1 // layout.cc -- lay out output file sections for gold
3 // Copyright 2006, 2007, 2008, 2009, 2010, 2011 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.
34 #include "libiberty.h"
38 #include "parameters.h"
42 #include "script-sections.h"
47 #include "compressed_output.h"
48 #include "reduced_debug_output.h"
50 #include "descriptors.h"
52 #include "incremental.h"
60 // The total number of free lists used.
61 unsigned int Free_list::num_lists = 0;
62 // The total number of free list nodes used.
63 unsigned int Free_list::num_nodes = 0;
64 // The total number of calls to Free_list::remove.
65 unsigned int Free_list::num_removes = 0;
66 // The total number of nodes visited during calls to Free_list::remove.
67 unsigned int Free_list::num_remove_visits = 0;
68 // The total number of calls to Free_list::allocate.
69 unsigned int Free_list::num_allocates = 0;
70 // The total number of nodes visited during calls to Free_list::allocate.
71 unsigned int Free_list::num_allocate_visits = 0;
73 // Initialize the free list. Creates a single free list node that
74 // describes the entire region of length LEN. If EXTEND is true,
75 // allocate() is allowed to extend the region beyond its initial
79 Free_list::init(off_t len, bool extend)
81 this->list_.push_front(Free_list_node(0, len));
82 this->last_remove_ = this->list_.begin();
83 this->extend_ = extend;
85 ++Free_list::num_lists;
86 ++Free_list::num_nodes;
89 // Remove a chunk from the free list. Because we start with a single
90 // node that covers the entire section, and remove chunks from it one
91 // at a time, we do not need to coalesce chunks or handle cases that
92 // span more than one free node. We expect to remove chunks from the
93 // free list in order, and we expect to have only a few chunks of free
94 // space left (corresponding to files that have changed since the last
95 // incremental link), so a simple linear list should provide sufficient
99 Free_list::remove(off_t start, off_t end)
103 gold_assert(start < end);
105 ++Free_list::num_removes;
107 Iterator p = this->last_remove_;
108 if (p->start_ > start)
109 p = this->list_.begin();
111 for (; p != this->list_.end(); ++p)
113 ++Free_list::num_remove_visits;
114 // Find a node that wholly contains the indicated region.
115 if (p->start_ <= start && p->end_ >= end)
117 // Case 1: the indicated region spans the whole node.
118 // Add some fuzz to avoid creating tiny free chunks.
119 if (p->start_ + 3 >= start && p->end_ <= end + 3)
120 p = this->list_.erase(p);
121 // Case 2: remove a chunk from the start of the node.
122 else if (p->start_ + 3 >= start)
124 // Case 3: remove a chunk from the end of the node.
125 else if (p->end_ <= end + 3)
127 // Case 4: remove a chunk from the middle, and split
128 // the node into two.
131 Free_list_node newnode(p->start_, start);
133 this->list_.insert(p, newnode);
134 ++Free_list::num_nodes;
136 this->last_remove_ = p;
141 // Did not find a node containing the given chunk. This could happen
142 // because a small chunk was already removed due to the fuzz.
143 gold_debug(DEBUG_INCREMENTAL,
144 "Free_list::remove(%d,%d) not found",
145 static_cast<int>(start), static_cast<int>(end));
148 // Allocate a chunk of size LEN from the free list. Returns -1ULL
149 // if a sufficiently large chunk of free space is not found.
150 // We use a simple first-fit algorithm.
153 Free_list::allocate(off_t len, uint64_t align, off_t minoff)
155 gold_debug(DEBUG_INCREMENTAL,
156 "Free_list::allocate(%08lx, %d, %08lx)",
157 static_cast<long>(len), static_cast<int>(align),
158 static_cast<long>(minoff));
160 return align_address(minoff, align);
162 ++Free_list::num_allocates;
164 for (Iterator p = this->list_.begin(); p != this->list_.end(); ++p)
166 ++Free_list::num_allocate_visits;
167 off_t start = p->start_ > minoff ? p->start_ : minoff;
168 start = align_address(start, align);
169 off_t end = start + len;
172 if (p->start_ + 3 >= start && p->end_ <= end + 3)
173 this->list_.erase(p);
174 else if (p->start_ + 3 >= start)
176 else if (p->end_ <= end + 3)
180 Free_list_node newnode(p->start_, start);
182 this->list_.insert(p, newnode);
183 ++Free_list::num_nodes;
191 // Dump the free list (for debugging).
195 gold_info("Free list:\n start end length\n");
196 for (Iterator p = this->list_.begin(); p != this->list_.end(); ++p)
197 gold_info(" %08lx %08lx %08lx", static_cast<long>(p->start_),
198 static_cast<long>(p->end_),
199 static_cast<long>(p->end_ - p->start_));
202 // Print the statistics for the free lists.
204 Free_list::print_stats()
206 fprintf(stderr, _("%s: total free lists: %u\n"),
207 program_name, Free_list::num_lists);
208 fprintf(stderr, _("%s: total free list nodes: %u\n"),
209 program_name, Free_list::num_nodes);
210 fprintf(stderr, _("%s: calls to Free_list::remove: %u\n"),
211 program_name, Free_list::num_removes);
212 fprintf(stderr, _("%s: nodes visited: %u\n"),
213 program_name, Free_list::num_remove_visits);
214 fprintf(stderr, _("%s: calls to Free_list::allocate: %u\n"),
215 program_name, Free_list::num_allocates);
216 fprintf(stderr, _("%s: nodes visited: %u\n"),
217 program_name, Free_list::num_allocate_visits);
220 // Layout::Relaxation_debug_check methods.
222 // Check that sections and special data are in reset states.
223 // We do not save states for Output_sections and special Output_data.
224 // So we check that they have not assigned any addresses or offsets.
225 // clean_up_after_relaxation simply resets their addresses and offsets.
227 Layout::Relaxation_debug_check::check_output_data_for_reset_values(
228 const Layout::Section_list& sections,
229 const Layout::Data_list& special_outputs)
231 for(Layout::Section_list::const_iterator p = sections.begin();
234 gold_assert((*p)->address_and_file_offset_have_reset_values());
236 for(Layout::Data_list::const_iterator p = special_outputs.begin();
237 p != special_outputs.end();
239 gold_assert((*p)->address_and_file_offset_have_reset_values());
242 // Save information of SECTIONS for checking later.
245 Layout::Relaxation_debug_check::read_sections(
246 const Layout::Section_list& sections)
248 for(Layout::Section_list::const_iterator p = sections.begin();
252 Output_section* os = *p;
254 info.output_section = os;
255 info.address = os->is_address_valid() ? os->address() : 0;
256 info.data_size = os->is_data_size_valid() ? os->data_size() : -1;
257 info.offset = os->is_offset_valid()? os->offset() : -1 ;
258 this->section_infos_.push_back(info);
262 // Verify SECTIONS using previously recorded information.
265 Layout::Relaxation_debug_check::verify_sections(
266 const Layout::Section_list& sections)
269 for(Layout::Section_list::const_iterator p = sections.begin();
273 Output_section* os = *p;
274 uint64_t address = os->is_address_valid() ? os->address() : 0;
275 off_t data_size = os->is_data_size_valid() ? os->data_size() : -1;
276 off_t offset = os->is_offset_valid()? os->offset() : -1 ;
278 if (i >= this->section_infos_.size())
280 gold_fatal("Section_info of %s missing.\n", os->name());
282 const Section_info& info = this->section_infos_[i];
283 if (os != info.output_section)
284 gold_fatal("Section order changed. Expecting %s but see %s\n",
285 info.output_section->name(), os->name());
286 if (address != info.address
287 || data_size != info.data_size
288 || offset != info.offset)
289 gold_fatal("Section %s changed.\n", os->name());
293 // Layout_task_runner methods.
295 // Lay out the sections. This is called after all the input objects
299 Layout_task_runner::run(Workqueue* workqueue, const Task* task)
301 Layout* layout = this->layout_;
302 off_t file_size = layout->finalize(this->input_objects_,
307 // Now we know the final size of the output file and we know where
308 // each piece of information goes.
310 if (this->mapfile_ != NULL)
312 this->mapfile_->print_discarded_sections(this->input_objects_);
313 layout->print_to_mapfile(this->mapfile_);
317 if (layout->incremental_base() == NULL)
319 of = new Output_file(parameters->options().output_file_name());
320 if (this->options_.oformat_enum() != General_options::OBJECT_FORMAT_ELF)
321 of->set_is_temporary();
326 of = layout->incremental_base()->output_file();
328 // Apply the incremental relocations for symbols whose values
329 // have changed. We do this before we resize the file and start
330 // writing anything else to it, so that we can read the old
331 // incremental information from the file before (possibly)
333 if (parameters->incremental_update())
334 layout->incremental_base()->apply_incremental_relocs(this->symtab_,
338 of->resize(file_size);
341 // Queue up the final set of tasks.
342 gold::queue_final_tasks(this->options_, this->input_objects_,
343 this->symtab_, layout, workqueue, of);
348 Layout::Layout(int number_of_input_files, Script_options* script_options)
349 : number_of_input_files_(number_of_input_files),
350 script_options_(script_options),
358 unattached_section_list_(),
359 special_output_list_(),
360 section_headers_(NULL),
362 relro_segment_(NULL),
363 interp_segment_(NULL),
365 symtab_section_(NULL),
366 symtab_xindex_(NULL),
367 dynsym_section_(NULL),
368 dynsym_xindex_(NULL),
369 dynamic_section_(NULL),
370 dynamic_symbol_(NULL),
372 eh_frame_section_(NULL),
373 eh_frame_data_(NULL),
374 added_eh_frame_data_(false),
375 eh_frame_hdr_section_(NULL),
376 build_id_note_(NULL),
380 output_file_size_(-1),
381 have_added_input_section_(false),
382 sections_are_attached_(false),
383 input_requires_executable_stack_(false),
384 input_with_gnu_stack_note_(false),
385 input_without_gnu_stack_note_(false),
386 has_static_tls_(false),
387 any_postprocessing_sections_(false),
388 resized_signatures_(false),
389 have_stabstr_section_(false),
390 incremental_inputs_(NULL),
391 record_output_section_data_from_script_(false),
392 script_output_section_data_list_(),
393 segment_states_(NULL),
394 relaxation_debug_check_(NULL),
395 incremental_base_(NULL),
398 // Make space for more than enough segments for a typical file.
399 // This is just for efficiency--it's OK if we wind up needing more.
400 this->segment_list_.reserve(12);
402 // We expect two unattached Output_data objects: the file header and
403 // the segment headers.
404 this->special_output_list_.reserve(2);
406 // Initialize structure needed for an incremental build.
407 if (parameters->incremental())
408 this->incremental_inputs_ = new Incremental_inputs;
410 // The section name pool is worth optimizing in all cases, because
411 // it is small, but there are often overlaps due to .rel sections.
412 this->namepool_.set_optimize();
415 // For incremental links, record the base file to be modified.
418 Layout::set_incremental_base(Incremental_binary* base)
420 this->incremental_base_ = base;
421 this->free_list_.init(base->output_file()->filesize(), true);
424 // Hash a key we use to look up an output section mapping.
427 Layout::Hash_key::operator()(const Layout::Key& k) const
429 return k.first + k.second.first + k.second.second;
432 // Returns whether the given section is in the list of
433 // debug-sections-used-by-some-version-of-gdb. Currently,
434 // we've checked versions of gdb up to and including 6.7.1.
436 static const char* gdb_sections[] =
438 // ".debug_aranges", // not used by gdb as of 6.7.1
445 // ".debug_pubnames", // not used by gdb as of 6.7.1
450 static const char* lines_only_debug_sections[] =
452 // ".debug_aranges", // not used by gdb as of 6.7.1
459 // ".debug_pubnames", // not used by gdb as of 6.7.1
465 is_gdb_debug_section(const char* str)
467 // We can do this faster: binary search or a hashtable. But why bother?
468 for (size_t i = 0; i < sizeof(gdb_sections)/sizeof(*gdb_sections); ++i)
469 if (strcmp(str, gdb_sections[i]) == 0)
475 is_lines_only_debug_section(const char* str)
477 // We can do this faster: binary search or a hashtable. But why bother?
479 i < sizeof(lines_only_debug_sections)/sizeof(*lines_only_debug_sections);
481 if (strcmp(str, lines_only_debug_sections[i]) == 0)
486 // Sometimes we compress sections. This is typically done for
487 // sections that are not part of normal program execution (such as
488 // .debug_* sections), and where the readers of these sections know
489 // how to deal with compressed sections. This routine doesn't say for
490 // certain whether we'll compress -- it depends on commandline options
491 // as well -- just whether this section is a candidate for compression.
492 // (The Output_compressed_section class decides whether to compress
493 // a given section, and picks the name of the compressed section.)
496 is_compressible_debug_section(const char* secname)
498 return (is_prefix_of(".debug", secname));
501 // We may see compressed debug sections in input files. Return TRUE
502 // if this is the name of a compressed debug section.
505 is_compressed_debug_section(const char* secname)
507 return (is_prefix_of(".zdebug", secname));
510 // Whether to include this section in the link.
512 template<int size, bool big_endian>
514 Layout::include_section(Sized_relobj_file<size, big_endian>*, const char* name,
515 const elfcpp::Shdr<size, big_endian>& shdr)
517 if (shdr.get_sh_flags() & elfcpp::SHF_EXCLUDE)
520 switch (shdr.get_sh_type())
522 case elfcpp::SHT_NULL:
523 case elfcpp::SHT_SYMTAB:
524 case elfcpp::SHT_DYNSYM:
525 case elfcpp::SHT_HASH:
526 case elfcpp::SHT_DYNAMIC:
527 case elfcpp::SHT_SYMTAB_SHNDX:
530 case elfcpp::SHT_STRTAB:
531 // Discard the sections which have special meanings in the ELF
532 // ABI. Keep others (e.g., .stabstr). We could also do this by
533 // checking the sh_link fields of the appropriate sections.
534 return (strcmp(name, ".dynstr") != 0
535 && strcmp(name, ".strtab") != 0
536 && strcmp(name, ".shstrtab") != 0);
538 case elfcpp::SHT_RELA:
539 case elfcpp::SHT_REL:
540 case elfcpp::SHT_GROUP:
541 // If we are emitting relocations these should be handled
543 gold_assert(!parameters->options().relocatable()
544 && !parameters->options().emit_relocs());
547 case elfcpp::SHT_PROGBITS:
548 if (parameters->options().strip_debug()
549 && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
551 if (is_debug_info_section(name))
554 if (parameters->options().strip_debug_non_line()
555 && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
557 // Debugging sections can only be recognized by name.
558 if (is_prefix_of(".debug", name)
559 && !is_lines_only_debug_section(name))
562 if (parameters->options().strip_debug_gdb()
563 && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
565 // Debugging sections can only be recognized by name.
566 if (is_prefix_of(".debug", name)
567 && !is_gdb_debug_section(name))
570 if (parameters->options().strip_lto_sections()
571 && !parameters->options().relocatable()
572 && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
574 // Ignore LTO sections containing intermediate code.
575 if (is_prefix_of(".gnu.lto_", name))
578 // The GNU linker strips .gnu_debuglink sections, so we do too.
579 // This is a feature used to keep debugging information in
581 if (strcmp(name, ".gnu_debuglink") == 0)
590 // Return an output section named NAME, or NULL if there is none.
593 Layout::find_output_section(const char* name) const
595 for (Section_list::const_iterator p = this->section_list_.begin();
596 p != this->section_list_.end();
598 if (strcmp((*p)->name(), name) == 0)
603 // Return an output segment of type TYPE, with segment flags SET set
604 // and segment flags CLEAR clear. Return NULL if there is none.
607 Layout::find_output_segment(elfcpp::PT type, elfcpp::Elf_Word set,
608 elfcpp::Elf_Word clear) const
610 for (Segment_list::const_iterator p = this->segment_list_.begin();
611 p != this->segment_list_.end();
613 if (static_cast<elfcpp::PT>((*p)->type()) == type
614 && ((*p)->flags() & set) == set
615 && ((*p)->flags() & clear) == 0)
620 // Return the output section to use for section NAME with type TYPE
621 // and section flags FLAGS. NAME must be canonicalized in the string
622 // pool, and NAME_KEY is the key. ORDER is where this should appear
623 // in the output sections. IS_RELRO is true for a relro section.
626 Layout::get_output_section(const char* name, Stringpool::Key name_key,
627 elfcpp::Elf_Word type, elfcpp::Elf_Xword flags,
628 Output_section_order order, bool is_relro)
630 elfcpp::Elf_Word lookup_type = type;
632 // For lookup purposes, treat INIT_ARRAY, FINI_ARRAY, and
633 // PREINIT_ARRAY like PROGBITS. This ensures that we combine
634 // .init_array, .fini_array, and .preinit_array sections by name
635 // whatever their type in the input file. We do this because the
636 // types are not always right in the input files.
637 if (lookup_type == elfcpp::SHT_INIT_ARRAY
638 || lookup_type == elfcpp::SHT_FINI_ARRAY
639 || lookup_type == elfcpp::SHT_PREINIT_ARRAY)
640 lookup_type = elfcpp::SHT_PROGBITS;
642 elfcpp::Elf_Xword lookup_flags = flags;
644 // Ignoring SHF_WRITE and SHF_EXECINSTR here means that we combine
645 // read-write with read-only sections. Some other ELF linkers do
646 // not do this. FIXME: Perhaps there should be an option
648 lookup_flags &= ~(elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR);
650 const Key key(name_key, std::make_pair(lookup_type, lookup_flags));
651 const std::pair<Key, Output_section*> v(key, NULL);
652 std::pair<Section_name_map::iterator, bool> ins(
653 this->section_name_map_.insert(v));
656 return ins.first->second;
659 // This is the first time we've seen this name/type/flags
660 // combination. For compatibility with the GNU linker, we
661 // combine sections with contents and zero flags with sections
662 // with non-zero flags. This is a workaround for cases where
663 // assembler code forgets to set section flags. FIXME: Perhaps
664 // there should be an option to control this.
665 Output_section* os = NULL;
667 if (lookup_type == elfcpp::SHT_PROGBITS)
671 Output_section* same_name = this->find_output_section(name);
672 if (same_name != NULL
673 && (same_name->type() == elfcpp::SHT_PROGBITS
674 || same_name->type() == elfcpp::SHT_INIT_ARRAY
675 || same_name->type() == elfcpp::SHT_FINI_ARRAY
676 || same_name->type() == elfcpp::SHT_PREINIT_ARRAY)
677 && (same_name->flags() & elfcpp::SHF_TLS) == 0)
680 else if ((flags & elfcpp::SHF_TLS) == 0)
682 elfcpp::Elf_Xword zero_flags = 0;
683 const Key zero_key(name_key, std::make_pair(lookup_type,
685 Section_name_map::iterator p =
686 this->section_name_map_.find(zero_key);
687 if (p != this->section_name_map_.end())
693 os = this->make_output_section(name, type, flags, order, is_relro);
695 ins.first->second = os;
700 // Pick the output section to use for section NAME, in input file
701 // RELOBJ, with type TYPE and flags FLAGS. RELOBJ may be NULL for a
702 // linker created section. IS_INPUT_SECTION is true if we are
703 // choosing an output section for an input section found in a input
704 // file. ORDER is where this section should appear in the output
705 // sections. IS_RELRO is true for a relro section. This will return
706 // NULL if the input section should be discarded.
709 Layout::choose_output_section(const Relobj* relobj, const char* name,
710 elfcpp::Elf_Word type, elfcpp::Elf_Xword flags,
711 bool is_input_section, Output_section_order order,
714 // We should not see any input sections after we have attached
715 // sections to segments.
