1 // layout.h -- lay out output file sections for gold -*- C++ -*-
3 // Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
6 // This file is part of gold.
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 3 of the License, or
11 // (at your option) any later version.
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 // GNU General Public License for more details.
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 // MA 02110-1301, USA.
34 #include "workqueue.h"
37 #include "stringpool.h"
42 class General_options;
43 class Incremental_inputs;
47 class Output_section_data;
49 class Output_section_headers;
50 class Output_segment_headers;
51 class Output_file_header;
54 class Output_data_dynamic;
55 class Output_symtab_xindex;
56 class Output_reduced_debug_abbrev_section;
57 class Output_reduced_debug_info_section;
61 // This task function handles mapping the input sections to output
62 // sections and laying them out in memory.
64 class Layout_task_runner : public Task_function_runner
67 // OPTIONS is the command line options, INPUT_OBJECTS is the list of
68 // input objects, SYMTAB is the symbol table, LAYOUT is the layout
70 Layout_task_runner(const General_options& options,
71 const Input_objects* input_objects,
76 : options_(options), input_objects_(input_objects), symtab_(symtab),
77 target_(target), layout_(layout), mapfile_(mapfile)
82 run(Workqueue*, const Task*);
85 Layout_task_runner(const Layout_task_runner&);
86 Layout_task_runner& operator=(const Layout_task_runner&);
88 const General_options& options_;
89 const Input_objects* input_objects_;
90 Symbol_table* symtab_;
96 // This class holds information about the comdat group or
97 // .gnu.linkonce section that will be kept for a given signature.
102 // For a comdat group, we build a mapping from the name of each
103 // section in the group to the section index and the size in object.
104 // When we discard a group in some other object file, we use this
105 // map to figure out which kept section the discarded section is
106 // associated with. We then use that mapping when processing relocs
107 // against discarded sections.
108 struct Comdat_section_info
110 // The section index.
115 Comdat_section_info(unsigned int a_shndx, uint64_t a_size)
116 : shndx(a_shndx), size(a_size)
120 // Most comdat groups have only one or two sections, so we use a
121 // std::map rather than an Unordered_map to optimize for that case
122 // without paying too heavily for groups with more sections.
123 typedef std::map<std::string, Comdat_section_info> Comdat_group;
127 : object_(NULL), shndx_(0), is_comdat_(false), is_group_name_(false)
128 { this->u_.linkonce_size = 0; }
130 // We need to support copies for the signature map in the Layout
131 // object, but we should never copy an object after it has been
132 // marked as a comdat section.
133 Kept_section(const Kept_section& k)
134 : object_(k.object_), shndx_(k.shndx_), is_comdat_(false),
135 is_group_name_(k.is_group_name_)
137 gold_assert(!k.is_comdat_);
138 this->u_.linkonce_size = 0;
143 if (this->is_comdat_)
144 delete this->u_.group_sections;
147 // The object where this section lives.
150 { return this->object_; }
154 set_object(Relobj* object)
156 gold_assert(this->object_ == NULL);
157 this->object_ = object;
160 // The section index.
163 { return this->shndx_; }
165 // Set the section index.
167 set_shndx(unsigned int shndx)
169 gold_assert(this->shndx_ == 0);
170 this->shndx_ = shndx;
173 // Whether this is a comdat group.
176 { return this->is_comdat_; }
178 // Set that this is a comdat group.
182 gold_assert(!this->is_comdat_);
183 this->is_comdat_ = true;
184 this->u_.group_sections = new Comdat_group();
187 // Whether this is associated with the name of a group or section
188 // rather than the symbol name derived from a linkonce section.
190 is_group_name() const
191 { return this->is_group_name_; }
193 // Note that this represents a comdat group rather than a single
197 { this->is_group_name_ = true; }
199 // Add a section to the group list.
201 add_comdat_section(const std::string& name, unsigned int shndx,
204 gold_assert(this->is_comdat_);
205 Comdat_section_info sinfo(shndx, size);
206 this->u_.group_sections->insert(std::make_pair(name, sinfo));
209 // Look for a section name in the group list, and return whether it
210 // was found. If found, returns the section index and size.
