_name = this->namepool_.add(group_section_name, true, NULL);
697 Output_section* os = this->make_output_section(group_section_name,
703 // We need to find a symbol with the signature in the symbol table.
704 // If we don't find one now, we need to look again later.
705 Symbol* sym = symtab->lookup(signature, NULL);
707 os->set_info_symndx(sym);
710 // Reserve some space to minimize reallocations.
711 if (this->group_signatures_.empty())
712 this->group_signatures_.reserve(this->number_of_input_files_ * 16);
714 // We will wind up using a symbol whose name is the signature.
715 // So just put the signature in the symbol name pool to save it.
716 signature = symtab->canonicalize_name(signature);
717 this->group_signatures_.push_back(Group_signature(os, signature));
720 os->set_should_link_to_symtab();
723 section_size_type entry_count =
724 convert_to_section_size_type(shdr.get_sh_size() / 4);
725 Output_section_data* posd =
726 new Output_data_group<size, big_endian>(object, entry_count, flags,
728 os->add_output_section_data(posd);
731 // Special GNU handling of sections name .eh_frame. They will
732 // normally hold exception frame data as defined by the C++ ABI
733 // (http://codesourcery.com/cxx-abi/).
735 template<int size, bool big_endian>
737 Layout::layout_eh_frame(Sized_relobj<size, big_endian>* object,
738 const unsigned char* symbols,
740 const unsigned char* symbol_names,
741 off_t symbol_names_size,
743 const elfcpp::Shdr<size, big_endian>& shdr,
744 unsigned int reloc_shndx, unsigned int reloc_type,
747 gold_assert(shdr.get_sh_type() == elfcpp::SHT_PROGBITS);
748 gold_assert((shdr.get_sh_flags() & elfcpp::SHF_ALLOC) != 0);
750 const char* const name = ".eh_frame";
751 Output_section* os = this->choose_output_section(object,
753 elfcpp::SHT_PROGBITS,
756 false, false, false);
760 if (this->eh_frame_section_ == NULL)
762 this->eh_frame_section_ = os;
763 this->eh_frame_data_ = new Eh_frame();
765 if (parameters->options().eh_frame_hdr())
767 Output_section* hdr_os =
768 this->choose_output_section(NULL,
770 elfcpp::SHT_PROGBITS,
773 false, false, false);
777 Eh_frame_hdr* hdr_posd = new Eh_frame_hdr(os,
778 this->eh_frame_data_);
779 hdr_os->add_output_section_data(hdr_posd);
781 hdr_os->set_after_input_sections();
783 if (!this->script_options_->saw_phdrs_clause())
785 Output_segment* hdr_oseg;
786 hdr_oseg = this->make_output_segment(elfcpp::PT_GNU_EH_FRAME,
788 hdr_oseg->add_output_section(hdr_os, elfcpp::PF_R, false);
791 this->eh_frame_data_->set_eh_frame_hdr(hdr_posd);
796 gold_assert(this->eh_frame_section_ == os);
798 if (this->eh_frame_data_->add_ehframe_input_section(object,
807 os->update_flags_for_input_section(shdr.get_sh_flags());
809 // We found a .eh_frame section we are going to optimize, so now
810 // we can add the set of optimized sections to the output
811 // section. We need to postpone adding this until we've found a
812 // section we can optimize so that the .eh_frame section in
813 // crtbegin.o winds up at the start of the output section.
814 if (!this->added_eh_frame_data_)
816 os->add_output_section_data(this->eh_frame_data_);
817 this->added_eh_frame_data_ = true;
823 // We couldn't handle this .eh_frame section for some reason.
824 // Add it as a normal section.
825 bool saw_sections_clause = this->script_options_->saw_sections_clause();
826 *off = os->add_input_section(object, shndx, name, shdr, reloc_shndx,
827 saw_sections_clause);
828 this->have_added_input_section_ = true;
834 // Add POSD to an output section using NAME, TYPE, and FLAGS. Return
835 // the output section.
838 Layout::add_output_section_data(const char* name, elfcpp::Elf_Word type,
839 elfcpp::Elf_Xword flags,
840 Output_section_data* posd,
841 bool is_dynamic_linker_section,
842 bool is_relro, bool is_last_relro,
843 bool is_first_non_relro)
845 Output_section* os = this->choose_output_section(NULL, name, type, flags,
847 is_dynamic_linker_section,
848 is_relro, is_last_relro,
851 os->add_output_section_data(posd);
855 // Map section flags to segment flags.
858 Layout::section_flags_to_segment(elfcpp::Elf_Xword flags)
860 elfcpp::Elf_Word ret = elfcpp::PF_R;
861 if ((flags & elfcpp::SHF_WRITE) != 0)
863 if ((flags & elfcpp::SHF_EXECINSTR) != 0)
868 // Sometimes we compress sections. This is typically done for
869 // sections that are not part of normal program execution (such as
870 // .debug_* sections), and where the readers of these sections know
871 // how to deal with compressed sections. This routine doesn't say for
872 // certain whether we'll compress -- it depends on commandline options
873 // as well -- just whether this section is a candidate for compression.
874 // (The Output_compressed_section class decides whether to compress
875 // a given section, and picks the name of the compressed section.)
878 is_compressible_debug_section(const char* secname)
880 return (strncmp(secname, ".debug", sizeof(".debug") - 1) == 0);
883 // Make a new Output_section, and attach it to segments as
884 // appropriate. IS_INTERP is true if this is the .interp section.
885 // IS_DYNAMIC_LINKER_SECTION is true if this section is used by the
886 // dynamic linker. IS_RELRO is true if this is a relro section.
887 // IS_LAST_RELRO is true if this is the last relro section.
888 // IS_FIRST_NON_RELRO is true if this is the first non relro section.
891 Layout::make_output_section(const char* name, elfcpp::Elf_Word type,
892 elfcpp::Elf_Xword flags, bool is_interp,
893 bool is_dynamic_linker_section, bool is_relro,
894 bool is_last_relro, bool is_first_non_relro)
897 if ((flags & elfcpp::SHF_ALLOC) == 0
898 && strcmp(parameters->options().compress_debug_sections(), "none") != 0
899 && is_compressible_debug_section(name))
900 os = new Output_compressed_section(¶meters->options(), name, type,
902 else if ((flags & elfcpp::SHF_ALLOC) == 0
903 && parameters->options().strip_debug_non_line()
904 && strcmp(".debug_abbrev", name) == 0)
906 os = this->debug_abbrev_ = new Output_reduced_debug_abbrev_section(
908 if (this->debug_info_)
909 this->debug_info_->set_abbreviations(this->debug_abbrev_);
911 else if ((flags & elfcpp::SHF_ALLOC) == 0
912 && parameters->options().strip_debug_non_line()
913 && strcmp(".debug_info", name) == 0)
915 os = this->debug_info_ = new Output_reduced_debug_info_section(
917 if (this->debug_abbrev_)
918 this->debug_info_->set_abbreviations(this->debug_abbrev_);
922 // FIXME: const_cast is ugly.
923 Target* target = const_cast<Target*>(¶meters->target());
924 os = target->make_output_section(name, type, flags);
929 if (is_dynamic_linker_section)
930 os->set_is_dynamic_linker_section();
934 os->set_is_last_relro();
935 if (is_first_non_relro)
936 os->set_is_first_non_relro();
938 parameters->target().new_output_section(os);
940 this->section_list_.push_back(os);
942 // The GNU linker by default sorts some sections by priority, so we
943 // do the same. We need to know that this might happen before we
944 // attach any input sections.
945 if (!this->script_options_->saw_sections_clause()
946 && (strcmp(name, ".ctors") == 0
947 || strcmp(name, ".dtors") == 0
948 || strcmp(name, ".init_array") == 0
949 || strcmp(name, ".fini_array") == 0))
950 os->set_may_sort_attached_input_sections();
952 // With -z relro, we have to recognize the special sections by name.
953 // There is no other way.
954 if (!this->script_options_->saw_sections_clause()
955 && parameters->options().relro()
956 && type == elfcpp::SHT_PROGBITS
957 && (flags & elfcpp::SHF_ALLOC) != 0
958 && (flags & elfcpp::SHF_WRITE) != 0)
960 if (strcmp(name, ".data.rel.ro") == 0)
962 else if (strcmp(name, ".data.rel.ro.local") == 0)
965 os->set_is_relro_local();
969 // Check for .stab*str sections, as .stab* sections need to link to
971 if (type == elfcpp::SHT_STRTAB
972 && !this->have_stabstr_section_
973 && strncmp(name, ".stab", 5) == 0
974 && strcmp(name + strlen(name) - 3, "str") == 0)
975 this->have_stabstr_section_ = true;
977 // If we have already attached the sections to segments, then we
978 // need to attach this one now. This happens for sections created
979 // directly by the linker.
980 if (this->sections_are_attached_)
981 this->attach_section_to_segment(os);
986 // Attach output sections to segments. This is called after we have
987 // seen all the input sections.
990 Layout::attach_sections_to_segments()
992 for (Section_list::iterator p = this->section_list_.begin();
993 p != this->section_list_.end();
995 this->attach_section_to_segment(*p);
997 this->sections_are_attached_ = true;
1000 // Attach an output section to a segment.
1003 Layout::attach_section_to_segment(Output_section* os)
1005 if ((os->flags() & elfcpp::SHF_ALLOC) == 0)
1006 this->unattached_section_list_.push_back(os);
1008 this->attach_allocated_section_to_segment(os);
1011 // Attach an allocated output section to a segment.
1014 Layout::attach_allocated_section_to_segment(Output_section* os)
1016 elfcpp::Elf_Xword flags = os->flags();
1017 gold_assert((flags & elfcpp::SHF_ALLOC) != 0);
1019 if (parameters->options().relocatable())
1022 // If we have a SECTIONS clause, we can't handle the attachment to
1023 // segments until after we've seen all the sections.
1024 if (this->script_options_->saw_sections_clause())
1027 gold_assert(!this->script_options_->saw_phdrs_clause());
1029 // This output section goes into a PT_LOAD segment.
1031 elfcpp::Elf_Word seg_flags = Layout::section_flags_to_segment(flags);
1033 // Check for --section-start.
1035 bool is_address_set = parameters->options().section_start(os->name(), &addr);
1037 // In general the only thing we really care about for PT_LOAD
1038 // segments is whether or not they are writable, so that is how we
1039 // search for them. Large data sections also go into their own
1040 // PT_LOAD segment. People who need segments sorted on some other
1041 // basis will have to use a linker script.
1043 Segment_list::const_iterator p;
1044 for (p = this->segment_list_.begin();
1045 p != this->segment_list_.end();
1048 if ((*p)->type() != elfcpp::PT_LOAD)
1050 if (!parameters->options().omagic()
1051 && ((*p)->flags() & elfcpp::PF_W) != (seg_flags & elfcpp::PF_W))
1053 // If -Tbss was specified, we need to separate the data and BSS
1055 if (parameters->options().user_set_Tbss())
1057 if ((os->type() == elfcpp::SHT_NOBITS)
1058 == (*p)->has_any_data_sections())
1061 if (os->is_large_data_section() && !(*p)->is_large_data_segment())
1066 if ((*p)->are_addresses_set())
1069 (*p)->add_initial_output_data(os);
1070 (*p)->update_flags_for_output_section(seg_flags);
1071 (*p)->set_addresses(addr, addr);
1075 (*p)->add_output_section(os, seg_flags, true);
1079 if (p == this->segment_list_.end())
1081 Output_segment* oseg = this->make_output_segment(elfcpp::PT_LOAD,
1083 if (os->is_large_data_section())
1084 oseg->set_is_large_data_segment();
1085 oseg->add_output_section(os, seg_flags, true);
1087 oseg->set_addresses(addr, addr);
1090 // If we see a loadable SHT_NOTE section, we create a PT_NOTE
1092 if (os->type() == elfcpp::SHT_NOTE)
1094 // See if we already have an equivalent PT_NOTE segment.
1095 for (p = this->segment_list_.begin();
1096 p != segment_list_.end();
1099 if ((*p)->type() == elfcpp::PT_NOTE
1100 && (((*p)->flags() & elfcpp::PF_W)
1101 == (seg_flags & elfcpp::PF_W)))
1103 (*p)->add_output_section(os, seg_flags, false);
1108 if (p == this->segment_list_.end())
1110 Output_segment* oseg = this->make_output_segment(elfcpp::PT_NOTE,
1112 oseg->add_output_section(os, seg_flags, false);
1116 // If we see a loadable SHF_TLS section, we create a PT_TLS
1117 // segment. There can only be one such segment.
1118 if ((flags & elfcpp::SHF_TLS) != 0)
1120 if (this->tls_segment_ == NULL)
1121 this->make_output_segment(elfcpp::PT_TLS, seg_flags);
1122 this->tls_segment_->add_output_section(os, seg_flags, false);
1125 // If -z relro is in effect, and we see a relro section, we create a
1126 // PT_GNU_RELRO segment. There can only be one such segment.
1127 if (os->is_relro() && parameters->options().relro())
1129 gold_assert(seg_flags == (elfcpp::PF_R | elfcpp::PF_W));
1130 if (this->relro_segment_ == NULL)
1131 this->make_output_segment(elfcpp::PT_GNU_RELRO, seg_flags);
1132 this->relro_segment_->add_output_section(os, seg_flags, false);
1136 // Make an output section for a script.
1139 Layout::make_output_section_for_script(const char* name)
1141 name = this->namepool_.add(name, false, NULL);
1142 Output_section* os = this->make_output_section(name, elfcpp::SHT_PROGBITS,
1143 elfcpp::SHF_ALLOC, false,
1144 false, false, false, false);
1145 os->set_found_in_sections_clause();
1149 // Return the number of segments we expect to see.
