1 // layout.cc -- lay out output file sections for gold
3 // Copyright 2006, 2007, 2008 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"
52 // Layout_task_runner methods.
54 // Lay out the sections. This is called after all the input objects
58 Layout_task_runner::run(Workqueue* workqueue, const Task* task)
60 off_t file_size = this->layout_->finalize(this->input_objects_,
65 // Now we know the final size of the output file and we know where
66 // each piece of information goes.
68 if (this->mapfile_ != NULL)
70 this->mapfile_->print_discarded_sections(this->input_objects_);
71 this->layout_->print_to_mapfile(this->mapfile_);
74 Output_file* of = new Output_file(parameters->options().output_file_name());
75 if (this->options_.oformat_enum() != General_options::OBJECT_FORMAT_ELF)
76 of->set_is_temporary();
79 // Queue up the final set of tasks.
80 gold::queue_final_tasks(this->options_, this->input_objects_,
81 this->symtab_, this->layout_, workqueue, of);
86 Layout::Layout(const General_options& options, Script_options* script_options)
88 script_options_(script_options),
96 unattached_section_list_(),
97 sections_are_attached_(false),
98 special_output_list_(),
99 section_headers_(NULL),
101 relro_segment_(NULL),
102 symtab_section_(NULL),
103 symtab_xindex_(NULL),
104 dynsym_section_(NULL),
105 dynsym_xindex_(NULL),
106 dynamic_section_(NULL),
108 eh_frame_section_(NULL),
109 eh_frame_data_(NULL),
110 added_eh_frame_data_(false),
111 eh_frame_hdr_section_(NULL),
112 build_id_note_(NULL),
114 output_file_size_(-1),
115 input_requires_executable_stack_(false),
116 input_with_gnu_stack_note_(false),
117 input_without_gnu_stack_note_(false),
118 has_static_tls_(false),
119 any_postprocessing_sections_(false)
121 // Make space for more than enough segments for a typical file.
122 // This is just for efficiency--it's OK if we wind up needing more.
123 this->segment_list_.reserve(12);
125 // We expect two unattached Output_data objects: the file header and
126 // the segment headers.
127 this->special_output_list_.reserve(2);
130 // Hash a key we use to look up an output section mapping.
133 Layout::Hash_key::operator()(const Layout::Key& k) const
135 return k.first + k.second.first + k.second.second;
138 // Return whether PREFIX is a prefix of STR.
141 is_prefix_of(const char* prefix, const char* str)
143 return strncmp(prefix, str, strlen(prefix)) == 0;
146 // Returns whether the given section is in the list of
147 // debug-sections-used-by-some-version-of-gdb. Currently,
148 // we've checked versions of gdb up to and including 6.7.1.
150 static const char* gdb_sections[] =
152 // ".debug_aranges", // not used by gdb as of 6.7.1
158 // ".debug_pubnames", // not used by gdb as of 6.7.1
164 is_gdb_debug_section(const char* str)
166 // We can do this faster: binary search or a hashtable. But why bother?
167 for (size_t i = 0; i < sizeof(gdb_sections)/sizeof(*gdb_sections); ++i)
168 if (strcmp(str, gdb_sections[i]) == 0)
173 // Whether to include this section in the link.
175 template<int size, bool big_endian>
177 Layout::include_section(Sized_relobj<size, big_endian>*, const char* name,
178 const elfcpp::Shdr<size, big_endian>& shdr)
180 switch (shdr.get_sh_type())
182 case elfcpp::SHT_NULL:
183 case elfcpp::SHT_SYMTAB:
184 case elfcpp::SHT_DYNSYM:
185 case elfcpp::SHT_STRTAB:
186 case elfcpp::SHT_HASH:
187 case elfcpp::SHT_DYNAMIC:
188 case elfcpp::SHT_SYMTAB_SHNDX:
191 case elfcpp::SHT_RELA:
192 case elfcpp::SHT_REL:
193 case elfcpp::SHT_GROUP:
194 // If we are emitting relocations these should be handled
196 gold_assert(!parameters->options().relocatable()
197 && !parameters->options().emit_relocs());
200 case elfcpp::SHT_PROGBITS:
201 if (parameters->options().strip_debug()
202 && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
204 if (is_debug_info_section(name))
207 if (parameters->options().strip_debug_gdb()
208 && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
210 // Debugging sections can only be recognized by name.
211 if (is_prefix_of(".debug", name)
212 && !is_gdb_debug_section(name))
222 // Return an output section named NAME, or NULL if there is none.
225 Layout::find_output_section(const char* name) const
227 for (Section_list::const_iterator p = this->section_list_.begin();
228 p != this->section_list_.end();
230 if (strcmp((*p)->name(), name) == 0)
235 // Return an output segment of type TYPE, with segment flags SET set
236 // and segment flags CLEAR clear. Return NULL if there is none.
239 Layout::find_output_segment(elfcpp::PT type, elfcpp::Elf_Word set,
240 elfcpp::Elf_Word clear) const
242 for (Segment_list::const_iterator p = this->segment_list_.begin();
243 p != this->segment_list_.end();
245 if (static_cast<elfcpp::PT>((*p)->type()) == type
246 && ((*p)->flags() & set) == set
247 && ((*p)->flags() & clear) == 0)
252 // Return the output section to use for section NAME with type TYPE
253 // and section flags FLAGS. NAME must be canonicalized in the string
254 // pool, and NAME_KEY is the key.
257 Layout::get_output_section(const char* name, Stringpool::Key name_key,
258 elfcpp::Elf_Word type, elfcpp::Elf_Xword flags)
260 elfcpp::Elf_Xword lookup_flags = flags;
262 // Ignoring SHF_WRITE and SHF_EXECINSTR here means that we combine
263 // read-write with read-only sections. Some other ELF linkers do
264 // not do this. FIXME: Perhaps there should be an option
266 lookup_flags &= ~(elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR);
268 const Key key(name_key, std::make_pair(type, lookup_flags));
269 const std::pair<Key, Output_section*> v(key, NULL);
270 std::pair<Section_name_map::iterator, bool> ins(
271 this->section_name_map_.insert(v));
274 return ins.first->second;
277 // This is the first time we've seen this name/type/flags
278 // combination. For compatibility with the GNU linker, we
279 // combine sections with contents and zero flags with sections
280 // with non-zero flags. This is a workaround for cases where
281 // assembler code forgets to set section flags. FIXME: Perhaps
282 // there should be an option to control this.
283 Output_section* os = NULL;
285 if (type == elfcpp::SHT_PROGBITS)
289 Output_section* same_name = this->find_output_section(name);
290 if (same_name != NULL
291 && same_name->type() == elfcpp::SHT_PROGBITS
292 && (same_name->flags() & elfcpp::SHF_TLS) == 0)
295 else if ((flags & elfcpp::SHF_TLS) == 0)
297 elfcpp::Elf_Xword zero_flags = 0;
298 const Key zero_key(name_key, std::make_pair(type, zero_flags));
299 Section_name_map::iterator p =
300 this->section_name_map_.find(zero_key);
301 if (p != this->section_name_map_.end())
307 os = this->make_output_section(name, type, flags);
308 ins.first->second = os;
313 // Pick the output section to use for section NAME, in input file
314 // RELOBJ, with type TYPE and flags FLAGS. RELOBJ may be NULL for a
315 // linker created section. IS_INPUT_SECTION is true if we are
316 // choosing an output section for an input section found in a input
317 // file. This will return NULL if the input section should be
321 Layout::choose_output_section(const Relobj* relobj, const char* name,
322 elfcpp::Elf_Word type, elfcpp::Elf_Xword flags,
323 bool is_input_section)
325 // We should not see any input sections after we have attached
326 // sections to segments.
327 gold_assert(!is_input_section || !this->sections_are_attached_);
329 // Some flags in the input section should not be automatically
330 // copied to the output section.
331 flags &= ~ (elfcpp::SHF_INFO_LINK
332 | elfcpp::SHF_LINK_ORDER
335 | elfcpp::SHF_STRINGS);
337 if (this->script_options_->saw_sections_clause())
339 // We are using a SECTIONS clause, so the output section is
340 // chosen based only on the name.
342 Script_sections* ss = this->script_options_->script_sections();
343 const char* file_name = relobj == NULL ? NULL : relobj->name().c_str();
344 Output_section** output_section_slot;
345 name = ss->output_section_name(file_name, name, &output_section_slot);
348 // The SECTIONS clause says to discard this input section.
352 // If this is an orphan section--one not mentioned in the linker
353 // script--then OUTPUT_SECTION_SLOT will be NULL, and we do the
354 // default processing below.
356 if (output_section_slot != NULL)
358 if (*output_section_slot != NULL)
359 return *output_section_slot;
361 // We don't put sections found in the linker script into
362 // SECTION_NAME_MAP_. That keeps us from getting confused
363 // if an orphan section is mapped to a section with the same
364 // name as one in the linker script.
366 name = this->namepool_.add(name, false, NULL);
368 Output_section* os = this->make_output_section(name, type, flags);
369 os->set_found_in_sections_clause();
370 *output_section_slot = os;
375 // FIXME: Handle SHF_OS_NONCONFORMING somewhere.
377 // Turn NAME from the name of the input section into the name of the
380 size_t len = strlen(name);
381 if (is_input_section && !parameters->options().relocatable())
382 name = Layout::output_section_name(name, &len);
384 Stringpool::Key name_key;
385 name = this->namepool_.add_with_length(name, len, true, &name_key);
387 // Find or make the output section. The output section is selected
388 // based on the section name, type, and flags.
389 return this->get_output_section(name, name_key, type, flags);
392 // Return the output section to use for input section SHNDX, with name
393 // NAME, with header HEADER, from object OBJECT. RELOC_SHNDX is the
394 // index of a relocation section which applies to this section, or 0
395 // if none, or -1U if more than one. RELOC_TYPE is the type of the
396 // relocation section if there is one. Set *OFF to the offset of this
397 // input section without the output section. Return NULL if the
398 // section should be discarded. Set *OFF to -1 if the section
399 // contents should not be written directly to the output file, but
400 // will instead receive special handling.
402 template<int size, bool big_endian>
404 Layout::layout(Sized_relobj<size, big_endian>* object, unsigned int shndx,
405 const char* name, const elfcpp::Shdr<size, big_endian>& shdr,
406 unsigned int reloc_shndx, unsigned int, off_t* off)
408 if (!this->include_section(object, name, shdr))
413 // In a relocatable link a grouped section must not be combined with
414 // any other sections.
415 if (parameters->options().relocatable()
416 && (shdr.get_sh_flags() & elfcpp::SHF_GROUP) != 0)
418 name = this->namepool_.add(name, true, NULL);
419 os = this->make_output_section(name, shdr.get_sh_type(),
420 shdr.get_sh_flags());
424 os = this->choose_output_section(object, name, shdr.get_sh_type(),
425 shdr.get_sh_flags(), true);
430 // By default the GNU linker sorts input sections whose names match
431 // .ctor.*, .dtor.*, .init_array.*, or .fini_array.*. The sections
432 // are sorted by name. This is used to implement constructor
433 // priority ordering. We are compatible.
434 if (!this->script_options_->saw_sections_clause()
435 && (is_prefix_of(".ctors.", name)
436 || is_prefix_of(".dtors.", name)
437 || is_prefix_of(".init_array.", name)
438 || is_prefix_of(".fini_array.", name)))
439 os->set_must_sort_attached_input_sections();
441 // FIXME: Handle SHF_LINK_ORDER somewhere.
443 *off = os->add_input_section(object, shndx, name, shdr, reloc_shndx,
444 this->script_options_->saw_sections_clause());
449 // Handle a relocation section when doing a relocatable link.
451 template<int size, bool big_endian>
453 Layout::layout_reloc(Sized_relobj<size, big_endian>* object,
455 const elfcpp::Shdr<size, big_endian>& shdr,
456 Output_section* data_section,
457 Relocatable_relocs* rr)
459 gold_assert(parameters->options().relocatable()
460 || parameters->options().emit_relocs());
462 int sh_type = shdr.get_sh_type();
465 if (sh_type == elfcpp::SHT_REL)
467 else if (sh_type == elfcpp::SHT_RELA)
471 name += data_section->name();
473 Output_section* os = this->choose_output_section(object, name.c_str(),
478 os->set_should_link_to_symtab();
479 os->set_info_section(data_section);
481 Output_section_data* posd;
482 if (sh_type == elfcpp::SHT_REL)
484 os->set_entsize(elfcpp::Elf_sizes<size>::rel_size);
485 posd = new Output_relocatable_relocs<elfcpp::SHT_REL,
489 else if (sh_type == elfcpp::SHT_RELA)
491 os->set_entsize(elfcpp::Elf_sizes<size>::rela_size);
492 posd = new Output_relocatable_relocs<elfcpp::SHT_RELA,
499 os->add_output_section_data(posd);
500 rr->set_output_data(posd);
505 // Handle a group section when doing a relocatable link.