716 gold_assert(!is_input_section || !this->sections_are_attached_);
718 // Some flags in the input section should not be automatically
719 // copied to the output section.
720 flags &= ~ (elfcpp::SHF_INFO_LINK
723 | elfcpp::SHF_STRINGS);
725 // We only clear the SHF_LINK_ORDER flag in for
726 // a non-relocatable link.
727 if (!parameters->options().relocatable())
728 flags &= ~elfcpp::SHF_LINK_ORDER;
730 if (this->script_options_->saw_sections_clause())
732 // We are using a SECTIONS clause, so the output section is
733 // chosen based only on the name.
735 Script_sections* ss = this->script_options_->script_sections();
736 const char* file_name = relobj == NULL ? NULL : relobj->name().c_str();
737 Output_section** output_section_slot;
738 Script_sections::Section_type script_section_type;
739 const char* orig_name = name;
740 name = ss->output_section_name(file_name, name, &output_section_slot,
741 &script_section_type);
744 gold_debug(DEBUG_SCRIPT, _("Unable to create output section '%s' "
745 "because it is not allowed by the "
746 "SECTIONS clause of the linker script"),
748 // The SECTIONS clause says to discard this input section.
752 // We can only handle script section types ST_NONE and ST_NOLOAD.
753 switch (script_section_type)
755 case Script_sections::ST_NONE:
757 case Script_sections::ST_NOLOAD:
758 flags &= elfcpp::SHF_ALLOC;
764 // If this is an orphan section--one not mentioned in the linker
765 // script--then OUTPUT_SECTION_SLOT will be NULL, and we do the
766 // default processing below.
768 if (output_section_slot != NULL)
770 if (*output_section_slot != NULL)
772 (*output_section_slot)->update_flags_for_input_section(flags);
773 return *output_section_slot;
776 // We don't put sections found in the linker script into
777 // SECTION_NAME_MAP_. That keeps us from getting confused
778 // if an orphan section is mapped to a section with the same
779 // name as one in the linker script.
781 name = this->namepool_.add(name, false, NULL);
783 Output_section* os = this->make_output_section(name, type, flags,
786 os->set_found_in_sections_clause();
788 // Special handling for NOLOAD sections.
789 if (script_section_type == Script_sections::ST_NOLOAD)
793 // The constructor of Output_section sets addresses of non-ALLOC
794 // sections to 0 by default. We don't want that for NOLOAD
795 // sections even if they have no SHF_ALLOC flag.
796 if ((os->flags() & elfcpp::SHF_ALLOC) == 0
797 && os->is_address_valid())
799 gold_assert(os->address() == 0
800 && !os->is_offset_valid()
801 && !os->is_data_size_valid());
802 os->reset_address_and_file_offset();
806 *output_section_slot = os;
811 // FIXME: Handle SHF_OS_NONCONFORMING somewhere.
813 size_t len = strlen(name);
814 char* uncompressed_name = NULL;
816 // Compressed debug sections should be mapped to the corresponding
817 // uncompressed section.
818 if (is_compressed_debug_section(name))
820 uncompressed_name = new char[len];
821 uncompressed_name[0] = '.';
822 gold_assert(name[0] == '.' && name[1] == 'z');
823 strncpy(&uncompressed_name[1], &name[2], len - 2);
824 uncompressed_name[len - 1] = '\0';
826 name = uncompressed_name;
829 // Turn NAME from the name of the input section into the name of the
832 && !this->script_options_->saw_sections_clause()
833 && !parameters->options().relocatable())
834 name = Layout::output_section_name(relobj, name, &len);
836 Stringpool::Key name_key;
837 name = this->namepool_.add_with_length(name, len, true, &name_key);
839 if (uncompressed_name != NULL)
840 delete[] uncompressed_name;
842 // Find or make the output section. The output section is selected
843 // based on the section name, type, and flags.
844 return this->get_output_section(name, name_key, type, flags, order, is_relro);
847 // For incremental links, record the initial fixed layout of a section
848 // from the base file, and return a pointer to the Output_section.
850 template<int size, bool big_endian>
852 Layout::init_fixed_output_section(const char* name,
853 elfcpp::Shdr<size, big_endian>& shdr)
855 unsigned int sh_type = shdr.get_sh_type();
857 // We preserve the layout of PROGBITS, NOBITS, and NOTE sections.
858 // All others will be created from scratch and reallocated.
859 if (sh_type != elfcpp::SHT_PROGBITS
860 && sh_type != elfcpp::SHT_NOBITS
861 && sh_type != elfcpp::SHT_NOTE)
864 typename elfcpp::Elf_types<size>::Elf_Addr sh_addr = shdr.get_sh_addr();
865 typename elfcpp::Elf_types<size>::Elf_Off sh_offset = shdr.get_sh_offset();
866 typename elfcpp::Elf_types<size>::Elf_WXword sh_size = shdr.get_sh_size();
867 typename elfcpp::Elf_types<size>::Elf_WXword sh_flags = shdr.get_sh_flags();
868 typename elfcpp::Elf_types<size>::Elf_WXword sh_addralign =
869 shdr.get_sh_addralign();
871 // Make the output section.
872 Stringpool::Key name_key;
873 name = this->namepool_.add(name, true, &name_key);
874 Output_section* os = this->get_output_section(name, name_key, sh_type,
875 sh_flags, ORDER_INVALID, false);
876 os->set_fixed_layout(sh_addr, sh_offset, sh_size, sh_addralign);
877 if (sh_type != elfcpp::SHT_NOBITS)
878 this->free_list_.remove(sh_offset, sh_offset + sh_size);
882 // Return the output section to use for input section SHNDX, with name
883 // NAME, with header HEADER, from object OBJECT. RELOC_SHNDX is the
884 // index of a relocation section which applies to this section, or 0
885 // if none, or -1U if more than one. RELOC_TYPE is the type of the
886 // relocation section if there is one. Set *OFF to the offset of this
887 // input section without the output section. Return NULL if the
888 // section should be discarded. Set *OFF to -1 if the section
889 // contents should not be written directly to the output file, but
890 // will instead receive special handling.
892 template<int size, bool big_endian>
894 Layout::layout(Sized_relobj_file<size, big_endian>* object, unsigned int shndx,
895 const char* name, const elfcpp::Shdr<size, big_endian>& shdr,
896 unsigned int reloc_shndx, unsigned int, off_t* off)
900 if (!this->include_section(object, name, shdr))
903 elfcpp::Elf_Word sh_type = shdr.get_sh_type();
905 // In a relocatable link a grouped section must not be combined with
906 // any other sections.
908 if (parameters->options().relocatable()
909 && (shdr.get_sh_flags() & elfcpp::SHF_GROUP) != 0)
911 name = this->namepool_.add(name, true, NULL);
912 os = this->make_output_section(name, sh_type, shdr.get_sh_flags(),
913 ORDER_INVALID, false);
917 os = this->choose_output_section(object, name, sh_type,
918 shdr.get_sh_flags(), true,
919 ORDER_INVALID, false);
924 // By default the GNU linker sorts input sections whose names match
925 // .ctor.*, .dtor.*, .init_array.*, or .fini_array.*. The sections
926 // are sorted by name. This is used to implement constructor
927 // priority ordering. We are compatible. When we put .ctor
928 // sections in .init_array and .dtor sections in .fini_array, we
929 // must also sort plain .ctor and .dtor sections.
930 if (!this->script_options_->saw_sections_clause()
931 && !parameters->options().relocatable()
932 && (is_prefix_of(".ctors.", name)
933 || is_prefix_of(".dtors.", name)
934 || is_prefix_of(".init_array.", name)
935 || is_prefix_of(".fini_array.", name)
936 || (parameters->options().ctors_in_init_array()
937 && (strcmp(name, ".ctors") == 0
938 || strcmp(name, ".dtors") == 0))))
939 os->set_must_sort_attached_input_sections();
941 // FIXME: Handle SHF_LINK_ORDER somewhere.
943 elfcpp::Elf_Xword orig_flags = os->flags();
945 *off = os->add_input_section(this, object, shndx, name, shdr, reloc_shndx,
946 this->script_options_->saw_sections_clause());
948 // If the flags changed, we may have to change the order.
949 if ((orig_flags & elfcpp::SHF_ALLOC) != 0)
951 orig_flags &= (elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR);
952 elfcpp::Elf_Xword new_flags =
953 os->flags() & (elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR);
954 if (orig_flags != new_flags)
955 os->set_order(this->default_section_order(os, false));
958 this->have_added_input_section_ = true;
963 // Handle a relocation section when doing a relocatable link.
965 template<int size, bool big_endian>
967 Layout::layout_reloc(Sized_relobj_file<size, big_endian>* object,
969 const elfcpp::Shdr<size, big_endian>& shdr,
970 Output_section* data_section,
971 Relocatable_relocs* rr)
973 gold_assert(parameters->options().relocatable()
974 || parameters->options().emit_relocs());
976 int sh_type = shdr.get_sh_type();
979 if (sh_type == elfcpp::SHT_REL)
981 else if (sh_type == elfcpp::SHT_RELA)
985 name += data_section->name();
987 // In a relocatable link relocs for a grouped section must not be
988 // combined with other reloc sections.
990 if (!parameters->options().relocatable()
991 || (data_section->flags() & elfcpp::SHF_GROUP) == 0)
992 os = this->choose_output_section(object, name.c_str(), sh_type,
993 shdr.get_sh_flags(), false,
994 ORDER_INVALID, false);
997 const char* n = this->namepool_.add(name.c_str(), true, NULL);
998 os = this->make_output_section(n, sh_type, shdr.get_sh_flags(),
999 ORDER_INVALID, false);
1002 os->set_should_link_to_symtab();
1003 os->set_info_section(data_section);
1005 Output_section_data* posd;
1006 if (sh_type == elfcpp::SHT_REL)
1008 os->set_entsize(elfcpp::Elf_sizes<size>::rel_size);
1009 posd = new Output_relocatable_relocs<elfcpp::SHT_REL,
1013 else if (sh_type == elfcpp::SHT_RELA)
1015 os->set_entsize(elfcpp::Elf_sizes<size>::rela_size);
1016 posd = new Output_relocatable_relocs<elfcpp::SHT_RELA,
1023 os->add_output_section_data(posd);
1024 rr->set_output_data(posd);
1029 // Handle a group section when doing a relocatable link.
1031 template<int size, bool big_endian>
1033 Layout::layout_group(Symbol_table* symtab,
1034 Sized_relobj_file<size, big_endian>* object,
1036 const char* group_section_name,
1037 const char* signature,
1038 const elfcpp::Shdr<size, big_endian>& shdr,
1039 elfcpp::Elf_Word flags,
1040 std::vector<unsigned int>* shndxes)
1042 gold_assert(parameters->options().relocatable());
1043 gold_assert(shdr.get_sh_type() == elfcpp::SHT_GROUP);
1044 group_section_name = this->namepool_.add(group_section_name, true, NULL);
1045 Output_section* os = this->make_output_section(group_section_name,
1047 shdr.get_sh_flags(),
1048 ORDER_INVALID, false);
1050 // We need to find a symbol with the signature in the symbol table.
1051 // If we don't find one now, we need to look again later.
1052 Symbol* sym = symtab->lookup(signature, NULL);
1054 os->set_info_symndx(sym);
1057 // Reserve some space to minimize reallocations.
1058 if (this->group_signatures_.empty())
1059 this->group_signatures_.reserve(this->number_of_input_files_ * 16);
1061 // We will wind up using a symbol whose name is the signature.
1062 // So just put the signature in the symbol name pool to save it.
1063 signature = symtab->canonicalize_name(signature);
1064 this->group_signatures_.push_back(Group_signature(os, signature));
1067 os->set_should_link_to_symtab();
1070 section_size_type entry_count =
1071 convert_to_section_size_type(shdr.get_sh_size() / 4);
1072 Output_section_data* posd =
1073 new Output_data_group<size, big_endian>(object, entry_count, flags,
1075 os->add_output_section_data(posd);
1078 // Special GNU handling of sections name .eh_frame. They will
1079 // normally hold exception frame data as defined by the C++ ABI
1080 // (http://codesourcery.com/cxx-abi/).
1082 template<int size, bool big_endian>
1084 Layout::layout_eh_frame(Sized_relobj_file<size, big_endian>* object,
1085 const unsigned char* symbols,
1087 const unsigned char* symbol_names,
1088 off_t symbol_names_size,
1090 const elfcpp::Shdr<size, big_endian>& shdr,
1091 unsigned int reloc_shndx, unsigned int reloc_type,
1094 gold_assert(shdr.get_sh_type() == elfcpp::SHT_PROGBITS);
1095 gold_assert((shdr.get_sh_flags() & elfcpp::SHF_ALLOC) != 0);
1097 const char* const name = ".eh_frame";
1098 Output_section* os = this->choose_output_section(object, name,
1099 elfcpp::SHT_PROGBITS,
1100 elfcpp::SHF_ALLOC, false,
1101 ORDER_EHFRAME, false);
1105 if (this->eh_frame_section_ == NULL)
1107 this->eh_frame_section_ = os;
1108 this->eh_frame_data_ = new Eh_frame();
1110 // For incremental linking, we do not optimize .eh_frame sections
1111 // or create a .eh_frame_hdr section.
1112 if (parameters->options().eh_frame_hdr() && !parameters->incremental())
1114 Output_section* hdr_os =
1115 this->choose_output_section(NULL, ".eh_frame_hdr",
1116 elfcpp::SHT_PROGBITS,
1117 elfcpp::SHF_ALLOC, false,
1118 ORDER_EHFRAME, false);
1122 Eh_frame_hdr* hdr_posd = new Eh_frame_hdr(os,
1123 this->eh_frame_data_);
1124 hdr_os->add_output_section_data(hdr_posd);
1126 hdr_os->set_after_input_sections();
1128 if (!this->script_options_->saw_phdrs_clause())
1130 Output_segment* hdr_oseg;
1131 hdr_oseg = this->make_output_segment(elfcpp::PT_GNU_EH_FRAME,
1133 hdr_oseg->add_output_section_to_nonload(hdr_os,
1137 this->eh_frame_data_->set_eh_frame_hdr(hdr_posd);
1142 gold_assert(this->eh_frame_section_ == os);
1144 elfcpp::Elf_Xword orig_flags = os->flags();
1146 if (!parameters->incremental()
1147 && this->eh_frame_data_->add_ehframe_input_section(object,
1156 os->update_flags_for_input_section(shdr.get_sh_flags());
1158 // A writable .eh_frame section is a RELRO section.
1159 if ((orig_flags & (elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR))
1160 != (os->flags() & (elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR)))
1163 os->set_order(ORDER_RELRO);
1166 // We found a .eh_frame section we are going to optimize, so now
1167 // we can add the set of optimized sections to the output
1168 // section. We need to postpone adding this until we've found a
1169 // section we can optimize so that the .eh_frame section in
1170 // crtbegin.o winds up at the start of the output section.
1171 if (!this->added_eh_frame_data_)
1173 os->add_output_section_data(this->eh_frame_data_);
1174 this->added_eh_frame_data_ = true;
1180 // We couldn't handle this .eh_frame section for some reason.
1181 // Add it as a normal section.
1182 bool saw_sections_clause = this->script_options_->saw_sections_clause();
1183 *off = os->add_input_section(this, object, shndx, name, shdr, reloc_shndx,
1184 saw_sections_clause);
1185 this->have_added_input_section_ = true;
1187 if ((orig_flags & (elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR))
1188 != (os->flags() & (elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR)))
1189 os->set_order(this->default_section_order(os, false));
1195 // Add POSD to an output section using NAME, TYPE, and FLAGS. Return
1196 // the output section.
1199 Layout::add_output_section_data(const char* name, elfcpp::Elf_Word type,
1200 elfcpp::Elf_Xword flags,
1201 Output_section_data* posd,
1202 Output_section_order order, bool is_relro)
1204 Output_section* os = this->choose_output_section(NULL, name, type, flags,
1205 false, order, is_relro);
1207 os->add_output_section_data(posd);
1211 // Map section flags to segment flags.
1214 Layout::section_flags_to_segment(elfcpp::Elf_Xword flags)
1216 elfcpp::Elf_Word ret = elfcpp::PF_R;
1217 if ((flags & elfcpp::SHF_WRITE) != 0)
1218 ret |= elfcpp::PF_W;
1219 if ((flags & elfcpp::SHF_EXECINSTR) != 0)
1220 ret |= elfcpp::PF_X;
1224 // Make a new Output_section, and attach it to segments as
1225 // appropriate. ORDER is the order in which this section should
1226 // appear in the output segment. IS_RELRO is true if this is a relro
1227 // (read-only after relocations) section.
1230 Layout::make_output_section(const char* name, elfcpp::Elf_Word type,
1231 elfcpp::Elf_Xword flags,
1232 Output_section_order order, bool is_relro)
1235 if ((flags & elfcpp::SHF_ALLOC) == 0
1236 && strcmp(parameters->options().compress_debug_sections(), "none") != 0
1237 && is_compressible_debug_section(name))
1238 os = new Output_compressed_section(¶meters->options(), name, type,
1240 else if ((flags & elfcpp::SHF_ALLOC) == 0
1241 && parameters->options().strip_debug_non_line()
1242 && strcmp(".debug_abbrev", name) == 0)
1244 os = this->debug_abbrev_ = new Output_reduced_debug_abbrev_section(
1246 if (this->debug_info_)
1247 this->debug_info_->set_abbreviations(this->debug_abbrev_);
1249 else if ((flags & elfcpp::SHF_ALLOC) == 0
1250 && parameters->options().strip_debug_non_line()
1251 && strcmp(".debug_info", name) == 0)
1253 os = this->debug_info_ = new Output_reduced_debug_info_section(
1255 if (this->debug_abbrev_)
1256 this->debug_info_->set_abbreviations(this->debug_abbrev_);
1260 // Sometimes .init_array*, .preinit_array* and .fini_array* do
1261 // not have correct section types. Force them here.
1262 if (type == elfcpp::SHT_PROGBITS)
1264 if (is_prefix_of(".init_array", name))
1265 type = elfcpp::SHT_INIT_ARRAY;
1266 else if (is_prefix_of(".preinit_array", name))
1267 type = elfcpp::SHT_PREINIT_ARRAY;
1268 else if (is_prefix_of(".fini_array", name))
1269 type = elfcpp::SHT_FINI_ARRAY;
1272 // FIXME: const_cast is ugly.
1273 Target* target = const_cast<Target*>(¶meters->target());
1274 os = target->make_output_section(name, type, flags);
1277 // With -z relro, we have to recognize the special sections by name.
1278 // There is no other way.
1279 bool is_relro_local = false;
1280 if (!this->script_options_->saw_sections_clause()
1281 && parameters->options().relro()
1282 && type == elfcpp::SHT_PROGBITS
1283 && (flags & elfcpp::SHF_ALLOC) != 0
1284 && (flags & elfcpp::SHF_WRITE) != 0)
1286 if (strcmp(name, ".data.rel.ro") == 0)
1288 else if (strcmp(name, ".data.rel.ro.local") == 0)
1291 is_relro_local = true;
1293 else if (type == elfcpp::SHT_INIT_ARRAY
1294 || type == elfcpp::SHT_FINI_ARRAY
1295 || type == elfcpp::SHT_PREINIT_ARRAY)
1297 else if (strcmp(name, ".ctors") == 0
1298 || strcmp(name, ".dtors") == 0
1299 || strcmp(name, ".jcr") == 0)
1306 if (order == ORDER_INVALID && (flags & elfcpp::SHF_ALLOC) != 0)
1307 order = this->default_section_order(os, is_relro_local);
1309 os->set_order(order);
1311 parameters->target().new_output_section(os);
1313 this->section_list_.push_back(os);
1315 // The GNU linker by default sorts some sections by priority, so we
1316 // do the same. We need to know that this might happen before we
1317 // attach any input sections.