1152 Layout::expected_segment_count() const
1154 size_t ret = this->segment_list_.size();
1156 // If we didn't see a SECTIONS clause in a linker script, we should
1157 // already have the complete list of segments. Otherwise we ask the
1158 // SECTIONS clause how many segments it expects, and add in the ones
1159 // we already have (PT_GNU_STACK, PT_GNU_EH_FRAME, etc.)
1161 if (!this->script_options_->saw_sections_clause())
1165 const Script_sections* ss = this->script_options_->script_sections();
1166 return ret + ss->expected_segment_count(this);
1170 // Handle the .note.GNU-stack section at layout time. SEEN_GNU_STACK
1171 // is whether we saw a .note.GNU-stack section in the object file.
1172 // GNU_STACK_FLAGS is the section flags. The flags give the
1173 // protection required for stack memory. We record this in an
1174 // executable as a PT_GNU_STACK segment. If an object file does not
1175 // have a .note.GNU-stack segment, we must assume that it is an old
1176 // object. On some targets that will force an executable stack.
1179 Layout::layout_gnu_stack(bool seen_gnu_stack, uint64_t gnu_stack_flags)
1181 if (!seen_gnu_stack)
1182 this->input_without_gnu_stack_note_ = true;
1185 this->input_with_gnu_stack_note_ = true;
1186 if ((gnu_stack_flags & elfcpp::SHF_EXECINSTR) != 0)
1187 this->input_requires_executable_stack_ = true;
1191 // Create automatic note sections.
1194 Layout::create_notes()
1196 this->create_gold_note();
1197 this->create_executable_stack_info();
1198 this->create_build_id();
1201 // Create the dynamic sections which are needed before we read the
1205 Layout::create_initial_dynamic_sections(Symbol_table* symtab)
1207 if (parameters->doing_static_link())
1210 this->dynamic_section_ = this->choose_output_section(NULL, ".dynamic",
1211 elfcpp::SHT_DYNAMIC,
1213 | elfcpp::SHF_WRITE),
1215 true, false, false);
1217 this->dynamic_symbol_ =
1218 symtab->define_in_output_data("_DYNAMIC", NULL, Symbol_table::PREDEFINED,
1219 this->dynamic_section_, 0, 0,
1220 elfcpp::STT_OBJECT, elfcpp::STB_LOCAL,
1221 elfcpp::STV_HIDDEN, 0, false, false);
1223 this->dynamic_data_ = new Output_data_dynamic(&this->dynpool_);
1225 this->dynamic_section_->add_output_section_data(this->dynamic_data_);
1228 // For each output section whose name can be represented as C symbol,
1229 // define __start and __stop symbols for the section. This is a GNU
1233 Layout::define_section_symbols(Symbol_table* symtab)
1235 for (Section_list::const_iterator p = this->section_list_.begin();
1236 p != this->section_list_.end();
1239 const char* const name = (*p)->name();
1240 if (is_cident(name))
1242 const std::string name_string(name);
1243 const std::string start_name(cident_section_start_prefix
1245 const std::string stop_name(cident_section_stop_prefix
1248 symtab->define_in_output_data(start_name.c_str(),
1250 Symbol_table::PREDEFINED,
1256 elfcpp::STV_DEFAULT,
1258 false, // offset_is_from_end
1259 true); // only_if_ref
1261 symtab->define_in_output_data(stop_name.c_str(),
1263 Symbol_table::PREDEFINED,
1269 elfcpp::STV_DEFAULT,
1271 true, // offset_is_from_end
1272 true); // only_if_ref
1277 // Define symbols for group signatures.
1280 Layout::define_group_signatures(Symbol_table* symtab)
1282 for (Group_signatures::iterator p = this->group_signatures_.begin();
1283 p != this->group_signatures_.end();
1286 Symbol* sym = symtab->lookup(p->signature, NULL);
1288 p->section->set_info_symndx(sym);
1291 // Force the name of the group section to the group
1292 // signature, and use the group's section symbol as the
1293 // signature symbol.
1294 if (strcmp(p->section->name(), p->signature) != 0)
1296 const char* name = this->namepool_.add(p->signature,
1298 p->section->set_name(name);
1300 p->section->set_needs_symtab_index();
1301 p->section->set_info_section_symndx(p->section);
1305 this->group_signatures_.clear();
1308 // Find the first read-only PT_LOAD segment, creating one if
1312 Layout::find_first_load_seg()
1314 for (Segment_list::const_iterator p = this->segment_list_.begin();
1315 p != this->segment_list_.end();
1318 if ((*p)->type() == elfcpp::PT_LOAD
1319 && ((*p)->flags() & elfcpp::PF_R) != 0
1320 && (parameters->options().omagic()
1321 || ((*p)->flags() & elfcpp::PF_W) == 0))
1325 gold_assert(!this->script_options_->saw_phdrs_clause());
1327 Output_segment* load_seg = this->make_output_segment(elfcpp::PT_LOAD,
1332 // Save states of all current output segments. Store saved states
1333 // in SEGMENT_STATES.
1336 Layout::save_segments(Segment_states* segment_states)
1338 for (Segment_list::const_iterator p = this->segment_list_.begin();
1339 p != this->segment_list_.end();
1342 Output_segment* segment = *p;
1344 Output_segment* copy = new Output_segment(*segment);
1345 (*segment_states)[segment] = copy;
1349 // Restore states of output segments and delete any segment not found in
1353 Layout::restore_segments(const Segment_states* segment_states)
1355 // Go through the segment list and remove any segment added in the
1357 this->tls_segment_ = NULL;
1358 this->relro_segment_ = NULL;
1359 Segment_list::iterator list_iter = this->segment_list_.begin();
1360 while (list_iter != this->segment_list_.end())
1362 Output_segment* segment = *list_iter;
1363 Segment_states::const_iterator states_iter =
1364 segment_states->find(segment);
1365 if (states_iter != segment_states->end())
1367 const Output_segment* copy = states_iter->second;
1368 // Shallow copy to restore states.
1371 // Also fix up TLS and RELRO segment pointers as appropriate.
1372 if (segment->type() == elfcpp::PT_TLS)
1373 this->tls_segment_ = segment;
1374 else if (segment->type() == elfcpp::PT_GNU_RELRO)
1375 this->relro_segment_ = segment;
1381 list_iter = this->segment_list_.erase(list_iter);
1382 // This is a segment created during section layout. It should be
1383 // safe to remove it since we should have removed all pointers to it.
1389 // Clean up after relaxation so that sections can be laid out again.
1392 Layout::clean_up_after_relaxation()
1394 // Restore the segments to point state just prior to the relaxation loop.
1395 Script_sections* script_section = this->script_options_->script_sections();
1396 script_section->release_segments();
1397 this->restore_segments(this->segment_states_);
1399 // Reset section addresses and file offsets
1400 for (Section_list::iterator p = this->section_list_.begin();
1401 p != this->section_list_.end();
1404 (*p)->restore_states();
1406 // If an input section changes size because of relaxation,
1407 // we need to adjust the section offsets of all input sections.
1408 // after such a section.
1409 if ((*p)->section_offsets_need_adjustment())
1410 (*p)->adjust_section_offsets();
1412 (*p)->reset_address_and_file_offset();
1415 // Reset special output object address and file offsets.
1416 for (Data_list::iterator p = this->special_output_list_.begin();
1417 p != this->special_output_list_.end();
1419 (*p)->reset_address_and_file_offset();
1421 // A linker script may have created some output section data objects.
1422 // They are useless now.
1423 for (Output_section_data_list::const_iterator p =
1424 this->script_output_section_data_list_.begin();
1425 p != this->script_output_section_data_list_.end();
1428 this->script_output_section_data_list_.clear();
1431 // Prepare for relaxation.
1434 Layout::prepare_for_relaxation()
1436 // Create an relaxation debug check if in debugging mode.
1437 if (is_debugging_enabled(DEBUG_RELAXATION))
1438 this->relaxation_debug_check_ = new Relaxation_debug_check();
1440 // Save segment states.
1441 this->segment_states_ = new Segment_states();
1442 this->save_segments(this->segment_states_);
1444 for(Section_list::const_iterator p = this->section_list_.begin();
1445 p != this->section_list_.end();
1447 (*p)->save_states();
1449 if (is_debugging_enabled(DEBUG_RELAXATION))
1450 this->relaxation_debug_check_->check_output_data_for_reset_values(
1451 this->section_list_, this->special_output_list_);
1453 // Also enable recording of output section data from scripts.
1454 this->record_output_section_data_from_script_ = true;
1457 // Relaxation loop body: If target has no relaxation, this runs only once
1458 // Otherwise, the target relaxation hook is called at the end of
1459 // each iteration. If the hook returns true, it means re-layout of
1460 // section is required.
1462 // The number of segments created by a linking script without a PHDRS
1463 // clause may be affected by section sizes and alignments. There is
1464 // a remote chance that relaxation causes different number of PT_LOAD
1465 // segments are created and sections are attached to different segments.
1466 // Therefore, we always throw away all segments created during section
1467 // layout. In order to be able to restart the section layout, we keep
1468 // a copy of the segment list right before the relaxation loop and use
1469 // that to restore the segments.
1471 // PASS is the current relaxation pass number.
1472 // SYMTAB is a symbol table.
1473 // PLOAD_SEG is the address of a pointer for the load segment.
1474 // PHDR_SEG is a pointer to the PHDR segment.
1475 // SEGMENT_HEADERS points to the output segment header.
1476 // FILE_HEADER points to the output file header.
1477 // PSHNDX is the address to store the output section index.
1480 Layout::relaxation_loop_body(
1483 Symbol_table* symtab,
1484 Output_segment** pload_seg,
1485 Output_segment* phdr_seg,
1486 Output_segment_headers* segment_headers,
1487 Output_file_header* file_header,
1488 unsigned int* pshndx)
1490 // If this is not the first iteration, we need to clean up after
1491 // relaxation so that we can lay out the sections again.
1493 this->clean_up_after_relaxation();
1495 // If there is a SECTIONS clause, put all the input sections into
1496 // the required order.
1497 Output_segment* load_seg;
1498 if (this->script_options_->saw_sections_clause())
1499 load_seg = this->set_section_addresses_from_script(symtab);
1500 else if (parameters->options().relocatable())
1503 load_seg = this->find_first_load_seg();
1505 if (parameters->options().oformat_enum()
1506 != General_options::OBJECT_FORMAT_ELF)
1509 // If the user set the address of the text segment, that may not be
1510 // compatible with putting the segment headers and file headers into
1512 if (parameters->options().user_set_Ttext())
1515 gold_assert(phdr_seg == NULL
1517 || this->script_options_->saw_sections_clause());
1519 // If the address of the load segment we found has been set by
1520 // --section-start rather than by a script, then we don't want to
1521 // use it for the file and segment headers.
1522 if (load_seg != NULL
1523 && load_seg->are_addresses_set()
1524 && !this->script_options_->saw_sections_clause())
1527 // Lay out the segment headers.
1528 if (!parameters->options().relocatable())
1530 gold_assert(segment_headers != NULL);
1531 if (load_seg != NULL)
1532 load_seg->add_initial_output_data(segment_headers);
1533 if (phdr_seg != NULL)
1534 phdr_seg->add_initial_output_data(segment_headers);
1537 // Lay out the file header.
1538 if (load_seg != NULL)
1539 load_seg->add_initial_output_data(file_header);
1541 if (this->script_options_->saw_phdrs_clause()
1542 && !parameters->options().relocatable())
1544 // Support use of FILEHDRS and PHDRS attachments in a PHDRS
1545 // clause in a linker script.
1546 Script_sections* ss = this->script_options_->script_sections();
1547 ss->put_headers_in_phdrs(file_header, segment_headers);
1550 // We set the output section indexes in set_segment_offsets and
1551 // set_section_indexes.
1554 // Set the file offsets of all the segments, and all the sections
1557 if (!parameters->options().relocatable())
1558 off = this->set_segment_offsets(target, load_seg, pshndx);
1560 off = this->set_relocatable_section_offsets(file_header, pshndx);
1562 // Verify that the dummy relaxation does not change anything.
1563 if (is_debugging_enabled(DEBUG_RELAXATION))
1566 this->relaxation_debug_check_->read_sections(this->section_list_);
1568 this->relaxation_debug_check_->verify_sections(this->section_list_);
1571 *pload_seg = load_seg;
1575 // Finalize the layout. When this is called, we have created all the
1576 // output sections and all the output segments which are based on
1577 // input sections. We have several things to do, and we have to do
1578 // them in the right order, so that we get the right results correctly
1581 // 1) Finalize the list of output segments and create the segment
1584 // 2) Finalize the dynamic symbol table and associated sections.
1586 // 3) Determine the final file offset of all the output segments.
1588 // 4) Determine the final file offset of all the SHF_ALLOC output
1591 // 5) Create the symbol table sections and the section name table
1594 // 6) Finalize the symbol table: set symbol values to their final
1595 // value and make a final determination of which symbols are going
1596 // into the output symbol table.
1598 // 7) Create the section table header.
1600 // 8) Determine the final file offset of all the output sections which
1601 // are not SHF_ALLOC, including the section table header.
1603 // 9) Finalize the ELF file header.
1605 // This function returns the size of the output file.
1608 Layout::finalize(const Input_objects* input_objects, Symbol_table* symtab,
1609 Target* target, const Task* task)
1611 target->finalize_sections(this, input_objects, symtab);
1613 this->count_local_symbols(task, input_objects);
1615 this->link_stabs_sections();
1617 Output_segment* phdr_seg = NULL;
1618 if (!parameters->options().relocatable() && !parameters->doing_static_link())
1620 // There was a dynamic object in the link. We need to create
1621 // some information for the dynamic linker.
1623 // Create the PT_PHDR segment which will hold the program
1625 if (!this->script_options_->saw_phdrs_clause())
1626 phdr_seg = this->make_output_segment(elfcpp::PT_PHDR, elfcpp::PF_R);
1628 // Create the dynamic symbol table, including the hash table.