507 template<int size, bool big_endian>
509 Layout::layout_group(Symbol_table* symtab,
510 Sized_relobj<size, big_endian>* object,
512 const char* group_section_name,
513 const char* signature,
514 const elfcpp::Shdr<size, big_endian>& shdr,
515 elfcpp::Elf_Word flags,
516 std::vector<unsigned int>* shndxes)
518 gold_assert(parameters->options().relocatable());
519 gold_assert(shdr.get_sh_type() == elfcpp::SHT_GROUP);
520 group_section_name = this->namepool_.add(group_section_name, true, NULL);
521 Output_section* os = this->make_output_section(group_section_name,
523 shdr.get_sh_flags());
525 // We need to find a symbol with the signature in the symbol table.
526 // If we don't find one now, we need to look again later.
527 Symbol* sym = symtab->lookup(signature, NULL);
529 os->set_info_symndx(sym);
532 // We will wind up using a symbol whose name is the signature.
533 // So just put the signature in the symbol name pool to save it.
534 signature = symtab->canonicalize_name(signature);
535 this->group_signatures_.push_back(Group_signature(os, signature));
538 os->set_should_link_to_symtab();
541 section_size_type entry_count =
542 convert_to_section_size_type(shdr.get_sh_size() / 4);
543 Output_section_data* posd =
544 new Output_data_group<size, big_endian>(object, entry_count, flags,
546 os->add_output_section_data(posd);
549 // Special GNU handling of sections name .eh_frame. They will
550 // normally hold exception frame data as defined by the C++ ABI
551 // (http://codesourcery.com/cxx-abi/).
553 template<int size, bool big_endian>
555 Layout::layout_eh_frame(Sized_relobj<size, big_endian>* object,
556 const unsigned char* symbols,
558 const unsigned char* symbol_names,
559 off_t symbol_names_size,
561 const elfcpp::Shdr<size, big_endian>& shdr,
562 unsigned int reloc_shndx, unsigned int reloc_type,
565 gold_assert(shdr.get_sh_type() == elfcpp::SHT_PROGBITS);
566 gold_assert((shdr.get_sh_flags() & elfcpp::SHF_ALLOC) != 0);
568 const char* const name = ".eh_frame";
569 Output_section* os = this->choose_output_section(object,
571 elfcpp::SHT_PROGBITS,
577 if (this->eh_frame_section_ == NULL)
579 this->eh_frame_section_ = os;
580 this->eh_frame_data_ = new Eh_frame();
582 if (this->options_.eh_frame_hdr())
584 Output_section* hdr_os =
585 this->choose_output_section(NULL,
587 elfcpp::SHT_PROGBITS,
593 Eh_frame_hdr* hdr_posd = new Eh_frame_hdr(os,
594 this->eh_frame_data_);
595 hdr_os->add_output_section_data(hdr_posd);
597 hdr_os->set_after_input_sections();
599 if (!this->script_options_->saw_phdrs_clause())
601 Output_segment* hdr_oseg;
602 hdr_oseg = this->make_output_segment(elfcpp::PT_GNU_EH_FRAME,
604 hdr_oseg->add_output_section(hdr_os, elfcpp::PF_R);
607 this->eh_frame_data_->set_eh_frame_hdr(hdr_posd);
612 gold_assert(this->eh_frame_section_ == os);
614 if (this->eh_frame_data_->add_ehframe_input_section(object,
623 os->update_flags_for_input_section(shdr.get_sh_flags());
625 // We found a .eh_frame section we are going to optimize, so now
626 // we can add the set of optimized sections to the output
627 // section. We need to postpone adding this until we've found a
628 // section we can optimize so that the .eh_frame section in
629 // crtbegin.o winds up at the start of the output section.
630 if (!this->added_eh_frame_data_)
632 os->add_output_section_data(this->eh_frame_data_);
633 this->added_eh_frame_data_ = true;
639 // We couldn't handle this .eh_frame section for some reason.
640 // Add it as a normal section.
641 bool saw_sections_clause = this->script_options_->saw_sections_clause();
642 *off = os->add_input_section(object, shndx, name, shdr, reloc_shndx,
643 saw_sections_clause);
649 // Add POSD to an output section using NAME, TYPE, and FLAGS. Return
650 // the output section.
653 Layout::add_output_section_data(const char* name, elfcpp::Elf_Word type,
654 elfcpp::Elf_Xword flags,
655 Output_section_data* posd)
657 Output_section* os = this->choose_output_section(NULL, name, type, flags,
660 os->add_output_section_data(posd);
664 // Map section flags to segment flags.
667 Layout::section_flags_to_segment(elfcpp::Elf_Xword flags)
669 elfcpp::Elf_Word ret = elfcpp::PF_R;
670 if ((flags & elfcpp::SHF_WRITE) != 0)
672 if ((flags & elfcpp::SHF_EXECINSTR) != 0)
677 // Sometimes we compress sections. This is typically done for
678 // sections that are not part of normal program execution (such as
679 // .debug_* sections), and where the readers of these sections know
680 // how to deal with compressed sections. (To make it easier for them,
681 // we will rename the ouput section in such cases from .foo to
682 // .foo.zlib.nnnn, where nnnn is the uncompressed size.) This routine
683 // doesn't say for certain whether we'll compress -- it depends on
684 // commandline options as well -- just whether this section is a
685 // candidate for compression.
688 is_compressible_debug_section(const char* secname)
690 return (strncmp(secname, ".debug", sizeof(".debug") - 1) == 0);
693 // Make a new Output_section, and attach it to segments as
697 Layout::make_output_section(const char* name, elfcpp::Elf_Word type,
698 elfcpp::Elf_Xword flags)
701 if ((flags & elfcpp::SHF_ALLOC) == 0
702 && strcmp(this->options_.compress_debug_sections(), "none") != 0
703 && is_compressible_debug_section(name))
704 os = new Output_compressed_section(&this->options_, name, type, flags);
706 os = new Output_section(name, type, flags);
708 this->section_list_.push_back(os);
710 // The GNU linker by default sorts some sections by priority, so we
711 // do the same. We need to know that this might happen before we
712 // attach any input sections.
713 if (!this->script_options_->saw_sections_clause()
714 && (strcmp(name, ".ctors") == 0
715 || strcmp(name, ".dtors") == 0
716 || strcmp(name, ".init_array") == 0
717 || strcmp(name, ".fini_array") == 0))
718 os->set_may_sort_attached_input_sections();
720 // With -z relro, we have to recognize the special sections by name.
721 // There is no other way.
722 if (!this->script_options_->saw_sections_clause()
723 && parameters->options().relro()
724 && type == elfcpp::SHT_PROGBITS
725 && (flags & elfcpp::SHF_ALLOC) != 0
726 && (flags & elfcpp::SHF_WRITE) != 0)
728 if (strcmp(name, ".data.rel.ro") == 0)
730 else if (strcmp(name, ".data.rel.ro.local") == 0)
733 os->set_is_relro_local();
737 // If we have already attached the sections to segments, then we
738 // need to attach this one now. This happens for sections created
739 // directly by the linker.
740 if (this->sections_are_attached_)
741 this->attach_section_to_segment(os);
746 // Attach output sections to segments. This is called after we have
747 // seen all the input sections.
750 Layout::attach_sections_to_segments()
752 for (Section_list::iterator p = this->section_list_.begin();
753 p != this->section_list_.end();
755 this->attach_section_to_segment(*p);
757 this->sections_are_attached_ = true;
760 // Attach an output section to a segment.
763 Layout::attach_section_to_segment(Output_section* os)
765 if ((os->flags() & elfcpp::SHF_ALLOC) == 0)
766 this->unattached_section_list_.push_back(os);
768 this->attach_allocated_section_to_segment(os);
771 // Attach an allocated output section to a segment.
774 Layout::attach_allocated_section_to_segment(Output_section* os)
776 elfcpp::Elf_Xword flags = os->flags();
777 gold_assert((flags & elfcpp::SHF_ALLOC) != 0);
779 if (parameters->options().relocatable())
782 // If we have a SECTIONS clause, we can't handle the attachment to
783 // segments until after we've seen all the sections.
784 if (this->script_options_->saw_sections_clause())
787 gold_assert(!this->script_options_->saw_phdrs_clause());
789 // This output section goes into a PT_LOAD segment.
791 elfcpp::Elf_Word seg_flags = Layout::section_flags_to_segment(flags);
793 // In general the only thing we really care about for PT_LOAD
794 // segments is whether or not they are writable, so that is how we
795 // search for them. People who need segments sorted on some other
796 // basis will have to use a linker script.
798 Segment_list::const_iterator p;
799 for (p = this->segment_list_.begin();
800 p != this->segment_list_.end();
803 if ((*p)->type() == elfcpp::PT_LOAD
804 && ((*p)->flags() & elfcpp::PF_W) == (seg_flags & elfcpp::PF_W))
806 // If -Tbss was specified, we need to separate the data
808 if (this->options_.user_set_Tbss())
810 if ((os->type() == elfcpp::SHT_NOBITS)
811 == (*p)->has_any_data_sections())
815 (*p)->add_output_section(os, seg_flags);
820 if (p == this->segment_list_.end())
822 Output_segment* oseg = this->make_output_segment(elfcpp::PT_LOAD,
824 oseg->add_output_section(os, seg_flags);
827 // If we see a loadable SHT_NOTE section, we create a PT_NOTE
829 if (os->type() == elfcpp::SHT_NOTE)
831 // See if we already have an equivalent PT_NOTE segment.
832 for (p = this->segment_list_.begin();
833 p != segment_list_.end();
836 if ((*p)->type() == elfcpp::PT_NOTE
837 && (((*p)->flags() & elfcpp::PF_W)
838 == (seg_flags & elfcpp::PF_W)))
840 (*p)->add_output_section(os, seg_flags);
845 if (p == this->segment_list_.end())
847 Output_segment* oseg = this->make_output_segment(elfcpp::PT_NOTE,
849 oseg->add_output_section(os, seg_flags);
853 // If we see a loadable SHF_TLS section, we create a PT_TLS
854 // segment. There can only be one such segment.
855 if ((flags & elfcpp::SHF_TLS) != 0)
857 if (this->tls_segment_ == NULL)
858 this->tls_segment_ = this->make_output_segment(elfcpp::PT_TLS,
860 this->tls_segment_->add_output_section(os, seg_flags);
863 // If -z relro is in effect, and we see a relro section, we create a
864 // PT_GNU_RELRO segment. There can only be one such segment.
865 if (os->is_relro() && parameters->options().relro())
867 gold_assert(seg_flags == (elfcpp::PF_R | elfcpp::PF_W));
868 if (this->relro_segment_ == NULL)
869 this->relro_segment_ = this->make_output_segment(elfcpp::PT_GNU_RELRO,
871 this->relro_segment_->add_output_section(os, seg_flags);
875 // Make an output section for a script.
878 Layout::make_output_section_for_script(const char* name)
880 name = this->namepool_.add(name, false, NULL);
881 Output_section* os = this->make_output_section(name, elfcpp::SHT_PROGBITS,
883 os->set_found_in_sections_clause();
887 // Return the number of segments we expect to see.
890 Layout::expected_segment_count() const
892 size_t ret = this->segment_list_.size();
894 // If we didn't see a SECTIONS clause in a linker script, we should
895 // already have the complete list of segments. Otherwise we ask the
896 // SECTIONS clause how many segments it expects, and add in the ones
897 // we already have (PT_GNU_STACK, PT_GNU_EH_FRAME, etc.)
899 if (!this->script_options_->saw_sections_clause())
903 const Script_sections* ss = this->script_options_->script_sections();
904 return ret + ss->expected_segment_count(this);
908 // Handle the .note.GNU-stack section at layout time. SEEN_GNU_STACK
909 // is whether we saw a .note.GNU-stack section in the object file.
910 // GNU_STACK_FLAGS is the section flags. The flags give the
911 // protection required for stack memory. We record this in an
912 // executable as a PT_GNU_STACK segment. If an object file does not
913 // have a .note.GNU-stack segment, we must assume that it is an old
914 // object. On some targets that will force an executable stack.