212 find_comdat_section(const std::string& name, unsigned int *pshndx,
213 uint64_t *psize) const
215 gold_assert(this->is_comdat_);
216 Comdat_group::const_iterator p = this->u_.group_sections->find(name);
217 if (p == this->u_.group_sections->end())
219 *pshndx = p->second.shndx;
220 *psize = p->second.size;
224 // If there is only one section in the group list, return true, and
225 // return the section index and size.
227 find_single_comdat_section(unsigned int *pshndx, uint64_t *psize) const
229 gold_assert(this->is_comdat_);
230 if (this->u_.group_sections->size() != 1)
232 Comdat_group::const_iterator p = this->u_.group_sections->begin();
233 *pshndx = p->second.shndx;
234 *psize = p->second.size;
238 // Return the size of a linkonce section.
240 linkonce_size() const
242 gold_assert(!this->is_comdat_);
243 return this->u_.linkonce_size;
246 // Set the size of a linkonce section.
248 set_linkonce_size(uint64_t size)
250 gold_assert(!this->is_comdat_);
251 this->u_.linkonce_size = size;
256 Kept_section& operator=(const Kept_section&);
258 // The object containing the comdat group or .gnu.linkonce section.
260 // Index of the group section for comdats and the section itself for
263 // True if this is for a comdat group rather than a .gnu.linkonce
266 // The Kept_sections are values of a mapping, that maps names to
267 // them. This field is true if this struct is associated with the
268 // name of a comdat or .gnu.linkonce, false if it is associated with
269 // the name of a symbol obtained from the .gnu.linkonce.* name
270 // through some heuristics.
274 // If the is_comdat_ field is true, this holds a map from names of
275 // the sections in the group to section indexes in object_ and to
277 Comdat_group* group_sections;
278 // If the is_comdat_ field is false, this holds the size of the
280 uint64_t linkonce_size;
284 // This class handles the details of laying out input sections.
289 Layout(int number_of_input_files, Script_options*);
293 delete this->relaxation_debug_check_;
294 delete this->segment_states_;
297 // Given an input section SHNDX, named NAME, with data in SHDR, from
298 // the object file OBJECT, return the output section where this
299 // input section should go. RELOC_SHNDX is the index of a
300 // relocation section which applies to this section, or 0 if none,
301 // or -1U if more than one. RELOC_TYPE is the type of the
302 // relocation section if there is one. Set *OFFSET to the offset
303 // within the output section.
304 template<int size, bool big_endian>
306 layout(Sized_relobj<size, big_endian> *object, unsigned int shndx,
307 const char* name, const elfcpp::Shdr<size, big_endian>& shdr,
308 unsigned int reloc_shndx, unsigned int reloc_type, off_t* offset);
310 // Layout an input reloc section when doing a relocatable link. The
311 // section is RELOC_SHNDX in OBJECT, with data in SHDR.
312 // DATA_SECTION is the reloc section to which it refers. RR is the
313 // relocatable information.
314 template<int size, bool big_endian>
316 layout_reloc(Sized_relobj<size, big_endian>* object,
317 unsigned int reloc_shndx,
318 const elfcpp::Shdr<size, big_endian>& shdr,
319 Output_section* data_section,
320 Relocatable_relocs* rr);
322 // Layout a group section when doing a relocatable link.
323 template<int size, bool big_endian>
325 layout_group(Symbol_table* symtab,
326 Sized_relobj<size, big_endian>* object,
327 unsigned int group_shndx,
328 const char* group_section_name,
329 const char* signature,
330 const elfcpp::Shdr<size, big_endian>& shdr,
331 elfcpp::Elf_Word flags,
332 std::vector<unsigned int>* shndxes);
334 // Like layout, only for exception frame sections. OBJECT is an
335 // object file. SYMBOLS is the contents of the symbol table
336 // section, with size SYMBOLS_SIZE. SYMBOL_NAMES is the contents of
337 // the symbol name section, with size SYMBOL_NAMES_SIZE. SHNDX is a
338 // .eh_frame section in OBJECT. SHDR is the section header.