1629 Output_section* dynstr;
1630 std::vector<Symbol*> dynamic_symbols;
1631 unsigned int local_dynamic_count;
1632 Versions versions(*this->script_options()->version_script_info(),
1634 this->create_dynamic_symtab(input_objects, symtab, &dynstr,
1635 &local_dynamic_count, &dynamic_symbols,
1638 // Create the .interp section to hold the name of the
1639 // interpreter, and put it in a PT_INTERP segment.
1640 if (!parameters->options().shared())
1641 this->create_interp(target);
1643 // Finish the .dynamic section to hold the dynamic data, and put
1644 // it in a PT_DYNAMIC segment.
1645 this->finish_dynamic_section(input_objects, symtab);
1647 // We should have added everything we need to the dynamic string
1649 this->dynpool_.set_string_offsets();
1651 // Create the version sections. We can't do this until the
1652 // dynamic string table is complete.
1653 this->create_version_sections(&versions, symtab, local_dynamic_count,
1654 dynamic_symbols, dynstr);
1656 // Set the size of the _DYNAMIC symbol. We can't do this until
1657 // after we call create_version_sections.
1658 this->set_dynamic_symbol_size(symtab);
1661 if (this->incremental_inputs_)
1663 this->incremental_inputs_->finalize();
1664 this->create_incremental_info_sections();
1667 // Create segment headers.
1668 Output_segment_headers* segment_headers =
1669 (parameters->options().relocatable()
1671 : new Output_segment_headers(this->segment_list_));
1673 // Lay out the file header.
1674 Output_file_header* file_header
1675 = new Output_file_header(target, symtab, segment_headers,
1676 parameters->options().entry());
1678 this->special_output_list_.push_back(file_header);
1679 if (segment_headers != NULL)
1680 this->special_output_list_.push_back(segment_headers);
1682 // Find approriate places for orphan output sections if we are using
1684 if (this->script_options_->saw_sections_clause())
1685 this->place_orphan_sections_in_script();
1687 Output_segment* load_seg;
1692 // Take a snapshot of the section layout as needed.
1693 if (target->may_relax())
1694 this->prepare_for_relaxation();
1696 // Run the relaxation loop to lay out sections.
1699 off = this->relaxation_loop_body(pass, target, symtab, &load_seg,
1700 phdr_seg, segment_headers, file_header,
1704 while (target->may_relax()
1705 && target->relax(pass, input_objects, symtab, this));
1707 // Set the file offsets of all the non-data sections we've seen so
1708 // far which don't have to wait for the input sections. We need
1709 // this in order to finalize local symbols in non-allocated
1711 off = this->set_section_offsets(off, BEFORE_INPUT_SECTIONS_PASS);
1713 // Set the section indexes of all unallocated sections seen so far,
1714 // in case any of them are somehow referenced by a symbol.
1715 shndx = this->set_section_indexes(shndx);
1717 // Create the symbol table sections.
1718 this->create_symtab_sections(input_objects, symtab, shndx, &off);
1719 if (!parameters->doing_static_link())
1720 this->assign_local_dynsym_offsets(input_objects);
1722 // Process any symbol assignments from a linker script. This must
1723 // be called after the symbol table has been finalized.
1724 this->script_options_->finalize_symbols(symtab, this);
1726 // Create the .shstrtab section.
1727 Output_section* shstrtab_section = this->create_shstrtab();
1729 // Set the file offsets of the rest of the non-data sections which
1730 // don't have to wait for the input sections.
1731 off = this->set_section_offsets(off, BEFORE_INPUT_SECTIONS_PASS);
1733 // Now that all sections have been created, set the section indexes
1734 // for any sections which haven't been done yet.
1735 shndx = this->set_section_indexes(shndx);
1737 // Create the section table header.
1738 this->create_shdrs(shstrtab_section, &off);
1740 // If there are no sections which require postprocessing, we can
1741 // handle the section names now, and avoid a resize later.
1742 if (!this->any_postprocessing_sections_)
1743 off = this->set_section_offsets(off,
1744 STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS);
1746 file_header->set_section_info(this->section_headers_, shstrtab_section);
1748 // Now we know exactly where everything goes in the output file
1749 // (except for non-allocated sections which require postprocessing).
1750 Output_data::layout_complete();
1752 this->output_file_size_ = off;
1757 // Create a note header following the format defined in the ELF ABI.
1758 // NAME is the name, NOTE_TYPE is the type, SECTION_NAME is the name
1759 // of the section to create, DESCSZ is the size of the descriptor.
1760 // ALLOCATE is true if the section should be allocated in memory.
1761 // This returns the new note section. It sets *TRAILING_PADDING to
1762 // the number of trailing zero bytes required.
1765 Layout::create_note(const char* name, int note_type,
1766 const char* section_name, size_t descsz,
1767 bool allocate, size_t* trailing_padding)
1769 // Authorities all agree that the values in a .note field should
1770 // be aligned on 4-byte boundaries for 32-bit binaries. However,
1771 // they differ on what the alignment is for 64-bit binaries.
1772 // The GABI says unambiguously they take 8-byte alignment:
1773 // http://sco.com/developers/gabi/latest/ch5.pheader.html#note_section
1774 // Other documentation says alignment should always be 4 bytes:
1775 // http://www.netbsd.org/docs/kernel/elf-notes.html#note-format
1776 // GNU ld and GNU readelf both support the latter (at least as of
1777 // version 2.16.91), and glibc always generates the latter for
1778 // .note.ABI-tag (as of version 1.6), so that's the one we go with
1780 #ifdef GABI_FORMAT_FOR_DOTNOTE_SECTION // This is not defined by default.
1781 const int size = parameters->target().get_size();
1783 const int size = 32;
1786 // The contents of the .note section.
1787 size_t namesz = strlen(name) + 1;
1788 size_t aligned_namesz = align_address(namesz, size / 8);
1789 size_t aligned_descsz = align_address(descsz, size / 8);
1791 size_t notehdrsz = 3 * (size / 8) + aligned_namesz;
1793 unsigned char* buffer = new unsigned char[notehdrsz];
1794 memset(buffer, 0, notehdrsz);
1796 bool is_big_endian = parameters->target().is_big_endian();
1802 elfcpp::Swap<32, false>::writeval(buffer, namesz);
1803 elfcpp::Swap<32, false>::writeval(buffer + 4, descsz);
1804 elfcpp::Swap<32, false>::writeval(buffer + 8, note_type);
1808 elfcpp::Swap<32, true>::writeval(buffer, namesz);
1809 elfcpp::Swap<32, true>::writeval(buffer + 4, descsz);
1810 elfcpp::Swap<32, true>::writeval(buffer + 8, note_type);
1813 else if (size == 64)
1817 elfcpp::Swap<64, false>::writeval(buffer, namesz);
1818 elfcpp::Swap<64, false>::writeval(buffer + 8, descsz);
1819 elfcpp::Swap<64, false>::writeval(buffer + 16, note_type);
1823 elfcpp::Swap<64, true>::writeval(buffer, namesz);
1824 elfcpp::Swap<64, true>::writeval(buffer + 8, descsz);
1825 elfcpp::Swap<64, true>::writeval(buffer + 16, note_type);
1831 memcpy(buffer + 3 * (size / 8), name, namesz);
1833 elfcpp::Elf_Xword flags = 0;
1835 flags = elfcpp::SHF_ALLOC;
1836 Output_section* os = this->choose_output_section(NULL, section_name,
1838 flags, false, false,
1839 false, false, false, false);
1843 Output_section_data* posd = new Output_data_const_buffer(buffer, notehdrsz,
1846 os->add_output_section_data(posd);
1848 *trailing_padding = aligned_descsz - descsz;
1853 // For an executable or shared library, create a note to record the
1854 // version of gold used to create the binary.
1857 Layout::create_gold_note()
1859 if (parameters->options().relocatable())
1862 std::string desc = std::string("gold ") + gold::get_version_string();
1864 size_t trailing_padding;
1865 Output_section *os = this->create_note("GNU", elfcpp::NT_GNU_GOLD_VERSION,
1866 ".note.gnu.gold-version", desc.size(),
1867 false, &trailing_padding);
1871 Output_section_data* posd = new Output_data_const(desc, 4);
1872 os->add_output_section_data(posd);
1874 if (trailing_padding > 0)
1876 posd = new Output_data_zero_fill(trailing_padding, 0);
1877 os->add_output_section_data(posd);
1881 // Record whether the stack should be executable. This can be set
1882 // from the command line using the -z execstack or -z noexecstack
1883 // options. Otherwise, if any input file has a .note.GNU-stack
1884 // section with the SHF_EXECINSTR flag set, the stack should be
1885 // executable. Otherwise, if at least one input file a
1886 // .note.GNU-stack section, and some input file has no .note.GNU-stack
1887 // section, we use the target default for whether the stack should be
1888 // executable. Otherwise, we don't generate a stack note. When
1889 // generating a object file, we create a .note.GNU-stack section with
1890 // the appropriate marking. When generating an executable or shared
1891 // library, we create a PT_GNU_STACK segment.
1894 Layout::create_executable_stack_info()
1896 bool is_stack_executable;
1897 if (parameters->options().is_execstack_set())
1898 is_stack_executable = parameters->options().is_stack_executable();
1899 else if (!this->input_with_gnu_stack_note_)
1903 if (this->input_requires_executable_stack_)
1904 is_stack_executable = true;
1905 else if (this->input_without_gnu_stack_note_)
1906 is_stack_executable =
1907 parameters->target().is_default_stack_executable();
1909 is_stack_executable = false;
1912 if (parameters->options().relocatable())
1914 const char* name = this->namepool_.add(".note.GNU-stack", false, NULL);
1915 elfcpp::Elf_Xword flags = 0;
1916 if (is_stack_executable)
1917 flags |= elfcpp::SHF_EXECINSTR;
1918 this->make_output_section(name, elfcpp::SHT_PROGBITS, flags, false,
1919 false, false, false, false);
1923 if (this->script_options_->saw_phdrs_clause())
1925 int flags = elfcpp::PF_R | elfcpp::PF_W;
1926 if (is_stack_executable)
1927 flags |= elfcpp::PF_X;
1928 this->make_output_segment(elfcpp::PT_GNU_STACK, flags);
1932 // If --build-id was used, set up the build ID note.
1935 Layout::create_build_id()
1937 if (!parameters->options().user_set_build_id())
1940 const char* style = parameters->options().build_id();
1941 if (strcmp(style, "none") == 0)
1944 // Set DESCSZ to the size of the note descriptor. When possible,
1945 // set DESC to the note descriptor contents.
1948 if (strcmp(style, "md5") == 0)
1950 else if (strcmp(style, "sha1") == 0)
1952 else if (strcmp(style, "uuid") == 0)
1954 const size_t uuidsz = 128 / 8;
1956 char buffer[uuidsz];
1957 memset(buffer, 0, uuidsz);
1959 int descriptor = open_descriptor(-1, "/dev/urandom", O_RDONLY);
1961 gold_error(_("--build-id=uuid failed: could not open /dev/urandom: %s"),
1965 ssize_t got = ::read(descriptor, buffer, uuidsz);
1966 release_descriptor(descriptor, true);
1968 gold_error(_("/dev/urandom: read failed: %s"), strerror(errno));
1969 else if (static_cast<size_t>(got) != uuidsz)
1970 gold_error(_("/dev/urandom: expected %zu bytes, got %zd bytes"),
1974 desc.assign(buffer, uuidsz);
1977 else if (strncmp(style, "0x", 2) == 0)
1980 const char* p = style + 2;
1983 if (hex_p(p[0]) && hex_p(p[1]))
1985 char c = (hex_value(p[0]) << 4) | hex_value(p[1]);
1989 else if (*p == '-' || *p == ':')
1992 gold_fatal(_("--build-id argument '%s' not a valid hex number"),
1995 descsz = desc.size();
1998 gold_fatal(_("unrecognized --build-id argument '%s'"), style);
2001 size_t trailing_padding;
2002 Output_section* os = this->create_note("GNU", elfcpp::NT_GNU_BUILD_ID,
2003 ".note.gnu.build-id", descsz, true,
2010 // We know the value already, so we fill it in now.
2011 gold_assert(desc.size() == descsz);
2013 Output_section_data* posd = new Output_data_const(desc, 4);
2014 os->add_output_section_data(posd);
2016 if (trailing_padding != 0)
2018 posd = new Output_data_zero_fill(trailing_padding, 0);
2019 os->add_output_section_data(posd);
2024 // We need to compute a checksum after we have completed the
2026 gold_assert(trailing_padding == 0);
2027 this->build_id_note_ = new Output_data_zero_fill(descsz, 4);
2028 os->add_output_section_data(this->build_id_note_);
2032 // If we have both .stabXX and .stabXXstr sections, then the sh_link
2033 // field of the former should point to the latter. I'm not sure who
2034 // started this, but the GNU linker does it, and some tools depend
2038 Layout::link_stabs_sections()
2040 if (!this->have_stabstr_section_)
2043 for (Section_list::iterator p = this->section_list_.begin();
2044 p != this->section_list_.end();
2047 if ((*p)->type() != elfcpp::SHT_STRTAB)
2050 const char* name = (*p)->name();
2051 if (strncmp(name, ".stab", 5) != 0)
2054 size_t len = strlen(name);
2055 if (strcmp(name + len - 3, "str") != 0)
2058 std::string stab_name(name, len - 3);
2059 Output_section* stab_sec;
2060 stab_sec = this->find_output_section(stab_name.c_str());
2061 if (stab_sec != NULL)
2062 stab_sec->set_link_section(*p);
2066 // Create .gnu_incremental_inputs and .gnu_incremental_strtab sections needed
2067 // for the next run of incremental linking to check what has changed.