917 Layout::layout_gnu_stack(bool seen_gnu_stack, uint64_t gnu_stack_flags)
920 this->input_without_gnu_stack_note_ = true;
923 this->input_with_gnu_stack_note_ = true;
924 if ((gnu_stack_flags & elfcpp::SHF_EXECINSTR) != 0)
925 this->input_requires_executable_stack_ = true;
929 // Create the dynamic sections which are needed before we read the
933 Layout::create_initial_dynamic_sections(Symbol_table* symtab)
935 if (parameters->doing_static_link())
938 this->dynamic_section_ = this->choose_output_section(NULL, ".dynamic",
941 | elfcpp::SHF_WRITE),
943 this->dynamic_section_->set_is_relro();
945 symtab->define_in_output_data("_DYNAMIC", NULL, this->dynamic_section_, 0, 0,
946 elfcpp::STT_OBJECT, elfcpp::STB_LOCAL,
947 elfcpp::STV_HIDDEN, 0, false, false);
949 this->dynamic_data_ = new Output_data_dynamic(&this->dynpool_);
951 this->dynamic_section_->add_output_section_data(this->dynamic_data_);
954 // For each output section whose name can be represented as C symbol,
955 // define __start and __stop symbols for the section. This is a GNU
959 Layout::define_section_symbols(Symbol_table* symtab)
961 for (Section_list::const_iterator p = this->section_list_.begin();
962 p != this->section_list_.end();
965 const char* const name = (*p)->name();
966 if (name[strspn(name,
968 "ABCDEFGHIJKLMNOPWRSTUVWXYZ"
969 "abcdefghijklmnopqrstuvwxyz"
973 const std::string name_string(name);
974 const std::string start_name("__start_" + name_string);
975 const std::string stop_name("__stop_" + name_string);
977 symtab->define_in_output_data(start_name.c_str(),
986 false, // offset_is_from_end
987 true); // only_if_ref
989 symtab->define_in_output_data(stop_name.c_str(),
998 true, // offset_is_from_end
999 true); // only_if_ref
1004 // Define symbols for group signatures.
1007 Layout::define_group_signatures(Symbol_table* symtab)
1009 for (Group_signatures::iterator p = this->group_signatures_.begin();
1010 p != this->group_signatures_.end();
1013 Symbol* sym = symtab->lookup(p->signature, NULL);
1015 p->section->set_info_symndx(sym);
1018 // Force the name of the group section to the group
1019 // signature, and use the group's section symbol as the
1020 // signature symbol.
1021 if (strcmp(p->section->name(), p->signature) != 0)
1023 const char* name = this->namepool_.add(p->signature,
1025 p->section->set_name(name);
1027 p->section->set_needs_symtab_index();
1028 p->section->set_info_section_symndx(p->section);
1032 this->group_signatures_.clear();
1035 // Find the first read-only PT_LOAD segment, creating one if
1039 Layout::find_first_load_seg()
1041 for (Segment_list::const_iterator p = this->segment_list_.begin();
1042 p != this->segment_list_.end();
1045 if ((*p)->type() == elfcpp::PT_LOAD
1046 && ((*p)->flags() & elfcpp::PF_R) != 0
1047 && ((*p)->flags() & elfcpp::PF_W) == 0)
1051 gold_assert(!this->script_options_->saw_phdrs_clause());
1053 Output_segment* load_seg = this->make_output_segment(elfcpp::PT_LOAD,
1058 // Finalize the layout. When this is called, we have created all the
1059 // output sections and all the output segments which are based on
1060 // input sections. We have several things to do, and we have to do
1061 // them in the right order, so that we get the right results correctly
1064 // 1) Finalize the list of output segments and create the segment
1067 // 2) Finalize the dynamic symbol table and associated sections.
1069 // 3) Determine the final file offset of all the output segments.
1071 // 4) Determine the final file offset of all the SHF_ALLOC output
1074 // 5) Create the symbol table sections and the section name table
1077 // 6) Finalize the symbol table: set symbol values to their final
1078 // value and make a final determination of which symbols are going
1079 // into the output symbol table.
1081 // 7) Create the section table header.
1083 // 8) Determine the final file offset of all the output sections which
1084 // are not SHF_ALLOC, including the section table header.
1086 // 9) Finalize the ELF file header.
1088 // This function returns the size of the output file.
1091 Layout::finalize(const Input_objects* input_objects, Symbol_table* symtab,
1092 Target* target, const Task* task)
1094 target->finalize_sections(this);
1096 this->count_local_symbols(task, input_objects);
1098 this->create_gold_note();
1099 this->create_executable_stack_info(target);
1100 this->create_build_id();
1102 Output_segment* phdr_seg = NULL;
1103 if (!parameters->options().relocatable() && !parameters->doing_static_link())
1105 // There was a dynamic object in the link. We need to create
1106 // some information for the dynamic linker.
1108 // Create the PT_PHDR segment which will hold the program
1110 if (!this->script_options_->saw_phdrs_clause())
1111 phdr_seg = this->make_output_segment(elfcpp::PT_PHDR, elfcpp::PF_R);
1113 // Create the dynamic symbol table, including the hash table.
1114 Output_section* dynstr;
1115 std::vector<Symbol*> dynamic_symbols;
1116 unsigned int local_dynamic_count;
1117 Versions versions(*this->script_options()->version_script_info(),
1119 this->create_dynamic_symtab(input_objects, symtab, &dynstr,
1120 &local_dynamic_count, &dynamic_symbols,
1123 // Create the .interp section to hold the name of the
1124 // interpreter, and put it in a PT_INTERP segment.
1125 if (!parameters->options().shared())
1126 this->create_interp(target);
1128 // Finish the .dynamic section to hold the dynamic data, and put
1129 // it in a PT_DYNAMIC segment.
1130 this->finish_dynamic_section(input_objects, symtab);
1132 // We should have added everything we need to the dynamic string
1134 this->dynpool_.set_string_offsets();
1136 // Create the version sections. We can't do this until the
1137 // dynamic string table is complete.
1138 this->create_version_sections(&versions, symtab, local_dynamic_count,
1139 dynamic_symbols, dynstr);
1142 // If there is a SECTIONS clause, put all the input sections into
1143 // the required order.
1144 Output_segment* load_seg;
1145 if (this->script_options_->saw_sections_clause())
1146 load_seg = this->set_section_addresses_from_script(symtab);
1147 else if (parameters->options().relocatable())
1150 load_seg = this->find_first_load_seg();
1152 if (this->options_.oformat_enum() != General_options::OBJECT_FORMAT_ELF)
1155 gold_assert(phdr_seg == NULL || load_seg != NULL);
1157 // Lay out the segment headers.
1158 Output_segment_headers* segment_headers;
1159 if (parameters->options().relocatable())
1160 segment_headers = NULL;
1163 segment_headers = new Output_segment_headers(this->segment_list_);
1164 if (load_seg != NULL)
1165 load_seg->add_initial_output_data(segment_headers);
1166 if (phdr_seg != NULL)
1167 phdr_seg->add_initial_output_data(segment_headers);
1170 // Lay out the file header.
1171 Output_file_header* file_header;
1172 file_header = new Output_file_header(target, symtab, segment_headers,
1173 this->options_.entry());
1174 if (load_seg != NULL)
1175 load_seg->add_initial_output_data(file_header);
1177 this->special_output_list_.push_back(file_header);
1178 if (segment_headers != NULL)
1179 this->special_output_list_.push_back(segment_headers);
1181 if (this->script_options_->saw_phdrs_clause()
1182 && !parameters->options().relocatable())
1184 // Support use of FILEHDRS and PHDRS attachments in a PHDRS
1185 // clause in a linker script.
1186 Script_sections* ss = this->script_options_->script_sections();
1187 ss->put_headers_in_phdrs(file_header, segment_headers);
1190 // We set the output section indexes in set_segment_offsets and
1191 // set_section_indexes.
1192 unsigned int shndx = 1;
1194 // Set the file offsets of all the segments, and all the sections
1197 if (!parameters->options().relocatable())
1198 off = this->set_segment_offsets(target, load_seg, &shndx);
1200 off = this->set_relocatable_section_offsets(file_header, &shndx);
1202 // Set the file offsets of all the non-data sections we've seen so
1203 // far which don't have to wait for the input sections. We need
1204 // this in order to finalize local symbols in non-allocated
1206 off = this->set_section_offsets(off, BEFORE_INPUT_SECTIONS_PASS);
1208 // Set the section indexes of all unallocated sections seen so far,
1209 // in case any of them are somehow referenced by a symbol.
1210 shndx = this->set_section_indexes(shndx);
1212 // Create the symbol table sections.
1213 this->create_symtab_sections(input_objects, symtab, shndx, &off);
1214 if (!parameters->doing_static_link())
1215 this->assign_local_dynsym_offsets(input_objects);
1217 // Process any symbol assignments from a linker script. This must
1218 // be called after the symbol table has been finalized.
1219 this->script_options_->finalize_symbols(symtab, this);
1221 // Create the .shstrtab section.
1222 Output_section* shstrtab_section = this->create_shstrtab();
1224 // Set the file offsets of the rest of the non-data sections which
1225 // don't have to wait for the input sections.
1226 off = this->set_section_offsets(off, BEFORE_INPUT_SECTIONS_PASS);
1228 // Now that all sections have been created, set the section indexes
1229 // for any sections which haven't been done yet.
1230 shndx = this->set_section_indexes(shndx);
1232 // Create the section table header.
1233 this->create_shdrs(shstrtab_section, &off);
1235 // If there are no sections which require postprocessing, we can
1236 // handle the section names now, and avoid a resize later.
1237 if (!this->any_postprocessing_sections_)
1238 off = this->set_section_offsets(off,
1239 STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS);
1241 file_header->set_section_info(this->section_headers_, shstrtab_section);
1243 // Now we know exactly where everything goes in the output file
1244 // (except for non-allocated sections which require postprocessing).
1245 Output_data::layout_complete();
1247 this->output_file_size_ = off;
1252 // Create a note header following the format defined in the ELF ABI.
1253 // NAME is the name, NOTE_TYPE is the type, DESCSZ is the size of the
1254 // descriptor. ALLOCATE is true if the section should be allocated in
1255 // memory. This returns the new note section. It sets
1256 // *TRAILING_PADDING to the number of trailing zero bytes required.
1259 Layout::create_note(const char* name, int note_type, size_t descsz,
1260 bool allocate, size_t* trailing_padding)
1262 // Authorities all agree that the values in a .note field should
1263 // be aligned on 4-byte boundaries for 32-bit binaries. However,
1264 // they differ on what the alignment is for 64-bit binaries.
1265 // The GABI says unambiguously they take 8-byte alignment:
1266 // http://sco.com/developers/gabi/latest/ch5.pheader.html#note_section
1267 // Other documentation says alignment should always be 4 bytes:
1268 // http://www.netbsd.org/docs/kernel/elf-notes.html#note-format
1269 // GNU ld and GNU readelf both support the latter (at least as of
1270 // version 2.16.91), and glibc always generates the latter for
1271 // .note.ABI-tag (as of version 1.6), so that's the one we go with
1273 #ifdef GABI_FORMAT_FOR_DOTNOTE_SECTION // This is not defined by default.
1274 const int size = parameters->target().get_size();
1276 const int size = 32;
1279 // The contents of the .note section.
1280 size_t namesz = strlen(name) + 1;
1281 size_t aligned_namesz = align_address(namesz, size / 8);
1282 size_t aligned_descsz = align_address(descsz, size / 8);
1284 size_t notehdrsz = 3 * (size / 8) + aligned_namesz;
1286 unsigned char* buffer = new unsigned char[notehdrsz];
1287 memset(buffer, 0, notehdrsz);
1289 bool is_big_endian = parameters->target().is_big_endian();
1295 elfcpp::Swap<32, false>::writeval(buffer, namesz);
1296 elfcpp::Swap<32, false>::writeval(buffer + 4, descsz);
1297 elfcpp::Swap<32, false>::writeval(buffer + 8, note_type);
1301 elfcpp::Swap<32, true>::writeval(buffer, namesz);
1302 elfcpp::Swap<32, true>::writeval(buffer + 4, descsz);
1303 elfcpp::Swap<32, true>::writeval(buffer + 8, note_type);
1306 else if (size == 64)
1310 elfcpp::Swap<64, false>::writeval(buffer, namesz);
1311 elfcpp::Swap<64, false>::writeval(buffer + 8, descsz);
1312 elfcpp::Swap<64, false>::writeval(buffer + 16, note_type);
1316 elfcpp::Swap<64, true>::writeval(buffer, namesz);
1317 elfcpp::Swap<64, true>::writeval(buffer + 8, descsz);
1318 elfcpp::Swap<64, true>::writeval(buffer + 16, note_type);
1324 memcpy(buffer + 3 * (size / 8), name, namesz);
1326 const char* note_name = this->namepool_.add(".note", false, NULL);
1327 elfcpp::Elf_Xword flags = 0;
1329 flags = elfcpp::SHF_ALLOC;
1330 Output_section* os = this->make_output_section(note_name,
1333 Output_section_data* posd = new Output_data_const_buffer(buffer, notehdrsz,
1336 os->add_output_section_data(posd);
1338 *trailing_padding = aligned_descsz - descsz;
1343 // For an executable or shared library, create a note to record the
1344 // version of gold used to create the binary.