339 // RELOC_SHNDX is the index of a relocation section which applies to
340 // this section, or 0 if none, or -1U if more than one. RELOC_TYPE
341 // is the type of the relocation section if there is one. This
342 // returns the output section, and sets *OFFSET to the offset.
343 template<int size, bool big_endian>
345 layout_eh_frame(Sized_relobj<size, big_endian>* object,
346 const unsigned char* symbols,
348 const unsigned char* symbol_names,
349 off_t symbol_names_size,
351 const elfcpp::Shdr<size, big_endian>& shdr,
352 unsigned int reloc_shndx, unsigned int reloc_type,
355 // Handle a GNU stack note. This is called once per input object
356 // file. SEEN_GNU_STACK is true if the object file has a
357 // .note.GNU-stack section. GNU_STACK_FLAGS is the section flags
358 // from that section if there was one.
360 layout_gnu_stack(bool seen_gnu_stack, uint64_t gnu_stack_flags);
362 // Add an Output_section_data to the layout. This is used for
363 // special sections like the GOT section. IS_DYNAMIC_LINKER_SECTION
364 // is true for sections which are used by the dynamic linker, such
365 // as dynamic reloc sections. IS_RELRO is true for relro sections.
366 // IS_LAST_RELRO is true for the last relro section.
367 // IS_FIRST_NON_RELRO is true for the first section after the relro
370 add_output_section_data(const char* name, elfcpp::Elf_Word type,
371 elfcpp::Elf_Xword flags,
372 Output_section_data*, bool is_dynamic_linker_section,
373 bool is_relro, bool is_last_relro,
374 bool is_first_non_relro);
376 // Increase the size of the relro segment by this much.
378 increase_relro(unsigned int s)
379 { this->increase_relro_ += s; }
381 // Create dynamic sections if necessary.
383 create_initial_dynamic_sections(Symbol_table*);
385 // Define __start and __stop symbols for output sections.
387 define_section_symbols(Symbol_table*);
389 // Create automatic note sections.
393 // Create sections for linker scripts.
395 create_script_sections()
396 { this->script_options_->create_script_sections(this); }
398 // Define symbols from any linker script.
400 define_script_symbols(Symbol_table* symtab)
401 { this->script_options_->add_symbols_to_table(symtab); }
403 // Define symbols for group signatures.
405 define_group_signatures(Symbol_table*);
407 // Return the Stringpool used for symbol names.
410 { return &this->sympool_; }
412 // Return the Stringpool used for dynamic symbol names and dynamic
416 { return &this->dynpool_; }
418 // Return the symtab_xindex section used to hold large section
419 // indexes for the normal symbol table.
420 Output_symtab_xindex*
421 symtab_xindex() const
422 { return this->symtab_xindex_; }
424 // Return the dynsym_xindex section used to hold large section
425 // indexes for the dynamic symbol table.
426 Output_symtab_xindex*
427 dynsym_xindex() const
428 { return this->dynsym_xindex_; }
430 // Return whether a section is a .gnu.linkonce section, given the
433 is_linkonce(const char* name)
434 { return strncmp(name, ".gnu.linkonce", sizeof(".gnu.linkonce") - 1) == 0; }
436 // Whether we have added an input section.
438 have_added_input_section() const
439 { return this->have_added_input_section_; }
441 // Return true if a section is a debugging section.
443 is_debug_info_section(const char* name)
445 // Debugging sections can only be recognized by name.
446 return (strncmp(name, ".debug", sizeof(".debug") - 1) == 0
447 || strncmp(name, ".gnu.linkonce.wi.",
448 sizeof(".gnu.linkonce.wi.") - 1) == 0
449 || strncmp(name, ".line", sizeof(".line") - 1) == 0
450 || strncmp(name, ".stab", sizeof(".stab") - 1) == 0);
453 // Check if a comdat group or .gnu.linkonce section with the given
454 // NAME is selected for the link. If there is already a section,
455 // *KEPT_SECTION is set to point to the signature and the function
456 // returns false. Otherwise, OBJECT, SHNDX,IS_COMDAT, and
457 // IS_GROUP_NAME are recorded for this NAME in the layout object,
458 // *KEPT_SECTION is set to the internal copy and the function return
461 find_or_add_kept_section(const std::string& name, Relobj* object,
462 unsigned int shndx, bool is_comdat,
463 bool is_group_name, Kept_section** kept_section);
465 // Finalize the layout after all the input sections have been added.