2070 Layout::create_incremental_info_sections()
2072 gold_assert(this->incremental_inputs_ != NULL);
2074 // Add the .gnu_incremental_inputs section.
2075 const char *incremental_inputs_name =
2076 this->namepool_.add(".gnu_incremental_inputs", false, NULL);
2077 Output_section* inputs_os =
2078 this->make_output_section(incremental_inputs_name,
2079 elfcpp::SHT_GNU_INCREMENTAL_INPUTS, 0,
2080 false, false, false, false, false);
2081 Output_section_data* posd =
2082 this->incremental_inputs_->create_incremental_inputs_section_data();
2083 inputs_os->add_output_section_data(posd);
2085 // Add the .gnu_incremental_strtab section.
2086 const char *incremental_strtab_name =
2087 this->namepool_.add(".gnu_incremental_strtab", false, NULL);
2088 Output_section* strtab_os = this->make_output_section(incremental_strtab_name,
2091 false, false, false);
2092 Output_data_strtab* strtab_data =
2093 new Output_data_strtab(this->incremental_inputs_->get_stringpool());
2094 strtab_os->add_output_section_data(strtab_data);
2096 inputs_os->set_link_section(strtab_data);
2099 // Return whether SEG1 should be before SEG2 in the output file. This
2100 // is based entirely on the segment type and flags. When this is
2101 // called the segment addresses has normally not yet been set.
2104 Layout::segment_precedes(const Output_segment* seg1,
2105 const Output_segment* seg2)
2107 elfcpp::Elf_Word type1 = seg1->type();
2108 elfcpp::Elf_Word type2 = seg2->type();
2110 // The single PT_PHDR segment is required to precede any loadable
2111 // segment. We simply make it always first.
2112 if (type1 == elfcpp::PT_PHDR)
2114 gold_assert(type2 != elfcpp::PT_PHDR);
2117 if (type2 == elfcpp::PT_PHDR)
2120 // The single PT_INTERP segment is required to precede any loadable
2121 // segment. We simply make it always second.
2122 if (type1 == elfcpp::PT_INTERP)
2124 gold_assert(type2 != elfcpp::PT_INTERP);
2127 if (type2 == elfcpp::PT_INTERP)
2130 // We then put PT_LOAD segments before any other segments.
2131 if (type1 == elfcpp::PT_LOAD && type2 != elfcpp::PT_LOAD)
2133 if (type2 == elfcpp::PT_LOAD && type1 != elfcpp::PT_LOAD)
2136 // We put the PT_TLS segment last except for the PT_GNU_RELRO
2137 // segment, because that is where the dynamic linker expects to find
2138 // it (this is just for efficiency; other positions would also work
2140 if (type1 == elfcpp::PT_TLS
2141 && type2 != elfcpp::PT_TLS
2142 && type2 != elfcpp::PT_GNU_RELRO)
2144 if (type2 == elfcpp::PT_TLS
2145 && type1 != elfcpp::PT_TLS
2146 && type1 != elfcpp::PT_GNU_RELRO)
2149 // We put the PT_GNU_RELRO segment last, because that is where the
2150 // dynamic linker expects to find it (as with PT_TLS, this is just
2152 if (type1 == elfcpp::PT_GNU_RELRO && type2 != elfcpp::PT_GNU_RELRO)
2154 if (type2 == elfcpp::PT_GNU_RELRO && type1 != elfcpp::PT_GNU_RELRO)
2157 const elfcpp::Elf_Word flags1 = seg1->flags();
2158 const elfcpp::Elf_Word flags2 = seg2->flags();
2160 // The order of non-PT_LOAD segments is unimportant. We simply sort
2161 // by the numeric segment type and flags values. There should not
2162 // be more than one segment with the same type and flags.
2163 if (type1 != elfcpp::PT_LOAD)
2166 return type1 < type2;
2167 gold_assert(flags1 != flags2);
2168 return flags1 < flags2;
2171 // If the addresses are set already, sort by load address.
2172 if (seg1->are_addresses_set())
2174 if (!seg2->are_addresses_set())
2177 unsigned int section_count1 = seg1->output_section_count();
2178 unsigned int section_count2 = seg2->output_section_count();
2179 if (section_count1 == 0 && section_count2 > 0)
2181 if (section_count1 > 0 && section_count2 == 0)
2184 uint64_t paddr1 = seg1->first_section_load_address();
2185 uint64_t paddr2 = seg2->first_section_load_address();
2186 if (paddr1 != paddr2)
2187 return paddr1 < paddr2;
2189 else if (seg2->are_addresses_set())
2192 // A segment which holds large data comes after a segment which does
2193 // not hold large data.
2194 if (seg1->is_large_data_segment())
2196 if (!seg2->is_large_data_segment())
2199 else if (seg2->is_large_data_segment())
2202 // Otherwise, we sort PT_LOAD segments based on the flags. Readonly
2203 // segments come before writable segments. Then writable segments
2204 // with data come before writable segments without data. Then
2205 // executable segments come before non-executable segments. Then
2206 // the unlikely case of a non-readable segment comes before the
2207 // normal case of a readable segment. If there are multiple
2208 // segments with the same type and flags, we require that the
2209 // address be set, and we sort by virtual address and then physical
2211 if ((flags1 & elfcpp::PF_W) != (flags2 & elfcpp::PF_W))
2212 return (flags1 & elfcpp::PF_W) == 0;
2213 if ((flags1 & elfcpp::PF_W) != 0
2214 && seg1->has_any_data_sections() != seg2->has_any_data_sections())
2215 return seg1->has_any_data_sections();
2216 if ((flags1 & elfcpp::PF_X) != (flags2 & elfcpp::PF_X))
2217 return (flags1 & elfcpp::PF_X) != 0;
2218 if ((flags1 & elfcpp::PF_R) != (flags2 & elfcpp::PF_R))
2219 return (flags1 & elfcpp::PF_R) == 0;
2221 // We shouldn't get here--we shouldn't create segments which we
2222 // can't distinguish.
2226 // Increase OFF so that it is congruent to ADDR modulo ABI_PAGESIZE.
2229 align_file_offset(off_t off, uint64_t addr, uint64_t abi_pagesize)
2231 uint64_t unsigned_off = off;
2232 uint64_t aligned_off = ((unsigned_off & ~(abi_pagesize - 1))
2233 | (addr & (abi_pagesize - 1)));
2234 if (aligned_off < unsigned_off)
2235 aligned_off += abi_pagesize;
2239 // Set the file offsets of all the segments, and all the sections they
2240 // contain. They have all been created. LOAD_SEG must be be laid out
2241 // first. Return the offset of the data to follow.
2244 Layout::set_segment_offsets(const Target* target, Output_segment* load_seg,
2245 unsigned int *pshndx)
2247 // Sort them into the final order.
2248 std::sort(this->segment_list_.begin(), this->segment_list_.end(),
2249 Layout::Compare_segments());
2251 // Find the PT_LOAD segments, and set their addresses and offsets
2252 // and their section's addresses and offsets.
2254 if (parameters->options().user_set_Ttext())
2255 addr = parameters->options().Ttext();
2256 else if (parameters->options().output_is_position_independent())
2259 addr = target->default_text_segment_address();
2262 // If LOAD_SEG is NULL, then the file header and segment headers
2263 // will not be loadable. But they still need to be at offset 0 in
2264 // the file. Set their offsets now.
2265 if (load_seg == NULL)
2267 for (Data_list::iterator p = this->special_output_list_.begin();
2268 p != this->special_output_list_.end();
2271 off = align_address(off, (*p)->addralign());
2272 (*p)->set_address_and_file_offset(0, off);
2273 off += (*p)->data_size();
2277 unsigned int increase_relro = this->increase_relro_;
2278 if (this->script_options_->saw_sections_clause())
2281 const bool check_sections = parameters->options().check_sections();
2282 Output_segment* last_load_segment = NULL;
2284 bool was_readonly = false;
2285 for (Segment_list::iterator p = this->segment_list_.begin();
2286 p != this->segment_list_.end();
2289 if ((*p)->type() == elfcpp::PT_LOAD)
2291 if (load_seg != NULL && load_seg != *p)
2295 bool are_addresses_set = (*p)->are_addresses_set();
2296 if (are_addresses_set)
2298 // When it comes to setting file offsets, we care about
2299 // the physical address.
2300 addr = (*p)->paddr();
2302 else if (parameters->options().user_set_Tdata()
2303 && ((*p)->flags() & elfcpp::PF_W) != 0
2304 && (!parameters->options().user_set_Tbss()
2305 || (*p)->has_any_data_sections()))
2307 addr = parameters->options().Tdata();
2308 are_addresses_set = true;
2310 else if (parameters->options().user_set_Tbss()
2311 && ((*p)->flags() & elfcpp::PF_W) != 0
2312 && !(*p)->has_any_data_sections())
2314 addr = parameters->options().Tbss();
2315 are_addresses_set = true;
2318 uint64_t orig_addr = addr;
2319 uint64_t orig_off = off;
2321 uint64_t aligned_addr = 0;
2322 uint64_t abi_pagesize = target->abi_pagesize();
2323 uint64_t common_pagesize = target->common_pagesize();
2325 if (!parameters->options().nmagic()
2326 && !parameters->options().omagic())
2327 (*p)->set_minimum_p_align(common_pagesize);
2329 if (!are_addresses_set)
2331 // If the last segment was readonly, and this one is
2332 // not, then skip the address forward one page,
2333 // maintaining the same position within the page. This
2334 // lets us store both segments overlapping on a single
2335 // page in the file, but the loader will put them on
2336 // different pages in memory.
2338 addr = align_address(addr, (*p)->maximum_alignment());
2339 aligned_addr = addr;
2341 if (was_readonly && ((*p)->flags() & elfcpp::PF_W) != 0)
2343 if ((addr & (abi_pagesize - 1)) != 0)
2344 addr = addr + abi_pagesize;
2347 off = orig_off + ((addr - orig_addr) & (abi_pagesize - 1));
2350 if (!parameters->options().nmagic()
2351 && !parameters->options().omagic())
2352 off = align_file_offset(off, addr, abi_pagesize);
2353 else if (load_seg == NULL)
2355 // This is -N or -n with a section script which prevents
2356 // us from using a load segment. We need to ensure that
2357 // the file offset is aligned to the alignment of the
2358 // segment. This is because the linker script
2359 // implicitly assumed a zero offset. If we don't align
2360 // here, then the alignment of the sections in the
2361 // linker script may not match the alignment of the
2362 // sections in the set_section_addresses call below,
2363 // causing an error about dot moving backward.
2364 off = align_address(off, (*p)->maximum_alignment());
2367 unsigned int shndx_hold = *pshndx;
2368 uint64_t new_addr = (*p)->set_section_addresses(this, false, addr,
2372 // Now that we know the size of this segment, we may be able
2373 // to save a page in memory, at the cost of wasting some
2374 // file space, by instead aligning to the start of a new
2375 // page. Here we use the real machine page size rather than
2376 // the ABI mandated page size.
2378 if (!are_addresses_set && aligned_addr != addr)
2380 uint64_t first_off = (common_pagesize
2382 & (common_pagesize - 1)));
2383 uint64_t last_off = new_addr & (common_pagesize - 1);
2386 && ((aligned_addr & ~ (common_pagesize - 1))
2387 != (new_addr & ~ (common_pagesize - 1)))
2388 && first_off + last_off <= common_pagesize)
2390 *pshndx = shndx_hold;
2391 addr = align_address(aligned_addr, common_pagesize);
2392 addr = align_address(addr, (*p)->maximum_alignment());
2393 off = orig_off + ((addr - orig_addr) & (abi_pagesize - 1));
2394 off = align_file_offset(off, addr, abi_pagesize);
2395 new_addr = (*p)->set_section_addresses(this, true, addr,
2403 if (((*p)->flags() & elfcpp::PF_W) == 0)
2404 was_readonly = true;
2406 // Implement --check-sections. We know that the segments
2407 // are sorted by LMA.
2408 if (check_sections && last_load_segment != NULL)
2410 gold_assert(last_load_segment->paddr() <= (*p)->paddr());
2411 if (last_load_segment->paddr() + last_load_segment->memsz()
2414 unsigned long long lb1 = last_load_segment->paddr();
2415 unsigned long long le1 = lb1 + last_load_segment->memsz();
2416 unsigned long long lb2 = (*p)->paddr();
2417 unsigned long long le2 = lb2 + (*p)->memsz();
2418 gold_error(_("load segment overlap [0x%llx -> 0x%llx] and "
2419 "[0x%llx -> 0x%llx]"),
2420 lb1, le1, lb2, le2);
2423 last_load_segment = *p;
2427 // Handle the non-PT_LOAD segments, setting their offsets from their
2428 // section's offsets.
2429 for (Segment_list::iterator p = this->segment_list_.begin();
2430 p != this->segment_list_.end();
2433 if ((*p)->type() != elfcpp::PT_LOAD)
2434 (*p)->set_offset((*p)->type() == elfcpp::PT_GNU_RELRO
2439 // Set the TLS offsets for each section in the PT_TLS segment.
2440 if (this->tls_segment_ != NULL)
2441 this->tls_segment_->set_tls_offsets();
2446 // Set the offsets of all the allocated sections when doing a
2447 // relocatable link. This does the same jobs as set_segment_offsets,
2448 // only for a relocatable link.
2451 Layout::set_relocatable_section_offsets(Output_data* file_header,
2452 unsigned int *pshndx)
2456 file_header->set_address_and_file_offset(0, 0);
2457 off += file_header->data_size();
2459 for (Section_list::iterator p = this->section_list_.begin();
2460 p != this->section_list_.end();
2463 // We skip unallocated sections here, except that group sections
2464 // have to come first.