1318 if (!this->script_options_->saw_sections_clause()
1319 && !parameters->options().relocatable()
1320 && (strcmp(name, ".init_array") == 0
1321 || strcmp(name, ".fini_array") == 0
1322 || (!parameters->options().ctors_in_init_array()
1323 && (strcmp(name, ".ctors") == 0
1324 || strcmp(name, ".dtors") == 0))))
1325 os->set_may_sort_attached_input_sections();
1327 // Check for .stab*str sections, as .stab* sections need to link to
1329 if (type == elfcpp::SHT_STRTAB
1330 && !this->have_stabstr_section_
1331 && strncmp(name, ".stab", 5) == 0
1332 && strcmp(name + strlen(name) - 3, "str") == 0)
1333 this->have_stabstr_section_ = true;
1335 // If we have already attached the sections to segments, then we
1336 // need to attach this one now. This happens for sections created
1337 // directly by the linker.
1338 if (this->sections_are_attached_)
1339 this->attach_section_to_segment(os);
1344 // Return the default order in which a section should be placed in an
1345 // output segment. This function captures a lot of the ideas in
1346 // ld/scripttempl/elf.sc in the GNU linker. Note that the order of a
1347 // linker created section is normally set when the section is created;
1348 // this function is used for input sections.
1350 Output_section_order
1351 Layout::default_section_order(Output_section* os, bool is_relro_local)
1353 gold_assert((os->flags() & elfcpp::SHF_ALLOC) != 0);
1354 bool is_write = (os->flags() & elfcpp::SHF_WRITE) != 0;
1355 bool is_execinstr = (os->flags() & elfcpp::SHF_EXECINSTR) != 0;
1356 bool is_bss = false;
1361 case elfcpp::SHT_PROGBITS:
1363 case elfcpp::SHT_NOBITS:
1366 case elfcpp::SHT_RELA:
1367 case elfcpp::SHT_REL:
1369 return ORDER_DYNAMIC_RELOCS;
1371 case elfcpp::SHT_HASH:
1372 case elfcpp::SHT_DYNAMIC:
1373 case elfcpp::SHT_SHLIB:
1374 case elfcpp::SHT_DYNSYM:
1375 case elfcpp::SHT_GNU_HASH:
1376 case elfcpp::SHT_GNU_verdef:
1377 case elfcpp::SHT_GNU_verneed:
1378 case elfcpp::SHT_GNU_versym:
1380 return ORDER_DYNAMIC_LINKER;
1382 case elfcpp::SHT_NOTE:
1383 return is_write ? ORDER_RW_NOTE : ORDER_RO_NOTE;
1386 if ((os->flags() & elfcpp::SHF_TLS) != 0)
1387 return is_bss ? ORDER_TLS_BSS : ORDER_TLS_DATA;
1389 if (!is_bss && !is_write)
1393 if (strcmp(os->name(), ".init") == 0)
1395 else if (strcmp(os->name(), ".fini") == 0)
1398 return is_execinstr ? ORDER_TEXT : ORDER_READONLY;
1402 return is_relro_local ? ORDER_RELRO_LOCAL : ORDER_RELRO;
1404 if (os->is_small_section())
1405 return is_bss ? ORDER_SMALL_BSS : ORDER_SMALL_DATA;
1406 if (os->is_large_section())
1407 return is_bss ? ORDER_LARGE_BSS : ORDER_LARGE_DATA;
1409 return is_bss ? ORDER_BSS : ORDER_DATA;
1412 // Attach output sections to segments. This is called after we have
1413 // seen all the input sections.
1416 Layout::attach_sections_to_segments()
1418 for (Section_list::iterator p = this->section_list_.begin();
1419 p != this->section_list_.end();
1421 this->attach_section_to_segment(*p);
1423 this->sections_are_attached_ = true;
1426 // Attach an output section to a segment.
1429 Layout::attach_section_to_segment(Output_section* os)
1431 if ((os->flags() & elfcpp::SHF_ALLOC) == 0)
1432 this->unattached_section_list_.push_back(os);
1434 this->attach_allocated_section_to_segment(os);
1437 // Attach an allocated output section to a segment.
1440 Layout::attach_allocated_section_to_segment(Output_section* os)
1442 elfcpp::Elf_Xword flags = os->flags();
1443 gold_assert((flags & elfcpp::SHF_ALLOC) != 0);
1445 if (parameters->options().relocatable())
1448 // If we have a SECTIONS clause, we can't handle the attachment to
1449 // segments until after we've seen all the sections.
1450 if (this->script_options_->saw_sections_clause())
1453 gold_assert(!this->script_options_->saw_phdrs_clause());
1455 // This output section goes into a PT_LOAD segment.
1457 elfcpp::Elf_Word seg_flags = Layout::section_flags_to_segment(flags);
1459 // Check for --section-start.
1461 bool is_address_set = parameters->options().section_start(os->name(), &addr);
1463 // In general the only thing we really care about for PT_LOAD
1464 // segments is whether or not they are writable or executable,
1465 // so that is how we search for them.
1466 // Large data sections also go into their own PT_LOAD segment.
1467 // People who need segments sorted on some other basis will
1468 // have to use a linker script.
1470 Segment_list::const_iterator p;
1471 for (p = this->segment_list_.begin();
1472 p != this->segment_list_.end();
1475 if ((*p)->type() != elfcpp::PT_LOAD)
1477 if (!parameters->options().omagic()
1478 && ((*p)->flags() & elfcpp::PF_W) != (seg_flags & elfcpp::PF_W))
1480 if (parameters->options().rosegment()
1481 && ((*p)->flags() & elfcpp::PF_X) != (seg_flags & elfcpp::PF_X))
1483 // If -Tbss was specified, we need to separate the data and BSS
1485 if (parameters->options().user_set_Tbss())
1487 if ((os->type() == elfcpp::SHT_NOBITS)
1488 == (*p)->has_any_data_sections())
1491 if (os->is_large_data_section() && !(*p)->is_large_data_segment())
1496 if ((*p)->are_addresses_set())
1499 (*p)->add_initial_output_data(os);
1500 (*p)->update_flags_for_output_section(seg_flags);
1501 (*p)->set_addresses(addr, addr);
1505 (*p)->add_output_section_to_load(this, os, seg_flags);
1509 if (p == this->segment_list_.end())
1511 Output_segment* oseg = this->make_output_segment(elfcpp::PT_LOAD,
1513 if (os->is_large_data_section())
1514 oseg->set_is_large_data_segment();
1515 oseg->add_output_section_to_load(this, os, seg_flags);
1517 oseg->set_addresses(addr, addr);
1520 // If we see a loadable SHT_NOTE section, we create a PT_NOTE
1522 if (os->type() == elfcpp::SHT_NOTE)
1524 // See if we already have an equivalent PT_NOTE segment.
1525 for (p = this->segment_list_.begin();
1526 p != segment_list_.end();
1529 if ((*p)->type() == elfcpp::PT_NOTE
1530 && (((*p)->flags() & elfcpp::PF_W)
1531 == (seg_flags & elfcpp::PF_W)))
1533 (*p)->add_output_section_to_nonload(os, seg_flags);
1538 if (p == this->segment_list_.end())
1540 Output_segment* oseg = this->make_output_segment(elfcpp::PT_NOTE,
1542 oseg->add_output_section_to_nonload(os, seg_flags);
1546 // If we see a loadable SHF_TLS section, we create a PT_TLS
1547 // segment. There can only be one such segment.
1548 if ((flags & elfcpp::SHF_TLS) != 0)
1550 if (this->tls_segment_ == NULL)
1551 this->make_output_segment(elfcpp::PT_TLS, seg_flags);
1552 this->tls_segment_->add_output_section_to_nonload(os, seg_flags);
1555 // If -z relro is in effect, and we see a relro section, we create a
1556 // PT_GNU_RELRO segment. There can only be one such segment.
1557 if (os->is_relro() && parameters->options().relro())
1559 gold_assert(seg_flags == (elfcpp::PF_R | elfcpp::PF_W));
1560 if (this->relro_segment_ == NULL)
1561 this->make_output_segment(elfcpp::PT_GNU_RELRO, seg_flags);
1562 this->relro_segment_->add_output_section_to_nonload(os, seg_flags);
1565 // If we see a section named .interp, put it into a PT_INTERP
1566 // segment. This seems broken to me, but this is what GNU ld does,
1567 // and glibc expects it.
1568 if (strcmp(os->name(), ".interp") == 0
1569 && !this->script_options_->saw_phdrs_clause())
1571 if (this->interp_segment_ == NULL)
1572 this->make_output_segment(elfcpp::PT_INTERP, seg_flags);
1574 gold_warning(_("multiple '.interp' sections in input files "
1575 "may cause confusing PT_INTERP segment"));
1576 this->interp_segment_->add_output_section_to_nonload(os, seg_flags);
1580 // Make an output section for a script.
1583 Layout::make_output_section_for_script(
1585 Script_sections::Section_type section_type)
1587 name = this->namepool_.add(name, false, NULL);
1588 elfcpp::Elf_Xword sh_flags = elfcpp::SHF_ALLOC;
1589 if (section_type == Script_sections::ST_NOLOAD)
1591 Output_section* os = this->make_output_section(name, elfcpp::SHT_PROGBITS,
1592 sh_flags, ORDER_INVALID,
1594 os->set_found_in_sections_clause();
1595 if (section_type == Script_sections::ST_NOLOAD)
1596 os->set_is_noload();
1600 // Return the number of segments we expect to see.
1603 Layout::expected_segment_count() const
1605 size_t ret = this->segment_list_.size();
1607 // If we didn't see a SECTIONS clause in a linker script, we should
1608 // already have the complete list of segments. Otherwise we ask the
1609 // SECTIONS clause how many segments it expects, and add in the ones
1610 // we already have (PT_GNU_STACK, PT_GNU_EH_FRAME, etc.)
1612 if (!this->script_options_->saw_sections_clause())
1616 const Script_sections* ss = this->script_options_->script_sections();
1617 return ret + ss->expected_segment_count(this);
1621 // Handle the .note.GNU-stack section at layout time. SEEN_GNU_STACK
1622 // is whether we saw a .note.GNU-stack section in the object file.
1623 // GNU_STACK_FLAGS is the section flags. The flags give the
1624 // protection required for stack memory. We record this in an
1625 // executable as a PT_GNU_STACK segment. If an object file does not
1626 // have a .note.GNU-stack segment, we must assume that it is an old
1627 // object. On some targets that will force an executable stack.
1630 Layout::layout_gnu_stack(bool seen_gnu_stack, uint64_t gnu_stack_flags,
1633 if (!seen_gnu_stack)
1635 this->input_without_gnu_stack_note_ = true;
1636 if (parameters->options().warn_execstack()
1637 && parameters->target().is_default_stack_executable())
1638 gold_warning(_("%s: missing .note.GNU-stack section"
1639 " implies executable stack"),
1640 obj->name().c_str());
1644 this->input_with_gnu_stack_note_ = true;
1645 if ((gnu_stack_flags & elfcpp::SHF_EXECINSTR) != 0)
1647 this->input_requires_executable_stack_ = true;
1648 if (parameters->options().warn_execstack()
1649 || parameters->options().is_stack_executable())
1650 gold_warning(_("%s: requires executable stack"),
1651 obj->name().c_str());
1656 // Create automatic note sections.
1659 Layout::create_notes()
1661 this->create_gold_note();
1662 this->create_executable_stack_info();
1663 this->create_build_id();
1666 // Create the dynamic sections which are needed before we read the
1670 Layout::create_initial_dynamic_sections(Symbol_table* symtab)
1672 if (parameters->doing_static_link())
1675 this->dynamic_section_ = this->choose_output_section(NULL, ".dynamic",
1676 elfcpp::SHT_DYNAMIC,
1678 | elfcpp::SHF_WRITE),
1682 this->dynamic_symbol_ =
1683 symtab->define_in_output_data("_DYNAMIC", NULL, Symbol_table::PREDEFINED,
1684 this->dynamic_section_, 0, 0,
1685 elfcpp::STT_OBJECT, elfcpp::STB_LOCAL,
1686 elfcpp::STV_HIDDEN, 0, false, false);
1688 this->dynamic_data_ = new Output_data_dynamic(&this->dynpool_);
1690 this->dynamic_section_->add_output_section_data(this->dynamic_data_);
1693 // For each output section whose name can be represented as C symbol,
1694 // define __start and __stop symbols for the section. This is a GNU
1698 Layout::define_section_symbols(Symbol_table* symtab)
1700 for (Section_list::const_iterator p = this->section_list_.begin();
1701 p != this->section_list_.end();
1704 const char* const name = (*p)->name();
1705 if (is_cident(name))
1707 const std::string name_string(name);
1708 const std::string start_name(cident_section_start_prefix
1710 const std::string stop_name(cident_section_stop_prefix
1713 symtab->define_in_output_data(start_name.c_str(),
1715 Symbol_table::PREDEFINED,
1721 elfcpp::STV_DEFAULT,
1723 false, // offset_is_from_end
1724 true); // only_if_ref
1726 symtab->define_in_output_data(stop_name.c_str(),
1728 Symbol_table::PREDEFINED,
1734 elfcpp::STV_DEFAULT,
1736 true, // offset_is_from_end
1737 true); // only_if_ref
1742 // Define symbols for group signatures.
1745 Layout::define_group_signatures(Symbol_table* symtab)
1747 for (Group_signatures::iterator p = this->group_signatures_.begin();
1748 p != this->group_signatures_.end();
1751 Symbol* sym = symtab->lookup(p->signature, NULL);
1753 p->section->set_info_symndx(sym);
1756 // Force the name of the group section to the group
1757 // signature, and use the group's section symbol as the
1758 // signature symbol.
1759 if (strcmp(p->section->name(), p->signature) != 0)
1761 const char* name = this->namepool_.add(p->signature,
1763 p->section->set_name(name);
1765 p->section->set_needs_symtab_index();
1766 p->section->set_info_section_symndx(p->section);
1770 this->group_signatures_.clear();
1773 // Find the first read-only PT_LOAD segment, creating one if
1777 Layout::find_first_load_seg()
1779 Output_segment* best = NULL;
1780 for (Segment_list::const_iterator p = this->segment_list_.begin();
1781 p != this->segment_list_.end();
1784 if ((*p)->type() == elfcpp::PT_LOAD
1785 && ((*p)->flags() & elfcpp::PF_R) != 0
1786 && (parameters->options().omagic()
1787 || ((*p)->flags() & elfcpp::PF_W) == 0))
1789 if (best == NULL || this->segment_precedes(*p, best))
1796 gold_assert(!this->script_options_->saw_phdrs_clause());
1798 Output_segment* load_seg = this->make_output_segment(elfcpp::PT_LOAD,
1803 // Save states of all current output segments. Store saved states
1804 // in SEGMENT_STATES.
1807 Layout::save_segments(Segment_states* segment_states)
1809 for (Segment_list::const_iterator p = this->segment_list_.begin();
1810 p != this->segment_list_.end();
1813 Output_segment* segment = *p;
1815 Output_segment* copy = new Output_segment(*segment);
1816 (*segment_states)[segment] = copy;
1820 // Restore states of output segments and delete any segment not found in
1824 Layout::restore_segments(const Segment_states* segment_states)
1826 // Go through the segment list and remove any segment added in the
1828 this->tls_segment_ = NULL;
1829 this->relro_segment_ = NULL;
1830 Segment_list::iterator list_iter = this->segment_list_.begin();
1831 while (list_iter != this->segment_list_.end())
1833 Output_segment* segment = *list_iter;
1834 Segment_states::const_iterator states_iter =
1835 segment_states->find(segment);
1836 if (states_iter != segment_states->end())
1838 const Output_segment* copy = states_iter->second;
1839 // Shallow copy to restore states.
1842 // Also fix up TLS and RELRO segment pointers as appropriate.
1843 if (segment->type() == elfcpp::PT_TLS)
1844 this->tls_segment_ = segment;
1845 else if (segment->type() == elfcpp::PT_GNU_RELRO)
1846 this->relro_segment_ = segment;
1852 list_iter = this->segment_list_.erase(list_iter);
1853 // This is a segment created during section layout. It should be
1854 // safe to remove it since we should have removed all pointers to it.
1860 // Clean up after relaxation so that sections can be laid out again.
1863 Layout::clean_up_after_relaxation()
1865 // Restore the segments to point state just prior to the relaxation loop.
1866 Script_sections* script_section = this->script_options_->script_sections();
1867 script_section->release_segments();
1868 this->restore_segments(this->segment_states_);
1870 // Reset section addresses and file offsets
1871 for (Section_list::iterator p = this->section_list_.begin();
1872 p != this->section_list_.end();
1875 (*p)->restore_states();
1877 // If an input section changes size because of relaxation,
1878 // we need to adjust the section offsets of all input sections.
1879 // after such a section.
1880 if ((*p)->section_offsets_need_adjustment())
1881 (*p)->adjust_section_offsets();
1883 (*p)->reset_address_and_file_offset();
1886 // Reset special output object address and file offsets.
1887 for (Data_list::iterator p = this->special_output_list_.begin();
1888 p != this->special_output_list_.end();
1890 (*p)->reset_address_and_file_offset();
1892 // A linker script may have created some output section data objects.
1893 // They are useless now.
1894 for (Output_section_data_list::const_iterator p =
1895 this->script_output_section_data_list_.begin();
1896 p != this->script_output_section_data_list_.end();
1899 this->script_output_section_data_list_.clear();
1902 // Prepare for relaxation.
1905 Layout::prepare_for_relaxation()
1907 // Create an relaxation debug check if in debugging mode.
1908 if (is_debugging_enabled(DEBUG_RELAXATION))
1909 this->relaxation_debug_check_ = new Relaxation_debug_check();
1911 // Save segment states.
1912 this->segment_states_ = new Segment_states();
1913 this->save_segments(this->segment_states_);
1915 for(Section_list::const_iterator p = this->section_list_.begin();
1916 p != this->section_list_.end();
1918 (*p)->save_states();
1920 if (is_debugging_enabled(DEBUG_RELAXATION))
1921 this->relaxation_debug_check_->check_output_data_for_reset_values(
1922 this->section_list_, this->special_output_list_);
1924 // Also enable recording of output section data from scripts.
1925 this->record_output_section_data_from_script_ = true;
1928 // Relaxation loop body: If target has no relaxation, this runs only once
1929 // Otherwise, the target relaxation hook is called at the end of
1930 // each iteration. If the hook returns true, it means re-layout of
1931 // section is required.
1933 // The number of segments created by a linking script without a PHDRS
1934 // clause may be affected by section sizes and alignments. There is
1935 // a remote chance that relaxation causes different number of PT_LOAD
1936 // segments are created and sections are attached to different segments.
1937 // Therefore, we always throw away all segments created during section
1938 // layout. In order to be able to restart the section layout, we keep
1939 // a copy of the segment list right before the relaxation loop and use
1940 // that to restore the segments.
1942 // PASS is the current relaxation pass number.
1943 // SYMTAB is a symbol table.
1944 // PLOAD_SEG is the address of a pointer for the load segment.
1945 // PHDR_SEG is a pointer to the PHDR segment.