467 finalize(const Input_objects*, Symbol_table*, Target*, const Task*);
469 // Return whether any sections require postprocessing.
471 any_postprocessing_sections() const
472 { return this->any_postprocessing_sections_; }
474 // Return the size of the output file.
476 output_file_size() const
477 { return this->output_file_size_; }
479 // Return the TLS segment. This will return NULL if there isn't
483 { return this->tls_segment_; }
485 // Return the normal symbol table.
487 symtab_section() const
489 gold_assert(this->symtab_section_ != NULL);
490 return this->symtab_section_;
493 // Return the dynamic symbol table.
495 dynsym_section() const
497 gold_assert(this->dynsym_section_ != NULL);
498 return this->dynsym_section_;
501 // Return the dynamic tags.
504 { return this->dynamic_data_; }
506 // Write out the output sections.
508 write_output_sections(Output_file* of) const;
510 // Write out data not associated with an input file or the symbol
513 write_data(const Symbol_table*, Output_file*) const;
515 // Write out output sections which can not be written until all the
516 // input sections are complete.
518 write_sections_after_input_sections(Output_file* of);
520 // Return an output section named NAME, or NULL if there is none.
522 find_output_section(const char* name) const;
524 // Return an output segment of type TYPE, with segment flags SET set
525 // and segment flags CLEAR clear. Return NULL if there is none.
527 find_output_segment(elfcpp::PT type, elfcpp::Elf_Word set,
528 elfcpp::Elf_Word clear) const;
530 // Return the number of segments we expect to produce.
532 expected_segment_count() const;
534 // Set a flag to indicate that an object file uses the static TLS model.
537 { this->has_static_tls_ = true; }
539 // Return true if any object file uses the static TLS model.
541 has_static_tls() const
542 { return this->has_static_tls_; }
544 // Return the options which may be set by a linker script.
547 { return this->script_options_; }
549 const Script_options*
550 script_options() const
551 { return this->script_options_; }
553 // Return the object managing inputs in incremental build. NULL in
554 // non-incremental builds.
557 { return this->incremental_inputs_; }
559 // For the target-specific code to add dynamic tags which are common
562 add_target_dynamic_tags(bool use_rel, const Output_data* plt_got,
563 const Output_data* plt_rel,
564 const Output_data* dyn_rel, bool add_debug);
566 // Compute and write out the build ID if needed.
568 write_build_id(Output_file*) const;
570 // Rewrite output file in binary format.
572 write_binary(Output_file* in) const;
574 // Print output sections to the map file.
576 print_to_mapfile(Mapfile*) const;
578 // Dump statistical information to stderr.
582 // A list of segments.
584 typedef std::vector<Output_segment*> Segment_list;
586 // A list of sections.
588 typedef std::vector<Output_section*> Section_list;
590 // The list of information to write out which is not attached to
591 // either a section or a segment.
592 typedef std::vector<Output_data*> Data_list;
594 // Store the allocated sections into the section list. This is used
595 // by the linker script code.
597 get_allocated_sections(Section_list*) const;
599 // Make a section for a linker script to hold data.
601 make_output_section_for_script(const char* name);
603 // Make a segment. This is used by the linker script code.
605 make_output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags);
607 // Return the number of segments.
609 segment_count() const
610 { return this->segment_list_.size(); }
612 // Map from section flags to segment flags.
613 static elfcpp::Elf_Word
614 section_flags_to_segment(elfcpp::Elf_Xword flags);
616 // Attach sections to segments.
618 attach_sections_to_segments();
620 // For relaxation clean up, we need to know output section data created
621 // from a linker script.