2465 if (((*p)->flags() & elfcpp::SHF_ALLOC) == 0
2466 && (*p)->type() != elfcpp::SHT_GROUP)
2469 off = align_address(off, (*p)->addralign());
2471 // The linker script might have set the address.
2472 if (!(*p)->is_address_valid())
2473 (*p)->set_address(0);
2474 (*p)->set_file_offset(off);
2475 (*p)->finalize_data_size();
2476 off += (*p)->data_size();
2478 (*p)->set_out_shndx(*pshndx);
2485 // Set the file offset of all the sections not associated with a
2489 Layout::set_section_offsets(off_t off, Layout::Section_offset_pass pass)
2491 for (Section_list::iterator p = this->unattached_section_list_.begin();
2492 p != this->unattached_section_list_.end();
2495 // The symtab section is handled in create_symtab_sections.
2496 if (*p == this->symtab_section_)
2499 // If we've already set the data size, don't set it again.
2500 if ((*p)->is_offset_valid() && (*p)->is_data_size_valid())
2503 if (pass == BEFORE_INPUT_SECTIONS_PASS
2504 && (*p)->requires_postprocessing())
2506 (*p)->create_postprocessing_buffer();
2507 this->any_postprocessing_sections_ = true;
2510 if (pass == BEFORE_INPUT_SECTIONS_PASS
2511 && (*p)->after_input_sections())
2513 else if (pass == POSTPROCESSING_SECTIONS_PASS
2514 && (!(*p)->after_input_sections()
2515 || (*p)->type() == elfcpp::SHT_STRTAB))
2517 else if (pass == STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS
2518 && (!(*p)->after_input_sections()
2519 || (*p)->type() != elfcpp::SHT_STRTAB))
2522 off = align_address(off, (*p)->addralign());
2523 (*p)->set_file_offset(off);
2524 (*p)->finalize_data_size();
2525 off += (*p)->data_size();
2527 // At this point the name must be set.
2528 if (pass != STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS)
2529 this->namepool_.add((*p)->name(), false, NULL);
2534 // Set the section indexes of all the sections not associated with a
2538 Layout::set_section_indexes(unsigned int shndx)
2540 for (Section_list::iterator p = this->unattached_section_list_.begin();
2541 p != this->unattached_section_list_.end();
2544 if (!(*p)->has_out_shndx())
2546 (*p)->set_out_shndx(shndx);
2553 // Set the section addresses according to the linker script. This is
2554 // only called when we see a SECTIONS clause. This returns the
2555 // program segment which should hold the file header and segment
2556 // headers, if any. It will return NULL if they should not be in a
2560 Layout::set_section_addresses_from_script(Symbol_table* symtab)
2562 Script_sections* ss = this->script_options_->script_sections();
2563 gold_assert(ss->saw_sections_clause());
2564 return this->script_options_->set_section_addresses(symtab, this);
2567 // Place the orphan sections in the linker script.
2570 Layout::place_orphan_sections_in_script()
2572 Script_sections* ss = this->script_options_->script_sections();
2573 gold_assert(ss->saw_sections_clause());
2575 // Place each orphaned output section in the script.
2576 for (Section_list::iterator p = this->section_list_.begin();
2577 p != this->section_list_.end();
2580 if (!(*p)->found_in_sections_clause())
2581 ss->place_orphan(*p);
2585 // Count the local symbols in the regular symbol table and the dynamic
2586 // symbol table, and build the respective string pools.
2589 Layout::count_local_symbols(const Task* task,
2590 const Input_objects* input_objects)
2592 // First, figure out an upper bound on the number of symbols we'll
2593 // be inserting into each pool. This helps us create the pools with
2594 // the right size, to avoid unnecessary hashtable resizing.
2595 unsigned int symbol_count = 0;
2596 for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
2597 p != input_objects->relobj_end();
2599 symbol_count += (*p)->local_symbol_count();
2601 // Go from "upper bound" to "estimate." We overcount for two
2602 // reasons: we double-count symbols that occur in more than one
2603 // object file, and we count symbols that are dropped from the
2604 // output. Add it all together and assume we overcount by 100%.
2607 // We assume all symbols will go into both the sympool and dynpool.
2608 this->sympool_.reserve(symbol_count);
2609 this->dynpool_.reserve(symbol_count);
2611 for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
2612 p != input_objects->relobj_end();
2615 Task_lock_obj<Object> tlo(task, *p);
2616 (*p)->count_local_symbols(&this->sympool_, &this->dynpool_);
2620 // Create the symbol table sections. Here we also set the final
2621 // values of the symbols. At this point all the loadable sections are
2622 // fully laid out. SHNUM is the number of sections so far.
2625 Layout::create_symtab_sections(const Input_objects* input_objects,
2626 Symbol_table* symtab,
2632 if (parameters->target().get_size() == 32)
2634 symsize = elfcpp::Elf_sizes<32>::sym_size;
2637 else if (parameters->target().get_size() == 64)
2639 symsize = elfcpp::Elf_sizes<64>::sym_size;
2646 off = align_address(off, align);
2647 off_t startoff = off;
2649 // Save space for the dummy symbol at the start of the section. We
2650 // never bother to write this out--it will just be left as zero.
2652 unsigned int local_symbol_index = 1;
2654 // Add STT_SECTION symbols for each Output section which needs one.
2655 for (Section_list::iterator p = this->section_list_.begin();
2656 p != this->section_list_.end();
2659 if (!(*p)->needs_symtab_index())
2660 (*p)->set_symtab_index(-1U);
2663 (*p)->set_symtab_index(local_symbol_index);
2664 ++local_symbol_index;
2669 for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
2670 p != input_objects->relobj_end();
2673 unsigned int index = (*p)->finalize_local_symbols(local_symbol_index,
2675 off += (index - local_symbol_index) * symsize;
2676 local_symbol_index = index;
2679 unsigned int local_symcount = local_symbol_index;
2680 gold_assert(static_cast<off_t>(local_symcount * symsize) == off - startoff);
2683 size_t dyn_global_index;
2685 if (this->dynsym_section_ == NULL)
2688 dyn_global_index = 0;
2693 dyn_global_index = this->dynsym_section_->info();
2694 off_t locsize = dyn_global_index * this->dynsym_section_->entsize();
2695 dynoff = this->dynsym_section_->offset() + locsize;
2696 dyncount = (this->dynsym_section_->data_size() - locsize) / symsize;
2697 gold_assert(static_cast<off_t>(dyncount * symsize)
2698 == this->dynsym_section_->data_size() - locsize);
2701 off = symtab->finalize(off, dynoff, dyn_global_index, dyncount,
2702 &this->sympool_, &local_symcount);
2704 if (!parameters->options().strip_all())
2706 this->sympool_.set_string_offsets();
2708 const char* symtab_name = this->namepool_.add(".symtab", false, NULL);
2709 Output_section* osymtab = this->make_output_section(symtab_name,
2712 false, false, false);
2713 this->symtab_section_ = osymtab;
2715 Output_section_data* pos = new Output_data_fixed_space(off - startoff,
2718 osymtab->add_output_section_data(pos);
2720 // We generate a .symtab_shndx section if we have more than
2721 // SHN_LORESERVE sections. Technically it is possible that we
2722 // don't need one, because it is possible that there are no
2723 // symbols in any of sections with indexes larger than
2724 // SHN_LORESERVE. That is probably unusual, though, and it is
2725 // easier to always create one than to compute section indexes
2726 // twice (once here, once when writing out the symbols).
2727 if (shnum >= elfcpp::SHN_LORESERVE)
2729 const char* symtab_xindex_name = this->namepool_.add(".symtab_shndx",
2731 Output_section* osymtab_xindex =
2732 this->make_output_section(symtab_xindex_name,
2733 elfcpp::SHT_SYMTAB_SHNDX, 0, false,
2734 false, false, false, false);
2736 size_t symcount = (off - startoff) / symsize;
2737 this->symtab_xindex_ = new Output_symtab_xindex(symcount);
2739 osymtab_xindex->add_output_section_data(this->symtab_xindex_);
2741 osymtab_xindex->set_link_section(osymtab);
2742 osymtab_xindex->set_addralign(4);
2743 osymtab_xindex->set_entsize(4);
2745 osymtab_xindex->set_after_input_sections();
2747 // This tells the driver code to wait until the symbol table
2748 // has written out before writing out the postprocessing
2749 // sections, including the .symtab_shndx section.
2750 this->any_postprocessing_sections_ = true;
2753 const char* strtab_name = this->namepool_.add(".strtab", false, NULL);
2754 Output_section* ostrtab = this->make_output_section(strtab_name,
2757 false, false, false);
2759 Output_section_data* pstr = new Output_data_strtab(&this->sympool_);
2760 ostrtab->add_output_section_data(pstr);
2762 osymtab->set_file_offset(startoff);
2763 osymtab->finalize_data_size();
2764 osymtab->set_link_section(ostrtab);
2765 osymtab->set_info(local_symcount);
2766 osymtab->set_entsize(symsize);
2772 // Create the .shstrtab section, which holds the names of the
2773 // sections. At the time this is called, we have created all the
2774 // output sections except .shstrtab itself.
2777 Layout::create_shstrtab()
2779 // FIXME: We don't need to create a .shstrtab section if we are
2780 // stripping everything.
2782 const char* name = this->namepool_.add(".shstrtab", false, NULL);
2784 Output_section* os = this->make_output_section(name, elfcpp::SHT_STRTAB, 0,
2785 false, false, false, false,
2788 if (strcmp(parameters->options().compress_debug_sections(), "none") != 0)
2790 // We can't write out this section until we've set all the
2791 // section names, and we don't set the names of compressed
2792 // output sections until relocations are complete. FIXME: With
2793 // the current names we use, this is unnecessary.
2794 os->set_after_input_sections();
2797 Output_section_data* posd = new Output_data_strtab(&this->namepool_);
2798 os->add_output_section_data(posd);
2803 // Create the section headers. SIZE is 32 or 64. OFF is the file
2807 Layout::create_shdrs(const Output_section* shstrtab_section, off_t* poff)
2809 Output_section_headers* oshdrs;
2810 oshdrs = new Output_section_headers(this,
2811 &this->segment_list_,
2812 &this->section_list_,
2813 &this->unattached_section_list_,
2816 off_t off = align_address(*poff, oshdrs->addralign());
2817 oshdrs->set_address_and_file_offset(0, off);
2818 off += oshdrs->data_size();
2820 this->section_headers_ = oshdrs;
2823 // Count the allocated sections.
2826 Layout::allocated_output_section_count() const
2828 size_t section_count = 0;
2829 for (Segment_list::const_iterator p = this->segment_list_.begin();
2830 p != this->segment_list_.end();
2832 section_count += (*p)->output_section_count();
2833 return section_count;
2836 // Create the dynamic symbol table.
2839 Layout::create_dynamic_symtab(const Input_objects* input_objects,
2840 Symbol_table* symtab,
2841 Output_section **pdynstr,
2842 unsigned int* plocal_dynamic_count,
2843 std::vector<Symbol*>* pdynamic_symbols,
2844 Versions* pversions)
2846 // Count all the symbols in the dynamic symbol table, and set the
2847 // dynamic symbol indexes.
2849 // Skip symbol 0, which is always all zeroes.
2850 unsigned int index = 1;
2852 // Add STT_SECTION symbols for each Output section which needs one.
2853 for (Section_list::iterator p = this->section_list_.begin();
2854 p != this->section_list_.end();
2857 if (!(*p)->needs_dynsym_index())
2858 (*p)->set_dynsym_index(-1U);
2861 (*p)->set_dynsym_index(index);
2866 // Count the local symbols that need to go in the dynamic symbol table,
2867 // and set the dynamic symbol indexes.
2868 for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
2869 p != input_objects->relobj_end();
2872 unsigned int new_index = (*p)->set_local_dynsym_indexes(index);
2876 unsigned int local_symcount = index;
2877 *plocal_dynamic_count = local_symcount;
2879 index = symtab->set_dynsym_indexes(index, pdynamic_symbols,
2880 &this->dynpool_, pversions);
2884 const int size = parameters->target().get_size();
2887 symsize = elfcpp::Elf_sizes<32>::sym_size;
2890 else if (size == 64)
2892 symsize = elfcpp::Elf_sizes<64>::sym_size;
2898 // Create the dynamic symbol table section.
2900 Output_section* dynsym = this->choose_output_section(NULL, ".dynsym",
2904 false, false, false);
2906 Output_section_data* odata = new Output_data_fixed_space(index * symsize,
2909 dynsym->add_output_section_data(odata);
2911 dynsym->set_info(local_symcount);
2912 dynsym->set_entsize(symsize);
2913 dynsym->set_addralign(align);
2915 this->dynsym_section_ = dynsym;
2917 Output_data_dynamic* const odyn = this->dynamic_data_;
2918 odyn->add_section_address(elfcpp::DT_SYMTAB, dynsym);
2919 odyn->add_constant(elfcpp::DT_SYMENT, symsize);
2921 // If there are more than SHN_LORESERVE allocated sections, we
2922 // create a .dynsym_shndx section. It is possible that we don't
2923 // need one, because it is possible that there are no dynamic
2924 // symbols in any of the sections with indexes larger than
2925 // SHN_LORESERVE. This is probably unusual, though, and at this
2926 // time we don't know the actual section indexes so it is
2927 // inconvenient to check.
2928 if (this->allocated_output_section_count() >= elfcpp::SHN_LORESERVE)
2930 Output_section* dynsym_xindex =
2931 this->choose_output_section(NULL, ".dynsym_shndx",
2932 elfcpp::SHT_SYMTAB_SHNDX,
2934 false, false, true, false, false, false);
2936 this->dynsym_xindex_ = new Output_symtab_xindex(index);
2938 dynsym_xindex->add_output_section_data(this->dynsym_xindex_);
2940 dynsym_xindex->set_link_section(dynsym);
2941 dynsym_xindex->set_addralign(4);
2942 dynsym_xindex->set_entsize(4);
2944 dynsym_xindex->set_after_input_sections();
2946 // This tells the driver code to wait until the symbol table has
2947 // written out before writing out the postprocessing sections,
2948 // including the .dynsym_shndx section.