1946 // SEGMENT_HEADERS points to the output segment header.
1947 // FILE_HEADER points to the output file header.
1948 // PSHNDX is the address to store the output section index.
1951 Layout::relaxation_loop_body(
1954 Symbol_table* symtab,
1955 Output_segment** pload_seg,
1956 Output_segment* phdr_seg,
1957 Output_segment_headers* segment_headers,
1958 Output_file_header* file_header,
1959 unsigned int* pshndx)
1961 // If this is not the first iteration, we need to clean up after
1962 // relaxation so that we can lay out the sections again.
1964 this->clean_up_after_relaxation();
1966 // If there is a SECTIONS clause, put all the input sections into
1967 // the required order.
1968 Output_segment* load_seg;
1969 if (this->script_options_->saw_sections_clause())
1970 load_seg = this->set_section_addresses_from_script(symtab);
1971 else if (parameters->options().relocatable())
1974 load_seg = this->find_first_load_seg();
1976 if (parameters->options().oformat_enum()
1977 != General_options::OBJECT_FORMAT_ELF)
1980 // If the user set the address of the text segment, that may not be
1981 // compatible with putting the segment headers and file headers into
1983 if (parameters->options().user_set_Ttext())
1986 gold_assert(phdr_seg == NULL
1988 || this->script_options_->saw_sections_clause());
1990 // If the address of the load segment we found has been set by
1991 // --section-start rather than by a script, then adjust the VMA and
1992 // LMA downward if possible to include the file and section headers.
1993 uint64_t header_gap = 0;
1994 if (load_seg != NULL
1995 && load_seg->are_addresses_set()
1996 && !this->script_options_->saw_sections_clause()
1997 && !parameters->options().relocatable())
1999 file_header->finalize_data_size();
2000 segment_headers->finalize_data_size();
2001 size_t sizeof_headers = (file_header->data_size()
2002 + segment_headers->data_size());
2003 const uint64_t abi_pagesize = target->abi_pagesize();
2004 uint64_t hdr_paddr = load_seg->paddr() - sizeof_headers;
2005 hdr_paddr &= ~(abi_pagesize - 1);
2006 uint64_t subtract = load_seg->paddr() - hdr_paddr;
2007 if (load_seg->paddr() < subtract || load_seg->vaddr() < subtract)
2011 load_seg->set_addresses(load_seg->vaddr() - subtract,
2012 load_seg->paddr() - subtract);
2013 header_gap = subtract - sizeof_headers;
2017 // Lay out the segment headers.
2018 if (!parameters->options().relocatable())
2020 gold_assert(segment_headers != NULL);
2021 if (header_gap != 0 && load_seg != NULL)
2023 Output_data_zero_fill* z = new Output_data_zero_fill(header_gap, 1);
2024 load_seg->add_initial_output_data(z);
2026 if (load_seg != NULL)
2027 load_seg->add_initial_output_data(segment_headers);
2028 if (phdr_seg != NULL)
2029 phdr_seg->add_initial_output_data(segment_headers);
2032 // Lay out the file header.
2033 if (load_seg != NULL)
2034 load_seg->add_initial_output_data(file_header);
2036 if (this->script_options_->saw_phdrs_clause()
2037 && !parameters->options().relocatable())
2039 // Support use of FILEHDRS and PHDRS attachments in a PHDRS
2040 // clause in a linker script.
2041 Script_sections* ss = this->script_options_->script_sections();
2042 ss->put_headers_in_phdrs(file_header, segment_headers);
2045 // We set the output section indexes in set_segment_offsets and
2046 // set_section_indexes.
2049 // Set the file offsets of all the segments, and all the sections
2052 if (!parameters->options().relocatable())
2053 off = this->set_segment_offsets(target, load_seg, pshndx);
2055 off = this->set_relocatable_section_offsets(file_header, pshndx);
2057 // Verify that the dummy relaxation does not change anything.
2058 if (is_debugging_enabled(DEBUG_RELAXATION))
2061 this->relaxation_debug_check_->read_sections(this->section_list_);
2063 this->relaxation_debug_check_->verify_sections(this->section_list_);
2066 *pload_seg = load_seg;
2070 // Search the list of patterns and find the postion of the given section
2071 // name in the output section. If the section name matches a glob
2072 // pattern and a non-glob name, then the non-glob position takes
2073 // precedence. Return 0 if no match is found.
2076 Layout::find_section_order_index(const std::string& section_name)
2078 Unordered_map<std::string, unsigned int>::iterator map_it;
2079 map_it = this->input_section_position_.find(section_name);
2080 if (map_it != this->input_section_position_.end())
2081 return map_it->second;
2083 // Absolute match failed. Linear search the glob patterns.
2084 std::vector<std::string>::iterator it;
2085 for (it = this->input_section_glob_.begin();
2086 it != this->input_section_glob_.end();
2089 if (fnmatch((*it).c_str(), section_name.c_str(), FNM_NOESCAPE) == 0)
2091 map_it = this->input_section_position_.find(*it);
2092 gold_assert(map_it != this->input_section_position_.end());
2093 return map_it->second;
2099 // Read the sequence of input sections from the file specified with
2100 // --section-ordering-file.
2103 Layout::read_layout_from_file()
2105 const char* filename = parameters->options().section_ordering_file();
2111 gold_fatal(_("unable to open --section-ordering-file file %s: %s"),
2112 filename, strerror(errno));
2114 std::getline(in, line); // this chops off the trailing \n, if any
2115 unsigned int position = 1;
2119 if (!line.empty() && line[line.length() - 1] == '\r') // Windows
2120 line.resize(line.length() - 1);
2121 // Ignore comments, beginning with '#'
2124 std::getline(in, line);
2127 this->input_section_position_[line] = position;
2128 // Store all glob patterns in a vector.
2129 if (is_wildcard_string(line.c_str()))
2130 this->input_section_glob_.push_back(line);
2132 std::getline(in, line);
2136 // Finalize the layout. When this is called, we have created all the
2137 // output sections and all the output segments which are based on
2138 // input sections. We have several things to do, and we have to do
2139 // them in the right order, so that we get the right results correctly
2142 // 1) Finalize the list of output segments and create the segment
2145 // 2) Finalize the dynamic symbol table and associated sections.
2147 // 3) Determine the final file offset of all the output segments.
2149 // 4) Determine the final file offset of all the SHF_ALLOC output
2152 // 5) Create the symbol table sections and the section name table
2155 // 6) Finalize the symbol table: set symbol values to their final
2156 // value and make a final determination of which symbols are going
2157 // into the output symbol table.
2159 // 7) Create the section table header.
2161 // 8) Determine the final file offset of all the output sections which
2162 // are not SHF_ALLOC, including the section table header.
2164 // 9) Finalize the ELF file header.
2166 // This function returns the size of the output file.
2169 Layout::finalize(const Input_objects* input_objects, Symbol_table* symtab,
2170 Target* target, const Task* task)
2172 target->finalize_sections(this, input_objects, symtab);
2174 this->count_local_symbols(task, input_objects);
2176 this->link_stabs_sections();
2178 Output_segment* phdr_seg = NULL;
2179 if (!parameters->options().relocatable() && !parameters->doing_static_link())
2181 // There was a dynamic object in the link. We need to create
2182 // some information for the dynamic linker.
2184 // Create the PT_PHDR segment which will hold the program
2186 if (!this->script_options_->saw_phdrs_clause())
2187 phdr_seg = this->make_output_segment(elfcpp::PT_PHDR, elfcpp::PF_R);
2189 // Create the dynamic symbol table, including the hash table.
2190 Output_section* dynstr;
2191 std::vector<Symbol*> dynamic_symbols;
2192 unsigned int local_dynamic_count;
2193 Versions versions(*this->script_options()->version_script_info(),
2195 this->create_dynamic_symtab(input_objects, symtab, &dynstr,
2196 &local_dynamic_count, &dynamic_symbols,
2199 // Create the .interp section to hold the name of the
2200 // interpreter, and put it in a PT_INTERP segment. Don't do it
2201 // if we saw a .interp section in an input file.
2202 if ((!parameters->options().shared()
2203 || parameters->options().dynamic_linker() != NULL)
2204 && this->interp_segment_ == NULL)
2205 this->create_interp(target);
2207 // Finish the .dynamic section to hold the dynamic data, and put
2208 // it in a PT_DYNAMIC segment.
2209 this->finish_dynamic_section(input_objects, symtab);
2211 // We should have added everything we need to the dynamic string
2213 this->dynpool_.set_string_offsets();
2215 // Create the version sections. We can't do this until the
2216 // dynamic string table is complete.
2217 this->create_version_sections(&versions, symtab, local_dynamic_count,
2218 dynamic_symbols, dynstr);
2220 // Set the size of the _DYNAMIC symbol. We can't do this until
2221 // after we call create_version_sections.
2222 this->set_dynamic_symbol_size(symtab);
2225 // Create segment headers.
2226 Output_segment_headers* segment_headers =
2227 (parameters->options().relocatable()
2229 : new Output_segment_headers(this->segment_list_));
2231 // Lay out the file header.
2232 Output_file_header* file_header = new Output_file_header(target, symtab,
2235 this->special_output_list_.push_back(file_header);
2236 if (segment_headers != NULL)
2237 this->special_output_list_.push_back(segment_headers);
2239 // Find approriate places for orphan output sections if we are using
2241 if (this->script_options_->saw_sections_clause())
2242 this->place_orphan_sections_in_script();
2244 Output_segment* load_seg;
2249 // Take a snapshot of the section layout as needed.
2250 if (target->may_relax())
2251 this->prepare_for_relaxation();
2253 // Run the relaxation loop to lay out sections.
2256 off = this->relaxation_loop_body(pass, target, symtab, &load_seg,
2257 phdr_seg, segment_headers, file_header,
2261 while (target->may_relax()
2262 && target->relax(pass, input_objects, symtab, this, task));
2264 // Set the file offsets of all the non-data sections we've seen so
2265 // far which don't have to wait for the input sections. We need
2266 // this in order to finalize local symbols in non-allocated
2268 off = this->set_section_offsets(off, BEFORE_INPUT_SECTIONS_PASS);
2270 // Set the section indexes of all unallocated sections seen so far,
2271 // in case any of them are somehow referenced by a symbol.
2272 shndx = this->set_section_indexes(shndx);
2274 // Create the symbol table sections.
2275 this->create_symtab_sections(input_objects, symtab, shndx, &off);
2276 if (!parameters->doing_static_link())
2277 this->assign_local_dynsym_offsets(input_objects);
2279 // Process any symbol assignments from a linker script. This must
2280 // be called after the symbol table has been finalized.
2281 this->script_options_->finalize_symbols(symtab, this);
2283 // Create the incremental inputs sections.
2284 if (this->incremental_inputs_)
2286 this->incremental_inputs_->finalize();
2287 this->create_incremental_info_sections(symtab);
2290 // Create the .shstrtab section.
2291 Output_section* shstrtab_section = this->create_shstrtab();
2293 // Set the file offsets of the rest of the non-data sections which
2294 // don't have to wait for the input sections.
2295 off = this->set_section_offsets(off, BEFORE_INPUT_SECTIONS_PASS);
2297 // Now that all sections have been created, set the section indexes
2298 // for any sections which haven't been done yet.
2299 shndx = this->set_section_indexes(shndx);
2301 // Create the section table header.
2302 this->create_shdrs(shstrtab_section, &off);
2304 // If there are no sections which require postprocessing, we can
2305 // handle the section names now, and avoid a resize later.
2306 if (!this->any_postprocessing_sections_)
2308 off = this->set_section_offsets(off,
2309 POSTPROCESSING_SECTIONS_PASS);
2311 this->set_section_offsets(off,
2312 STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS);
2315 file_header->set_section_info(this->section_headers_, shstrtab_section);
2317 // Now we know exactly where everything goes in the output file
2318 // (except for non-allocated sections which require postprocessing).
2319 Output_data::layout_complete();
2321 this->output_file_size_ = off;
2326 // Create a note header following the format defined in the ELF ABI.
2327 // NAME is the name, NOTE_TYPE is the type, SECTION_NAME is the name
2328 // of the section to create, DESCSZ is the size of the descriptor.
2329 // ALLOCATE is true if the section should be allocated in memory.
2330 // This returns the new note section. It sets *TRAILING_PADDING to
2331 // the number of trailing zero bytes required.
2334 Layout::create_note(const char* name, int note_type,
2335 const char* section_name, size_t descsz,
2336 bool allocate, size_t* trailing_padding)
2338 // Authorities all agree that the values in a .note field should
2339 // be aligned on 4-byte boundaries for 32-bit binaries. However,
2340 // they differ on what the alignment is for 64-bit binaries.
2341 // The GABI says unambiguously they take 8-byte alignment:
2342 // http://sco.com/developers/gabi/latest/ch5.pheader.html#note_section
2343 // Other documentation says alignment should always be 4 bytes:
2344 // http://www.netbsd.org/docs/kernel/elf-notes.html#note-format
2345 // GNU ld and GNU readelf both support the latter (at least as of
2346 // version 2.16.91), and glibc always generates the latter for
2347 // .note.ABI-tag (as of version 1.6), so that's the one we go with
2349 #ifdef GABI_FORMAT_FOR_DOTNOTE_SECTION // This is not defined by default.
2350 const int size = parameters->target().get_size();
2352 const int size = 32;
2355 // The contents of the .note section.
2356 size_t namesz = strlen(name) + 1;
2357 size_t aligned_namesz = align_address(namesz, size / 8);
2358 size_t aligned_descsz = align_address(descsz, size / 8);
2360 size_t notehdrsz = 3 * (size / 8) + aligned_namesz;
2362 unsigned char* buffer = new unsigned char[notehdrsz];
2363 memset(buffer, 0, notehdrsz);
2365 bool is_big_endian = parameters->target().is_big_endian();
2371 elfcpp::Swap<32, false>::writeval(buffer, namesz);
2372 elfcpp::Swap<32, false>::writeval(buffer + 4, descsz);
2373 elfcpp::Swap<32, false>::writeval(buffer + 8, note_type);
2377 elfcpp::Swap<32, true>::writeval(buffer, namesz);
2378 elfcpp::Swap<32, true>::writeval(buffer + 4, descsz);
2379 elfcpp::Swap<32, true>::writeval(buffer + 8, note_type);
2382 else if (size == 64)
2386 elfcpp::Swap<64, false>::writeval(buffer, namesz);
2387 elfcpp::Swap<64, false>::writeval(buffer + 8, descsz);
2388 elfcpp::Swap<64, false>::writeval(buffer + 16, note_type);
2392 elfcpp::Swap<64, true>::writeval(buffer, namesz);
2393 elfcpp::Swap<64, true>::writeval(buffer + 8, descsz);
2394 elfcpp::Swap<64, true>::writeval(buffer + 16, note_type);
2400 memcpy(buffer + 3 * (size / 8), name, namesz);
2402 elfcpp::Elf_Xword flags = 0;
2403 Output_section_order order = ORDER_INVALID;
2406 flags = elfcpp::SHF_ALLOC;
2407 order = ORDER_RO_NOTE;
2409 Output_section* os = this->choose_output_section(NULL, section_name,
2411 flags, false, order, false);
2415 Output_section_data* posd = new Output_data_const_buffer(buffer, notehdrsz,
2418 os->add_output_section_data(posd);
2420 *trailing_padding = aligned_descsz - descsz;
2425 // For an executable or shared library, create a note to record the
2426 // version of gold used to create the binary.
2429 Layout::create_gold_note()
2431 if (parameters->options().relocatable()
2432 || parameters->incremental_update())
2435 std::string desc = std::string("gold ") + gold::get_version_string();
2437 size_t trailing_padding;
2438 Output_section* os = this->create_note("GNU", elfcpp::NT_GNU_GOLD_VERSION,
2439 ".note.gnu.gold-version", desc.size(),
2440 false, &trailing_padding);
2444 Output_section_data* posd = new Output_data_const(desc, 4);
2445 os->add_output_section_data(posd);
2447 if (trailing_padding > 0)
2449 posd = new Output_data_zero_fill(trailing_padding, 0);
2450 os->add_output_section_data(posd);
2454 // Record whether the stack should be executable. This can be set
2455 // from the command line using the -z execstack or -z noexecstack
2456 // options. Otherwise, if any input file has a .note.GNU-stack
2457 // section with the SHF_EXECINSTR flag set, the stack should be
2458 // executable. Otherwise, if at least one input file a
2459 // .note.GNU-stack section, and some input file has no .note.GNU-stack
2460 // section, we use the target default for whether the stack should be
2461 // executable. Otherwise, we don't generate a stack note. When
2462 // generating a object file, we create a .note.GNU-stack section with
2463 // the appropriate marking. When generating an executable or shared
2464 // library, we create a PT_GNU_STACK segment.
2467 Layout::create_executable_stack_info()
2469 bool is_stack_executable;
2470 if (parameters->options().is_execstack_set())
2471 is_stack_executable = parameters->options().is_stack_executable();
2472 else if (!this->input_with_gnu_stack_note_)
2476 if (this->input_requires_executable_stack_)
2477 is_stack_executable = true;
2478 else if (this->input_without_gnu_stack_note_)
2479 is_stack_executable =
2480 parameters->target().is_default_stack_executable();
2482 is_stack_executable = false;
2485 if (parameters->options().relocatable())
2487 const char* name = this->namepool_.add(".note.GNU-stack", false, NULL);
2488 elfcpp::Elf_Xword flags = 0;
2489 if (is_stack_executable)
2490 flags |= elfcpp::SHF_EXECINSTR;
2491 this->make_output_section(name, elfcpp::SHT_PROGBITS, flags,
2492 ORDER_INVALID, false);
2496 if (this->script_options_->saw_phdrs_clause())
2498 int flags = elfcpp::PF_R | elfcpp::PF_W;
2499 if (is_stack_executable)
2500 flags |= elfcpp::PF_X;
2501 this->make_output_segment(elfcpp::PT_GNU_STACK, flags);
2505 // If --build-id was used, set up the build ID note.
2508 Layout::create_build_id()
2510 if (!parameters->options().user_set_build_id())
2513 const char* style = parameters->options().build_id();
2514 if (strcmp(style, "none") == 0)
2517 // Set DESCSZ to the size of the note descriptor. When possible,
2518 // set DESC to the note descriptor contents.
2521 if (strcmp(style, "md5") == 0)
2523 else if (strcmp(style, "sha1") == 0)
2525 else if (strcmp(style, "uuid") == 0)
2527 const size_t uuidsz = 128 / 8;
2529 char buffer[uuidsz];
2530 memset(buffer, 0, uuidsz);
2532 int descriptor = open_descriptor(-1, "/dev/urandom", O_RDONLY);
2534 gold_error(_("--build-id=uuid failed: could not open /dev/urandom: %s"),
2538 ssize_t got = ::read(descriptor, buffer, uuidsz);
2539 release_descriptor(descriptor, true);
2541 gold_error(_("/dev/urandom: read failed: %s"), strerror(errno));
2542 else if (static_cast<size_t>(got) != uuidsz)
2543 gold_error(_("/dev/urandom: expected %zu bytes, got %zd bytes"),
2547 desc.assign(buffer, uuidsz);
2550 else if (strncmp(style, "0x", 2) == 0)
2553 const char* p = style + 2;
2556 if (hex_p(p[0]) && hex_p(p[1]))
2558 char c = (hex_value(p[0]) << 4) | hex_value(p[1]);
2562 else if (*p == '-' || *p == ':')
2565 gold_fatal(_("--build-id argument '%s' not a valid hex number"),
2568 descsz = desc.size();
2571 gold_fatal(_("unrecognized --build-id argument '%s'"), style);
2574 size_t trailing_padding;
2575 Output_section* os = this->create_note("GNU", elfcpp::NT_GNU_BUILD_ID,
2576 ".note.gnu.build-id", descsz, true,
2583 // We know the value already, so we fill it in now.