623 new_output_section_data_from_script(Output_section_data* posd)
625 if (this->record_output_section_data_from_script_)
626 this->script_output_section_data_list_.push_back(posd);
629 // Return section list.
632 { return this->section_list_; }
635 Layout(const Layout&);
636 Layout& operator=(const Layout&);
638 // Mapping from input section names to output section names.
639 struct Section_name_mapping
646 static const Section_name_mapping section_name_mapping[];
647 static const int section_name_mapping_count;
649 // During a relocatable link, a list of group sections and
651 struct Group_signature
653 // The group section.
654 Output_section* section;
656 const char* signature;
659 : section(NULL), signature(NULL)
662 Group_signature(Output_section* sectiona, const char* signaturea)
663 : section(sectiona), signature(signaturea)
666 typedef std::vector<Group_signature> Group_signatures;
668 // Create a note section, filling in the header.
670 create_note(const char* name, int note_type, const char *section_name,
671 size_t descsz, bool allocate, size_t* trailing_padding);
673 // Create a note section for gold version.
677 // Record whether the stack must be executable.
679 create_executable_stack_info();
681 // Create a build ID note if needed.
685 // Link .stab and .stabstr sections.
687 link_stabs_sections();
689 // Create .gnu_incremental_inputs and .gnu_incremental_strtab sections needed
690 // for the next run of incremental linking to check what has changed.
692 create_incremental_info_sections();
694 // Find the first read-only PT_LOAD segment, creating one if
697 find_first_load_seg();
699 // Count the local symbols in the regular symbol table and the dynamic
700 // symbol table, and build the respective string pools.
702 count_local_symbols(const Task*, const Input_objects*);
704 // Create the output sections for the symbol table.
706 create_symtab_sections(const Input_objects*, Symbol_table*,
707 unsigned int, off_t*);
709 // Create the .shstrtab section.
713 // Create the section header table.
715 create_shdrs(const Output_section* shstrtab_section, off_t*);
717 // Create the dynamic symbol table.
719 create_dynamic_symtab(const Input_objects*, Symbol_table*,
720 Output_section** pdynstr,
721 unsigned int* plocal_dynamic_count,
722 std::vector<Symbol*>* pdynamic_symbols,
725 // Assign offsets to each local portion of the dynamic symbol table.
727 assign_local_dynsym_offsets(const Input_objects*);
729 // Finish the .dynamic section and PT_DYNAMIC segment.
731 finish_dynamic_section(const Input_objects*, const Symbol_table*);
733 // Set the size of the _DYNAMIC symbol.
735 set_dynamic_symbol_size(const Symbol_table*);
737 // Create the .interp section and PT_INTERP segment.
739 create_interp(const Target* target);
741 // Create the version sections.
743 create_version_sections(const Versions*,
745 unsigned int local_symcount,
746 const std::vector<Symbol*>& dynamic_symbols,
747 const Output_section* dynstr);
749 template<int size, bool big_endian>
751 sized_create_version_sections(const Versions* versions,
753 unsigned int local_symcount,
754 const std::vector<Symbol*>& dynamic_symbols,
755 const Output_section* dynstr);
757 // Return whether to include this section in the link.
758 template<int size, bool big_endian>
760 include_section(Sized_relobj<size, big_endian>* object, const char* name,
761 const elfcpp::Shdr<size, big_endian>&);
763 // Return the output section name to use given an input section
764 // name. Set *PLEN to the length of the name. *PLEN must be
765 // initialized to the length of NAME.
767 output_section_name(const char* name, size_t* plen);
769 // Return the number of allocated output sections.
771 allocated_output_section_count() const;
773 // Return the output section for NAME, TYPE and FLAGS.
775 get_output_section(const char* name, Stringpool::Key name_key,
776 elfcpp::Elf_Word type, elfcpp::Elf_Xword flags,
777 bool is_interp, bool is_dynamic_linker_section,
778 bool is_relro, bool is_last_relro,
779 bool is_first_non_relro);
781 // Choose the output section for NAME in RELOBJ.