1347 Layout::create_gold_note()
1349 if (parameters->options().relocatable())
1352 std::string desc = std::string("gold ") + gold::get_version_string();
1354 size_t trailing_padding;
1355 Output_section *os = this->create_note("GNU", elfcpp::NT_GNU_GOLD_VERSION,
1356 desc.size(), false, &trailing_padding);
1358 Output_section_data* posd = new Output_data_const(desc, 4);
1359 os->add_output_section_data(posd);
1361 if (trailing_padding > 0)
1363 posd = new Output_data_zero_fill(trailing_padding, 0);
1364 os->add_output_section_data(posd);
1368 // Record whether the stack should be executable. This can be set
1369 // from the command line using the -z execstack or -z noexecstack
1370 // options. Otherwise, if any input file has a .note.GNU-stack
1371 // section with the SHF_EXECINSTR flag set, the stack should be
1372 // executable. Otherwise, if at least one input file a
1373 // .note.GNU-stack section, and some input file has no .note.GNU-stack
1374 // section, we use the target default for whether the stack should be
1375 // executable. Otherwise, we don't generate a stack note. When
1376 // generating a object file, we create a .note.GNU-stack section with
1377 // the appropriate marking. When generating an executable or shared
1378 // library, we create a PT_GNU_STACK segment.
1381 Layout::create_executable_stack_info(const Target* target)
1383 bool is_stack_executable;
1384 if (this->options_.is_execstack_set())
1385 is_stack_executable = this->options_.is_stack_executable();
1386 else if (!this->input_with_gnu_stack_note_)
1390 if (this->input_requires_executable_stack_)
1391 is_stack_executable = true;
1392 else if (this->input_without_gnu_stack_note_)
1393 is_stack_executable = target->is_default_stack_executable();
1395 is_stack_executable = false;
1398 if (parameters->options().relocatable())
1400 const char* name = this->namepool_.add(".note.GNU-stack", false, NULL);
1401 elfcpp::Elf_Xword flags = 0;
1402 if (is_stack_executable)
1403 flags |= elfcpp::SHF_EXECINSTR;
1404 this->make_output_section(name, elfcpp::SHT_PROGBITS, flags);
1408 if (this->script_options_->saw_phdrs_clause())
1410 int flags = elfcpp::PF_R | elfcpp::PF_W;
1411 if (is_stack_executable)
1412 flags |= elfcpp::PF_X;
1413 this->make_output_segment(elfcpp::PT_GNU_STACK, flags);
1417 // If --build-id was used, set up the build ID note.
1420 Layout::create_build_id()
1422 if (!parameters->options().user_set_build_id())
1425 const char* style = parameters->options().build_id();
1426 if (strcmp(style, "none") == 0)
1429 // Set DESCSZ to the size of the note descriptor. When possible,
1430 // set DESC to the note descriptor contents.
1433 if (strcmp(style, "md5") == 0)
1435 else if (strcmp(style, "sha1") == 0)
1437 else if (strcmp(style, "uuid") == 0)
1439 const size_t uuidsz = 128 / 8;
1441 char buffer[uuidsz];
1442 memset(buffer, 0, uuidsz);
1444 int descriptor = ::open("/dev/urandom", O_RDONLY);
1446 gold_error(_("--build-id=uuid failed: could not open /dev/urandom: %s"),
1450 ssize_t got = ::read(descriptor, buffer, uuidsz);
1451 ::close(descriptor);
1453 gold_error(_("/dev/urandom: read failed: %s"), strerror(errno));
1454 else if (static_cast<size_t>(got) != uuidsz)
1455 gold_error(_("/dev/urandom: expected %zu bytes, got %zd bytes"),
1459 desc.assign(buffer, uuidsz);
1462 else if (strncmp(style, "0x", 2) == 0)
1465 const char* p = style + 2;
1468 if (hex_p(p[0]) && hex_p(p[1]))
1470 char c = (hex_value(p[0]) << 4) | hex_value(p[1]);
1474 else if (*p == '-' || *p == ':')
1477 gold_fatal(_("--build-id argument '%s' not a valid hex number"),
1480 descsz = desc.size();
1483 gold_fatal(_("unrecognized --build-id argument '%s'"), style);
1486 size_t trailing_padding;
1487 Output_section* os = this->create_note("GNU", elfcpp::NT_GNU_BUILD_ID,
1488 descsz, true, &trailing_padding);
1492 // We know the value already, so we fill it in now.
1493 gold_assert(desc.size() == descsz);
1495 Output_section_data* posd = new Output_data_const(desc, 4);
1496 os->add_output_section_data(posd);
1498 if (trailing_padding != 0)
1500 posd = new Output_data_zero_fill(trailing_padding, 0);
1501 os->add_output_section_data(posd);
1506 // We need to compute a checksum after we have completed the
1508 gold_assert(trailing_padding == 0);
1509 this->build_id_note_ = new Output_data_zero_fill(descsz, 4);
1510 os->add_output_section_data(this->build_id_note_);
1511 os->set_after_input_sections();
1515 // Return whether SEG1 should be before SEG2 in the output file. This
1516 // is based entirely on the segment type and flags. When this is
1517 // called the segment addresses has normally not yet been set.
1520 Layout::segment_precedes(const Output_segment* seg1,
1521 const Output_segment* seg2)
1523 elfcpp::Elf_Word type1 = seg1->type();
1524 elfcpp::Elf_Word type2 = seg2->type();
1526 // The single PT_PHDR segment is required to precede any loadable
1527 // segment. We simply make it always first.
1528 if (type1 == elfcpp::PT_PHDR)
1530 gold_assert(type2 != elfcpp::PT_PHDR);
1533 if (type2 == elfcpp::PT_PHDR)
1536 // The single PT_INTERP segment is required to precede any loadable
1537 // segment. We simply make it always second.
1538 if (type1 == elfcpp::PT_INTERP)
1540 gold_assert(type2 != elfcpp::PT_INTERP);
1543 if (type2 == elfcpp::PT_INTERP)
1546 // We then put PT_LOAD segments before any other segments.
1547 if (type1 == elfcpp::PT_LOAD && type2 != elfcpp::PT_LOAD)
1549 if (type2 == elfcpp::PT_LOAD && type1 != elfcpp::PT_LOAD)
1552 // We put the PT_TLS segment last except for the PT_GNU_RELRO
1553 // segment, because that is where the dynamic linker expects to find
1554 // it (this is just for efficiency; other positions would also work
1556 if (type1 == elfcpp::PT_TLS
1557 && type2 != elfcpp::PT_TLS
1558 && type2 != elfcpp::PT_GNU_RELRO)
1560 if (type2 == elfcpp::PT_TLS
1561 && type1 != elfcpp::PT_TLS
1562 && type1 != elfcpp::PT_GNU_RELRO)
1565 // We put the PT_GNU_RELRO segment last, because that is where the
1566 // dynamic linker expects to find it (as with PT_TLS, this is just
1568 if (type1 == elfcpp::PT_GNU_RELRO && type2 != elfcpp::PT_GNU_RELRO)
1570 if (type2 == elfcpp::PT_GNU_RELRO && type1 != elfcpp::PT_GNU_RELRO)
1573 const elfcpp::Elf_Word flags1 = seg1->flags();
1574 const elfcpp::Elf_Word flags2 = seg2->flags();
1576 // The order of non-PT_LOAD segments is unimportant. We simply sort
1577 // by the numeric segment type and flags values. There should not
1578 // be more than one segment with the same type and flags.
1579 if (type1 != elfcpp::PT_LOAD)
1582 return type1 < type2;
1583 gold_assert(flags1 != flags2);
1584 return flags1 < flags2;
1587 // If the addresses are set already, sort by load address.
1588 if (seg1->are_addresses_set())
1590 if (!seg2->are_addresses_set())
1593 unsigned int section_count1 = seg1->output_section_count();
1594 unsigned int section_count2 = seg2->output_section_count();
1595 if (section_count1 == 0 && section_count2 > 0)
1597 if (section_count1 > 0 && section_count2 == 0)
1600 uint64_t paddr1 = seg1->first_section_load_address();
1601 uint64_t paddr2 = seg2->first_section_load_address();
1602 if (paddr1 != paddr2)
1603 return paddr1 < paddr2;
1605 else if (seg2->are_addresses_set())
1608 // We sort PT_LOAD segments based on the flags. Readonly segments
1609 // come before writable segments. Then writable segments with data
1610 // come before writable segments without data. Then executable
1611 // segments come before non-executable segments. Then the unlikely
1612 // case of a non-readable segment comes before the normal case of a
1613 // readable segment. If there are multiple segments with the same
1614 // type and flags, we require that the address be set, and we sort
1615 // by virtual address and then physical address.
1616 if ((flags1 & elfcpp::PF_W) != (flags2 & elfcpp::PF_W))
1617 return (flags1 & elfcpp::PF_W) == 0;
1618 if ((flags1 & elfcpp::PF_W) != 0
1619 && seg1->has_any_data_sections() != seg2->has_any_data_sections())
1620 return seg1->has_any_data_sections();
1621 if ((flags1 & elfcpp::PF_X) != (flags2 & elfcpp::PF_X))
1622 return (flags1 & elfcpp::PF_X) != 0;
1623 if ((flags1 & elfcpp::PF_R) != (flags2 & elfcpp::PF_R))
1624 return (flags1 & elfcpp::PF_R) == 0;
1626 // We shouldn't get here--we shouldn't create segments which we
1627 // can't distinguish.
1631 // Set the file offsets of all the segments, and all the sections they
1632 // contain. They have all been created. LOAD_SEG must be be laid out
1633 // first. Return the offset of the data to follow.
1636 Layout::set_segment_offsets(const Target* target, Output_segment* load_seg,
1637 unsigned int *pshndx)
1639 // Sort them into the final order.
1640 std::sort(this->segment_list_.begin(), this->segment_list_.end(),
1641 Layout::Compare_segments());
1643 // Find the PT_LOAD segments, and set their addresses and offsets
1644 // and their section's addresses and offsets.
1646 if (this->options_.user_set_Ttext())
1647 addr = this->options_.Ttext();
1648 else if (parameters->options().shared())
1651 addr = target->default_text_segment_address();
1654 // If LOAD_SEG is NULL, then the file header and segment headers
1655 // will not be loadable. But they still need to be at offset 0 in
1656 // the file. Set their offsets now.
1657 if (load_seg == NULL)
1659 for (Data_list::iterator p = this->special_output_list_.begin();
1660 p != this->special_output_list_.end();
1663 off = align_address(off, (*p)->addralign());
1664 (*p)->set_address_and_file_offset(0, off);
1665 off += (*p)->data_size();
1669 bool was_readonly = false;
1670 for (Segment_list::iterator p = this->segment_list_.begin();
1671 p != this->segment_list_.end();
1674 if ((*p)->type() == elfcpp::PT_LOAD)
1676 if (load_seg != NULL && load_seg != *p)
1680 bool are_addresses_set = (*p)->are_addresses_set();
1681 if (are_addresses_set)
1683 // When it comes to setting file offsets, we care about
1684 // the physical address.
1685 addr = (*p)->paddr();
1687 else if (this->options_.user_set_Tdata()
1688 && ((*p)->flags() & elfcpp::PF_W) != 0
1689 && (!this->options_.user_set_Tbss()
1690 || (*p)->has_any_data_sections()))
1692 addr = this->options_.Tdata();
1693 are_addresses_set = true;
1695 else if (this->options_.user_set_Tbss()
1696 && ((*p)->flags() & elfcpp::PF_W) != 0
1697 && !(*p)->has_any_data_sections())
1699 addr = this->options_.Tbss();
1700 are_addresses_set = true;
1703 uint64_t orig_addr = addr;
1704 uint64_t orig_off = off;
1706 uint64_t aligned_addr = 0;
1707 uint64_t abi_pagesize = target->abi_pagesize();
1709 // FIXME: This should depend on the -n and -N options.