2584 gold_assert(desc.size() == descsz);
2586 Output_section_data* posd = new Output_data_const(desc, 4);
2587 os->add_output_section_data(posd);
2589 if (trailing_padding != 0)
2591 posd = new Output_data_zero_fill(trailing_padding, 0);
2592 os->add_output_section_data(posd);
2597 // We need to compute a checksum after we have completed the
2599 gold_assert(trailing_padding == 0);
2600 this->build_id_note_ = new Output_data_zero_fill(descsz, 4);
2601 os->add_output_section_data(this->build_id_note_);
2605 // If we have both .stabXX and .stabXXstr sections, then the sh_link
2606 // field of the former should point to the latter. I'm not sure who
2607 // started this, but the GNU linker does it, and some tools depend
2611 Layout::link_stabs_sections()
2613 if (!this->have_stabstr_section_)
2616 for (Section_list::iterator p = this->section_list_.begin();
2617 p != this->section_list_.end();
2620 if ((*p)->type() != elfcpp::SHT_STRTAB)
2623 const char* name = (*p)->name();
2624 if (strncmp(name, ".stab", 5) != 0)
2627 size_t len = strlen(name);
2628 if (strcmp(name + len - 3, "str") != 0)
2631 std::string stab_name(name, len - 3);
2632 Output_section* stab_sec;
2633 stab_sec = this->find_output_section(stab_name.c_str());
2634 if (stab_sec != NULL)
2635 stab_sec->set_link_section(*p);
2639 // Create .gnu_incremental_inputs and related sections needed
2640 // for the next run of incremental linking to check what has changed.
2643 Layout::create_incremental_info_sections(Symbol_table* symtab)
2645 Incremental_inputs* incr = this->incremental_inputs_;
2647 gold_assert(incr != NULL);
2649 // Create the .gnu_incremental_inputs, _symtab, and _relocs input sections.
2650 incr->create_data_sections(symtab);
2652 // Add the .gnu_incremental_inputs section.
2653 const char* incremental_inputs_name =
2654 this->namepool_.add(".gnu_incremental_inputs", false, NULL);
2655 Output_section* incremental_inputs_os =
2656 this->make_output_section(incremental_inputs_name,
2657 elfcpp::SHT_GNU_INCREMENTAL_INPUTS, 0,
2658 ORDER_INVALID, false);
2659 incremental_inputs_os->add_output_section_data(incr->inputs_section());
2661 // Add the .gnu_incremental_symtab section.
2662 const char* incremental_symtab_name =
2663 this->namepool_.add(".gnu_incremental_symtab", false, NULL);
2664 Output_section* incremental_symtab_os =
2665 this->make_output_section(incremental_symtab_name,
2666 elfcpp::SHT_GNU_INCREMENTAL_SYMTAB, 0,
2667 ORDER_INVALID, false);
2668 incremental_symtab_os->add_output_section_data(incr->symtab_section());
2669 incremental_symtab_os->set_entsize(4);
2671 // Add the .gnu_incremental_relocs section.
2672 const char* incremental_relocs_name =
2673 this->namepool_.add(".gnu_incremental_relocs", false, NULL);
2674 Output_section* incremental_relocs_os =
2675 this->make_output_section(incremental_relocs_name,
2676 elfcpp::SHT_GNU_INCREMENTAL_RELOCS, 0,
2677 ORDER_INVALID, false);
2678 incremental_relocs_os->add_output_section_data(incr->relocs_section());
2679 incremental_relocs_os->set_entsize(incr->relocs_entsize());
2681 // Add the .gnu_incremental_got_plt section.
2682 const char* incremental_got_plt_name =
2683 this->namepool_.add(".gnu_incremental_got_plt", false, NULL);
2684 Output_section* incremental_got_plt_os =
2685 this->make_output_section(incremental_got_plt_name,
2686 elfcpp::SHT_GNU_INCREMENTAL_GOT_PLT, 0,
2687 ORDER_INVALID, false);
2688 incremental_got_plt_os->add_output_section_data(incr->got_plt_section());
2690 // Add the .gnu_incremental_strtab section.
2691 const char* incremental_strtab_name =
2692 this->namepool_.add(".gnu_incremental_strtab", false, NULL);
2693 Output_section* incremental_strtab_os = this->make_output_section(incremental_strtab_name,
2694 elfcpp::SHT_STRTAB, 0,
2695 ORDER_INVALID, false);
2696 Output_data_strtab* strtab_data =
2697 new Output_data_strtab(incr->get_stringpool());
2698 incremental_strtab_os->add_output_section_data(strtab_data);
2700 incremental_inputs_os->set_after_input_sections();
2701 incremental_symtab_os->set_after_input_sections();
2702 incremental_relocs_os->set_after_input_sections();
2703 incremental_got_plt_os->set_after_input_sections();
2705 incremental_inputs_os->set_link_section(incremental_strtab_os);
2706 incremental_symtab_os->set_link_section(incremental_inputs_os);
2707 incremental_relocs_os->set_link_section(incremental_inputs_os);
2708 incremental_got_plt_os->set_link_section(incremental_inputs_os);
2711 // Return whether SEG1 should be before SEG2 in the output file. This
2712 // is based entirely on the segment type and flags. When this is
2713 // called the segment addresses has normally not yet been set.
2716 Layout::segment_precedes(const Output_segment* seg1,
2717 const Output_segment* seg2)
2719 elfcpp::Elf_Word type1 = seg1->type();
2720 elfcpp::Elf_Word type2 = seg2->type();
2722 // The single PT_PHDR segment is required to precede any loadable
2723 // segment. We simply make it always first.
2724 if (type1 == elfcpp::PT_PHDR)
2726 gold_assert(type2 != elfcpp::PT_PHDR);
2729 if (type2 == elfcpp::PT_PHDR)
2732 // The single PT_INTERP segment is required to precede any loadable
2733 // segment. We simply make it always second.
2734 if (type1 == elfcpp::PT_INTERP)
2736 gold_assert(type2 != elfcpp::PT_INTERP);
2739 if (type2 == elfcpp::PT_INTERP)
2742 // We then put PT_LOAD segments before any other segments.
2743 if (type1 == elfcpp::PT_LOAD && type2 != elfcpp::PT_LOAD)
2745 if (type2 == elfcpp::PT_LOAD && type1 != elfcpp::PT_LOAD)
2748 // We put the PT_TLS segment last except for the PT_GNU_RELRO
2749 // segment, because that is where the dynamic linker expects to find
2750 // it (this is just for efficiency; other positions would also work
2752 if (type1 == elfcpp::PT_TLS
2753 && type2 != elfcpp::PT_TLS
2754 && type2 != elfcpp::PT_GNU_RELRO)
2756 if (type2 == elfcpp::PT_TLS
2757 && type1 != elfcpp::PT_TLS
2758 && type1 != elfcpp::PT_GNU_RELRO)
2761 // We put the PT_GNU_RELRO segment last, because that is where the
2762 // dynamic linker expects to find it (as with PT_TLS, this is just
2764 if (type1 == elfcpp::PT_GNU_RELRO && type2 != elfcpp::PT_GNU_RELRO)
2766 if (type2 == elfcpp::PT_GNU_RELRO && type1 != elfcpp::PT_GNU_RELRO)
2769 const elfcpp::Elf_Word flags1 = seg1->flags();
2770 const elfcpp::Elf_Word flags2 = seg2->flags();
2772 // The order of non-PT_LOAD segments is unimportant. We simply sort
2773 // by the numeric segment type and flags values. There should not
2774 // be more than one segment with the same type and flags.
2775 if (type1 != elfcpp::PT_LOAD)
2778 return type1 < type2;
2779 gold_assert(flags1 != flags2);
2780 return flags1 < flags2;
2783 // If the addresses are set already, sort by load address.
2784 if (seg1->are_addresses_set())
2786 if (!seg2->are_addresses_set())
2789 unsigned int section_count1 = seg1->output_section_count();
2790 unsigned int section_count2 = seg2->output_section_count();
2791 if (section_count1 == 0 && section_count2 > 0)
2793 if (section_count1 > 0 && section_count2 == 0)
2796 uint64_t paddr1 = (seg1->are_addresses_set()
2798 : seg1->first_section_load_address());
2799 uint64_t paddr2 = (seg2->are_addresses_set()
2801 : seg2->first_section_load_address());
2803 if (paddr1 != paddr2)
2804 return paddr1 < paddr2;
2806 else if (seg2->are_addresses_set())
2809 // A segment which holds large data comes after a segment which does
2810 // not hold large data.
2811 if (seg1->is_large_data_segment())
2813 if (!seg2->is_large_data_segment())
2816 else if (seg2->is_large_data_segment())
2819 // Otherwise, we sort PT_LOAD segments based on the flags. Readonly
2820 // segments come before writable segments. Then writable segments
2821 // with data come before writable segments without data. Then
2822 // executable segments come before non-executable segments. Then
2823 // the unlikely case of a non-readable segment comes before the
2824 // normal case of a readable segment. If there are multiple
2825 // segments with the same type and flags, we require that the
2826 // address be set, and we sort by virtual address and then physical
2828 if ((flags1 & elfcpp::PF_W) != (flags2 & elfcpp::PF_W))
2829 return (flags1 & elfcpp::PF_W) == 0;
2830 if ((flags1 & elfcpp::PF_W) != 0
2831 && seg1->has_any_data_sections() != seg2->has_any_data_sections())
2832 return seg1->has_any_data_sections();
2833 if ((flags1 & elfcpp::PF_X) != (flags2 & elfcpp::PF_X))
2834 return (flags1 & elfcpp::PF_X) != 0;
2835 if ((flags1 & elfcpp::PF_R) != (flags2 & elfcpp::PF_R))
2836 return (flags1 & elfcpp::PF_R) == 0;
2838 // We shouldn't get here--we shouldn't create segments which we
2839 // can't distinguish.
2843 // Increase OFF so that it is congruent to ADDR modulo ABI_PAGESIZE.
2846 align_file_offset(off_t off, uint64_t addr, uint64_t abi_pagesize)
2848 uint64_t unsigned_off = off;
2849 uint64_t aligned_off = ((unsigned_off & ~(abi_pagesize - 1))
2850 | (addr & (abi_pagesize - 1)));
2851 if (aligned_off < unsigned_off)
2852 aligned_off += abi_pagesize;
2856 // Set the file offsets of all the segments, and all the sections they
2857 // contain. They have all been created. LOAD_SEG must be be laid out
2858 // first. Return the offset of the data to follow.
2861 Layout::set_segment_offsets(const Target* target, Output_segment* load_seg,
2862 unsigned int* pshndx)
2864 // Sort them into the final order.
2865 std::sort(this->segment_list_.begin(), this->segment_list_.end(),
2866 Layout::Compare_segments());
2868 // Find the PT_LOAD segments, and set their addresses and offsets
2869 // and their section's addresses and offsets.
2871 if (parameters->options().user_set_Ttext())
2872 addr = parameters->options().Ttext();
2873 else if (parameters->options().output_is_position_independent())
2876 addr = target->default_text_segment_address();
2879 // If LOAD_SEG is NULL, then the file header and segment headers
2880 // will not be loadable. But they still need to be at offset 0 in
2881 // the file. Set their offsets now.
2882 if (load_seg == NULL)
2884 for (Data_list::iterator p = this->special_output_list_.begin();
2885 p != this->special_output_list_.end();
2888 off = align_address(off, (*p)->addralign());
2889 (*p)->set_address_and_file_offset(0, off);
2890 off += (*p)->data_size();
2894 unsigned int increase_relro = this->increase_relro_;
2895 if (this->script_options_->saw_sections_clause())
2898 const bool check_sections = parameters->options().check_sections();
2899 Output_segment* last_load_segment = NULL;
2901 for (Segment_list::iterator p = this->segment_list_.begin();
2902 p != this->segment_list_.end();
2905 if ((*p)->type() == elfcpp::PT_LOAD)
2907 if (load_seg != NULL && load_seg != *p)
2911 bool are_addresses_set = (*p)->are_addresses_set();
2912 if (are_addresses_set)
2914 // When it comes to setting file offsets, we care about
2915 // the physical address.
2916 addr = (*p)->paddr();
2918 else if (parameters->options().user_set_Tdata()
2919 && ((*p)->flags() & elfcpp::PF_W) != 0
2920 && (!parameters->options().user_set_Tbss()
2921 || (*p)->has_any_data_sections()))
2923 addr = parameters->options().Tdata();
2924 are_addresses_set = true;
2926 else if (parameters->options().user_set_Tbss()
2927 && ((*p)->flags() & elfcpp::PF_W) != 0
2928 && !(*p)->has_any_data_sections())
2930 addr = parameters->options().Tbss();
2931 are_addresses_set = true;
2934 uint64_t orig_addr = addr;
2935 uint64_t orig_off = off;
2937 uint64_t aligned_addr = 0;
2938 uint64_t abi_pagesize = target->abi_pagesize();
2939 uint64_t common_pagesize = target->common_pagesize();
2941 if (!parameters->options().nmagic()
2942 && !parameters->options().omagic())
2943 (*p)->set_minimum_p_align(common_pagesize);
2945 if (!are_addresses_set)
2947 // Skip the address forward one page, maintaining the same
2948 // position within the page. This lets us store both segments
2949 // overlapping on a single page in the file, but the loader will
2950 // put them on different pages in memory. We will revisit this
2951 // decision once we know the size of the segment.
2953 addr = align_address(addr, (*p)->maximum_alignment());
2954 aligned_addr = addr;
2956 if ((addr & (abi_pagesize - 1)) != 0)
2957 addr = addr + abi_pagesize;
2959 off = orig_off + ((addr - orig_addr) & (abi_pagesize - 1));
2962 if (!parameters->options().nmagic()
2963 && !parameters->options().omagic())
2964 off = align_file_offset(off, addr, abi_pagesize);
2965 else if (load_seg == NULL)
2967 // This is -N or -n with a section script which prevents
2968 // us from using a load segment. We need to ensure that
2969 // the file offset is aligned to the alignment of the
2970 // segment. This is because the linker script
2971 // implicitly assumed a zero offset. If we don't align
2972 // here, then the alignment of the sections in the
2973 // linker script may not match the alignment of the
2974 // sections in the set_section_addresses call below,
2975 // causing an error about dot moving backward.
2976 off = align_address(off, (*p)->maximum_alignment());
2979 unsigned int shndx_hold = *pshndx;
2980 bool has_relro = false;
2981 uint64_t new_addr = (*p)->set_section_addresses(this, false, addr,
2986 // Now that we know the size of this segment, we may be able
2987 // to save a page in memory, at the cost of wasting some
2988 // file space, by instead aligning to the start of a new
2989 // page. Here we use the real machine page size rather than
2990 // the ABI mandated page size. If the segment has been
2991 // aligned so that the relro data ends at a page boundary,
2992 // we do not try to realign it.
2994 if (!are_addresses_set
2996 && aligned_addr != addr
2997 && !parameters->incremental())
2999 uint64_t first_off = (common_pagesize
3001 & (common_pagesize - 1)));
3002 uint64_t last_off = new_addr & (common_pagesize - 1);
3005 && ((aligned_addr & ~ (common_pagesize - 1))
3006 != (new_addr & ~ (common_pagesize - 1)))
3007 && first_off + last_off <= common_pagesize)
3009 *pshndx = shndx_hold;
3010 addr = align_address(aligned_addr, common_pagesize);
3011 addr = align_address(addr, (*p)->maximum_alignment());
3012 off = orig_off + ((addr - orig_addr) & (abi_pagesize - 1));
3013 off = align_file_offset(off, addr, abi_pagesize);
3015 increase_relro = this->increase_relro_;
3016 if (this->script_options_->saw_sections_clause())
3020 new_addr = (*p)->set_section_addresses(this, true, addr,
3029 // Implement --check-sections. We know that the segments
3030 // are sorted by LMA.
3031 if (check_sections && last_load_segment != NULL)
3033 gold_assert(last_load_segment->paddr() <= (*p)->paddr());
3034 if (last_load_segment->paddr() + last_load_segment->memsz()
3037 unsigned long long lb1 = last_load_segment->paddr();
3038 unsigned long long le1 = lb1 + last_load_segment->memsz();
3039 unsigned long long lb2 = (*p)->paddr();
3040 unsigned long long le2 = lb2 + (*p)->memsz();
3041 gold_error(_("load segment overlap [0x%llx -> 0x%llx] and "
3042 "[0x%llx -> 0x%llx]"),
3043 lb1, le1, lb2, le2);
3046 last_load_segment = *p;
3050 // Handle the non-PT_LOAD segments, setting their offsets from their
3051 // section's offsets.
3052 for (Segment_list::iterator p = this->segment_list_.begin();
3053 p != this->segment_list_.end();
3056 if ((*p)->type() != elfcpp::PT_LOAD)
3057 (*p)->set_offset((*p)->type() == elfcpp::PT_GNU_RELRO
3062 // Set the TLS offsets for each section in the PT_TLS segment.
3063 if (this->tls_segment_ != NULL)
3064 this->tls_segment_->set_tls_offsets();
3069 // Set the offsets of all the allocated sections when doing a
3070 // relocatable link. This does the same jobs as set_segment_offsets,
3071 // only for a relocatable link.
3074 Layout::set_relocatable_section_offsets(Output_data* file_header,
3075 unsigned int* pshndx)
3079 file_header->set_address_and_file_offset(0, 0);
3080 off += file_header->data_size();
3082 for (Section_list::iterator p = this->section_list_.begin();
3083 p != this->section_list_.end();
3086 // We skip unallocated sections here, except that group sections
3087 // have to come first.
3088 if (((*p)->flags() & elfcpp::SHF_ALLOC) == 0
3089 && (*p)->type() != elfcpp::SHT_GROUP)
3092 off = align_address(off, (*p)->addralign());
3094 // The linker script might have set the address.
3095 if (!(*p)->is_address_valid())
3096 (*p)->set_address(0);
3097 (*p)->set_file_offset(off);
3098 (*p)->finalize_data_size();
3099 off += (*p)->data_size();
3101 (*p)->set_out_shndx(*pshndx);
3108 // Set the file offset of all the sections not associated with a
3112 Layout::set_section_offsets(off_t off, Layout::Section_offset_pass pass)
3114 off_t startoff = off;
3117 for (Section_list::iterator p = this->unattached_section_list_.begin();
3118 p != this->unattached_section_list_.end();
3121 // The symtab section is handled in create_symtab_sections.
3122 if (*p == this->symtab_section_)
3125 // If we've already set the data size, don't set it again.
3126 if ((*p)->is_offset_valid() && (*p)->is_data_size_valid())
3129 if (pass == BEFORE_INPUT_SECTIONS_PASS
3130 && (*p)->requires_postprocessing())
3132 (*p)->create_postprocessing_buffer();
3133 this->any_postprocessing_sections_ = true;
3136 if (pass == BEFORE_INPUT_SECTIONS_PASS
3137 && (*p)->after_input_sections())
3139 else if (pass == POSTPROCESSING_SECTIONS_PASS
3140 && (!(*p)->after_input_sections()
3141 || (*p)->type() == elfcpp::SHT_STRTAB))
3143 else if (pass == STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS
3144 && (!(*p)->after_input_sections()
3145 || (*p)->type() != elfcpp::SHT_STRTAB))
3148 if (!parameters->incremental_update())
3150 off = align_address(off, (*p)->addralign());
3151 (*p)->set_file_offset(off);
3152 (*p)->finalize_data_size();
3156 // Incremental update: allocate file space from free list.