783 choose_output_section(const Relobj* relobj, const char* name,
784 elfcpp::Elf_Word type, elfcpp::Elf_Xword flags,
785 bool is_input_section, bool is_interp,
786 bool is_dynamic_linker_section, bool is_relro,
787 bool is_last_relro, bool is_first_non_relro);
789 // Create a new Output_section.
791 make_output_section(const char* name, elfcpp::Elf_Word type,
792 elfcpp::Elf_Xword flags, bool is_interp,
793 bool is_dynamic_linker_section, bool is_relro,
794 bool is_last_relro, bool is_first_non_relro);
796 // Attach a section to a segment.
798 attach_section_to_segment(Output_section*);
800 // Attach an allocated section to a segment.
802 attach_allocated_section_to_segment(Output_section*);
804 // Set the final file offsets of all the segments.
806 set_segment_offsets(const Target*, Output_segment*, unsigned int* pshndx);
808 // Set the file offsets of the sections when doing a relocatable
811 set_relocatable_section_offsets(Output_data*, unsigned int* pshndx);
813 // Set the final file offsets of all the sections not associated
814 // with a segment. We set section offsets in three passes: the
815 // first handles all allocated sections, the second sections that
816 // require postprocessing, and the last the late-bound STRTAB
817 // sections (probably only shstrtab, which is the one we care about
818 // because it holds section names).
819 enum Section_offset_pass
821 BEFORE_INPUT_SECTIONS_PASS,
822 POSTPROCESSING_SECTIONS_PASS,
823 STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS
826 set_section_offsets(off_t, Section_offset_pass pass);
828 // Set the final section indexes of all the sections not associated
829 // with a segment. Returns the next unused index.
831 set_section_indexes(unsigned int pshndx);
833 // Set the section addresses when using a script.
835 set_section_addresses_from_script(Symbol_table*);
837 // Find appropriate places or orphan sections in a script.
839 place_orphan_sections_in_script();
841 // Return whether SEG1 comes before SEG2 in the output file.
843 segment_precedes(const Output_segment* seg1, const Output_segment* seg2);
845 // Use to save and restore segments during relaxation.
846 typedef Unordered_map<const Output_segment*, const Output_segment*>
849 // Save states of current output segments.
851 save_segments(Segment_states*);
853 // Restore output segment states.
855 restore_segments(const Segment_states*);
857 // Clean up after relaxation so that it is possible to lay out the
858 // sections and segments again.
860 clean_up_after_relaxation();
862 // Doing preparation work for relaxation. This is factored out to make
863 // Layout::finalized a bit smaller and easier to read.
865 prepare_for_relaxation();
867 // Main body of the relaxation loop, which lays out the section.
869 relaxation_loop_body(int, Target*, Symbol_table*, Output_segment**,
870 Output_segment*, Output_segment_headers*,
871 Output_file_header*, unsigned int*);
873 // A mapping used for kept comdats/.gnu.linkonce group signatures.
874 typedef Unordered_map<std::string, Kept_section> Signatures;
876 // Mapping from input section name/type/flags to output section. We
877 // use canonicalized strings here.
879 typedef std::pair<Stringpool::Key,
880 std::pair<elfcpp::Elf_Word, elfcpp::Elf_Xword> > Key;
885 operator()(const Key& k) const;
888 typedef Unordered_map<Key, Output_section*, Hash_key> Section_name_map;
890 // A comparison class for segments.
892 struct Compare_segments
895 operator()(const Output_segment* seg1, const Output_segment* seg2)
896 { return Layout::segment_precedes(seg1, seg2); }
899 typedef std::vector<Output_section_data*> Output_section_data_list;
901 // Debug checker class.
902 class Relaxation_debug_check
905 Relaxation_debug_check()
909 // Check that sections and special data are in reset states.
911 check_output_data_for_reset_values(const Layout::Section_list&,
912 const Layout::Data_list&);
914 // Record information of a section list.
916 read_sections(const Layout::Section_list&);
918 // Verify a section list with recorded information.