1710 (*p)->set_minimum_p_align(target->common_pagesize());
1712 if (are_addresses_set)
1714 // Adjust the file offset to the same address modulo the
1716 uint64_t unsigned_off = off;
1717 uint64_t aligned_off = ((unsigned_off & ~(abi_pagesize - 1))
1718 | (addr & (abi_pagesize - 1)));
1719 if (aligned_off < unsigned_off)
1720 aligned_off += abi_pagesize;
1725 // If the last segment was readonly, and this one is
1726 // not, then skip the address forward one page,
1727 // maintaining the same position within the page. This
1728 // lets us store both segments overlapping on a single
1729 // page in the file, but the loader will put them on
1730 // different pages in memory.
1732 addr = align_address(addr, (*p)->maximum_alignment());
1733 aligned_addr = addr;
1735 if (was_readonly && ((*p)->flags() & elfcpp::PF_W) != 0)
1737 if ((addr & (abi_pagesize - 1)) != 0)
1738 addr = addr + abi_pagesize;
1741 off = orig_off + ((addr - orig_addr) & (abi_pagesize - 1));
1744 unsigned int shndx_hold = *pshndx;
1745 uint64_t new_addr = (*p)->set_section_addresses(this, false, addr,
1748 // Now that we know the size of this segment, we may be able
1749 // to save a page in memory, at the cost of wasting some
1750 // file space, by instead aligning to the start of a new
1751 // page. Here we use the real machine page size rather than
1752 // the ABI mandated page size.
1754 if (!are_addresses_set && aligned_addr != addr)
1756 uint64_t common_pagesize = target->common_pagesize();
1757 uint64_t first_off = (common_pagesize
1759 & (common_pagesize - 1)));
1760 uint64_t last_off = new_addr & (common_pagesize - 1);
1763 && ((aligned_addr & ~ (common_pagesize - 1))
1764 != (new_addr & ~ (common_pagesize - 1)))
1765 && first_off + last_off <= common_pagesize)
1767 *pshndx = shndx_hold;
1768 addr = align_address(aligned_addr, common_pagesize);
1769 addr = align_address(addr, (*p)->maximum_alignment());
1770 off = orig_off + ((addr - orig_addr) & (abi_pagesize - 1));
1771 new_addr = (*p)->set_section_addresses(this, true, addr,
1778 if (((*p)->flags() & elfcpp::PF_W) == 0)
1779 was_readonly = true;
1783 // Handle the non-PT_LOAD segments, setting their offsets from their
1784 // section's offsets.
1785 for (Segment_list::iterator p = this->segment_list_.begin();
1786 p != this->segment_list_.end();
1789 if ((*p)->type() != elfcpp::PT_LOAD)
1793 // Set the TLS offsets for each section in the PT_TLS segment.
1794 if (this->tls_segment_ != NULL)
1795 this->tls_segment_->set_tls_offsets();
1800 // Set the offsets of all the allocated sections when doing a
1801 // relocatable link. This does the same jobs as set_segment_offsets,
1802 // only for a relocatable link.
1805 Layout::set_relocatable_section_offsets(Output_data* file_header,
1806 unsigned int *pshndx)
1810 file_header->set_address_and_file_offset(0, 0);
1811 off += file_header->data_size();
1813 for (Section_list::iterator p = this->section_list_.begin();
1814 p != this->section_list_.end();
1817 // We skip unallocated sections here, except that group sections
1818 // have to come first.
1819 if (((*p)->flags() & elfcpp::SHF_ALLOC) == 0
1820 && (*p)->type() != elfcpp::SHT_GROUP)
1823 off = align_address(off, (*p)->addralign());
1825 // The linker script might have set the address.
1826 if (!(*p)->is_address_valid())
1827 (*p)->set_address(0);
1828 (*p)->set_file_offset(off);
1829 (*p)->finalize_data_size();
1830 off += (*p)->data_size();
1832 (*p)->set_out_shndx(*pshndx);
1839 // Set the file offset of all the sections not associated with a
1843 Layout::set_section_offsets(off_t off, Layout::Section_offset_pass pass)
1845 for (Section_list::iterator p = this->unattached_section_list_.begin();
1846 p != this->unattached_section_list_.end();
1849 // The symtab section is handled in create_symtab_sections.
1850 if (*p == this->symtab_section_)
1853 // If we've already set the data size, don't set it again.
1854 if ((*p)->is_offset_valid() && (*p)->is_data_size_valid())
1857 if (pass == BEFORE_INPUT_SECTIONS_PASS
1858 && (*p)->requires_postprocessing())
1860 (*p)->create_postprocessing_buffer();
1861 this->any_postprocessing_sections_ = true;
1864 if (pass == BEFORE_INPUT_SECTIONS_PASS
1865 && (*p)->after_input_sections())
1867 else if (pass == POSTPROCESSING_SECTIONS_PASS
1868 && (!(*p)->after_input_sections()
1869 || (*p)->type() == elfcpp::SHT_STRTAB))
1871 else if (pass == STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS
1872 && (!(*p)->after_input_sections()
1873 || (*p)->type() != elfcpp::SHT_STRTAB))
1876 off = align_address(off, (*p)->addralign());
1877 (*p)->set_file_offset(off);
1878 (*p)->finalize_data_size();
1879 off += (*p)->data_size();
1881 // At this point the name must be set.
1882 if (pass != STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS)
1883 this->namepool_.add((*p)->name(), false, NULL);
1888 // Set the section indexes of all the sections not associated with a
1892 Layout::set_section_indexes(unsigned int shndx)
1894 for (Section_list::iterator p = this->unattached_section_list_.begin();
1895 p != this->unattached_section_list_.end();
1898 if (!(*p)->has_out_shndx())
1900 (*p)->set_out_shndx(shndx);
1907 // Set the section addresses according to the linker script. This is
1908 // only called when we see a SECTIONS clause. This returns the
1909 // program segment which should hold the file header and segment
1910 // headers, if any. It will return NULL if they should not be in a
1914 Layout::set_section_addresses_from_script(Symbol_table* symtab)
1916 Script_sections* ss = this->script_options_->script_sections();
1917 gold_assert(ss->saw_sections_clause());
1919 // Place each orphaned output section in the script.
1920 for (Section_list::iterator p = this->section_list_.begin();
1921 p != this->section_list_.end();
1924 if (!(*p)->found_in_sections_clause())
1925 ss->place_orphan(*p);
1928 return this->script_options_->set_section_addresses(symtab, this);
1931 // Count the local symbols in the regular symbol table and the dynamic
1932 // symbol table, and build the respective string pools.
1935 Layout::count_local_symbols(const Task* task,
1936 const Input_objects* input_objects)
1938 // First, figure out an upper bound on the number of symbols we'll
1939 // be inserting into each pool. This helps us create the pools with
1940 // the right size, to avoid unnecessary hashtable resizing.
1941 unsigned int symbol_count = 0;
1942 for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
1943 p != input_objects->relobj_end();
1945 symbol_count += (*p)->local_symbol_count();
1947 // Go from "upper bound" to "estimate." We overcount for two
1948 // reasons: we double-count symbols that occur in more than one
1949 // object file, and we count symbols that are dropped from the
1950 // output. Add it all together and assume we overcount by 100%.
1953 // We assume all symbols will go into both the sympool and dynpool.
1954 this->sympool_.reserve(symbol_count);
1955 this->dynpool_.reserve(symbol_count);
1957 for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
1958 p != input_objects->relobj_end();
1961 Task_lock_obj<Object> tlo(task, *p);
1962 (*p)->count_local_symbols(&this->sympool_, &this->dynpool_);
1966 // Create the symbol table sections. Here we also set the final
1967 // values of the symbols. At this point all the loadable sections are
1968 // fully laid out. SHNUM is the number of sections so far.
1971 Layout::create_symtab_sections(const Input_objects* input_objects,
1972 Symbol_table* symtab,
1978 if (parameters->target().get_size() == 32)
1980 symsize = elfcpp::Elf_sizes<32>::sym_size;
1983 else if (parameters->target().get_size() == 64)
1985 symsize = elfcpp::Elf_sizes<64>::sym_size;
1992 off = align_address(off, align);
1993 off_t startoff = off;
1995 // Save space for the dummy symbol at the start of the section. We
1996 // never bother to write this out--it will just be left as zero.
1998 unsigned int local_symbol_index = 1;
2000 // Add STT_SECTION symbols for each Output section which needs one.
2001 for (Section_list::iterator p = this->section_list_.begin();
2002 p != this->section_list_.end();
2005 if (!(*p)->needs_symtab_index())
2006 (*p)->set_symtab_index(-1U);
2009 (*p)->set_symtab_index(local_symbol_index);
2010 ++local_symbol_index;
2015 for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
2016 p != input_objects->relobj_end();
2019 unsigned int index = (*p)->finalize_local_symbols(local_symbol_index,
2021 off += (index - local_symbol_index) * symsize;
2022 local_symbol_index = index;
2025 unsigned int local_symcount = local_symbol_index;
2026 gold_assert(local_symcount * symsize == off - startoff);
2029 size_t dyn_global_index;
2031 if (this->dynsym_section_ == NULL)
2034 dyn_global_index = 0;
2039 dyn_global_index = this->dynsym_section_->info();
2040 off_t locsize = dyn_global_index * this->dynsym_section_->entsize();
2041 dynoff = this->dynsym_section_->offset() + locsize;
2042 dyncount = (this->dynsym_section_->data_size() - locsize) / symsize;
2043 gold_assert(static_cast<off_t>(dyncount * symsize)
2044 == this->dynsym_section_->data_size() - locsize);
2047 off = symtab->finalize(off, dynoff, dyn_global_index, dyncount,
2048 &this->sympool_, &local_symcount);
2050 if (!parameters->options().strip_all())
2052 this->sympool_.set_string_offsets();
2054 const char* symtab_name = this->namepool_.add(".symtab", false, NULL);
2055 Output_section* osymtab = this->make_output_section(symtab_name,
2058 this->symtab_section_ = osymtab;
2060 Output_section_data* pos = new Output_data_fixed_space(off - startoff,
2063 osymtab->add_output_section_data(pos);
2065 // We generate a .symtab_shndx section if we have more than
2066 // SHN_LORESERVE sections. Technically it is possible that we
2067 // don't need one, because it is possible that there are no
2068 // symbols in any of sections with indexes larger than
2069 // SHN_LORESERVE. That is probably unusual, though, and it is
2070 // easier to always create one than to compute section indexes
2071 // twice (once here, once when writing out the symbols).
2072 if (shnum >= elfcpp::SHN_LORESERVE)
2074 const char* symtab_xindex_name = this->namepool_.add(".symtab_shndx",
2076 Output_section* osymtab_xindex =
2077 this->make_output_section(symtab_xindex_name,
2078 elfcpp::SHT_SYMTAB_SHNDX, 0);
2080 size_t symcount = (off - startoff) / symsize;
2081 this->symtab_xindex_ = new Output_symtab_xindex(symcount);
2083 osymtab_xindex->add_output_section_data(this->symtab_xindex_);
2085 osymtab_xindex->set_link_section(osymtab);
2086 osymtab_xindex->set_addralign(4);
2087 osymtab_xindex->set_entsize(4);
2089 osymtab_xindex->set_after_input_sections();
2091 // This tells the driver code to wait until the symbol table
2092 // has written out before writing out the postprocessing
2093 // sections, including the .symtab_shndx section.
2094 this->any_postprocessing_sections_ = true;
2097 const char* strtab_name = this->namepool_.add(".strtab", false, NULL);
2098 Output_section* ostrtab = this->make_output_section(strtab_name,
2102 Output_section_data* pstr = new Output_data_strtab(&this->sympool_);
2103 ostrtab->add_output_section_data(pstr);
2105 osymtab->set_file_offset(startoff);
2106 osymtab->finalize_data_size();
2107 osymtab->set_link_section(ostrtab);
2108 osymtab->set_info(local_symcount);
2109 osymtab->set_entsize(symsize);
2115 // Create the .shstrtab section, which holds the names of the
2116 // sections. At the time this is called, we have created all the
2117 // output sections except .shstrtab itself.
2120 Layout::create_shstrtab()
2122 // FIXME: We don't need to create a .shstrtab section if we are
2123 // stripping everything.
2125 const char* name = this->namepool_.add(".shstrtab", false, NULL);
2127 Output_section* os = this->make_output_section(name, elfcpp::SHT_STRTAB, 0);
2129 // We can't write out this section until we've set all the section
2130 // names, and we don't set the names of compressed output sections
2131 // until relocations are complete.