3157 (*p)->pre_finalize_data_size();
3158 off_t current_size = (*p)->current_data_size();
3159 off = this->allocate(current_size, (*p)->addralign(), startoff);
3162 if (is_debugging_enabled(DEBUG_INCREMENTAL))
3163 this->free_list_.dump();
3164 gold_assert((*p)->output_section() != NULL);
3165 gold_fallback(_("out of patch space for section %s; "
3166 "relink with --incremental-full"),
3167 (*p)->output_section()->name());
3169 (*p)->set_file_offset(off);
3170 (*p)->finalize_data_size();
3171 if ((*p)->data_size() > current_size)
3173 gold_assert((*p)->output_section() != NULL);
3174 gold_fallback(_("%s: section changed size; "
3175 "relink with --incremental-full"),
3176 (*p)->output_section()->name());
3178 gold_debug(DEBUG_INCREMENTAL,
3179 "set_section_offsets: %08lx %08lx %s",
3180 static_cast<long>(off),
3181 static_cast<long>((*p)->data_size()),
3182 ((*p)->output_section() != NULL
3183 ? (*p)->output_section()->name() : "(special)"));
3186 off += (*p)->data_size();
3190 // At this point the name must be set.
3191 if (pass != STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS)
3192 this->namepool_.add((*p)->name(), false, NULL);
3197 // Set the section indexes of all the sections not associated with a
3201 Layout::set_section_indexes(unsigned int shndx)
3203 for (Section_list::iterator p = this->unattached_section_list_.begin();
3204 p != this->unattached_section_list_.end();
3207 if (!(*p)->has_out_shndx())
3209 (*p)->set_out_shndx(shndx);
3216 // Set the section addresses according to the linker script. This is
3217 // only called when we see a SECTIONS clause. This returns the
3218 // program segment which should hold the file header and segment
3219 // headers, if any. It will return NULL if they should not be in a
3223 Layout::set_section_addresses_from_script(Symbol_table* symtab)
3225 Script_sections* ss = this->script_options_->script_sections();
3226 gold_assert(ss->saw_sections_clause());
3227 return this->script_options_->set_section_addresses(symtab, this);
3230 // Place the orphan sections in the linker script.
3233 Layout::place_orphan_sections_in_script()
3235 Script_sections* ss = this->script_options_->script_sections();
3236 gold_assert(ss->saw_sections_clause());
3238 // Place each orphaned output section in the script.
3239 for (Section_list::iterator p = this->section_list_.begin();
3240 p != this->section_list_.end();
3243 if (!(*p)->found_in_sections_clause())
3244 ss->place_orphan(*p);
3248 // Count the local symbols in the regular symbol table and the dynamic
3249 // symbol table, and build the respective string pools.
3252 Layout::count_local_symbols(const Task* task,
3253 const Input_objects* input_objects)
3255 // First, figure out an upper bound on the number of symbols we'll
3256 // be inserting into each pool. This helps us create the pools with
3257 // the right size, to avoid unnecessary hashtable resizing.
3258 unsigned int symbol_count = 0;
3259 for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
3260 p != input_objects->relobj_end();
3262 symbol_count += (*p)->local_symbol_count();
3264 // Go from "upper bound" to "estimate." We overcount for two
3265 // reasons: we double-count symbols that occur in more than one
3266 // object file, and we count symbols that are dropped from the
3267 // output. Add it all together and assume we overcount by 100%.
3270 // We assume all symbols will go into both the sympool and dynpool.
3271 this->sympool_.reserve(symbol_count);
3272 this->dynpool_.reserve(symbol_count);
3274 for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
3275 p != input_objects->relobj_end();
3278 Task_lock_obj<Object> tlo(task, *p);
3279 (*p)->count_local_symbols(&this->sympool_, &this->dynpool_);
3283 // Create the symbol table sections. Here we also set the final
3284 // values of the symbols. At this point all the loadable sections are
3285 // fully laid out. SHNUM is the number of sections so far.
3288 Layout::create_symtab_sections(const Input_objects* input_objects,
3289 Symbol_table* symtab,
3295 if (parameters->target().get_size() == 32)
3297 symsize = elfcpp::Elf_sizes<32>::sym_size;
3300 else if (parameters->target().get_size() == 64)
3302 symsize = elfcpp::Elf_sizes<64>::sym_size;
3308 // Compute file offsets relative to the start of the symtab section.
3311 // Save space for the dummy symbol at the start of the section. We
3312 // never bother to write this out--it will just be left as zero.
3314 unsigned int local_symbol_index = 1;
3316 // Add STT_SECTION symbols for each Output section which needs one.
3317 for (Section_list::iterator p = this->section_list_.begin();
3318 p != this->section_list_.end();
3321 if (!(*p)->needs_symtab_index())
3322 (*p)->set_symtab_index(-1U);
3325 (*p)->set_symtab_index(local_symbol_index);
3326 ++local_symbol_index;
3331 for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
3332 p != input_objects->relobj_end();
3335 unsigned int index = (*p)->finalize_local_symbols(local_symbol_index,
3337 off += (index - local_symbol_index) * symsize;
3338 local_symbol_index = index;
3341 unsigned int local_symcount = local_symbol_index;
3342 gold_assert(static_cast<off_t>(local_symcount * symsize) == off);
3345 size_t dyn_global_index;
3347 if (this->dynsym_section_ == NULL)
3350 dyn_global_index = 0;
3355 dyn_global_index = this->dynsym_section_->info();
3356 off_t locsize = dyn_global_index * this->dynsym_section_->entsize();
3357 dynoff = this->dynsym_section_->offset() + locsize;
3358 dyncount = (this->dynsym_section_->data_size() - locsize) / symsize;
3359 gold_assert(static_cast<off_t>(dyncount * symsize)
3360 == this->dynsym_section_->data_size() - locsize);
3363 off_t global_off = off;
3364 off = symtab->finalize(off, dynoff, dyn_global_index, dyncount,
3365 &this->sympool_, &local_symcount);
3367 if (!parameters->options().strip_all())
3369 this->sympool_.set_string_offsets();
3371 const char* symtab_name = this->namepool_.add(".symtab", false, NULL);
3372 Output_section* osymtab = this->make_output_section(symtab_name,
3376 this->symtab_section_ = osymtab;
3378 Output_section_data* pos = new Output_data_fixed_space(off, align,
3380 osymtab->add_output_section_data(pos);
3382 // We generate a .symtab_shndx section if we have more than
3383 // SHN_LORESERVE sections. Technically it is possible that we
3384 // don't need one, because it is possible that there are no
3385 // symbols in any of sections with indexes larger than
3386 // SHN_LORESERVE. That is probably unusual, though, and it is
3387 // easier to always create one than to compute section indexes
3388 // twice (once here, once when writing out the symbols).
3389 if (shnum >= elfcpp::SHN_LORESERVE)
3391 const char* symtab_xindex_name = this->namepool_.add(".symtab_shndx",
3393 Output_section* osymtab_xindex =
3394 this->make_output_section(symtab_xindex_name,
3395 elfcpp::SHT_SYMTAB_SHNDX, 0,
3396 ORDER_INVALID, false);
3398 size_t symcount = off / symsize;
3399 this->symtab_xindex_ = new Output_symtab_xindex(symcount);
3401 osymtab_xindex->add_output_section_data(this->symtab_xindex_);
3403 osymtab_xindex->set_link_section(osymtab);
3404 osymtab_xindex->set_addralign(4);
3405 osymtab_xindex->set_entsize(4);
3407 osymtab_xindex->set_after_input_sections();
3409 // This tells the driver code to wait until the symbol table
3410 // has written out before writing out the postprocessing
3411 // sections, including the .symtab_shndx section.
3412 this->any_postprocessing_sections_ = true;
3415 const char* strtab_name = this->namepool_.add(".strtab", false, NULL);
3416 Output_section* ostrtab = this->make_output_section(strtab_name,
3421 Output_section_data* pstr = new Output_data_strtab(&this->sympool_);
3422 ostrtab->add_output_section_data(pstr);
3425 if (!parameters->incremental_update())
3426 symtab_off = align_address(*poff, align);
3429 symtab_off = this->allocate(off, align, *poff);
3431 gold_fallback(_("out of patch space for symbol table; "
3432 "relink with --incremental-full"));
3433 gold_debug(DEBUG_INCREMENTAL,
3434 "create_symtab_sections: %08lx %08lx .symtab",
3435 static_cast<long>(symtab_off),
3436 static_cast<long>(off));
3439 symtab->set_file_offset(symtab_off + global_off);
3440 osymtab->set_file_offset(symtab_off);
3441 osymtab->finalize_data_size();
3442 osymtab->set_link_section(ostrtab);
3443 osymtab->set_info(local_symcount);
3444 osymtab->set_entsize(symsize);
3446 if (symtab_off + off > *poff)
3447 *poff = symtab_off + off;
3451 // Create the .shstrtab section, which holds the names of the
3452 // sections. At the time this is called, we have created all the
3453 // output sections except .shstrtab itself.
3456 Layout::create_shstrtab()
3458 // FIXME: We don't need to create a .shstrtab section if we are
3459 // stripping everything.
3461 const char* name = this->namepool_.add(".shstrtab", false, NULL);
3463 Output_section* os = this->make_output_section(name, elfcpp::SHT_STRTAB, 0,
3464 ORDER_INVALID, false);
3466 if (strcmp(parameters->options().compress_debug_sections(), "none") != 0)
3468 // We can't write out this section until we've set all the
3469 // section names, and we don't set the names of compressed
3470 // output sections until relocations are complete. FIXME: With
3471 // the current names we use, this is unnecessary.
3472 os->set_after_input_sections();
3475 Output_section_data* posd = new Output_data_strtab(&this->namepool_);
3476 os->add_output_section_data(posd);
3481 // Create the section headers. SIZE is 32 or 64. OFF is the file
3485 Layout::create_shdrs(const Output_section* shstrtab_section, off_t* poff)
3487 Output_section_headers* oshdrs;
3488 oshdrs = new Output_section_headers(this,
3489 &this->segment_list_,
3490 &this->section_list_,
3491 &this->unattached_section_list_,
3495 if (!parameters->incremental_update())
3496 off = align_address(*poff, oshdrs->addralign());
3499 oshdrs->pre_finalize_data_size();
3500 off = this->allocate(oshdrs->data_size(), oshdrs->addralign(), *poff);
3502 gold_fallback(_("out of patch space for section header table; "
3503 "relink with --incremental-full"));
3504 gold_debug(DEBUG_INCREMENTAL,
3505 "create_shdrs: %08lx %08lx (section header table)",
3506 static_cast<long>(off),
3507 static_cast<long>(off + oshdrs->data_size()));
3509 oshdrs->set_address_and_file_offset(0, off);
3510 off += oshdrs->data_size();
3513 this->section_headers_ = oshdrs;
3516 // Count the allocated sections.
3519 Layout::allocated_output_section_count() const
3521 size_t section_count = 0;
3522 for (Segment_list::const_iterator p = this->segment_list_.begin();
3523 p != this->segment_list_.end();
3525 section_count += (*p)->output_section_count();
3526 return section_count;
3529 // Create the dynamic symbol table.
3532 Layout::create_dynamic_symtab(const Input_objects* input_objects,
3533 Symbol_table* symtab,
3534 Output_section** pdynstr,
3535 unsigned int* plocal_dynamic_count,
3536 std::vector<Symbol*>* pdynamic_symbols,
3537 Versions* pversions)
3539 // Count all the symbols in the dynamic symbol table, and set the
3540 // dynamic symbol indexes.
3542 // Skip symbol 0, which is always all zeroes.
3543 unsigned int index = 1;
3545 // Add STT_SECTION symbols for each Output section which needs one.
3546 for (Section_list::iterator p = this->section_list_.begin();
3547 p != this->section_list_.end();
3550 if (!(*p)->needs_dynsym_index())
3551 (*p)->set_dynsym_index(-1U);
3554 (*p)->set_dynsym_index(index);
3559 // Count the local symbols that need to go in the dynamic symbol table,
3560 // and set the dynamic symbol indexes.
3561 for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
3562 p != input_objects->relobj_end();
3565 unsigned int new_index = (*p)->set_local_dynsym_indexes(index);
3569 unsigned int local_symcount = index;
3570 *plocal_dynamic_count = local_symcount;
3572 index = symtab->set_dynsym_indexes(index, pdynamic_symbols,
3573 &this->dynpool_, pversions);
3577 const int size = parameters->target().get_size();
3580 symsize = elfcpp::Elf_sizes<32>::sym_size;
3583 else if (size == 64)
3585 symsize = elfcpp::Elf_sizes<64>::sym_size;
3591 // Create the dynamic symbol table section.
3593 Output_section* dynsym = this->choose_output_section(NULL, ".dynsym",
3597 ORDER_DYNAMIC_LINKER,
3600 Output_section_data* odata = new Output_data_fixed_space(index * symsize,
3603 dynsym->add_output_section_data(odata);
3605 dynsym->set_info(local_symcount);
3606 dynsym->set_entsize(symsize);
3607 dynsym->set_addralign(align);
3609 this->dynsym_section_ = dynsym;
3611 Output_data_dynamic* const odyn = this->dynamic_data_;
3612 odyn->add_section_address(elfcpp::DT_SYMTAB, dynsym);
3613 odyn->add_constant(elfcpp::DT_SYMENT, symsize);
3615 // If there are more than SHN_LORESERVE allocated sections, we
3616 // create a .dynsym_shndx section. It is possible that we don't
3617 // need one, because it is possible that there are no dynamic
3618 // symbols in any of the sections with indexes larger than
3619 // SHN_LORESERVE. This is probably unusual, though, and at this
3620 // time we don't know the actual section indexes so it is
3621 // inconvenient to check.
3622 if (this->allocated_output_section_count() >= elfcpp::SHN_LORESERVE)
3624 Output_section* dynsym_xindex =
3625 this->choose_output_section(NULL, ".dynsym_shndx",
3626 elfcpp::SHT_SYMTAB_SHNDX,
3628 false, ORDER_DYNAMIC_LINKER, false);
3630 this->dynsym_xindex_ = new Output_symtab_xindex(index);
3632 dynsym_xindex->add_output_section_data(this->dynsym_xindex_);
3634 dynsym_xindex->set_link_section(dynsym);
3635 dynsym_xindex->set_addralign(4);
3636 dynsym_xindex->set_entsize(4);
3638 dynsym_xindex->set_after_input_sections();
3640 // This tells the driver code to wait until the symbol table has
3641 // written out before writing out the postprocessing sections,
3642 // including the .dynsym_shndx section.
3643 this->any_postprocessing_sections_ = true;
3646 // Create the dynamic string table section.
3648 Output_section* dynstr = this->choose_output_section(NULL, ".dynstr",
3652 ORDER_DYNAMIC_LINKER,
3655 Output_section_data* strdata = new Output_data_strtab(&this->dynpool_);
3656 dynstr->add_output_section_data(strdata);
3658 dynsym->set_link_section(dynstr);
3659 this->dynamic_section_->set_link_section(dynstr);
3661 odyn->add_section_address(elfcpp::DT_STRTAB, dynstr);
3662 odyn->add_section_size(elfcpp::DT_STRSZ, dynstr);
3666 // Create the hash tables.
3668 if (strcmp(parameters->options().hash_style(), "sysv") == 0
3669 || strcmp(parameters->options().hash_style(), "both") == 0)
3671 unsigned char* phash;
3672 unsigned int hashlen;
3673 Dynobj::create_elf_hash_table(*pdynamic_symbols, local_symcount,
3676 Output_section* hashsec =
3677 this->choose_output_section(NULL, ".hash", elfcpp::SHT_HASH,
3678 elfcpp::SHF_ALLOC, false,
3679 ORDER_DYNAMIC_LINKER, false);
3681 Output_section_data* hashdata = new Output_data_const_buffer(phash,
3685 hashsec->add_output_section_data(hashdata);
3687 hashsec->set_link_section(dynsym);
3688 hashsec->set_entsize(4);
3690 odyn->add_section_address(elfcpp::DT_HASH, hashsec);
3693 if (strcmp(parameters->options().hash_style(), "gnu") == 0
3694 || strcmp(parameters->options().hash_style(), "both") == 0)
3696 unsigned char* phash;
3697 unsigned int hashlen;
3698 Dynobj::create_gnu_hash_table(*pdynamic_symbols, local_symcount,
3701 Output_section* hashsec =
3702 this->choose_output_section(NULL, ".gnu.hash", elfcpp::SHT_GNU_HASH,
3703 elfcpp::SHF_ALLOC, false,
3704 ORDER_DYNAMIC_LINKER, false);
3706 Output_section_data* hashdata = new Output_data_const_buffer(phash,
3710 hashsec->add_output_section_data(hashdata);
3712 hashsec->set_link_section(dynsym);
3714 // For a 64-bit target, the entries in .gnu.hash do not have a
3715 // uniform size, so we only set the entry size for a 32-bit
3717 if (parameters->target().get_size() == 32)
3718 hashsec->set_entsize(4);
3720 odyn->add_section_address(elfcpp::DT_GNU_HASH, hashsec);
3724 // Assign offsets to each local portion of the dynamic symbol table.
3727 Layout::assign_local_dynsym_offsets(const Input_objects* input_objects)
3729 Output_section* dynsym = this->dynsym_section_;
3730 gold_assert(dynsym != NULL);
3732 off_t off = dynsym->offset();
3734 // Skip the dummy symbol at the start of the section.
3735 off += dynsym->entsize();
3737 for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
3738 p != input_objects->relobj_end();
3741 unsigned int count = (*p)->set_local_dynsym_offset(off);
3742 off += count * dynsym->entsize();
3746 // Create the version sections.
3749 Layout::create_version_sections(const Versions* versions,
3750 const Symbol_table* symtab,
3751 unsigned int local_symcount,
3752 const std::vector<Symbol*>& dynamic_symbols,
3753 const Output_section* dynstr)
3755 if (!versions->any_defs() && !versions->any_needs())
3758 switch (parameters->size_and_endianness())
3760 #ifdef HAVE_TARGET_32_LITTLE
3761 case Parameters::TARGET_32_LITTLE:
3762 this->sized_create_version_sections<32, false>(versions, symtab,
3764 dynamic_symbols, dynstr);
3767 #ifdef HAVE_TARGET_32_BIG
3768 case Parameters::TARGET_32_BIG:
3769 this->sized_create_version_sections<32, true>(versions, symtab,
3771 dynamic_symbols, dynstr);
3774 #ifdef HAVE_TARGET_64_LITTLE
3775 case Parameters::TARGET_64_LITTLE:
3776 this->sized_create_version_sections<64, false>(versions, symtab,
3778 dynamic_symbols, dynstr);
3781 #ifdef HAVE_TARGET_64_BIG
3782 case Parameters::TARGET_64_BIG:
3783 this->sized_create_version_sections<64, true>(versions, symtab,
3785 dynamic_symbols, dynstr);
3793 // Create the version sections, sized version.