920 verify_sections(const Layout::Section_list&);
923 // Information we care about a section.
926 // Output section described by this.
927 Output_section* output_section;
936 // Section information.
937 std::vector<Section_info> section_infos_;
940 // The number of input files, for sizing tables.
941 int number_of_input_files_;
942 // Information set by scripts or by command line options.
943 Script_options* script_options_;
944 // The output section names.
945 Stringpool namepool_;
946 // The output symbol names.
948 // The dynamic strings, if needed.
950 // The list of group sections and linkonce sections which we have seen.
951 Signatures signatures_;
952 // The mapping from input section name/type/flags to output sections.
953 Section_name_map section_name_map_;
954 // The list of output segments.
955 Segment_list segment_list_;
956 // The list of output sections.
957 Section_list section_list_;
958 // The list of output sections which are not attached to any output
960 Section_list unattached_section_list_;
961 // The list of unattached Output_data objects which require special
962 // handling because they are not Output_sections.
963 Data_list special_output_list_;
964 // The section headers.
965 Output_section_headers* section_headers_;
966 // A pointer to the PT_TLS segment if there is one.
967 Output_segment* tls_segment_;
968 // A pointer to the PT_GNU_RELRO segment if there is one.
969 Output_segment* relro_segment_;
970 // A backend may increase the size of the PT_GNU_RELRO segment if
971 // there is one. This is the amount to increase it by.
972 unsigned int increase_relro_;
973 // The SHT_SYMTAB output section.
974 Output_section* symtab_section_;
975 // The SHT_SYMTAB_SHNDX for the regular symbol table if there is one.
976 Output_symtab_xindex* symtab_xindex_;
977 // The SHT_DYNSYM output section if there is one.
978 Output_section* dynsym_section_;
979 // The SHT_SYMTAB_SHNDX for the dynamic symbol table if there is one.
980 Output_symtab_xindex* dynsym_xindex_;
981 // The SHT_DYNAMIC output section if there is one.
982 Output_section* dynamic_section_;
983 // The _DYNAMIC symbol if there is one.
984 Symbol* dynamic_symbol_;
985 // The dynamic data which goes into dynamic_section_.
986 Output_data_dynamic* dynamic_data_;
987 // The exception frame output section if there is one.
988 Output_section* eh_frame_section_;
989 // The exception frame data for eh_frame_section_.
990 Eh_frame* eh_frame_data_;
991 // Whether we have added eh_frame_data_ to the .eh_frame section.
992 bool added_eh_frame_data_;
993 // The exception frame header output section if there is one.
994 Output_section* eh_frame_hdr_section_;
995 // The space for the build ID checksum if there is one.
996 Output_section_data* build_id_note_;
997 // The output section containing dwarf abbreviations
998 Output_reduced_debug_abbrev_section* debug_abbrev_;
999 // The output section containing the dwarf debug info tree
1000 Output_reduced_debug_info_section* debug_info_;
1001 // A list of group sections and their signatures.
1002 Group_signatures group_signatures_;
1003 // The size of the output file.
1004 off_t output_file_size_;
1005 // Whether we have added an input section to an output section.
1006 bool have_added_input_section_;
1007 // Whether we have attached the sections to the segments.
1008 bool sections_are_attached_;
1009 // Whether we have seen an object file marked to require an
1010 // executable stack.
1011 bool input_requires_executable_stack_;
1012 // Whether we have seen at least one object file with an executable
1014 bool input_with_gnu_stack_note_;
1015 // Whether we have seen at least one object file without an
1016 // executable stack marker.
1017 bool input_without_gnu_stack_note_;
1018 // Whether we have seen an object file that uses the static TLS model.
1019 bool has_static_tls_;
1020 // Whether any sections require postprocessing.
1021 bool any_postprocessing_sections_;
1022 // Whether we have resized the signatures_ hash table.
1023 bool resized_signatures_;
1024 // Whether we have created a .stab*str output section.
1025 bool have_stabstr_section_;
1026 // In incremental build, holds information check the inputs and build the
1027 // .gnu_incremental_inputs section.