2132 os->set_after_input_sections();
2134 Output_section_data* posd = new Output_data_strtab(&this->namepool_);
2135 os->add_output_section_data(posd);
2140 // Create the section headers. SIZE is 32 or 64. OFF is the file
2144 Layout::create_shdrs(const Output_section* shstrtab_section, off_t* poff)
2146 Output_section_headers* oshdrs;
2147 oshdrs = new Output_section_headers(this,
2148 &this->segment_list_,
2149 &this->section_list_,
2150 &this->unattached_section_list_,
2153 off_t off = align_address(*poff, oshdrs->addralign());
2154 oshdrs->set_address_and_file_offset(0, off);
2155 off += oshdrs->data_size();
2157 this->section_headers_ = oshdrs;
2160 // Count the allocated sections.
2163 Layout::allocated_output_section_count() const
2165 size_t section_count = 0;
2166 for (Segment_list::const_iterator p = this->segment_list_.begin();
2167 p != this->segment_list_.end();
2169 section_count += (*p)->output_section_count();
2170 return section_count;
2173 // Create the dynamic symbol table.
2176 Layout::create_dynamic_symtab(const Input_objects* input_objects,
2177 Symbol_table* symtab,
2178 Output_section **pdynstr,
2179 unsigned int* plocal_dynamic_count,
2180 std::vector<Symbol*>* pdynamic_symbols,
2181 Versions* pversions)
2183 // Count all the symbols in the dynamic symbol table, and set the
2184 // dynamic symbol indexes.
2186 // Skip symbol 0, which is always all zeroes.
2187 unsigned int index = 1;
2189 // Add STT_SECTION symbols for each Output section which needs one.
2190 for (Section_list::iterator p = this->section_list_.begin();
2191 p != this->section_list_.end();
2194 if (!(*p)->needs_dynsym_index())
2195 (*p)->set_dynsym_index(-1U);
2198 (*p)->set_dynsym_index(index);
2203 // Count the local symbols that need to go in the dynamic symbol table,
2204 // and set the dynamic symbol indexes.
2205 for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
2206 p != input_objects->relobj_end();
2209 unsigned int new_index = (*p)->set_local_dynsym_indexes(index);
2213 unsigned int local_symcount = index;
2214 *plocal_dynamic_count = local_symcount;
2216 index = symtab->set_dynsym_indexes(index, pdynamic_symbols,
2217 &this->dynpool_, pversions);
2221 const int size = parameters->target().get_size();
2224 symsize = elfcpp::Elf_sizes<32>::sym_size;
2227 else if (size == 64)
2229 symsize = elfcpp::Elf_sizes<64>::sym_size;
2235 // Create the dynamic symbol table section.
2237 Output_section* dynsym = this->choose_output_section(NULL, ".dynsym",
2242 Output_section_data* odata = new Output_data_fixed_space(index * symsize,
2245 dynsym->add_output_section_data(odata);
2247 dynsym->set_info(local_symcount);
2248 dynsym->set_entsize(symsize);
2249 dynsym->set_addralign(align);
2251 this->dynsym_section_ = dynsym;
2253 Output_data_dynamic* const odyn = this->dynamic_data_;
2254 odyn->add_section_address(elfcpp::DT_SYMTAB, dynsym);
2255 odyn->add_constant(elfcpp::DT_SYMENT, symsize);
2257 // If there are more than SHN_LORESERVE allocated sections, we
2258 // create a .dynsym_shndx section. It is possible that we don't
2259 // need one, because it is possible that there are no dynamic
2260 // symbols in any of the sections with indexes larger than
2261 // SHN_LORESERVE. This is probably unusual, though, and at this
2262 // time we don't know the actual section indexes so it is
2263 // inconvenient to check.
2264 if (this->allocated_output_section_count() >= elfcpp::SHN_LORESERVE)
2266 Output_section* dynsym_xindex =
2267 this->choose_output_section(NULL, ".dynsym_shndx",
2268 elfcpp::SHT_SYMTAB_SHNDX,
2272 this->dynsym_xindex_ = new Output_symtab_xindex(index);
2274 dynsym_xindex->add_output_section_data(this->dynsym_xindex_);
2276 dynsym_xindex->set_link_section(dynsym);
2277 dynsym_xindex->set_addralign(4);
2278 dynsym_xindex->set_entsize(4);
2280 dynsym_xindex->set_after_input_sections();
2282 // This tells the driver code to wait until the symbol table has
2283 // written out before writing out the postprocessing sections,
2284 // including the .dynsym_shndx section.
2285 this->any_postprocessing_sections_ = true;
2288 // Create the dynamic string table section.
2290 Output_section* dynstr = this->choose_output_section(NULL, ".dynstr",
2295 Output_section_data* strdata = new Output_data_strtab(&this->dynpool_);
2296 dynstr->add_output_section_data(strdata);
2298 dynsym->set_link_section(dynstr);
2299 this->dynamic_section_->set_link_section(dynstr);
2301 odyn->add_section_address(elfcpp::DT_STRTAB, dynstr);
2302 odyn->add_section_size(elfcpp::DT_STRSZ, dynstr);
2306 // Create the hash tables.
2308 if (strcmp(parameters->options().hash_style(), "sysv") == 0
2309 || strcmp(parameters->options().hash_style(), "both") == 0)
2311 unsigned char* phash;
2312 unsigned int hashlen;
2313 Dynobj::create_elf_hash_table(*pdynamic_symbols, local_symcount,
2316 Output_section* hashsec = this->choose_output_section(NULL, ".hash",
2321 Output_section_data* hashdata = new Output_data_const_buffer(phash,
2325 hashsec->add_output_section_data(hashdata);
2327 hashsec->set_link_section(dynsym);
2328 hashsec->set_entsize(4);
2330 odyn->add_section_address(elfcpp::DT_HASH, hashsec);
2333 if (strcmp(parameters->options().hash_style(), "gnu") == 0
2334 || strcmp(parameters->options().hash_style(), "both") == 0)
2336 unsigned char* phash;
2337 unsigned int hashlen;
2338 Dynobj::create_gnu_hash_table(*pdynamic_symbols, local_symcount,
2341 Output_section* hashsec = this->choose_output_section(NULL, ".gnu.hash",
2342 elfcpp::SHT_GNU_HASH,
2346 Output_section_data* hashdata = new Output_data_const_buffer(phash,
2350 hashsec->add_output_section_data(hashdata);
2352 hashsec->set_link_section(dynsym);
2353 hashsec->set_entsize(4);
2355 odyn->add_section_address(elfcpp::DT_GNU_HASH, hashsec);
2359 // Assign offsets to each local portion of the dynamic symbol table.
2362 Layout::assign_local_dynsym_offsets(const Input_objects* input_objects)
2364 Output_section* dynsym = this->dynsym_section_;
2365 gold_assert(dynsym != NULL);
2367 off_t off = dynsym->offset();
2369 // Skip the dummy symbol at the start of the section.
2370 off += dynsym->entsize();
2372 for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
2373 p != input_objects->relobj_end();
2376 unsigned int count = (*p)->set_local_dynsym_offset(off);
2377 off += count * dynsym->entsize();
2381 // Create the version sections.
2384 Layout::create_version_sections(const Versions* versions,
2385 const Symbol_table* symtab,
2386 unsigned int local_symcount,
2387 const std::vector<Symbol*>& dynamic_symbols,
2388 const Output_section* dynstr)
2390 if (!versions->any_defs() && !versions->any_needs())
2393 switch (parameters->size_and_endianness())
2395 #ifdef HAVE_TARGET_32_LITTLE
2396 case Parameters::TARGET_32_LITTLE:
2397 this->sized_create_version_sections<32, false>(versions, symtab,
2399 dynamic_symbols, dynstr);
2402 #ifdef HAVE_TARGET_32_BIG
2403 case Parameters::TARGET_32_BIG:
2404 this->sized_create_version_sections<32, true>(versions, symtab,
2406 dynamic_symbols, dynstr);
2409 #ifdef HAVE_TARGET_64_LITTLE
2410 case Parameters::TARGET_64_LITTLE:
2411 this->sized_create_version_sections<64, false>(versions, symtab,
2413 dynamic_symbols, dynstr);
2416 #ifdef HAVE_TARGET_64_BIG
2417 case Parameters::TARGET_64_BIG:
2418 this->sized_create_version_sections<64, true>(versions, symtab,
2420 dynamic_symbols, dynstr);
2428 // Create the version sections, sized version.
2430 template<int size, bool big_endian>
2432 Layout::sized_create_version_sections(
2433 const Versions* versions,
2434 const Symbol_table* symtab,
2435 unsigned int local_symcount,
2436 const std::vector<Symbol*>& dynamic_symbols,
2437 const Output_section* dynstr)
2439 Output_section* vsec = this->choose_output_section(NULL, ".gnu.version",
2440 elfcpp::SHT_GNU_versym,
2444 unsigned char* vbuf;
2446 versions->symbol_section_contents<size, big_endian>(symtab, &this->dynpool_,
2451 Output_section_data* vdata = new Output_data_const_buffer(vbuf, vsize, 2,
2454 vsec->add_output_section_data(vdata);
2455 vsec->set_entsize(2);
2456 vsec->set_link_section(this->dynsym_section_);
2458 Output_data_dynamic* const odyn = this->dynamic_data_;
2459 odyn->add_section_address(elfcpp::DT_VERSYM, vsec);
2461 if (versions->any_defs())
2463 Output_section* vdsec;
2464 vdsec= this->choose_output_section(NULL, ".gnu.version_d",
2465 elfcpp::SHT_GNU_verdef,
2469 unsigned char* vdbuf;
2470 unsigned int vdsize;
2471 unsigned int vdentries;
2472 versions->def_section_contents<size, big_endian>(&this->dynpool_, &vdbuf,
2473 &vdsize, &vdentries);
2475 Output_section_data* vddata =
2476 new Output_data_const_buffer(vdbuf, vdsize, 4, "** version defs");
2478 vdsec->add_output_section_data(vddata);
2479 vdsec->set_link_section(dynstr);
2480 vdsec->set_info(vdentries);
2482 odyn->add_section_address(elfcpp::DT_VERDEF, vdsec);
2483 odyn->add_constant(elfcpp::DT_VERDEFNUM, vdentries);
2486 if (versions->any_needs())
2488 Output_section* vnsec;
2489 vnsec = this->choose_output_section(NULL, ".gnu.version_r",
2490 elfcpp::SHT_GNU_verneed,
2494 unsigned char* vnbuf;
2495 unsigned int vnsize;
2496 unsigned int vnentries;
2497 versions->need_section_contents<size, big_endian>(&this->dynpool_,
2501 Output_section_data* vndata =
2502 new Output_data_const_buffer(vnbuf, vnsize, 4, "** version refs");
2504 vnsec->add_output_section_data(vndata);
2505 vnsec->set_link_section(dynstr);
2506 vnsec->set_info(vnentries);
2508 odyn->add_section_address(elfcpp::DT_VERNEED, vnsec);
2509 odyn->add_constant(elfcpp::DT_VERNEEDNUM, vnentries);
2513 // Create the .interp section and PT_INTERP segment.
2516 Layout::create_interp(const Target* target)
2518 const char* interp = this->options_.dynamic_linker();
2521 interp = target->dynamic_linker();
2522 gold_assert(interp != NULL);
2525 size_t len = strlen(interp) + 1;
2527 Output_section_data* odata = new Output_data_const(interp, len, 1);
2529 Output_section* osec = this->choose_output_section(NULL, ".interp",
2530 elfcpp::SHT_PROGBITS,
2533 osec->add_output_section_data(odata);
2535 if (!this->script_options_->saw_phdrs_clause())
2537 Output_segment* oseg = this->make_output_segment(elfcpp::PT_INTERP,
2539 oseg->add_output_section(osec, elfcpp::PF_R);
2543 // Finish the .dynamic section and PT_DYNAMIC segment.
2546 Layout::finish_dynamic_section(const Input_objects* input_objects,
2547 const Symbol_table* symtab)
2549 if (!this->script_options_->saw_phdrs_clause())
2551 Output_segment* oseg = this->make_output_segment(elfcpp::PT_DYNAMIC,
2554 oseg->add_output_section(this->dynamic_section_,
2555 elfcpp::PF_R | elfcpp::PF_W);
2558 Output_data_dynamic* const odyn = this->dynamic_data_;
2560 for (Input_objects::Dynobj_iterator p = input_objects->dynobj_begin();
2561 p != input_objects->dynobj_end();
2564 // FIXME: Handle --as-needed.
2565 odyn->add_string(elfcpp::DT_NEEDED, (*p)->soname());
2568 if (parameters->options().shared())
2570 const char* soname = this->options_.soname();
2572 odyn->add_string(elfcpp::DT_SONAME, soname);
2575 // FIXME: Support --init and --fini.