3795 template<int size, bool big_endian>
3797 Layout::sized_create_version_sections(
3798 const Versions* versions,
3799 const Symbol_table* symtab,
3800 unsigned int local_symcount,
3801 const std::vector<Symbol*>& dynamic_symbols,
3802 const Output_section* dynstr)
3804 Output_section* vsec = this->choose_output_section(NULL, ".gnu.version",
3805 elfcpp::SHT_GNU_versym,
3808 ORDER_DYNAMIC_LINKER,
3811 unsigned char* vbuf;
3813 versions->symbol_section_contents<size, big_endian>(symtab, &this->dynpool_,
3818 Output_section_data* vdata = new Output_data_const_buffer(vbuf, vsize, 2,
3821 vsec->add_output_section_data(vdata);
3822 vsec->set_entsize(2);
3823 vsec->set_link_section(this->dynsym_section_);
3825 Output_data_dynamic* const odyn = this->dynamic_data_;
3826 odyn->add_section_address(elfcpp::DT_VERSYM, vsec);
3828 if (versions->any_defs())
3830 Output_section* vdsec;
3831 vdsec= this->choose_output_section(NULL, ".gnu.version_d",
3832 elfcpp::SHT_GNU_verdef,
3834 false, ORDER_DYNAMIC_LINKER, false);
3836 unsigned char* vdbuf;
3837 unsigned int vdsize;
3838 unsigned int vdentries;
3839 versions->def_section_contents<size, big_endian>(&this->dynpool_, &vdbuf,
3840 &vdsize, &vdentries);
3842 Output_section_data* vddata =
3843 new Output_data_const_buffer(vdbuf, vdsize, 4, "** version defs");
3845 vdsec->add_output_section_data(vddata);
3846 vdsec->set_link_section(dynstr);
3847 vdsec->set_info(vdentries);
3849 odyn->add_section_address(elfcpp::DT_VERDEF, vdsec);
3850 odyn->add_constant(elfcpp::DT_VERDEFNUM, vdentries);
3853 if (versions->any_needs())
3855 Output_section* vnsec;
3856 vnsec = this->choose_output_section(NULL, ".gnu.version_r",
3857 elfcpp::SHT_GNU_verneed,
3859 false, ORDER_DYNAMIC_LINKER, false);
3861 unsigned char* vnbuf;
3862 unsigned int vnsize;
3863 unsigned int vnentries;
3864 versions->need_section_contents<size, big_endian>(&this->dynpool_,
3868 Output_section_data* vndata =
3869 new Output_data_const_buffer(vnbuf, vnsize, 4, "** version refs");
3871 vnsec->add_output_section_data(vndata);
3872 vnsec->set_link_section(dynstr);
3873 vnsec->set_info(vnentries);
3875 odyn->add_section_address(elfcpp::DT_VERNEED, vnsec);
3876 odyn->add_constant(elfcpp::DT_VERNEEDNUM, vnentries);
3880 // Create the .interp section and PT_INTERP segment.
3883 Layout::create_interp(const Target* target)
3885 gold_assert(this->interp_segment_ == NULL);
3887 const char* interp = parameters->options().dynamic_linker();
3890 interp = target->dynamic_linker();
3891 gold_assert(interp != NULL);
3894 size_t len = strlen(interp) + 1;
3896 Output_section_data* odata = new Output_data_const(interp, len, 1);
3898 Output_section* osec = this->choose_output_section(NULL, ".interp",
3899 elfcpp::SHT_PROGBITS,
3901 false, ORDER_INTERP,
3903 osec->add_output_section_data(odata);
3906 // Add dynamic tags for the PLT and the dynamic relocs. This is
3907 // called by the target-specific code. This does nothing if not doing
3910 // USE_REL is true for REL relocs rather than RELA relocs.
3912 // If PLT_GOT is not NULL, then DT_PLTGOT points to it.
3914 // If PLT_REL is not NULL, it is used for DT_PLTRELSZ, and DT_JMPREL,
3915 // and we also set DT_PLTREL. We use PLT_REL's output section, since
3916 // some targets have multiple reloc sections in PLT_REL.
3918 // If DYN_REL is not NULL, it is used for DT_REL/DT_RELA,
3919 // DT_RELSZ/DT_RELASZ, DT_RELENT/DT_RELAENT.
3921 // If ADD_DEBUG is true, we add a DT_DEBUG entry when generating an
3925 Layout::add_target_dynamic_tags(bool use_rel, const Output_data* plt_got,
3926 const Output_data* plt_rel,
3927 const Output_data_reloc_generic* dyn_rel,
3928 bool add_debug, bool dynrel_includes_plt)
3930 Output_data_dynamic* odyn = this->dynamic_data_;
3934 if (plt_got != NULL && plt_got->output_section() != NULL)
3935 odyn->add_section_address(elfcpp::DT_PLTGOT, plt_got);
3937 if (plt_rel != NULL && plt_rel->output_section() != NULL)
3939 odyn->add_section_size(elfcpp::DT_PLTRELSZ, plt_rel->output_section());
3940 odyn->add_section_address(elfcpp::DT_JMPREL, plt_rel->output_section());
3941 odyn->add_constant(elfcpp::DT_PLTREL,
3942 use_rel ? elfcpp::DT_REL : elfcpp::DT_RELA);
3945 if (dyn_rel != NULL && dyn_rel->output_section() != NULL)
3947 odyn->add_section_address(use_rel ? elfcpp::DT_REL : elfcpp::DT_RELA,
3949 if (plt_rel != NULL && dynrel_includes_plt)
3950 odyn->add_section_size(use_rel ? elfcpp::DT_RELSZ : elfcpp::DT_RELASZ,
3953 odyn->add_section_size(use_rel ? elfcpp::DT_RELSZ : elfcpp::DT_RELASZ,
3955 const int size = parameters->target().get_size();
3960 rel_tag = elfcpp::DT_RELENT;
3962 rel_size = Reloc_types<elfcpp::SHT_REL, 32, false>::reloc_size;
3963 else if (size == 64)
3964 rel_size = Reloc_types<elfcpp::SHT_REL, 64, false>::reloc_size;
3970 rel_tag = elfcpp::DT_RELAENT;
3972 rel_size = Reloc_types<elfcpp::SHT_RELA, 32, false>::reloc_size;
3973 else if (size == 64)
3974 rel_size = Reloc_types<elfcpp::SHT_RELA, 64, false>::reloc_size;
3978 odyn->add_constant(rel_tag, rel_size);
3980 if (parameters->options().combreloc())
3982 size_t c = dyn_rel->relative_reloc_count();
3984 odyn->add_constant((use_rel
3985 ? elfcpp::DT_RELCOUNT
3986 : elfcpp::DT_RELACOUNT),
3991 if (add_debug && !parameters->options().shared())
3993 // The value of the DT_DEBUG tag is filled in by the dynamic
3994 // linker at run time, and used by the debugger.
3995 odyn->add_constant(elfcpp::DT_DEBUG, 0);
3999 // Finish the .dynamic section and PT_DYNAMIC segment.
4002 Layout::finish_dynamic_section(const Input_objects* input_objects,
4003 const Symbol_table* symtab)
4005 if (!this->script_options_->saw_phdrs_clause())
4007 Output_segment* oseg = this->make_output_segment(elfcpp::PT_DYNAMIC,
4010 oseg->add_output_section_to_nonload(this->dynamic_section_,
4011 elfcpp::PF_R | elfcpp::PF_W);
4014 Output_data_dynamic* const odyn = this->dynamic_data_;
4016 for (Input_objects::Dynobj_iterator p = input_objects->dynobj_begin();
4017 p != input_objects->dynobj_end();
4020 if (!(*p)->is_needed() && (*p)->as_needed())
4022 // This dynamic object was linked with --as-needed, but it
4027 odyn->add_string(elfcpp::DT_NEEDED, (*p)->soname());
4030 if (parameters->options().shared())
4032 const char* soname = parameters->options().soname();
4034 odyn->add_string(elfcpp::DT_SONAME, soname);
4037 Symbol* sym = symtab->lookup(parameters->options().init());
4038 if (sym != NULL && sym->is_defined() && !sym->is_from_dynobj())
4039 odyn->add_symbol(elfcpp::DT_INIT, sym);
4041 sym = symtab->lookup(parameters->options().fini());
4042 if (sym != NULL && sym->is_defined() && !sym->is_from_dynobj())
4043 odyn->add_symbol(elfcpp::DT_FINI, sym);
4045 // Look for .init_array, .preinit_array and .fini_array by checking
4047 for(Layout::Section_list::const_iterator p = this->section_list_.begin();
4048 p != this->section_list_.end();
4050 switch((*p)->type())
4052 case elfcpp::SHT_FINI_ARRAY:
4053 odyn->add_section_address(elfcpp::DT_FINI_ARRAY, *p);
4054 odyn->add_section_size(elfcpp::DT_FINI_ARRAYSZ, *p);
4056 case elfcpp::SHT_INIT_ARRAY:
4057 odyn->add_section_address(elfcpp::DT_INIT_ARRAY, *p);
4058 odyn->add_section_size(elfcpp::DT_INIT_ARRAYSZ, *p);
4060 case elfcpp::SHT_PREINIT_ARRAY:
4061 odyn->add_section_address(elfcpp::DT_PREINIT_ARRAY, *p);
4062 odyn->add_section_size(elfcpp::DT_PREINIT_ARRAYSZ, *p);
4068 // Add a DT_RPATH entry if needed.
4069 const General_options::Dir_list& rpath(parameters->options().rpath());
4072 std::string rpath_val;
4073 for (General_options::Dir_list::const_iterator p = rpath.begin();
4077 if (rpath_val.empty())
4078 rpath_val = p->name();
4081 // Eliminate duplicates.
4082 General_options::Dir_list::const_iterator q;
4083 for (q = rpath.begin(); q != p; ++q)
4084 if (q->name() == p->name())
4089 rpath_val += p->name();
4094 odyn->add_string(elfcpp::DT_RPATH, rpath_val);
4095 if (parameters->options().enable_new_dtags())
4096 odyn->add_string(elfcpp::DT_RUNPATH, rpath_val);
4099 // Look for text segments that have dynamic relocations.
4100 bool have_textrel = false;
4101 if (!this->script_options_->saw_sections_clause())
4103 for (Segment_list::const_iterator p = this->segment_list_.begin();
4104 p != this->segment_list_.end();
4107 if ((*p)->type() == elfcpp::PT_LOAD
4108 && ((*p)->flags() & elfcpp::PF_W) == 0
4109 && (*p)->has_dynamic_reloc())
4111 have_textrel = true;
4118 // We don't know the section -> segment mapping, so we are
4119 // conservative and just look for readonly sections with
4120 // relocations. If those sections wind up in writable segments,
4121 // then we have created an unnecessary DT_TEXTREL entry.
4122 for (Section_list::const_iterator p = this->section_list_.begin();
4123 p != this->section_list_.end();
4126 if (((*p)->flags() & elfcpp::SHF_ALLOC) != 0
4127 && ((*p)->flags() & elfcpp::SHF_WRITE) == 0
4128 && (*p)->has_dynamic_reloc())
4130 have_textrel = true;
4136 // Add a DT_FLAGS entry. We add it even if no flags are set so that
4137 // post-link tools can easily modify these flags if desired.
4138 unsigned int flags = 0;
4141 // Add a DT_TEXTREL for compatibility with older loaders.
4142 odyn->add_constant(elfcpp::DT_TEXTREL, 0);
4143 flags |= elfcpp::DF_TEXTREL;
4145 if (parameters->options().text())
4146 gold_error(_("read-only segment has dynamic relocations"));
4147 else if (parameters->options().warn_shared_textrel()
4148 && parameters->options().shared())
4149 gold_warning(_("shared library text segment is not shareable"));
4151 if (parameters->options().shared() && this->has_static_tls())
4152 flags |= elfcpp::DF_STATIC_TLS;
4153 if (parameters->options().origin())
4154 flags |= elfcpp::DF_ORIGIN;
4155 if (parameters->options().Bsymbolic())
4157 flags |= elfcpp::DF_SYMBOLIC;
4158 // Add DT_SYMBOLIC for compatibility with older loaders.
4159 odyn->add_constant(elfcpp::DT_SYMBOLIC, 0);
4161 if (parameters->options().now())
4162 flags |= elfcpp::DF_BIND_NOW;
4164 odyn->add_constant(elfcpp::DT_FLAGS, flags);
4167 if (parameters->options().initfirst())
4168 flags |= elfcpp::DF_1_INITFIRST;
4169 if (parameters->options().interpose())
4170 flags |= elfcpp::DF_1_INTERPOSE;
4171 if (parameters->options().loadfltr())
4172 flags |= elfcpp::DF_1_LOADFLTR;
4173 if (parameters->options().nodefaultlib())
4174 flags |= elfcpp::DF_1_NODEFLIB;
4175 if (parameters->options().nodelete())
4176 flags |= elfcpp::DF_1_NODELETE;
4177 if (parameters->options().nodlopen())
4178 flags |= elfcpp::DF_1_NOOPEN;
4179 if (parameters->options().nodump())
4180 flags |= elfcpp::DF_1_NODUMP;
4181 if (!parameters->options().shared())
4182 flags &= ~(elfcpp::DF_1_INITFIRST
4183 | elfcpp::DF_1_NODELETE
4184 | elfcpp::DF_1_NOOPEN);
4185 if (parameters->options().origin())
4186 flags |= elfcpp::DF_1_ORIGIN;
4187 if (parameters->options().now())
4188 flags |= elfcpp::DF_1_NOW;
4190 odyn->add_constant(elfcpp::DT_FLAGS_1, flags);
4193 // Set the size of the _DYNAMIC symbol table to be the size of the
4197 Layout::set_dynamic_symbol_size(const Symbol_table* symtab)
4199 Output_data_dynamic* const odyn = this->dynamic_data_;
4200 odyn->finalize_data_size();
4201 off_t data_size = odyn->data_size();
4202 const int size = parameters->target().get_size();
4204 symtab->get_sized_symbol<32>(this->dynamic_symbol_)->set_symsize(data_size);
4205 else if (size == 64)
4206 symtab->get_sized_symbol<64>(this->dynamic_symbol_)->set_symsize(data_size);
4211 // The mapping of input section name prefixes to output section names.
4212 // In some cases one prefix is itself a prefix of another prefix; in
4213 // such a case the longer prefix must come first. These prefixes are
4214 // based on the GNU linker default ELF linker script.
4216 #define MAPPING_INIT(f, t) { f, sizeof(f) - 1, t, sizeof(t) - 1 }
4217 const Layout::Section_name_mapping Layout::section_name_mapping[] =
4219 MAPPING_INIT(".text.", ".text"),
4220 MAPPING_INIT(".rodata.", ".rodata"),
4221 MAPPING_INIT(".data.rel.ro.local", ".data.rel.ro.local"),
4222 MAPPING_INIT(".data.rel.ro", ".data.rel.ro"),
4223 MAPPING_INIT(".data.", ".data"),
4224 MAPPING_INIT(".bss.", ".bss"),
4225 MAPPING_INIT(".tdata.", ".tdata"),
4226 MAPPING_INIT(".tbss.", ".tbss"),
4227 MAPPING_INIT(".init_array.", ".init_array"),
4228 MAPPING_INIT(".fini_array.", ".fini_array"),
4229 MAPPING_INIT(".sdata.", ".sdata"),
4230 MAPPING_INIT(".sbss.", ".sbss"),
4231 // FIXME: In the GNU linker, .sbss2 and .sdata2 are handled
4232 // differently depending on whether it is creating a shared library.
4233 MAPPING_INIT(".sdata2.", ".sdata"),
4234 MAPPING_INIT(".sbss2.", ".sbss"),
4235 MAPPING_INIT(".lrodata.", ".lrodata"),
4236 MAPPING_INIT(".ldata.", ".ldata"),
4237 MAPPING_INIT(".lbss.", ".lbss"),
4238 MAPPING_INIT(".gcc_except_table.", ".gcc_except_table"),
4239 MAPPING_INIT(".gnu.linkonce.d.rel.ro.local.", ".data.rel.ro.local"),
4240 MAPPING_INIT(".gnu.linkonce.d.rel.ro.", ".data.rel.ro"),
4241 MAPPING_INIT(".gnu.linkonce.t.", ".text"),
4242 MAPPING_INIT(".gnu.linkonce.r.", ".rodata"),
4243 MAPPING_INIT(".gnu.linkonce.d.", ".data"),
4244 MAPPING_INIT(".gnu.linkonce.b.", ".bss"),
4245 MAPPING_INIT(".gnu.linkonce.s.", ".sdata"),
4246 MAPPING_INIT(".gnu.linkonce.sb.", ".sbss"),
4247 MAPPING_INIT(".gnu.linkonce.s2.", ".sdata"),
4248 MAPPING_INIT(".gnu.linkonce.sb2.", ".sbss"),
4249 MAPPING_INIT(".gnu.linkonce.wi.", ".debug_info"),
4250 MAPPING_INIT(".gnu.linkonce.td.", ".tdata"),
4251 MAPPING_INIT(".gnu.linkonce.tb.", ".tbss"),
4252 MAPPING_INIT(".gnu.linkonce.lr.", ".lrodata"),
4253 MAPPING_INIT(".gnu.linkonce.l.", ".ldata"),
4254 MAPPING_INIT(".gnu.linkonce.lb.", ".lbss"),
4255 MAPPING_INIT(".ARM.extab", ".ARM.extab"),
4256 MAPPING_INIT(".gnu.linkonce.armextab.", ".ARM.extab"),
4257 MAPPING_INIT(".ARM.exidx", ".ARM.exidx"),
4258 MAPPING_INIT(".gnu.linkonce.armexidx.", ".ARM.exidx"),
4262 const int Layout::section_name_mapping_count =
4263 (sizeof(Layout::section_name_mapping)
4264 / sizeof(Layout::section_name_mapping[0]));
4266 // Choose the output section name to use given an input section name.
4267 // Set *PLEN to the length of the name. *PLEN is initialized to the
4271 Layout::output_section_name(const Relobj* relobj, const char* name,
4274 // gcc 4.3 generates the following sorts of section names when it
4275 // needs a section name specific to a function:
4281 // .data.rel.local.FN
4283 // .data.rel.ro.local.FN
4290 // The GNU linker maps all of those to the part before the .FN,
4291 // except that .data.rel.local.FN is mapped to .data, and
4292 // .data.rel.ro.local.FN is mapped to .data.rel.ro. The sections
4293 // beginning with .data.rel.ro.local are grouped together.
4295 // For an anonymous namespace, the string FN can contain a '.'.
4297 // Also of interest: .rodata.strN.N, .rodata.cstN, both of which the
4298 // GNU linker maps to .rodata.
4300 // The .data.rel.ro sections are used with -z relro. The sections
4301 // are recognized by name. We use the same names that the GNU
4302 // linker does for these sections.
4304 // It is hard to handle this in a principled way, so we don't even
4305 // try. We use a table of mappings. If the input section name is
4306 // not found in the table, we simply use it as the output section
4309 const Section_name_mapping* psnm = section_name_mapping;
4310 for (int i = 0; i < section_name_mapping_count; ++i, ++psnm)
4312 if (strncmp(name, psnm->from, psnm->fromlen) == 0)
4314 *plen = psnm->tolen;
4319 // As an additional complication, .ctors sections are output in
4320 // either .ctors or .init_array sections, and .dtors sections are
4321 // output in either .dtors or .fini_array sections.