1028 Incremental_inputs* incremental_inputs_;
1029 // Whether we record output section data created in script
1030 bool record_output_section_data_from_script_;
1031 // List of output data that needs to be removed at relexation clean up.
1032 Output_section_data_list script_output_section_data_list_;
1033 // Structure to save segment states before entering the relaxation loop.
1034 Segment_states* segment_states_;
1035 // A relaxation debug checker. We only create one when in debugging mode.
1036 Relaxation_debug_check* relaxation_debug_check_;
1039 // This task handles writing out data in output sections which is not
1040 // part of an input section, or which requires special handling. When
1041 // this is done, it unblocks both output_sections_blocker and
1044 class Write_sections_task : public Task
1047 Write_sections_task(const Layout* layout, Output_file* of,
1048 Task_token* output_sections_blocker,
1049 Task_token* final_blocker)
1050 : layout_(layout), of_(of),
1051 output_sections_blocker_(output_sections_blocker),
1052 final_blocker_(final_blocker)
1055 // The standard Task methods.
1061 locks(Task_locker*);
1068 { return "Write_sections_task"; }
1071 class Write_sections_locker;
1073 const Layout* layout_;
1075 Task_token* output_sections_blocker_;
1076 Task_token* final_blocker_;
1079 // This task handles writing out data which is not part of a section
1082 class Write_data_task : public Task
1085 Write_data_task(const Layout* layout, const Symbol_table* symtab,
1086 Output_file* of, Task_token* final_blocker)
1087 : layout_(layout), symtab_(symtab), of_(of), final_blocker_(final_blocker)
1090 // The standard Task methods.
1096 locks(Task_locker*);
1103 { return "Write_data_task"; }
1106 const Layout* layout_;
1107 const Symbol_table* symtab_;
1109 Task_token* final_blocker_;
1112 // This task handles writing out the global symbols.
1114 class Write_symbols_task : public Task
1117 Write_symbols_task(const Layout* layout, const Symbol_table* symtab,
1118 const Input_objects* input_objects,
1119 const Stringpool* sympool, const Stringpool* dynpool,
1120 Output_file* of, Task_token* final_blocker)
1121 : layout_(layout), symtab_(symtab), input_objects_(input_objects),
1122 sympool_(sympool), dynpool_(dynpool), of_(of),
1123 final_blocker_(final_blocker)
1126 // The standard Task methods.
1132 locks(Task_locker*);
1139 { return "Write_symbols_task"; }
1142 const Layout* layout_;
1143 const Symbol_table* symtab_;
1144 const Input_objects* input_objects_;
1145 const Stringpool* sympool_;
1146 const Stringpool* dynpool_;
1148 Task_token* final_blocker_;
1151 // This task handles writing out data in output sections which can't
1152 // be written out until all the input sections have been handled.
1153 // This is for sections whose contents is based on the contents of
1154 // other output sections.
1156 class Write_after_input_sections_task : public Task
1159 Write_after_input_sections_task(Layout* layout, Output_file* of,
1160 Task_token* input_sections_blocker,
1161 Task_token* final_blocker)
1162 : layout_(layout), of_(of),
1163 input_sections_blocker_(input_sections_blocker),
1164 final_blocker_(final_blocker)
1167 // The standard Task methods.
1173 locks(Task_locker*);
1180 { return "Write_after_input_sections_task"; }
1185 Task_token* input_sections_blocker_;
1186 Task_token* final_blocker_;
1189 // This task function handles closing the file.
1191 class Close_task_runner : public Task_function_runner
1194 Close_task_runner(const General_options* options, const Layout* layout,
1196 : options_(options), layout_(layout), of_(of)
1199 // Run the operation.
1201 run(Workqueue*, const Task*);
1204 const General_options* options_;
1205 const Layout* layout_;
1209 // A small helper function to align an address.
1212 align_address(uint64_t address, uint64_t addralign)
1215 address = (address + addralign - 1) &~ (addralign - 1);
1219 } // End namespace gold.
1221 #endif // !defined(GOLD_LAYOUT_H)