2576 Symbol* sym = symtab->lookup("_init");
2577 if (sym != NULL && sym->is_defined() && !sym->is_from_dynobj())
2578 odyn->add_symbol(elfcpp::DT_INIT, sym);
2580 sym = symtab->lookup("_fini");
2581 if (sym != NULL && sym->is_defined() && !sym->is_from_dynobj())
2582 odyn->add_symbol(elfcpp::DT_FINI, sym);
2584 // FIXME: Support DT_INIT_ARRAY and DT_FINI_ARRAY.
2586 // Add a DT_RPATH entry if needed.
2587 const General_options::Dir_list& rpath(this->options_.rpath());
2590 std::string rpath_val;
2591 for (General_options::Dir_list::const_iterator p = rpath.begin();
2595 if (rpath_val.empty())
2596 rpath_val = p->name();
2599 // Eliminate duplicates.
2600 General_options::Dir_list::const_iterator q;
2601 for (q = rpath.begin(); q != p; ++q)
2602 if (q->name() == p->name())
2607 rpath_val += p->name();
2612 odyn->add_string(elfcpp::DT_RPATH, rpath_val);
2613 if (parameters->options().enable_new_dtags())
2614 odyn->add_string(elfcpp::DT_RUNPATH, rpath_val);
2617 // Look for text segments that have dynamic relocations.
2618 bool have_textrel = false;
2619 if (!this->script_options_->saw_sections_clause())
2621 for (Segment_list::const_iterator p = this->segment_list_.begin();
2622 p != this->segment_list_.end();
2625 if (((*p)->flags() & elfcpp::PF_W) == 0
2626 && (*p)->dynamic_reloc_count() > 0)
2628 have_textrel = true;
2635 // We don't know the section -> segment mapping, so we are
2636 // conservative and just look for readonly sections with
2637 // relocations. If those sections wind up in writable segments,
2638 // then we have created an unnecessary DT_TEXTREL entry.
2639 for (Section_list::const_iterator p = this->section_list_.begin();
2640 p != this->section_list_.end();
2643 if (((*p)->flags() & elfcpp::SHF_ALLOC) != 0
2644 && ((*p)->flags() & elfcpp::SHF_WRITE) == 0
2645 && ((*p)->dynamic_reloc_count() > 0))
2647 have_textrel = true;
2653 // Add a DT_FLAGS entry. We add it even if no flags are set so that
2654 // post-link tools can easily modify these flags if desired.
2655 unsigned int flags = 0;
2658 // Add a DT_TEXTREL for compatibility with older loaders.
2659 odyn->add_constant(elfcpp::DT_TEXTREL, 0);
2660 flags |= elfcpp::DF_TEXTREL;
2662 if (parameters->options().shared() && this->has_static_tls())
2663 flags |= elfcpp::DF_STATIC_TLS;
2664 odyn->add_constant(elfcpp::DT_FLAGS, flags);
2667 if (parameters->options().initfirst())
2668 flags |= elfcpp::DF_1_INITFIRST;
2669 if (parameters->options().interpose())
2670 flags |= elfcpp::DF_1_INTERPOSE;
2671 if (parameters->options().loadfltr())
2672 flags |= elfcpp::DF_1_LOADFLTR;
2673 if (parameters->options().nodefaultlib())
2674 flags |= elfcpp::DF_1_NODEFLIB;
2675 if (parameters->options().nodelete())
2676 flags |= elfcpp::DF_1_NODELETE;
2677 if (parameters->options().nodlopen())
2678 flags |= elfcpp::DF_1_NOOPEN;
2679 if (parameters->options().nodump())
2680 flags |= elfcpp::DF_1_NODUMP;
2681 if (!parameters->options().shared())
2682 flags &= ~(elfcpp::DF_1_INITFIRST
2683 | elfcpp::DF_1_NODELETE
2684 | elfcpp::DF_1_NOOPEN);
2686 odyn->add_constant(elfcpp::DT_FLAGS_1, flags);
2689 // The mapping of .gnu.linkonce section names to real section names.
2691 #define MAPPING_INIT(f, t) { f, sizeof(f) - 1, t, sizeof(t) - 1 }
2692 const Layout::Linkonce_mapping Layout::linkonce_mapping[] =
2694 MAPPING_INIT("d.rel.ro.local", ".data.rel.ro.local"), // Before "d.rel.ro".
2695 MAPPING_INIT("d.rel.ro", ".data.rel.ro"), // Before "d".
2696 MAPPING_INIT("t", ".text"),
2697 MAPPING_INIT("r", ".rodata"),
2698 MAPPING_INIT("d", ".data"),
2699 MAPPING_INIT("b", ".bss"),
2700 MAPPING_INIT("s", ".sdata"),
2701 MAPPING_INIT("sb", ".sbss"),
2702 MAPPING_INIT("s2", ".sdata2"),
2703 MAPPING_INIT("sb2", ".sbss2"),
2704 MAPPING_INIT("wi", ".debug_info"),
2705 MAPPING_INIT("td", ".tdata"),
2706 MAPPING_INIT("tb", ".tbss"),
2707 MAPPING_INIT("lr", ".lrodata"),
2708 MAPPING_INIT("l", ".ldata"),
2709 MAPPING_INIT("lb", ".lbss"),
2713 const int Layout::linkonce_mapping_count =
2714 sizeof(Layout::linkonce_mapping) / sizeof(Layout::linkonce_mapping[0]);
2716 // Return the name of the output section to use for a .gnu.linkonce
2717 // section. This is based on the default ELF linker script of the old
2718 // GNU linker. For example, we map a name like ".gnu.linkonce.t.foo"
2719 // to ".text". Set *PLEN to the length of the name. *PLEN is
2720 // initialized to the length of NAME.
2723 Layout::linkonce_output_name(const char* name, size_t *plen)
2725 const char* s = name + sizeof(".gnu.linkonce") - 1;
2729 const Linkonce_mapping* plm = linkonce_mapping;
2730 for (int i = 0; i < linkonce_mapping_count; ++i, ++plm)
2732 if (strncmp(s, plm->from, plm->fromlen) == 0 && s[plm->fromlen] == '.')
2741 // Choose the output section name to use given an input section name.
2742 // Set *PLEN to the length of the name. *PLEN is initialized to the
2746 Layout::output_section_name(const char* name, size_t* plen)
2748 if (Layout::is_linkonce(name))
2750 // .gnu.linkonce sections are laid out as though they were named
2751 // for the sections are placed into.
2752 return Layout::linkonce_output_name(name, plen);
2755 // gcc 4.3 generates the following sorts of section names when it
2756 // needs a section name specific to a function:
2762 // .data.rel.local.FN
2764 // .data.rel.ro.local.FN
2771 // The GNU linker maps all of those to the part before the .FN,
2772 // except that .data.rel.local.FN is mapped to .data, and
2773 // .data.rel.ro.local.FN is mapped to .data.rel.ro. The sections
2774 // beginning with .data.rel.ro.local are grouped together.
2776 // For an anonymous namespace, the string FN can contain a '.'.
2778 // Also of interest: .rodata.strN.N, .rodata.cstN, both of which the
2779 // GNU linker maps to .rodata.
2781 // The .data.rel.ro sections enable a security feature triggered by
2782 // the -z relro option. Section which need to be relocated at
2783 // program startup time but which may be readonly after startup are
2784 // grouped into .data.rel.ro. They are then put into a PT_GNU_RELRO
2785 // segment. The dynamic linker will make that segment writable,
2786 // perform relocations, and then make it read-only. FIXME: We do
2787 // not yet implement this optimization.
2789 // It is hard to handle this in a principled way.
2791 // These are the rules we follow:
2793 // If the section name has no initial '.', or no dot other than an
2794 // initial '.', we use the name unchanged (i.e., "mysection" and
2795 // ".text" are unchanged).
2797 // If the name starts with ".data.rel.ro.local" we use
2798 // ".data.rel.ro.local".
2800 // If the name starts with ".data.rel.ro" we use ".data.rel.ro".
2802 // Otherwise, we drop the second '.' and everything that comes after
2803 // it (i.e., ".text.XXX" becomes ".text").
2805 const char* s = name;
2809 const char* sdot = strchr(s, '.');
2813 const char* const data_rel_ro_local = ".data.rel.ro.local";
2814 if (strncmp(name, data_rel_ro_local, strlen(data_rel_ro_local)) == 0)
2816 *plen = strlen(data_rel_ro_local);
2817 return data_rel_ro_local;
2820 const char* const data_rel_ro = ".data.rel.ro";
2821 if (strncmp(name, data_rel_ro, strlen(data_rel_ro)) == 0)
2823 *plen = strlen(data_rel_ro);
2827 *plen = sdot - name;
2831 // Record the signature of a comdat section, and return whether to
2832 // include it in the link. If GROUP is true, this is a regular
2833 // section group. If GROUP is false, this is a group signature
2834 // derived from the name of a linkonce section. We want linkonce
2835 // signatures and group signatures to block each other, but we don't
2836 // want a linkonce signature to block another linkonce signature.
2839 Layout::add_comdat(Relobj* object, unsigned int shndx,
2840 const std::string& signature, bool group)
2842 Kept_section kept(object, shndx, group);
2843 std::pair<Signatures::iterator, bool> ins(
2844 this->signatures_.insert(std::make_pair(signature, kept)));
2848 // This is the first time we've seen this signature.
2852 if (ins.first->second.group_)
2854 // We've already seen a real section group with this signature.
2859 // This is a real section group, and we've already seen a
2860 // linkonce section with this signature. Record that we've seen
2861 // a section group, and don't include this section group.
2862 ins.first->second.group_ = true;
2867 // We've already seen a linkonce section and this is a linkonce
2868 // section. These don't block each other--this may be the same
2869 // symbol name with different section types.
2874 // Find the given comdat signature, and return the object and section
2875 // index of the kept group.
2877 Layout::find_kept_object(const std::string& signature,
2878 unsigned int* pshndx) const
2880 Signatures::const_iterator p = this->signatures_.find(signature);
2881 if (p == this->signatures_.end())
2884 *pshndx = p->second.shndx_;
2885 return p->second.object_;
2888 // Store the allocated sections into the section list.
2891 Layout::get_allocated_sections(Section_list* section_list) const
2893 for (Section_list::const_iterator p = this->section_list_.begin();
2894 p != this->section_list_.end();
2896 if (((*p)->flags() & elfcpp::SHF_ALLOC) != 0)
2897 section_list->push_back(*p);
2900 // Create an output segment.
2903 Layout::make_output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags)
2905 gold_assert(!parameters->options().relocatable());
2906 Output_segment* oseg = new Output_segment(type, flags);
2907 this->segment_list_.push_back(oseg);
2911 // Write out the Output_sections. Most won't have anything to write,
2912 // since most of the data will come from input sections which are
2913 // handled elsewhere. But some Output_sections do have Output_data.
2916 Layout::write_output_sections(Output_file* of) const
2918 for (Section_list::const_iterator p = this->section_list_.begin();
2919 p != this->section_list_.end();
2922 if (!(*p)->after_input_sections())
2927 // Write out data not associated with a section or the symbol table.
2930 Layout::write_data(const Symbol_table* symtab, Output_file* of) const
2932 if (!parameters->options().strip_all())
2934 const Output_section* symtab_section = this->symtab_section_;
2935 for (Section_list::const_iterator p = this->section_list_.begin();
2936 p != this->section_list_.end();
2939 if ((*p)->needs_symtab_index())
2941 gold_assert(symtab_section != NULL);
2942 unsigned int index = (*p)->symtab_index();
2943 gold_assert(index > 0 && index != -1U);
2944 off_t off = (symtab_section->offset()
2945 + index * symtab_section->entsize());
2946 symtab->write_section_symbol(*p, this->symtab_xindex_, of, off);
2951 const Output_section* dynsym_section = this->dynsym_section_;
2952 for (Section_list::const_iterator p = this->section_list_.begin();
2953 p != this->section_list_.end();
2956 if ((*p)->needs_dynsym_index())
2958 gold_assert(dynsym_section != NULL);
2959 unsigned int index = (*p)->dynsym_index();
2960 gold_assert(index > 0 && index != -1U);
2961 off_t off = (dynsym_section->offset()
2962 + index * dynsym_section->entsize());
2963 symtab->write_section_symbol(*p, this->dynsym_xindex_, of, off);
2967 // Write out the Output_data which are not in an Output_section.
2968 for (Data_list::const_iterator p = this->special_output_list_.begin();
2969 p != this->special_output_list_.end();
2974 // Write out the Output_sections which can only be written after the
2975 // input sections are complete.