4322 if (is_prefix_of(".ctors.", name) || is_prefix_of(".dtors.", name))
4324 if (parameters->options().ctors_in_init_array())
4327 return name[1] == 'c' ? ".init_array" : ".fini_array";
4332 return name[1] == 'c' ? ".ctors" : ".dtors";
4335 if (parameters->options().ctors_in_init_array()
4336 && (strcmp(name, ".ctors") == 0 || strcmp(name, ".dtors") == 0))
4338 // To make .init_array/.fini_array work with gcc we must exclude
4339 // .ctors and .dtors sections from the crtbegin and crtend
4342 || (!Layout::match_file_name(relobj, "crtbegin")
4343 && !Layout::match_file_name(relobj, "crtend")))
4346 return name[1] == 'c' ? ".init_array" : ".fini_array";
4353 // Return true if RELOBJ is an input file whose base name matches
4354 // FILE_NAME. The base name must have an extension of ".o", and must
4355 // be exactly FILE_NAME.o or FILE_NAME, one character, ".o". This is
4356 // to match crtbegin.o as well as crtbeginS.o without getting confused
4357 // by other possibilities. Overall matching the file name this way is
4358 // a dreadful hack, but the GNU linker does it in order to better
4359 // support gcc, and we need to be compatible.
4362 Layout::match_file_name(const Relobj* relobj, const char* match)
4364 const std::string& file_name(relobj->name());
4365 const char* base_name = lbasename(file_name.c_str());
4366 size_t match_len = strlen(match);
4367 if (strncmp(base_name, match, match_len) != 0)
4369 size_t base_len = strlen(base_name);
4370 if (base_len != match_len + 2 && base_len != match_len + 3)
4372 return memcmp(base_name + base_len - 2, ".o", 2) == 0;
4375 // Check if a comdat group or .gnu.linkonce section with the given
4376 // NAME is selected for the link. If there is already a section,
4377 // *KEPT_SECTION is set to point to the existing section and the
4378 // function returns false. Otherwise, OBJECT, SHNDX, IS_COMDAT, and
4379 // IS_GROUP_NAME are recorded for this NAME in the layout object,
4380 // *KEPT_SECTION is set to the internal copy and the function returns
4384 Layout::find_or_add_kept_section(const std::string& name,
4389 Kept_section** kept_section)
4391 // It's normal to see a couple of entries here, for the x86 thunk
4392 // sections. If we see more than a few, we're linking a C++
4393 // program, and we resize to get more space to minimize rehashing.
4394 if (this->signatures_.size() > 4
4395 && !this->resized_signatures_)
4397 reserve_unordered_map(&this->signatures_,
4398 this->number_of_input_files_ * 64);
4399 this->resized_signatures_ = true;
4402 Kept_section candidate;
4403 std::pair<Signatures::iterator, bool> ins =
4404 this->signatures_.insert(std::make_pair(name, candidate));
4406 if (kept_section != NULL)
4407 *kept_section = &ins.first->second;
4410 // This is the first time we've seen this signature.
4411 ins.first->second.set_object(object);
4412 ins.first->second.set_shndx(shndx);
4414 ins.first->second.set_is_comdat();
4416 ins.first->second.set_is_group_name();
4420 // We have already seen this signature.
4422 if (ins.first->second.is_group_name())
4424 // We've already seen a real section group with this signature.
4425 // If the kept group is from a plugin object, and we're in the
4426 // replacement phase, accept the new one as a replacement.
4427 if (ins.first->second.object() == NULL
4428 && parameters->options().plugins()->in_replacement_phase())
4430 ins.first->second.set_object(object);
4431 ins.first->second.set_shndx(shndx);
4436 else if (is_group_name)
4438 // This is a real section group, and we've already seen a
4439 // linkonce section with this signature. Record that we've seen
4440 // a section group, and don't include this section group.
4441 ins.first->second.set_is_group_name();
4446 // We've already seen a linkonce section and this is a linkonce
4447 // section. These don't block each other--this may be the same
4448 // symbol name with different section types.
4453 // Store the allocated sections into the section list.
4456 Layout::get_allocated_sections(Section_list* section_list) const
4458 for (Section_list::const_iterator p = this->section_list_.begin();
4459 p != this->section_list_.end();
4461 if (((*p)->flags() & elfcpp::SHF_ALLOC) != 0)
4462 section_list->push_back(*p);
4465 // Create an output segment.
4468 Layout::make_output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags)
4470 gold_assert(!parameters->options().relocatable());
4471 Output_segment* oseg = new Output_segment(type, flags);
4472 this->segment_list_.push_back(oseg);
4474 if (type == elfcpp::PT_TLS)
4475 this->tls_segment_ = oseg;
4476 else if (type == elfcpp::PT_GNU_RELRO)
4477 this->relro_segment_ = oseg;
4478 else if (type == elfcpp::PT_INTERP)
4479 this->interp_segment_ = oseg;
4484 // Return the file offset of the normal symbol table.
4487 Layout::symtab_section_offset() const
4489 if (this->symtab_section_ != NULL)
4490 return this->symtab_section_->offset();
4494 // Write out the Output_sections. Most won't have anything to write,
4495 // since most of the data will come from input sections which are
4496 // handled elsewhere. But some Output_sections do have Output_data.
4499 Layout::write_output_sections(Output_file* of) const
4501 for (Section_list::const_iterator p = this->section_list_.begin();
4502 p != this->section_list_.end();
4505 if (!(*p)->after_input_sections())
4510 // Write out data not associated with a section or the symbol table.
4513 Layout::write_data(const Symbol_table* symtab, Output_file* of) const
4515 if (!parameters->options().strip_all())
4517 const Output_section* symtab_section = this->symtab_section_;
4518 for (Section_list::const_iterator p = this->section_list_.begin();
4519 p != this->section_list_.end();
4522 if ((*p)->needs_symtab_index())
4524 gold_assert(symtab_section != NULL);
4525 unsigned int index = (*p)->symtab_index();
4526 gold_assert(index > 0 && index != -1U);
4527 off_t off = (symtab_section->offset()
4528 + index * symtab_section->entsize());
4529 symtab->write_section_symbol(*p, this->symtab_xindex_, of, off);
4534 const Output_section* dynsym_section = this->dynsym_section_;
4535 for (Section_list::const_iterator p = this->section_list_.begin();
4536 p != this->section_list_.end();
4539 if ((*p)->needs_dynsym_index())
4541 gold_assert(dynsym_section != NULL);
4542 unsigned int index = (*p)->dynsym_index();
4543 gold_assert(index > 0 && index != -1U);
4544 off_t off = (dynsym_section->offset()
4545 + index * dynsym_section->entsize());
4546 symtab->write_section_symbol(*p, this->dynsym_xindex_, of, off);
4550 // Write out the Output_data which are not in an Output_section.
4551 for (Data_list::const_iterator p = this->special_output_list_.begin();
4552 p != this->special_output_list_.end();
4557 // Write out the Output_sections which can only be written after the
4558 // input sections are complete.
4561 Layout::write_sections_after_input_sections(Output_file* of)
4563 // Determine the final section offsets, and thus the final output
4564 // file size. Note we finalize the .shstrab last, to allow the
4565 // after_input_section sections to modify their section-names before
4567 if (this->any_postprocessing_sections_)
4569 off_t off = this->output_file_size_;
4570 off = this->set_section_offsets(off, POSTPROCESSING_SECTIONS_PASS);
4572 // Now that we've finalized the names, we can finalize the shstrab.
4574 this->set_section_offsets(off,
4575 STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS);
4577 if (off > this->output_file_size_)
4580 this->output_file_size_ = off;
4584 for (Section_list::const_iterator p = this->section_list_.begin();
4585 p != this->section_list_.end();
4588 if ((*p)->after_input_sections())
4592 this->section_headers_->write(of);
4595 // If the build ID requires computing a checksum, do so here, and
4596 // write it out. We compute a checksum over the entire file because
4597 // that is simplest.
4600 Layout::write_build_id(Output_file* of) const
4602 if (this->build_id_note_ == NULL)
4605 const unsigned char* iv = of->get_input_view(0, this->output_file_size_);
4607 unsigned char* ov = of->get_output_view(this->build_id_note_->offset(),
4608 this->build_id_note_->data_size());
4610 const char* style = parameters->options().build_id();
4611 if (strcmp(style, "sha1") == 0)
4614 sha1_init_ctx(&ctx);
4615 sha1_process_bytes(iv, this->output_file_size_, &ctx);
4616 sha1_finish_ctx(&ctx, ov);
4618 else if (strcmp(style, "md5") == 0)
4622 md5_process_bytes(iv, this->output_file_size_, &ctx);
4623 md5_finish_ctx(&ctx, ov);
4628 of->write_output_view(this->build_id_note_->offset(),
4629 this->build_id_note_->data_size(),
4632 of->free_input_view(0, this->output_file_size_, iv);
4635 // Write out a binary file. This is called after the link is
4636 // complete. IN is the temporary output file we used to generate the
4637 // ELF code. We simply walk through the segments, read them from
4638 // their file offset in IN, and write them to their load address in
4639 // the output file. FIXME: with a bit more work, we could support
4640 // S-records and/or Intel hex format here.
4643 Layout::write_binary(Output_file* in) const
4645 gold_assert(parameters->options().oformat_enum()
4646 == General_options::OBJECT_FORMAT_BINARY);
4648 // Get the size of the binary file.
4649 uint64_t max_load_address = 0;
4650 for (Segment_list::const_iterator p = this->segment_list_.begin();
4651 p != this->segment_list_.end();
4654 if ((*p)->type() == elfcpp::PT_LOAD && (*p)->filesz() > 0)
4656 uint64_t max_paddr = (*p)->paddr() + (*p)->filesz();
4657 if (max_paddr > max_load_address)
4658 max_load_address = max_paddr;
4662 Output_file out(parameters->options().output_file_name());
4663 out.open(max_load_address);
4665 for (Segment_list::const_iterator p = this->segment_list_.begin();
4666 p != this->segment_list_.end();
4669 if ((*p)->type() == elfcpp::PT_LOAD && (*p)->filesz() > 0)
4671 const unsigned char* vin = in->get_input_view((*p)->offset(),
4673 unsigned char* vout = out.get_output_view((*p)->paddr(),
4675 memcpy(vout, vin, (*p)->filesz());
4676 out.write_output_view((*p)->paddr(), (*p)->filesz(), vout);
4677 in->free_input_view((*p)->offset(), (*p)->filesz(), vin);
4684 // Print the output sections to the map file.
4687 Layout::print_to_mapfile(Mapfile* mapfile) const
4689 for (Segment_list::const_iterator p = this->segment_list_.begin();
4690 p != this->segment_list_.end();
4692 (*p)->print_sections_to_mapfile(mapfile);
4695 // Print statistical information to stderr. This is used for --stats.
4698 Layout::print_stats() const
4700 this->namepool_.print_stats("section name pool");
4701 this->sympool_.print_stats("output symbol name pool");
4702 this->dynpool_.print_stats("dynamic name pool");
4704 for (Section_list::const_iterator p = this->section_list_.begin();
4705 p != this->section_list_.end();
4707 (*p)->print_merge_stats();
4710 // Write_sections_task methods.
4712 // We can always run this task.
4715 Write_sections_task::is_runnable()
4720 // We need to unlock both OUTPUT_SECTIONS_BLOCKER and FINAL_BLOCKER
4724 Write_sections_task::locks(Task_locker* tl)
4726 tl->add(this, this->output_sections_blocker_);
4727 tl->add(this, this->final_blocker_);
4730 // Run the task--write out the data.
4733 Write_sections_task::run(Workqueue*)
4735 this->layout_->write_output_sections(this->of_);
4738 // Write_data_task methods.
4740 // We can always run this task.
4743 Write_data_task::is_runnable()
4748 // We need to unlock FINAL_BLOCKER when finished.
4751 Write_data_task::locks(Task_locker* tl)
4753 tl->add(this, this->final_blocker_);
4756 // Run the task--write out the data.
4759 Write_data_task::run(Workqueue*)
4761 this->layout_->write_data(this->symtab_, this->of_);
4764 // Write_symbols_task methods.
4766 // We can always run this task.
4769 Write_symbols_task::is_runnable()
4774 // We need to unlock FINAL_BLOCKER when finished.
4777 Write_symbols_task::locks(Task_locker* tl)
4779 tl->add(this, this->final_blocker_);
4782 // Run the task--write out the symbols.
4785 Write_symbols_task::run(Workqueue*)
4787 this->symtab_->write_globals(this->sympool_, this->dynpool_,
4788 this->layout_->symtab_xindex(),
4789 this->layout_->dynsym_xindex(), this->of_);
4792 // Write_after_input_sections_task methods.
4794 // We can only run this task after the input sections have completed.
4797 Write_after_input_sections_task::is_runnable()
4799 if (this->input_sections_blocker_->is_blocked())
4800 return this->input_sections_blocker_;
4804 // We need to unlock FINAL_BLOCKER when finished.
4807 Write_after_input_sections_task::locks(Task_locker* tl)
4809 tl->add(this, this->final_blocker_);
4815 Write_after_input_sections_task::run(Workqueue*)
4817 this->layout_->write_sections_after_input_sections(this->of_);
4820 // Close_task_runner methods.
4822 // Run the task--close the file.
4825 Close_task_runner::run(Workqueue*, const Task*)
4827 // If we need to compute a checksum for the BUILD if, we do so here.
4828 this->layout_->write_build_id(this->of_);
4830 // If we've been asked to create a binary file, we do so here.
4831 if (this->options_->oformat_enum() != General_options::OBJECT_FORMAT_ELF)
4832 this->layout_->write_binary(this->of_);
4837 // Instantiate the templates we need. We could use the configure
4838 // script to restrict this to only the ones for implemented targets.
4840 #ifdef HAVE_TARGET_32_LITTLE
4843 Layout::init_fixed_output_section<32, false>(
4845 elfcpp::Shdr<32, false>& shdr);
4848 #ifdef HAVE_TARGET_32_BIG
4851 Layout::init_fixed_output_section<32, true>(
4853 elfcpp::Shdr<32, true>& shdr);
4856 #ifdef HAVE_TARGET_64_LITTLE
4859 Layout::init_fixed_output_section<64, false>(
4861 elfcpp::Shdr<64, false>& shdr);
4864 #ifdef HAVE_TARGET_64_BIG
4867 Layout::init_fixed_output_section<64, true>(
4869 elfcpp::Shdr<64, true>& shdr);
4872 #ifdef HAVE_TARGET_32_LITTLE
4875 Layout::layout<32, false>(Sized_relobj_file<32, false>* object,
4878 const elfcpp::Shdr<32, false>& shdr,
4879 unsigned int, unsigned int, off_t*);
4882 #ifdef HAVE_TARGET_32_BIG
4885 Layout::layout<32, true>(Sized_relobj_file<32, true>* object,
4888 const elfcpp::Shdr<32, true>& shdr,
4889 unsigned int, unsigned int, off_t*);
4892 #ifdef HAVE_TARGET_64_LITTLE
4895 Layout::layout<64, false>(Sized_relobj_file<64, false>* object,
4898 const elfcpp::Shdr<64, false>& shdr,
4899 unsigned int, unsigned int, off_t*);
4902 #ifdef HAVE_TARGET_64_BIG
4905 Layout::layout<64, true>(Sized_relobj_file<64, true>* object,
4908 const elfcpp::Shdr<64, true>& shdr,
4909 unsigned int, unsigned int, off_t*);
4912 #ifdef HAVE_TARGET_32_LITTLE
4915 Layout::layout_reloc<32, false>(Sized_relobj_file<32, false>* object,
4916 unsigned int reloc_shndx,
4917 const elfcpp::Shdr<32, false>& shdr,
4918 Output_section* data_section,
4919 Relocatable_relocs* rr);
4922 #ifdef HAVE_TARGET_32_BIG
4925 Layout::layout_reloc<32, true>(Sized_relobj_file<32, true>* object,
4926 unsigned int reloc_shndx,
4927 const elfcpp::Shdr<32, true>& shdr,
4928 Output_section* data_section,
4929 Relocatable_relocs* rr);
4932 #ifdef HAVE_TARGET_64_LITTLE
4935 Layout::layout_reloc<64, false>(Sized_relobj_file<64, false>* object,
4936 unsigned int reloc_shndx,
4937 const elfcpp::Shdr<64, false>& shdr,
4938 Output_section* data_section,
4939 Relocatable_relocs* rr);
4942 #ifdef HAVE_TARGET_64_BIG
4945 Layout::layout_reloc<64, true>(Sized_relobj_file<64, true>* object,
4946 unsigned int reloc_shndx,
4947 const elfcpp::Shdr<64, true>& shdr,
4948 Output_section* data_section,
4949 Relocatable_relocs* rr);
4952 #ifdef HAVE_TARGET_32_LITTLE
4955 Layout::layout_group<32, false>(Symbol_table* symtab,
4956 Sized_relobj_file<32, false>* object,
4958 const char* group_section_name,
4959 const char* signature,
4960 const elfcpp::Shdr<32, false>& shdr,
4961 elfcpp::Elf_Word flags,
4962 std::vector<unsigned int>* shndxes);
4965 #ifdef HAVE_TARGET_32_BIG
4968 Layout::layout_group<32, true>(Symbol_table* symtab,
4969 Sized_relobj_file<32, true>* object,
4971 const char* group_section_name,
4972 const char* signature,
4973 const elfcpp::Shdr<32, true>& shdr,
4974 elfcpp::Elf_Word flags,
4975 std::vector<unsigned int>* shndxes);
4978 #ifdef HAVE_TARGET_64_LITTLE
4981 Layout::layout_group<64, false>(Symbol_table* symtab,
4982 Sized_relobj_file<64, false>* object,
4984 const char* group_section_name,
4985 const char* signature,
4986 const elfcpp::Shdr<64, false>& shdr,
4987 elfcpp::Elf_Word flags,
4988 std::vector<unsigned int>* shndxes);
4991 #ifdef HAVE_TARGET_64_BIG
4994 Layout::layout_group<64, true>(Symbol_table* symtab,
4995 Sized_relobj_file<64, true>* object,
4997 const char* group_section_name,
4998 const char* signature,
4999 const elfcpp::Shdr<64, true>& shdr,
5000 elfcpp::Elf_Word flags,
5001 std::vector<unsigned int>* shndxes);
5004 #ifdef HAVE_TARGET_32_LITTLE
5007 Layout::layout_eh_frame<32, false>(Sized_relobj_file<32, false>* object,
5008 const unsigned char* symbols,
5010 const unsigned char* symbol_names,
5011 off_t symbol_names_size,
5013 const elfcpp::Shdr<32, false>& shdr,
5014 unsigned int reloc_shndx,
5015 unsigned int reloc_type,
5019 #ifdef HAVE_TARGET_32_BIG
5022 Layout::layout_eh_frame<32, true>(Sized_relobj_file<32, true>* object,
5023 const unsigned char* symbols,
5025 const unsigned char* symbol_names,
5026 off_t symbol_names_size,
5028 const elfcpp::Shdr<32, true>& shdr,
5029 unsigned int reloc_shndx,
5030 unsigned int reloc_type,
5034 #ifdef HAVE_TARGET_64_LITTLE
5037 Layout::layout_eh_frame<64, false>(Sized_relobj_file<64, false>* object,
5038 const unsigned char* symbols,
5040 const unsigned char* symbol_names,
5041 off_t symbol_names_size,
5043 const elfcpp::Shdr<64, false>& shdr,
5044 unsigned int reloc_shndx,
5045 unsigned int reloc_type,
5049 #ifdef HAVE_TARGET_64_BIG
5052 Layout::layout_eh_frame<64, true>(Sized_relobj_file<64, true>* object,
5053 const unsigned char* symbols,
5055 const unsigned char* symbol_names,
5056 off_t symbol_names_size,
5058 const elfcpp::Shdr<64, true>& shdr,
5059 unsigned int reloc_shndx,
5060 unsigned int reloc_type,
5064 } // End namespace gold.