2949 this->any_postprocessing_sections_ = true;
2952 // Create the dynamic string table section.
2954 Output_section* dynstr = this->choose_output_section(NULL, ".dynstr",
2958 false, false, false);
2960 Output_section_data* strdata = new Output_data_strtab(&this->dynpool_);
2961 dynstr->add_output_section_data(strdata);
2963 dynsym->set_link_section(dynstr);
2964 this->dynamic_section_->set_link_section(dynstr);
2966 odyn->add_section_address(elfcpp::DT_STRTAB, dynstr);
2967 odyn->add_section_size(elfcpp::DT_STRSZ, dynstr);
2971 // Create the hash tables.
2973 if (strcmp(parameters->options().hash_style(), "sysv") == 0
2974 || strcmp(parameters->options().hash_style(), "both") == 0)
2976 unsigned char* phash;
2977 unsigned int hashlen;
2978 Dynobj::create_elf_hash_table(*pdynamic_symbols, local_symcount,
2981 Output_section* hashsec = this->choose_output_section(NULL, ".hash",
2988 Output_section_data* hashdata = new Output_data_const_buffer(phash,
2992 hashsec->add_output_section_data(hashdata);
2994 hashsec->set_link_section(dynsym);
2995 hashsec->set_entsize(4);
2997 odyn->add_section_address(elfcpp::DT_HASH, hashsec);
3000 if (strcmp(parameters->options().hash_style(), "gnu") == 0
3001 || strcmp(parameters->options().hash_style(), "both") == 0)
3003 unsigned char* phash;
3004 unsigned int hashlen;
3005 Dynobj::create_gnu_hash_table(*pdynamic_symbols, local_symcount,
3008 Output_section* hashsec = this->choose_output_section(NULL, ".gnu.hash",
3009 elfcpp::SHT_GNU_HASH,
3015 Output_section_data* hashdata = new Output_data_const_buffer(phash,
3019 hashsec->add_output_section_data(hashdata);
3021 hashsec->set_link_section(dynsym);
3023 // For a 64-bit target, the entries in .gnu.hash do not have a
3024 // uniform size, so we only set the entry size for a 32-bit
3026 if (parameters->target().get_size() == 32)
3027 hashsec->set_entsize(4);
3029 odyn->add_section_address(elfcpp::DT_GNU_HASH, hashsec);
3033 // Assign offsets to each local portion of the dynamic symbol table.
3036 Layout::assign_local_dynsym_offsets(const Input_objects* input_objects)
3038 Output_section* dynsym = this->dynsym_section_;
3039 gold_assert(dynsym != NULL);
3041 off_t off = dynsym->offset();
3043 // Skip the dummy symbol at the start of the section.
3044 off += dynsym->entsize();
3046 for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
3047 p != input_objects->relobj_end();
3050 unsigned int count = (*p)->set_local_dynsym_offset(off);
3051 off += count * dynsym->entsize();
3055 // Create the version sections.
3058 Layout::create_version_sections(const Versions* versions,
3059 const Symbol_table* symtab,
3060 unsigned int local_symcount,
3061 const std::vector<Symbol*>& dynamic_symbols,
3062 const Output_section* dynstr)
3064 if (!versions->any_defs() && !versions->any_needs())
3067 switch (parameters->size_and_endianness())
3069 #ifdef HAVE_TARGET_32_LITTLE
3070 case Parameters::TARGET_32_LITTLE:
3071 this->sized_create_version_sections<32, false>(versions, symtab,
3073 dynamic_symbols, dynstr);
3076 #ifdef HAVE_TARGET_32_BIG
3077 case Parameters::TARGET_32_BIG:
3078 this->sized_create_version_sections<32, true>(versions, symtab,
3080 dynamic_symbols, dynstr);
3083 #ifdef HAVE_TARGET_64_LITTLE
3084 case Parameters::TARGET_64_LITTLE:
3085 this->sized_create_version_sections<64, false>(versions, symtab,
3087 dynamic_symbols, dynstr);
3090 #ifdef HAVE_TARGET_64_BIG
3091 case Parameters::TARGET_64_BIG:
3092 this->sized_create_version_sections<64, true>(versions, symtab,
3094 dynamic_symbols, dynstr);
3102 // Create the version sections, sized version.
3104 template<int size, bool big_endian>
3106 Layout::sized_create_version_sections(
3107 const Versions* versions,
3108 const Symbol_table* symtab,
3109 unsigned int local_symcount,
3110 const std::vector<Symbol*>& dynamic_symbols,
3111 const Output_section* dynstr)
3113 Output_section* vsec = this->choose_output_section(NULL, ".gnu.version",
3114 elfcpp::SHT_GNU_versym,
3117 false, false, false);
3119 unsigned char* vbuf;
3121 versions->symbol_section_contents<size, big_endian>(symtab, &this->dynpool_,
3126 Output_section_data* vdata = new Output_data_const_buffer(vbuf, vsize, 2,
3129 vsec->add_output_section_data(vdata);
3130 vsec->set_entsize(2);
3131 vsec->set_link_section(this->dynsym_section_);
3133 Output_data_dynamic* const odyn = this->dynamic_data_;
3134 odyn->add_section_address(elfcpp::DT_VERSYM, vsec);
3136 if (versions->any_defs())
3138 Output_section* vdsec;
3139 vdsec= this->choose_output_section(NULL, ".gnu.version_d",
3140 elfcpp::SHT_GNU_verdef,
3142 false, false, true, false, false,
3145 unsigned char* vdbuf;
3146 unsigned int vdsize;
3147 unsigned int vdentries;
3148 versions->def_section_contents<size, big_endian>(&this->dynpool_, &vdbuf,
3149 &vdsize, &vdentries);
3151 Output_section_data* vddata =
3152 new Output_data_const_buffer(vdbuf, vdsize, 4, "** version defs");
3154 vdsec->add_output_section_data(vddata);
3155 vdsec->set_link_section(dynstr);
3156 vdsec->set_info(vdentries);
3158 odyn->add_section_address(elfcpp::DT_VERDEF, vdsec);
3159 odyn->add_constant(elfcpp::DT_VERDEFNUM, vdentries);
3162 if (versions->any_needs())
3164 Output_section* vnsec;
3165 vnsec = this->choose_output_section(NULL, ".gnu.version_r",
3166 elfcpp::SHT_GNU_verneed,
3168 false, false, true, false, false,
3171 unsigned char* vnbuf;
3172 unsigned int vnsize;
3173 unsigned int vnentries;
3174 versions->need_section_contents<size, big_endian>(&this->dynpool_,
3178 Output_section_data* vndata =
3179 new Output_data_const_buffer(vnbuf, vnsize, 4, "** version refs");
3181 vnsec->add_output_section_data(vndata);
3182 vnsec->set_link_section(dynstr);
3183 vnsec->set_info(vnentries);
3185 odyn->add_section_address(elfcpp::DT_VERNEED, vnsec);
3186 odyn->add_constant(elfcpp::DT_VERNEEDNUM, vnentries);
3190 // Create the .interp section and PT_INTERP segment.
3193 Layout::create_interp(const Target* target)
3195 const char* interp = parameters->options().dynamic_linker();
3198 interp = target->dynamic_linker();
3199 gold_assert(interp != NULL);
3202 size_t len = strlen(interp) + 1;
3204 Output_section_data* odata = new Output_data_const(interp, len, 1);
3206 Output_section* osec = this->choose_output_section(NULL, ".interp",
3207 elfcpp::SHT_PROGBITS,
3210 false, false, false);
3211 osec->add_output_section_data(odata);
3213 if (!this->script_options_->saw_phdrs_clause())
3215 Output_segment* oseg = this->make_output_segment(elfcpp::PT_INTERP,
3217 oseg->add_output_section(osec, elfcpp::PF_R, false);
3221 // Add dynamic tags for the PLT and the dynamic relocs. This is
3222 // called by the target-specific code. This does nothing if not doing
3225 // USE_REL is true for REL relocs rather than RELA relocs.
3227 // If PLT_GOT is not NULL, then DT_PLTGOT points to it.
3229 // If PLT_REL is not NULL, it is used for DT_PLTRELSZ, and DT_JMPREL,
3230 // and we also set DT_PLTREL. We use PLT_REL's output section, since
3231 // some targets have multiple reloc sections in PLT_REL.
3233 // If DYN_REL is not NULL, it is used for DT_REL/DT_RELA,
3234 // DT_RELSZ/DT_RELASZ, DT_RELENT/DT_RELAENT.
3236 // If ADD_DEBUG is true, we add a DT_DEBUG entry when generating an
3240 Layout::add_target_dynamic_tags(bool use_rel, const Output_data* plt_got,
3241 const Output_data* plt_rel,
3242 const Output_data_reloc_generic* dyn_rel,
3243 bool add_debug, bool dynrel_includes_plt)
3245 Output_data_dynamic* odyn = this->dynamic_data_;
3249 if (plt_got != NULL && plt_got->output_section() != NULL)
3250 odyn->add_section_address(elfcpp::DT_PLTGOT, plt_got);
3252 if (plt_rel != NULL && plt_rel->output_section() != NULL)
3254 odyn->add_section_size(elfcpp::DT_PLTRELSZ, plt_rel->output_section());
3255 odyn->add_section_address(elfcpp::DT_JMPREL, plt_rel->output_section());
3256 odyn->add_constant(elfcpp::DT_PLTREL,
3257 use_rel ? elfcpp::DT_REL : elfcpp::DT_RELA);
3260 if (dyn_rel != NULL && dyn_rel->output_section() != NULL)
3262 odyn->add_section_address(use_rel ? elfcpp::DT_REL : elfcpp::DT_RELA,
3264 if (plt_rel != NULL && dynrel_includes_plt)
3265 odyn->add_section_size(use_rel ? elfcpp::DT_RELSZ : elfcpp::DT_RELASZ,
3268 odyn->add_section_size(use_rel ? elfcpp::DT_RELSZ : elfcpp::DT_RELASZ,
3270 const int size = parameters->target().get_size();
3275 rel_tag = elfcpp::DT_RELENT;
3277 rel_size = Reloc_types<elfcpp::SHT_REL, 32, false>::reloc_size;
3278 else if (size == 64)
3279 rel_size = Reloc_types<elfcpp::SHT_REL, 64, false>::reloc_size;
3285 rel_tag = elfcpp::DT_RELAENT;
3287 rel_size = Reloc_types<elfcpp::SHT_RELA, 32, false>::reloc_size;
3288 else if (size == 64)
3289 rel_size = Reloc_types<elfcpp::SHT_RELA, 64, false>::reloc_size;
3293 odyn->add_constant(rel_tag, rel_size);
3295 if (parameters->options().combreloc())
3297 size_t c = dyn_rel->relative_reloc_count();
3299 odyn->add_constant((use_rel
3300 ? elfcpp::DT_RELCOUNT
3301 : elfcpp::DT_RELACOUNT),
3306 if (add_debug && !parameters->options().shared())
3308 // The value of the DT_DEBUG tag is filled in by the dynamic
3309 // linker at run time, and used by the debugger.
3310 odyn->add_constant(elfcpp::DT_DEBUG, 0);
3314 // Finish the .dynamic section and PT_DYNAMIC segment.
3317 Layout::finish_dynamic_section(const Input_objects* input_objects,
3318 const Symbol_table* symtab)
3320 if (!this->script_options_->saw_phdrs_clause())
3322 Output_segment* oseg = this->make_output_segment(elfcpp::PT_DYNAMIC,
3325 oseg->add_output_section(this->dynamic_section_,
3326 elfcpp::PF_R | elfcpp::PF_W,
3330 Output_data_dynamic* const odyn = this->dynamic_data_;
3332 for (Input_objects::Dynobj_iterator p = input_objects->dynobj_begin();
3333 p != input_objects->dynobj_end();
3336 if (!(*p)->is_needed()
3337 && (*p)->input_file()->options().as_needed())
3339 // This dynamic object was linked with --as-needed, but it
3344 odyn->add_string(elfcpp::DT_NEEDED, (*p)->soname());
3347 if (parameters->options().shared())
3349 const char* soname = parameters->options().soname();
3351 odyn->add_string(elfcpp::DT_SONAME, soname);
3354 Symbol* sym = symtab->lookup(parameters->options().init());
3355 if (sym != NULL && sym->is_defined() && !sym->is_from_dynobj())
3356 odyn->add_symbol(elfcpp::DT_INIT, sym);
3358 sym = symtab->lookup(parameters->options().fini());
3359 if (sym != NULL && sym->is_defined() && !sym->is_from_dynobj())
3360 odyn->add_symbol(elfcpp::DT_FINI, sym);
3362 // Look for .init_array, .preinit_array and .fini_array by checking
3364 for(Layout::Section_list::const_iterator p = this->section_list_.begin();
3365 p != this->section_list_.end();
3367 switch((*p)->type())
3369 case elfcpp::SHT_FINI_ARRAY:
3370 odyn->add_section_address(elfcpp::DT_FINI_ARRAY, *p);
3371 odyn->add_section_size(elfcpp::DT_FINI_ARRAYSZ, *p);
3373 case elfcpp::SHT_INIT_ARRAY:
3374 odyn->add_section_address(elfcpp::DT_INIT_ARRAY, *p);
3375 odyn->add_section_size(elfcpp::DT_INIT_ARRAYSZ, *p);
3377 case elfcpp::SHT_PREINIT_ARRAY:
3378 odyn->add_section_address(elfcpp::DT_PREINIT_ARRAY, *p);
3379 odyn->add_section_size(elfcpp::DT_PREINIT_ARRAYSZ, *p);
3385 // Add a DT_RPATH entry if needed.