2978 Layout::write_sections_after_input_sections(Output_file* of)
2980 // Determine the final section offsets, and thus the final output
2981 // file size. Note we finalize the .shstrab last, to allow the
2982 // after_input_section sections to modify their section-names before
2984 if (this->any_postprocessing_sections_)
2986 off_t off = this->output_file_size_;
2987 off = this->set_section_offsets(off, POSTPROCESSING_SECTIONS_PASS);
2989 // Now that we've finalized the names, we can finalize the shstrab.
2991 this->set_section_offsets(off,
2992 STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS);
2994 if (off > this->output_file_size_)
2997 this->output_file_size_ = off;
3001 for (Section_list::const_iterator p = this->section_list_.begin();
3002 p != this->section_list_.end();
3005 if ((*p)->after_input_sections())
3009 this->section_headers_->write(of);
3012 // If the build ID requires computing a checksum, do so here, and
3013 // write it out. We compute a checksum over the entire file because
3014 // that is simplest.
3017 Layout::write_build_id(Output_file* of) const
3019 if (this->build_id_note_ == NULL)
3022 const unsigned char* iv = of->get_input_view(0, this->output_file_size_);
3024 unsigned char* ov = of->get_output_view(this->build_id_note_->offset(),
3025 this->build_id_note_->data_size());
3027 const char* style = parameters->options().build_id();
3028 if (strcmp(style, "sha1") == 0)
3031 sha1_init_ctx(&ctx);
3032 sha1_process_bytes(iv, this->output_file_size_, &ctx);
3033 sha1_finish_ctx(&ctx, ov);
3035 else if (strcmp(style, "md5") == 0)
3039 md5_process_bytes(iv, this->output_file_size_, &ctx);
3040 md5_finish_ctx(&ctx, ov);
3045 of->write_output_view(this->build_id_note_->offset(),
3046 this->build_id_note_->data_size(),
3049 of->free_input_view(0, this->output_file_size_, iv);
3052 // Write out a binary file. This is called after the link is
3053 // complete. IN is the temporary output file we used to generate the
3054 // ELF code. We simply walk through the segments, read them from
3055 // their file offset in IN, and write them to their load address in
3056 // the output file. FIXME: with a bit more work, we could support
3057 // S-records and/or Intel hex format here.
3060 Layout::write_binary(Output_file* in) const
3062 gold_assert(this->options_.oformat_enum()
3063 == General_options::OBJECT_FORMAT_BINARY);
3065 // Get the size of the binary file.
3066 uint64_t max_load_address = 0;
3067 for (Segment_list::const_iterator p = this->segment_list_.begin();
3068 p != this->segment_list_.end();
3071 if ((*p)->type() == elfcpp::PT_LOAD && (*p)->filesz() > 0)
3073 uint64_t max_paddr = (*p)->paddr() + (*p)->filesz();
3074 if (max_paddr > max_load_address)
3075 max_load_address = max_paddr;
3079 Output_file out(parameters->options().output_file_name());
3080 out.open(max_load_address);
3082 for (Segment_list::const_iterator p = this->segment_list_.begin();
3083 p != this->segment_list_.end();
3086 if ((*p)->type() == elfcpp::PT_LOAD && (*p)->filesz() > 0)
3088 const unsigned char* vin = in->get_input_view((*p)->offset(),
3090 unsigned char* vout = out.get_output_view((*p)->paddr(),
3092 memcpy(vout, vin, (*p)->filesz());
3093 out.write_output_view((*p)->paddr(), (*p)->filesz(), vout);
3094 in->free_input_view((*p)->offset(), (*p)->filesz(), vin);
3101 // Print the output sections to the map file.
3104 Layout::print_to_mapfile(Mapfile* mapfile) const
3106 for (Segment_list::const_iterator p = this->segment_list_.begin();
3107 p != this->segment_list_.end();
3109 (*p)->print_sections_to_mapfile(mapfile);
3112 // Print statistical information to stderr. This is used for --stats.
3115 Layout::print_stats() const
3117 this->namepool_.print_stats("section name pool");
3118 this->sympool_.print_stats("output symbol name pool");
3119 this->dynpool_.print_stats("dynamic name pool");
3121 for (Section_list::const_iterator p = this->section_list_.begin();
3122 p != this->section_list_.end();
3124 (*p)->print_merge_stats();
3127 // Write_sections_task methods.
3129 // We can always run this task.
3132 Write_sections_task::is_runnable()
3137 // We need to unlock both OUTPUT_SECTIONS_BLOCKER and FINAL_BLOCKER
3141 Write_sections_task::locks(Task_locker* tl)
3143 tl->add(this, this->output_sections_blocker_);
3144 tl->add(this, this->final_blocker_);
3147 // Run the task--write out the data.
3150 Write_sections_task::run(Workqueue*)
3152 this->layout_->write_output_sections(this->of_);
3155 // Write_data_task methods.
3157 // We can always run this task.
3160 Write_data_task::is_runnable()
3165 // We need to unlock FINAL_BLOCKER when finished.
3168 Write_data_task::locks(Task_locker* tl)
3170 tl->add(this, this->final_blocker_);
3173 // Run the task--write out the data.
3176 Write_data_task::run(Workqueue*)
3178 this->layout_->write_data(this->symtab_, this->of_);
3181 // Write_symbols_task methods.
3183 // We can always run this task.
3186 Write_symbols_task::is_runnable()
3191 // We need to unlock FINAL_BLOCKER when finished.
3194 Write_symbols_task::locks(Task_locker* tl)
3196 tl->add(this, this->final_blocker_);
3199 // Run the task--write out the symbols.
3202 Write_symbols_task::run(Workqueue*)
3204 this->symtab_->write_globals(this->input_objects_, this->sympool_,
3205 this->dynpool_, this->layout_->symtab_xindex(),
3206 this->layout_->dynsym_xindex(), this->of_);
3209 // Write_after_input_sections_task methods.
3211 // We can only run this task after the input sections have completed.
3214 Write_after_input_sections_task::is_runnable()
3216 if (this->input_sections_blocker_->is_blocked())
3217 return this->input_sections_blocker_;
3221 // We need to unlock FINAL_BLOCKER when finished.
3224 Write_after_input_sections_task::locks(Task_locker* tl)
3226 tl->add(this, this->final_blocker_);
3232 Write_after_input_sections_task::run(Workqueue*)
3234 this->layout_->write_sections_after_input_sections(this->of_);
3237 // Close_task_runner methods.
3239 // Run the task--close the file.
3242 Close_task_runner::run(Workqueue*, const Task*)
3244 // If we need to compute a checksum for the BUILD if, we do so here.
3245 this->layout_->write_build_id(this->of_);
3247 // If we've been asked to create a binary file, we do so here.
3248 if (this->options_->oformat_enum() != General_options::OBJECT_FORMAT_ELF)
3249 this->layout_->write_binary(this->of_);
3254 // Instantiate the templates we need. We could use the configure
3255 // script to restrict this to only the ones for implemented targets.
3257 #ifdef HAVE_TARGET_32_LITTLE
3260 Layout::layout<32, false>(Sized_relobj<32, false>* object, unsigned int shndx,
3262 const elfcpp::Shdr<32, false>& shdr,
3263 unsigned int, unsigned int, off_t*);
3266 #ifdef HAVE_TARGET_32_BIG
3269 Layout::layout<32, true>(Sized_relobj<32, true>* object, unsigned int shndx,
3271 const elfcpp::Shdr<32, true>& shdr,
3272 unsigned int, unsigned int, off_t*);
3275 #ifdef HAVE_TARGET_64_LITTLE
3278 Layout::layout<64, false>(Sized_relobj<64, false>* object, unsigned int shndx,
3280 const elfcpp::Shdr<64, false>& shdr,
3281 unsigned int, unsigned int, off_t*);
3284 #ifdef HAVE_TARGET_64_BIG
3287 Layout::layout<64, true>(Sized_relobj<64, true>* object, unsigned int shndx,
3289 const elfcpp::Shdr<64, true>& shdr,
3290 unsigned int, unsigned int, off_t*);
3293 #ifdef HAVE_TARGET_32_LITTLE
3296 Layout::layout_reloc<32, false>(Sized_relobj<32, false>* object,
3297 unsigned int reloc_shndx,
3298 const elfcpp::Shdr<32, false>& shdr,
3299 Output_section* data_section,
3300 Relocatable_relocs* rr);
3303 #ifdef HAVE_TARGET_32_BIG
3306 Layout::layout_reloc<32, true>(Sized_relobj<32, true>* object,
3307 unsigned int reloc_shndx,
3308 const elfcpp::Shdr<32, true>& shdr,
3309 Output_section* data_section,
3310 Relocatable_relocs* rr);
3313 #ifdef HAVE_TARGET_64_LITTLE
3316 Layout::layout_reloc<64, false>(Sized_relobj<64, false>* object,
3317 unsigned int reloc_shndx,
3318 const elfcpp::Shdr<64, false>& shdr,
3319 Output_section* data_section,
3320 Relocatable_relocs* rr);
3323 #ifdef HAVE_TARGET_64_BIG
3326 Layout::layout_reloc<64, true>(Sized_relobj<64, true>* object,
3327 unsigned int reloc_shndx,
3328 const elfcpp::Shdr<64, true>& shdr,
3329 Output_section* data_section,
3330 Relocatable_relocs* rr);
3333 #ifdef HAVE_TARGET_32_LITTLE
3336 Layout::layout_group<32, false>(Symbol_table* symtab,
3337 Sized_relobj<32, false>* object,
3339 const char* group_section_name,
3340 const char* signature,
3341 const elfcpp::Shdr<32, false>& shdr,
3342 elfcpp::Elf_Word flags,
3343 std::vector<unsigned int>* shndxes);
3346 #ifdef HAVE_TARGET_32_BIG
3349 Layout::layout_group<32, true>(Symbol_table* symtab,
3350 Sized_relobj<32, true>* object,
3352 const char* group_section_name,
3353 const char* signature,
3354 const elfcpp::Shdr<32, true>& shdr,
3355 elfcpp::Elf_Word flags,
3356 std::vector<unsigned int>* shndxes);
3359 #ifdef HAVE_TARGET_64_LITTLE
3362 Layout::layout_group<64, false>(Symbol_table* symtab,
3363 Sized_relobj<64, false>* object,
3365 const char* group_section_name,
3366 const char* signature,
3367 const elfcpp::Shdr<64, false>& shdr,
3368 elfcpp::Elf_Word flags,
3369 std::vector<unsigned int>* shndxes);
3372 #ifdef HAVE_TARGET_64_BIG
3375 Layout::layout_group<64, true>(Symbol_table* symtab,
3376 Sized_relobj<64, true>* object,
3378 const char* group_section_name,
3379 const char* signature,
3380 const elfcpp::Shdr<64, true>& shdr,
3381 elfcpp::Elf_Word flags,
3382 std::vector<unsigned int>* shndxes);
3385 #ifdef HAVE_TARGET_32_LITTLE
3388 Layout::layout_eh_frame<32, false>(Sized_relobj<32, false>* object,
3389 const unsigned char* symbols,
3391 const unsigned char* symbol_names,
3392 off_t symbol_names_size,
3394 const elfcpp::Shdr<32, false>& shdr,
3395 unsigned int reloc_shndx,
3396 unsigned int reloc_type,
3400 #ifdef HAVE_TARGET_32_BIG
3403 Layout::layout_eh_frame<32, true>(Sized_relobj<32, true>* object,
3404 const unsigned char* symbols,
3406 const unsigned char* symbol_names,
3407 off_t symbol_names_size,
3409 const elfcpp::Shdr<32, true>& shdr,
3410 unsigned int reloc_shndx,
3411 unsigned int reloc_type,
3415 #ifdef HAVE_TARGET_64_LITTLE
3418 Layout::layout_eh_frame<64, false>(Sized_relobj<64, false>* object,
3419 const unsigned char* symbols,
3421 const unsigned char* symbol_names,
3422 off_t symbol_names_size,
3424 const elfcpp::Shdr<64, false>& shdr,
3425 unsigned int reloc_shndx,
3426 unsigned int reloc_type,
3430 #ifdef HAVE_TARGET_64_BIG
3433 Layout::layout_eh_frame<64, true>(Sized_relobj<64, true>* object,
3434 const unsigned char* symbols,
3436 const unsigned char* symbol_names,
3437 off_t symbol_names_size,
3439 const elfcpp::Shdr<64, true>& shdr,
3440 unsigned int reloc_shndx,
3441 unsigned int reloc_type,
3445 } // End namespace gold.