3386 const General_options::Dir_list& rpath(parameters->options().rpath());
3389 std::string rpath_val;
3390 for (General_options::Dir_list::const_iterator p = rpath.begin();
3394 if (rpath_val.empty())
3395 rpath_val = p->name();
3398 // Eliminate duplicates.
3399 General_options::Dir_list::const_iterator q;
3400 for (q = rpath.begin(); q != p; ++q)
3401 if (q->name() == p->name())
3406 rpath_val += p->name();
3411 odyn->add_string(elfcpp::DT_RPATH, rpath_val);
3412 if (parameters->options().enable_new_dtags())
3413 odyn->add_string(elfcpp::DT_RUNPATH, rpath_val);
3416 // Look for text segments that have dynamic relocations.
3417 bool have_textrel = false;
3418 if (!this->script_options_->saw_sections_clause())
3420 for (Segment_list::const_iterator p = this->segment_list_.begin();
3421 p != this->segment_list_.end();
3424 if (((*p)->flags() & elfcpp::PF_W) == 0
3425 && (*p)->dynamic_reloc_count() > 0)
3427 have_textrel = true;
3434 // We don't know the section -> segment mapping, so we are
3435 // conservative and just look for readonly sections with
3436 // relocations. If those sections wind up in writable segments,
3437 // then we have created an unnecessary DT_TEXTREL entry.
3438 for (Section_list::const_iterator p = this->section_list_.begin();
3439 p != this->section_list_.end();
3442 if (((*p)->flags() & elfcpp::SHF_ALLOC) != 0
3443 && ((*p)->flags() & elfcpp::SHF_WRITE) == 0
3444 && ((*p)->dynamic_reloc_count() > 0))
3446 have_textrel = true;
3452 // Add a DT_FLAGS entry. We add it even if no flags are set so that
3453 // post-link tools can easily modify these flags if desired.
3454 unsigned int flags = 0;
3457 // Add a DT_TEXTREL for compatibility with older loaders.
3458 odyn->add_constant(elfcpp::DT_TEXTREL, 0);
3459 flags |= elfcpp::DF_TEXTREL;
3461 if (parameters->options().text())
3462 gold_error(_("read-only segment has dynamic relocations"));
3463 else if (parameters->options().warn_shared_textrel()
3464 && parameters->options().shared())
3465 gold_warning(_("shared library text segment is not shareable"));
3467 if (parameters->options().shared() && this->has_static_tls())
3468 flags |= elfcpp::DF_STATIC_TLS;
3469 if (parameters->options().origin())
3470 flags |= elfcpp::DF_ORIGIN;
3471 if (parameters->options().Bsymbolic())
3473 flags |= elfcpp::DF_SYMBOLIC;
3474 // Add DT_SYMBOLIC for compatibility with older loaders.
3475 odyn->add_constant(elfcpp::DT_SYMBOLIC, 0);
3477 if (parameters->options().now())
3478 flags |= elfcpp::DF_BIND_NOW;
3479 odyn->add_constant(elfcpp::DT_FLAGS, flags);
3482 if (parameters->options().initfirst())
3483 flags |= elfcpp::DF_1_INITFIRST;
3484 if (parameters->options().interpose())
3485 flags |= elfcpp::DF_1_INTERPOSE;
3486 if (parameters->options().loadfltr())
3487 flags |= elfcpp::DF_1_LOADFLTR;
3488 if (parameters->options().nodefaultlib())
3489 flags |= elfcpp::DF_1_NODEFLIB;
3490 if (parameters->options().nodelete())
3491 flags |= elfcpp::DF_1_NODELETE;
3492 if (parameters->options().nodlopen())
3493 flags |= elfcpp::DF_1_NOOPEN;
3494 if (parameters->options().nodump())
3495 flags |= elfcpp::DF_1_NODUMP;
3496 if (!parameters->options().shared())
3497 flags &= ~(elfcpp::DF_1_INITFIRST
3498 | elfcpp::DF_1_NODELETE
3499 | elfcpp::DF_1_NOOPEN);
3500 if (parameters->options().origin())
3501 flags |= elfcpp::DF_1_ORIGIN;
3502 if (parameters->options().now())
3503 flags |= elfcpp::DF_1_NOW;
3505 odyn->add_constant(elfcpp::DT_FLAGS_1, flags);
3508 // Set the size of the _DYNAMIC symbol table to be the size of the
3512 Layout::set_dynamic_symbol_size(const Symbol_table* symtab)
3514 Output_data_dynamic* const odyn = this->dynamic_data_;
3515 odyn->finalize_data_size();
3516 off_t data_size = odyn->data_size();
3517 const int size = parameters->target().get_size();
3519 symtab->get_sized_symbol<32>(this->dynamic_symbol_)->set_symsize(data_size);
3520 else if (size == 64)
3521 symtab->get_sized_symbol<64>(this->dynamic_symbol_)->set_symsize(data_size);
3526 // The mapping of input section name prefixes to output section names.
3527 // In some cases one prefix is itself a prefix of another prefix; in
3528 // such a case the longer prefix must come first. These prefixes are
3529 // based on the GNU linker default ELF linker script.
3531 #define MAPPING_INIT(f, t) { f, sizeof(f) - 1, t, sizeof(t) - 1 }
3532 const Layout::Section_name_mapping Layout::section_name_mapping[] =
3534 MAPPING_INIT(".text.", ".text"),
3535 MAPPING_INIT(".ctors.", ".ctors"),
3536 MAPPING_INIT(".dtors.", ".dtors"),
3537 MAPPING_INIT(".rodata.", ".rodata"),
3538 MAPPING_INIT(".data.rel.ro.local", ".data.rel.ro.local"),
3539 MAPPING_INIT(".data.rel.ro", ".data.rel.ro"),
3540 MAPPING_INIT(".data.", ".data"),
3541 MAPPING_INIT(".bss.", ".bss"),
3542 MAPPING_INIT(".tdata.", ".tdata"),
3543 MAPPING_INIT(".tbss.", ".tbss"),
3544 MAPPING_INIT(".init_array.", ".init_array"),
3545 MAPPING_INIT(".fini_array.", ".fini_array"),
3546 MAPPING_INIT(".sdata.", ".sdata"),
3547 MAPPING_INIT(".sbss.", ".sbss"),
3548 // FIXME: In the GNU linker, .sbss2 and .sdata2 are handled
3549 // differently depending on whether it is creating a shared library.
3550 MAPPING_INIT(".sdata2.", ".sdata"),
3551 MAPPING_INIT(".sbss2.", ".sbss"),
3552 MAPPING_INIT(".lrodata.", ".lrodata"),
3553 MAPPING_INIT(".ldata.", ".ldata"),
3554 MAPPING_INIT(".lbss.", ".lbss"),
3555 MAPPING_INIT(".gcc_except_table.", ".gcc_except_table"),
3556 MAPPING_INIT(".gnu.linkonce.d.rel.ro.local.", ".data.rel.ro.local"),
3557 MAPPING_INIT(".gnu.linkonce.d.rel.ro.", ".data.rel.ro"),
3558 MAPPING_INIT(".gnu.linkonce.t.", ".text"),
3559 MAPPING_INIT(".gnu.linkonce.r.", ".rodata"),
3560 MAPPING_INIT(".gnu.linkonce.d.", ".data"),
3561 MAPPING_INIT(".gnu.linkonce.b.", ".bss"),
3562 MAPPING_INIT(".gnu.linkonce.s.", ".sdata"),
3563 MAPPING_INIT(".gnu.linkonce.sb.", ".sbss"),
3564 MAPPING_INIT(".gnu.linkonce.s2.", ".sdata"),
3565 MAPPING_INIT(".gnu.linkonce.sb2.", ".sbss"),
3566 MAPPING_INIT(".gnu.linkonce.wi.", ".debug_info"),
3567 MAPPING_INIT(".gnu.linkonce.td.", ".tdata"),
3568 MAPPING_INIT(".gnu.linkonce.tb.", ".tbss"),
3569 MAPPING_INIT(".gnu.linkonce.lr.", ".lrodata"),
3570 MAPPING_INIT(".gnu.linkonce.l.", ".ldata"),
3571 MAPPING_INIT(".gnu.linkonce.lb.", ".lbss"),
3572 MAPPING_INIT(".ARM.extab.", ".ARM.extab"),
3573 MAPPING_INIT(".gnu.linkonce.armextab.", ".ARM.extab"),
3574 MAPPING_INIT(".ARM.exidx.", ".ARM.exidx"),
3575 MAPPING_INIT(".gnu.linkonce.armexidx.", ".ARM.exidx"),
3579 const int Layout::section_name_mapping_count =
3580 (sizeof(Layout::section_name_mapping)
3581 / sizeof(Layout::section_name_mapping[0]));
3583 // Choose the output section name to use given an input section name.
3584 // Set *PLEN to the length of the name. *PLEN is initialized to the
3588 Layout::output_section_name(const char* name, size_t* plen)
3590 // gcc 4.3 generates the following sorts of section names when it
3591 // needs a section name specific to a function:
3597 // .data.rel.local.FN
3599 // .data.rel.ro.local.FN
3606 // The GNU linker maps all of those to the part before the .FN,
3607 // except that .data.rel.local.FN is mapped to .data, and
3608 // .data.rel.ro.local.FN is mapped to .data.rel.ro. The sections
3609 // beginning with .data.rel.ro.local are grouped together.
3611 // For an anonymous namespace, the string FN can contain a '.'.
3613 // Also of interest: .rodata.strN.N, .rodata.cstN, both of which the
3614 // GNU linker maps to .rodata.
3616 // The .data.rel.ro sections are used with -z relro. The sections
3617 // are recognized by name. We use the same names that the GNU
3618 // linker does for these sections.
3620 // It is hard to handle this in a principled way, so we don't even
3621 // try. We use a table of mappings. If the input section name is
3622 // not found in the table, we simply use it as the output section
3625 const Section_name_mapping* psnm = section_name_mapping;
3626 for (int i = 0; i < section_name_mapping_count; ++i, ++psnm)
3628 if (strncmp(name, psnm->from, psnm->fromlen) == 0)
3630 *plen = psnm->tolen;
3638 // Check if a comdat group or .gnu.linkonce section with the given
3639 // NAME is selected for the link. If there is already a section,
3640 // *KEPT_SECTION is set to point to the existing section and the
3641 // function returns false. Otherwise, OBJECT, SHNDX, IS_COMDAT, and
3642 // IS_GROUP_NAME are recorded for this NAME in the layout object,
3643 // *KEPT_SECTION is set to the internal copy and the function returns
3647 Layout::find_or_add_kept_section(const std::string& name,
3652 Kept_section** kept_section)
3654 // It's normal to see a couple of entries here, for the x86 thunk
3655 // sections. If we see more than a few, we're linking a C++
3656 // program, and we resize to get more space to minimize rehashing.
3657 if (this->signatures_.size() > 4
3658 && !this->resized_signatures_)
3660 reserve_unordered_map(&this->signatures_,
3661 this->number_of_input_files_ * 64);
3662 this->resized_signatures_ = true;
3665 Kept_section candidate;
3666 std::pair<Signatures::iterator, bool> ins =
3667 this->signatures_.insert(std::make_pair(name, candidate));
3669 if (kept_section != NULL)
3670 *kept_section = &ins.first->second;
3673 // This is the first time we've seen this signature.
3674 ins.first->second.set_object(object);
3675 ins.first->second.set_shndx(shndx);
3677 ins.first->second.set_is_comdat();
3679 ins.first->second.set_is_group_name();
3683 // We have already seen this signature.
3685 if (ins.first->second.is_group_name())
3687 // We've already seen a real section group with this signature.
3688 // If the kept group is from a plugin object, and we're in the
3689 // replacement phase, accept the new one as a replacement.
3690 if (ins.first->second.object() == NULL
3691 && parameters->options().plugins()->in_replacement_phase())
3693 ins.first->second.set_object(object);
3694 ins.first->second.set_shndx(shndx);
3699 else if (is_group_name)
3701 // This is a real section group, and we've already seen a
3702 // linkonce section with this signature. Record that we've seen
3703 // a section group, and don't include this section group.
3704 ins.first->second.set_is_group_name();
3709 // We've already seen a linkonce section and this is a linkonce
3710 // section. These don't block each other--this may be the same
3711 // symbol name with different section types.
3716 // Store the allocated sections into the section list.
3719 Layout::get_allocated_sections(Section_list* section_list) const
3721 for (Section_list::const_iterator p = this->section_list_.begin();
3722 p != this->section_list_.end();
3724 if (((*p)->flags() & elfcpp::SHF_ALLOC) != 0)
3725 section_list->push_back(*p);
3728 // Create an output segment.
3731 Layout::make_output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags)
3733 gold_assert(!parameters->options().relocatable());
3734 Output_segment* oseg = new Output_segment(type, flags);
3735 this->segment_list_.push_back(oseg);
3737 if (type == elfcpp::PT_TLS)
3738 this->tls_segment_ = oseg;
3739 else if (type == elfcpp::PT_GNU_RELRO)
3740 this->relro_segment_ = oseg;
3745 // Write out the Output_sections. Most won't have anything to write,
3746 // since most of the data will come from input sections which are
3747 // handled elsewhere. But some Output_sections do have Output_data.
3750 Layout::write_output_sections(Output_file* of) const
3752 for (Section_list::const_iterator p = this->section_list_.begin();
3753 p != this->section_list_.end();
3756 if (!(*p)->after_input_sections())
3761 // Write out data not associated with a section or the symbol table.
3764 Layout::write_data(const Symbol_table* symtab, Output_file* of) const
3766 if (!parameters->options().strip_all())
3768 const Output_section* symtab_section = this->symtab_section_;
3769 for (Section_list::const_iterator p = this->section_list_.begin();
3770 p != this->section_list_.end();
3773 if ((*p)->needs_symtab_index())
3775 gold_assert(symtab_section != NULL);
3776 unsigned int index = (*p)->symtab_index();
3777 gold_assert(index > 0 && index != -1U);
3778 off_t off = (symtab_section->offset()
3779 + index * symtab_section->entsize());
3780 symtab->write_section_symbol(*p, this->symtab_xindex_, of, off);
3785 const Output_section* dynsym_section = this->dynsym_section_;
3786 for (Section_list::const_iterator p = this->section_list_.begin();
3787 p != this->section_list_.end();
3790 if ((*p)->needs_dynsym_index())
3792 gold_assert(dynsym_section != NULL);
3793 unsigned int index = (*p)->dynsym_index();
3794 gold_assert(index > 0 && index != -1U);
3795 off_t off = (dynsym_section->offset()
3796 + index * dynsym_section->entsize());
3797 symtab->write_section_symbol(*p, this->dynsym_xindex_, of, off);
3801 // Write out the Output_data which are not in an Output_section.
3802 for (Data_list::const_iterator p = this->special_output_list_.begin();
3803 p != this->special_output_list_.end();
3808 // Write out the Output_sections which can only be written after the
3809 // input sections are complete.
3812 Layout::write_sections_after_input_sections(Output_file* of)
3814 // Determine the final section offsets, and thus the final output
3815 // file size. Note we finalize the .shstrab last, to allow the
3816 // after_input_section sections to modify their section-names before
3818 if (this->any_postprocessing_sections_)
3820 off_t off = this->output_file_size_;
3821 off = this->set_section_offsets(off, POSTPROCESSING_SECTIONS_PASS);
3823 // Now that we've finalized the names, we can finalize the shstrab.
3825 this->set_section_offsets(off,
3826 STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS);
3828 if (off > this->output_file_size_)
3831 this->output_file_size_ = off;
3835 for (Section_list::const_iterator p = this->section_list_.begin();
3836 p != this->section_list_.end();
3839 if ((*p)->after_input_sections())
3843 this->section_headers_->write(of);
3846 // If the build ID requires computing a checksum, do so here, and
3847 // write it out. We compute a checksum over the entire file because
3848 // that is simplest.
3851 Layout::write_build_id(Output_file* of) const
3853 if (this->build_id_note_ == NULL)
3856 const unsigned char* iv = of->get_input_view(0, this->output_file_size_);
3858 unsigned char* ov = of->get_output_view(this->build_id_note_->offset(),
3859 this->build_id_note_->data_size());
3861 const char* style = parameters->options().build_id();
3862 if (strcmp(style, "sha1") == 0)
3865 sha1_init_ctx(&ctx);
3866 sha1_process_bytes(iv, this->output_file_size_, &ctx);
3867 sha1_finish_ctx(&ctx, ov);
3869 else if (strcmp(style, "md5") == 0)
3873 md5_process_bytes(iv, this->output_file_size_, &ctx);
3874 md5_finish_ctx(&ctx, ov);
3879 of->write_output_view(this->build_id_note_->offset(),
3880 this->build_id_note_->data_size(),
3883 of->free_input_view(0, this->output_file_size_, iv);
3886 // Write out a binary file. This is called after the link is
3887 // complete. IN is the temporary output file we used to generate the
3888 // ELF code. We simply walk through the segments, read them from
3889 // their file offset in IN, and write them to their load address in
3890 // the output file. FIXME: with a bit more work, we could support
3891 // S-records and/or Intel hex format here.
3894 Layout::write_binary(Output_file* in) const
3896 gold_assert(parameters->options().oformat_enum()
3897 == General_options::OBJECT_FORMAT_BINARY);
3899 // Get the size of the binary file.
3900 uint64_t max_load_address = 0;
3901 for (Segment_list::const_iterator p = this->segment_list_.begin();
3902 p != this->segment_list_.end();
3905 if ((*p)->type() == elfcpp::PT_LOAD && (*p)->filesz() > 0)
3907 uint64_t max_paddr = (*p)->paddr() + (*p)->filesz();
3908 if (max_paddr > max_load_address)
3909 max_load_address = max_paddr;
3913 Output_file out(parameters->options().output_file_name());
3914 out.open(max_load_address);
3916 for (Segment_list::const_iterator p = this->segment_list_.begin();
3917 p != this->segment_list_.end();
3920 if ((*p)->type() == elfcpp::PT_LOAD && (*p)->filesz() > 0)
3922 const unsigned char* vin = in->get_input_view((*p)->offset(),
3924 unsigned char* vout = out.get_output_view((*p)->paddr(),
3926 memcpy(vout, vin, (*p)->filesz());
3927 out.write_output_view((*p)->paddr(), (*p)->filesz(), vout);
3928 in->free_input_view((*p)->offset(), (*p)->filesz(), vin);
3935 // Print the output sections to the map file.
3938 Layout::print_to_mapfile(Mapfile* mapfile) const
3940 for (Segment_list::const_iterator p = this->segment_list_.begin();
3941 p != this->segment_list_.end();
3943 (*p)->print_sections_to_mapfile(mapfile);
3946 // Print statistical information to stderr. This is used for --stats.
3949 Layout::print_stats() const
3951 this->namepool_.print_stats("section name pool");
3952 this->sympool_.print_stats("output symbol name pool");
3953 this->dynpool_.print_stats("dynamic name pool");
3955 for (Section_list::const_iterator p = this->section_list_.begin();
3956 p != this->section_list_.end();
3958 (*p)->print_merge_stats();
3961 // Write_sections_task methods.
3963 // We can always run this task.
3966 Write_sections_task::is_runnable()
3971 // We need to unlock both OUTPUT_SECTIONS_BLOCKER and FINAL_BLOCKER
3975 Write_sections_task::locks(Task_locker* tl)
3977 tl->add(this, this->output_sections_blocker_);
3978 tl->add(this, this->final_blocker_);
3981 // Run the task--write out the data.
3984 Write_sections_task::run(Workqueue*)
3986 this->layout_->write_output_sections(this->of_);
3989 // Write_data_task methods.
3991 // We can always run this task.
3994 Write_data_task::is_runnable()
3999 // We need to unlock FINAL_BLOCKER when finished.
4002 Write_data_task::locks(Task_locker* tl)
4004 tl->add(this, this->final_blocker_);
4007 // Run the task--write out the data.
4010 Write_data_task::run(Workqueue*)
4012 this->layout_->write_data(this->symtab_, this->of_);
4015 // Write_symbols_task methods.
4017 // We can always run this task.
4020 Write_symbols_task::is_runnable()
4025 // We need to unlock FINAL_BLOCKER when finished.
4028 Write_symbols_task::locks(Task_locker* tl)
4030 tl->add(this, this->final_blocker_);
4033 // Run the task--write out the symbols.
4036 Write_symbols_task::run(Workqueue*)
4038 this->symtab_->write_globals(this->sympool_, this->dynpool_,
4039 this->layout_->symtab_xindex(),
4040 this->layout_->dynsym_xindex(), this->of_);
4043 // Write_after_input_sections_task methods.
4045 // We can only run this task after the input sections have completed.
4048 Write_after_input_sections_task::is_runnable()
4050 if (this->input_sections_blocker_->is_blocked())
4051 return this->input_sections_blocker_;
4055 // We need to unlock FINAL_BLOCKER when finished.
4058 Write_after_input_sections_task::locks(Task_locker* tl)
4060 tl->add(this, this->final_blocker_);
4066 Write_after_input_sections_task::run(Workqueue*)
4068 this->layout_->write_sections_after_input_sections(this->of_);
4071 // Close_task_runner methods.
4073 // Run the task--close the file.
4076 Close_task_runner::run(Workqueue*, const Task*)
4078 // If we need to compute a checksum for the BUILD if, we do so here.
4079 this->layout_->write_build_id(this->of_);
4081 // If we've been asked to create a binary file, we do so here.
4082 if (this->options_->oformat_enum() != General_options::OBJECT_FORMAT_ELF)
4083 this->layout_->write_binary(this->of_);
4088 // Instantiate the templates we need. We could use the configure
4089 // script to restrict this to only the ones for implemented targets.
4091 #ifdef HAVE_TARGET_32_LITTLE
4094 Layout::layout<32, false>(Sized_relobj<32, false>* object, unsigned int shndx,
4096 const elfcpp::Shdr<32, false>& shdr,
4097 unsigned int, unsigned int, off_t*);
4100 #ifdef HAVE_TARGET_32_BIG
4103 Layout::layout<32, true>(Sized_relobj<32, true>* object, unsigned int shndx,
4105 const elfcpp::Shdr<32, true>& shdr,
4106 unsigned int, unsigned int, off_t*);
4109 #ifdef HAVE_TARGET_64_LITTLE
4112 Layout::layout<64, false>(Sized_relobj<64, false>* object, unsigned int shndx,
4114 const elfcpp::Shdr<64, false>& shdr,
4115 unsigned int, unsigned int, off_t*);
4118 #ifdef HAVE_TARGET_64_BIG
4121 Layout::layout<64, true>(Sized_relobj<64, true>* object, unsigned int shndx,
4123 const elfcpp::Shdr<64, true>& shdr,
4124 unsigned int, unsigned int, off_t*);
4127 #ifdef HAVE_TARGET_32_LITTLE
4130 Layout::layout_reloc<32, false>(Sized_relobj<32, false>* object,
4131 unsigned int reloc_shndx,
4132 const elfcpp::Shdr<32, false>& shdr,
4133 Output_section* data_section,
4134 Relocatable_relocs* rr);
4137 #ifdef HAVE_TARGET_32_BIG
4140 Layout::layout_reloc<32, true>(Sized_relobj<32, true>* object,
4141 unsigned int reloc_shndx,
4142 const elfcpp::Shdr<32, true>& shdr,
4143 Output_section* data_section,
4144 Relocatable_relocs* rr);
4147 #ifdef HAVE_TARGET_64_LITTLE
4150 Layout::layout_reloc<64, false>(Sized_relobj<64, false>* object,
4151 unsigned int reloc_shndx,
4152 const elfcpp::Shdr<64, false>& shdr,
4153 Output_section* data_section,
4154 Relocatable_relocs* rr);
4157 #ifdef HAVE_TARGET_64_BIG
4160 Layout::layout_reloc<64, true>(Sized_relobj<64, true>* object,
4161 unsigned int reloc_shndx,
4162 const elfcpp::Shdr<64, true>& shdr,
4163 Output_section* data_section,
4164 Relocatable_relocs* rr);
4167 #ifdef HAVE_TARGET_32_LITTLE
4170 Layout::layout_group<32, false>(Symbol_table* symtab,
4171 Sized_relobj<32, false>* object,
4173 const char* group_section_name,
4174 const char* signature,
4175 const elfcpp::Shdr<32, false>& shdr,
4176 elfcpp::Elf_Word flags,
4177 std::vector<unsigned int>* shndxes);
4180 #ifdef HAVE_TARGET_32_BIG
4183 Layout::layout_group<32, true>(Symbol_table* symtab,
4184 Sized_relobj<32, true>* object,
4186 const char* group_section_name,
4187 const char* signature,
4188 const elfcpp::Shdr<32, true>& shdr,
4189 elfcpp::Elf_Word flags,
4190 std::vector<unsigned int>* shndxes);
4193 #ifdef HAVE_TARGET_64_LITTLE
4196 Layout::layout_group<64, false>(Symbol_table* symtab,
4197 Sized_relobj<64, false>* object,
4199 const char* group_section_name,
4200 const char* signature,
4201 const elfcpp::Shdr<64, false>& shdr,
4202 elfcpp::Elf_Word flags,
4203 std::vector<unsigned int>* shndxes);
4206 #ifdef HAVE_TARGET_64_BIG
4209 Layout::layout_group<64, true>(Symbol_table* symtab,
4210 Sized_relobj<64, true>* object,
4212 const char* group_section_name,
4213 const char* signature,
4214 const elfcpp::Shdr<64, true>& shdr,
4215 elfcpp::Elf_Word flags,
4216 std::vector<unsigned int>* shndxes);
4219 #ifdef HAVE_TARGET_32_LITTLE
4222 Layout::layout_eh_frame<32, false>(Sized_relobj<32, false>* object,
4223 const unsigned char* symbols,
4225 const unsigned char* symbol_names,
4226 off_t symbol_names_size,
4228 const elfcpp::Shdr<32, false>& shdr,
4229 unsigned int reloc_shndx,
4230 unsigned int reloc_type,
4234 #ifdef HAVE_TARGET_32_BIG
4237 Layout::layout_eh_frame<32, true>(Sized_relobj<32, true>* object,
4238 const unsigned char* symbols,
4240 const unsigned char* symbol_names,
4241 off_t symbol_names_size,
4243 const elfcpp::Shdr<32, true>& shdr,
4244 unsigned int reloc_shndx,
4245 unsigned int reloc_type,
4249 #ifdef HAVE_TARGET_64_LITTLE
4252 Layout::layout_eh_frame<64, false>(Sized_relobj<64, false>* object,
4253 const unsigned char* symbols,
4255 const unsigned char* symbol_names,
4256 off_t symbol_names_size,
4258 const elfcpp::Shdr<64, false>& shdr,
4259 unsigned int reloc_shndx,
4260 unsigned int reloc_type,
4264 #ifdef HAVE_TARGET_64_BIG
4267 Layout::layout_eh_frame<64, true>(Sized_relobj<64, true>* object,
4268 const unsigned char* symbols,
4270 const unsigned char* symbol_names,
4271 off_t symbol_names_size,
4273 const elfcpp::Shdr<64, true>& shdr,
4274 unsigned int reloc_shndx,
4275 unsigned int reloc_type,
4279 } // End namespace gold.